surround sound - Page 162

Trying to get these list items to display inline

- by Joel

I have several unordered lists that I want to display like this: <ul> <li><img></li> <li><p></li> //inline </ul> //linebreak <ul> <li><img></li> <li><p></li> //inline </ul> ...etc I'm not able to get the li items to be inline with eachother. They are stacking vertically. I have stripped away most styling but still can't figure out what I'm doing wrong: html: <ul class="instrument"> <li class="imagebox"><img src="/images/matepe.jpg" width="247" height="228" alt="Matepe" /></li> <li class="textbox"><p>The matepe is a 24 key instrument that is played by the Kore-Kore people in North-Eastern Zimbabwe and Mozambique. It utilizes four fingers-each playing an individual melody. These melodies also interwieve to create resultant melodies that can be manipulated thru accenting different fingers. The matepe is used in Rattletree as the bridge from the physical world to the spirit world. The matepe is used in the Kore-Kore culture to summon the Mhondoro spirits which are thought to be able to communicate directly with Mwari (God) without the need of an intermediary.</p></li> </ul> <ul class="instrument"> <li class="imagebox"><img src="/images/soprano_little.jpg" border="0" width="247" height="170" alt="Soprano" /></li> <li class="textbox"><p>The highest voice of the Rattletree Marimba orchestra is the Soprano marimba. The soprano is used to whip up the energy on the dancefloor and help people reach ecstatic state with it's high and clear singing voice. The range of these sopranos goes much lower than 'typical' Zimbabwean style sopranos. The sopranos play the range of the right hand of the matepe and go two notes higher and five notes lower. Rattletree uses two sopranos.</p></li> </ul> <ul class="instrument"> <li class="imagebox"><img src="/images/bari_little.jpg" border="0" width="247" height="170" alt="Baritone" /></li> <li class="textbox"><p>The Baritone is the next lower voice in the orchestra. The bari is where the funk is. Generally bubbling over the Bass line, the baritone creates the syncopations and polyrhythms that messes with the 'minds' of the dancers and helps seperate the listener from the physical realm of thought. The range of the baritone covers the full range of the left hand side of the matepe.</p></li> </ul> <ul class="instrument"> <li class="imagebox"><img src="/images/darren_littlebass.jpg" border="0" width="247" height="195" alt="Bass"/><strong>Bass Marimba</strong></li> <li class="textbox"><p>The towering Bass Marimba is the foundation of the Rattletree Marimba sound. Putting out frequencies as low as 22hZ, the bass creates the drive that gets the dancefloor moving. It is 5.5' tall, 9' long, and 4' deep. It is played by standing on a platform and struck with mallets that have lacross-ball size heads (they are actually made with rubber dog balls). The Bass marimba's range covers the lowest five notes of the matepe and goes another five notes lower.</p></li> </ul> <ul class="instrument"> <li class="imagebox"><img src="/images/wayne_little.jpg" border="0" width="247" height="177" alt="Drums"/><strong>Drumset</strong></li> <li class="textbox"><p>All the intricate polyrhythms are held together tastefully with the drumset. The drums provides the consistancy and grounding that the dancers need to keep going all night. While the steady kick and high-hat provide that grounding function, the toms and snare and allowed to be another voice in the poylrhythmic texture-helping the dancers abandon the concept of a "one" within this cyclical music.</p></li> </ul> css: ul.instrument { text-align:left; display:inline; } ul.instrument li { list-style-type: none; } li.imagebox { } li.textbox { } li.textbox p{ width: 247px; }

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Python - Converting CSV to Objects - Code Design

- by victorhooi

Hi, I have a small script we're using to read in a CSV file containing employees, and perform some basic manipulations on that data. We read in the data (import_gd_dump), and create an Employees object, containing a list of Employee objects (maybe I should think of a better naming convention...lol). We then call clean_all_phone_numbers() on Employees, which calls clean_phone_number() on each Employee, as well as lookup_all_supervisors(), on Employees. import csv import re import sys #class CSVLoader: # """Virtual class to assist with loading in CSV files.""" # def import_gd_dump(self, input_file='Gp Directory 20100331 original.csv'): # gd_extract = csv.DictReader(open(input_file), dialect='excel') # employees = [] # for row in gd_extract: # curr_employee = Employee(row) # employees.append(curr_employee) # return employees # #self.employees = {row['dbdirid']:row for row in gd_extract} # Previously, this was inside a (virtual) class called "CSVLoader". # However, according to here (http://tomayko.com/writings/the-static-method-thing) - the idiomatic way of doing this in Python is not with a class-fucntion but with a module-level function def import_gd_dump(input_file='Gp Directory 20100331 original.csv'): """Return a list ('employee') of dict objects, taken from a Group Directory CSV file.""" gd_extract = csv.DictReader(open(input_file), dialect='excel') employees = [] for row in gd_extract: employees.append(row) return employees def write_gd_formatted(employees_dict, output_file="gd_formatted.csv"): """Read in an Employees() object, and write out each Employee() inside this to a CSV file""" gd_output_fieldnames = ('hrid', 'mail', 'givenName', 'sn', 'dbcostcenter', 'dbdirid', 'hrreportsto', 'PHFull', 'PHFull_message', 'SupervisorEmail', 'SupervisorFirstName', 'SupervisorSurname') try: gd_formatted = csv.DictWriter(open(output_file, 'w', newline=''), fieldnames=gd_output_fieldnames, extrasaction='ignore', dialect='excel') except IOError: print('Unable to open file, IO error (Is it locked?)') sys.exit(1) headers = {n:n for n in gd_output_fieldnames} gd_formatted.writerow(headers) for employee in employees_dict.employee_list: # We're using the employee object's inbuilt __dict__ attribute - hmm, is this good practice? gd_formatted.writerow(employee.__dict__) class Employee: """An Employee in the system, with employee attributes (name, email, cost-centre etc.)""" def __init__(self, employee_attributes): """We use the Employee constructor to convert a dictionary into instance attributes.""" for k, v in employee_attributes.items(): setattr(self, k, v) def clean_phone_number(self): """Perform some rudimentary checks and corrections, to make sure numbers are in the right format. Numbers should be in the form 0XYYYYYYYY, where X is the area code, and Y is the local number.""" if self.telephoneNumber is None or self.telephoneNumber == '': return '', 'Missing phone number.' else: standard_format = re.compile(r'^\+(?P<intl_prefix>\d{2})$(?P<area_code>\d)$(?P<local_first_half>\d{4})-(?P<local_second_half>\d{4})') extra_zero = re.compile(r'^\+(?P<intl_prefix>\d{2})$0(?P<area_code>\d)$(?P<local_first_half>\d{4})-(?P<local_second_half>\d{4})') missing_hyphen = re.compile(r'^\+(?P<intl_prefix>\d{2})$0(?P<area_code>\d)$(?P<local_first_half>\d{4})(?P<local_second_half>\d{4})') if standard_format.search(self.telephoneNumber): result = standard_format.search(self.telephoneNumber) return '0' + result.group('area_code') + result.group('local_first_half') + result.group('local_second_half'), '' elif extra_zero.search(self.telephoneNumber): result = extra_zero.search(self.telephoneNumber) return '0' + result.group('area_code') + result.group('local_first_half') + result.group('local_second_half'), 'Extra zero in area code - ask user to remediate. ' elif missing_hyphen.search(self.telephoneNumber): result = missing_hyphen.search(self.telephoneNumber) return '0' + result.group('area_code') + result.group('local_first_half') + result.group('local_second_half'), 'Missing hyphen in local component - ask user to remediate. ' else: return '', "Number didn't match recognised format. Original text is: " + self.telephoneNumber class Employees: def __init__(self, import_list): self.employee_list = [] for employee in import_list: self.employee_list.append(Employee(employee)) def clean_all_phone_numbers(self): for employee in self.employee_list: #Should we just set this directly in Employee.clean_phone_number() instead? employee.PHFull, employee.PHFull_message = employee.clean_phone_number() # Hmm, the search is O(n^2) - there's probably a better way of doing this search? def lookup_all_supervisors(self): for employee in self.employee_list: if employee.hrreportsto is not None and employee.hrreportsto != '': for supervisor in self.employee_list: if supervisor.hrid == employee.hrreportsto: (employee.SupervisorEmail, employee.SupervisorFirstName, employee.SupervisorSurname) = supervisor.mail, supervisor.givenName, supervisor.sn break else: (employee.SupervisorEmail, employee.SupervisorFirstName, employee.SupervisorSurname) = ('Supervisor not found.', 'Supervisor not found.', 'Supervisor not found.') else: (employee.SupervisorEmail, employee.SupervisorFirstName, employee.SupervisorSurname) = ('Supervisor not set.', 'Supervisor not set.', 'Supervisor not set.') #Is thre a more pythonic way of doing this? def print_employees(self): for employee in self.employee_list: print(employee.__dict__) if __name__ == '__main__': db_employees = Employees(import_gd_dump()) db_employees.clean_all_phone_numbers() db_employees.lookup_all_supervisors() #db_employees.print_employees() write_gd_formatted(db_employees) Firstly, my preamble question is, can you see anything inherently wrong with the above, from either a class design or Python point-of-view? Is the logic/design sound? Anyhow, to the specifics: The Employees object has a method, clean_all_phone_numbers(), which calls clean_phone_number() on each Employee object inside it. Is this bad design? If so, why? Also, is the way I'm calling lookup_all_supervisors() bad? Originally, I wrapped the clean_phone_number() and lookup_supervisor() method in a single function, with a single for-loop inside it. clean_phone_number is O(n), I believe, lookup_supervisor is O(n^2) - is it ok splitting it into two loops like this? In clean_all_phone_numbers(), I'm looping on the Employee objects, and settings their values using return/assignment - should I be setting this inside clean_phone_number() itself? There's also a few things that I'm sorted of hacked out, not sure if they're bad practice - e.g. print_employee() and gd_formatted() both use __dict__, and the constructor for Employee uses setattr() to convert a dictionary into instance attributes. I'd value any thoughts at all. If you think the questions are too broad, let me know and I can repost as several split up (I just didn't want to pollute the boards with multiple similar questions, and the three questions are more or less fairly tightly related). Cheers, Victor

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Trouble with copying dictionaries and using deepcopy on an SQLAlchemy ORM object

- by Az

Hi there, I'm doing a Simulated Annealing algorithm to optimise a given allocation of students and projects. This is language-agnostic pseudocode from Wikipedia: s ? s0; e ? E(s) // Initial state, energy. sbest ? s; ebest ? e // Initial "best" solution k ? 0 // Energy evaluation count. while k < kmax and e > emax // While time left & not good enough: snew ? neighbour(s) // Pick some neighbour. enew ? E(snew) // Compute its energy. if enew < ebest then // Is this a new best? sbest ? snew; ebest ? enew // Save 'new neighbour' to 'best found'. if P(e, enew, temp(k/kmax)) > random() then // Should we move to it? s ? snew; e ? enew // Yes, change state. k ? k + 1 // One more evaluation done return sbest // Return the best solution found. The following is an adaptation of the technique. My supervisor said the idea is fine in theory. First I pick up some allocation (i.e. an entire dictionary of students and their allocated projects, including the ranks for the projects) from entire set of randomised allocations, copy it and pass it to my function. Let's call this allocation aOld (it is a dictionary). aOld has a weight related to it called wOld. The weighting is described below. The function does the following: Let this allocation, aOld be the best_node From all the students, pick a random number of students and stick in a list Strip (DEALLOCATE) them of their projects ++ reflect the changes for projects (allocated parameter is now False) and lecturers (free up slots if one or more of their projects are no longer allocated) Randomise that list Try assigning (REALLOCATE) everyone in that list projects again Calculate the weight (add up ranks, rank 1 = 1, rank 2 = 2... and no project rank = 101) For this new allocation aNew, if the weight wNew is smaller than the allocation weight wOld I picked up at the beginning, then this is the best_node (as defined by the Simulated Annealing algorithm above). Apply the algorithm to aNew and continue. If wOld < wNew, then apply the algorithm to aOld again and continue. The allocations/data-points are expressed as "nodes" such that a node = (weight, allocation_dict, projects_dict, lecturers_dict) Right now, I can only perform this algorithm once, but I'll need to try for a number N (denoted by kmax in the Wikipedia snippet) and make sure I always have with me, the previous node and the best_node. So that I don't modify my original dictionaries (which I might want to reset to), I've done a shallow copy of the dictionaries. From what I've read in the docs, it seems that it only copies the references and since my dictionaries contain objects, changing the copied dictionary ends up changing the objects anyway. So I tried to use copy.deepcopy().These dictionaries refer to objects that have been mapped with SQLA. Questions: I've been given some solutions to the problems faced but due to my über green-ness with using Python, they all sound rather cryptic to me. Deepcopy isn't playing nicely with SQLA. I've been told thatdeepcopy on ORM objects probably has issues that prevent it from working as you'd expect. Apparently I'd be better off "building copy constructors, i.e. def copy(self): return FooBar(....)." Can someone please explain what that means? I checked and found out that deepcopy has issues because SQLAlchemy places extra information on your objects, i.e. an _sa_instance_state attribute, that I wouldn't want in the copy but is necessary for the object to have. I've been told: "There are ways to manually blow away the old _sa_instance_state and put a new one on the object, but the most straightforward is to make a new object with __init__() and set up the attributes that are significant, instead of doing a full deep copy." What exactly does that mean? Do I create a new, unmapped class similar to the old, mapped one? An alternate solution is that I'd have to "implement __deepcopy__() on your objects and ensure that a new _sa_instance_state is set up, there are functions in sqlalchemy.orm.attributes which can help with that." Once again this is beyond me so could someone kindly explain what it means? A more general question: given the above information are there any suggestions on how I can maintain the information/state for the best_node (which must always persist through my while loop) and the previous_node, if my actual objects (referenced by the dictionaries, therefore the nodes) are changing due to the deallocation/reallocation taking place? That is, without using copy?

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Why does use of H264 in sender/receiver pipelines introduce just HUGE delay?

- by Serguey Zefirov

When I try to create pipeline that uses H264 to transmit video, I get some enormous delay, up to 10 seconds to transmit video from my machine to... my machine! This is unacceptable for my goals and I'd like to consult StackOverflow over what I (or someone else) do wrong. I took pipelines from gstrtpbin documentation page and slightly modified them to use Speex: This is sender pipeline: #!/bin/sh gst-launch -v gstrtpbin name=rtpbin \ v4l2src ! ffmpegcolorspace ! ffenc_h263 ! rtph263ppay ! rtpbin.send_rtp_sink_0 \ rtpbin.send_rtp_src_0 ! udpsink host=127.0.0.1 port=5000 \ rtpbin.send_rtcp_src_0 ! udpsink host=127.0.0.1 port=5001 sync=false async=false \ udpsrc port=5005 ! rtpbin.recv_rtcp_sink_0 \ pulsesrc ! audioconvert ! audioresample ! audio/x-raw-int,rate=16000 ! \ speexenc bitrate=16000 ! rtpspeexpay ! rtpbin.send_rtp_sink_1 \ rtpbin.send_rtp_src_1 ! udpsink host=127.0.0.1 port=5002 \ rtpbin.send_rtcp_src_1 ! udpsink host=127.0.0.1 port=5003 sync=false async=false \ udpsrc port=5007 ! rtpbin.recv_rtcp_sink_1 Receiver pipeline: !/bin/sh gst-launch -v\ gstrtpbin name=rtpbin \ udpsrc caps="application/x-rtp,media=(string)video, clock-rate=(int)90000, encoding-name=(string)H263-1998" \ port=5000 ! rtpbin.recv_rtp_sink_0 \ rtpbin. ! rtph263pdepay ! ffdec_h263 ! xvimagesink \ udpsrc port=5001 ! rtpbin.recv_rtcp_sink_0 \ rtpbin.send_rtcp_src_0 ! udpsink port=5005 sync=false async=false \ udpsrc caps="application/x-rtp,media=(string)audio, clock-rate=(int)16000, encoding-name=(string)SPEEX, encoding-params=(string)1, payload=(int)110" \ port=5002 ! rtpbin.recv_rtp_sink_1 \ rtpbin. ! rtpspeexdepay ! speexdec ! audioresample ! audioconvert ! alsasink \ udpsrc port=5003 ! rtpbin.recv_rtcp_sink_1 \ rtpbin.send_rtcp_src_1 ! udpsink host=127.0.0.1 port=5007 sync=false async=false Those pipelines, a combination of H263 and Speex, work fine enough. I snap my fingers near camera and micropohne and then I see movement and hear sound at the same time. Then I changed pipelines to use H264 along the video path. The sender becomes: #!/bin/sh gst-launch -v gstrtpbin name=rtpbin \ v4l2src ! ffmpegcolorspace ! x264enc bitrate=300 ! rtph264pay ! rtpbin.send_rtp_sink_0 \ rtpbin.send_rtp_src_0 ! udpsink host=127.0.0.1 port=5000 \ rtpbin.send_rtcp_src_0 ! udpsink host=127.0.0.1 port=5001 sync=false async=false \ udpsrc port=5005 ! rtpbin.recv_rtcp_sink_0 \ pulsesrc ! audioconvert ! audioresample ! audio/x-raw-int,rate=16000 ! \ speexenc bitrate=16000 ! rtpspeexpay ! rtpbin.send_rtp_sink_1 \ rtpbin.send_rtp_src_1 ! udpsink host=127.0.0.1 port=5002 \ rtpbin.send_rtcp_src_1 ! udpsink host=127.0.0.1 port=5003 sync=false async=false \ udpsrc port=5007 ! rtpbin.recv_rtcp_sink_1 And receiver becomes: #!/bin/sh gst-launch -v\ gstrtpbin name=rtpbin \ udpsrc caps="application/x-rtp,media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264" \ port=5000 ! rtpbin.recv_rtp_sink_0 \ rtpbin. ! rtph264depay ! ffdec_h264 ! xvimagesink \ udpsrc port=5001 ! rtpbin.recv_rtcp_sink_0 \ rtpbin.send_rtcp_src_0 ! udpsink port=5005 sync=false async=false \ udpsrc caps="application/x-rtp,media=(string)audio, clock-rate=(int)16000, encoding-name=(string)SPEEX, encoding-params=(string)1, payload=(int)110" \ port=5002 ! rtpbin.recv_rtp_sink_1 \ rtpbin. ! rtpspeexdepay ! speexdec ! audioresample ! audioconvert ! alsasink \ udpsrc port=5003 ! rtpbin.recv_rtcp_sink_1 \ rtpbin.send_rtcp_src_1 ! udpsink host=127.0.0.1 port=5007 sync=false async=false This is what happen under Ubuntu 10.04. I didn't noticed such huge delays on Ubuntu 9.04 - the delays there was in range 2-3 seconds, AFAIR.

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Fetch a specific tag from Rally in order to compute a value in another field

- by 4jas

I'm extremely new to Rally development so my question may sound dumb (but couldn't find how to do it from rally's help or from previous posts here) :) I've started from the rally freeform grid example - my purpose is to implement a Business Value calculator: I fill the score field with a 5-digit figure where each number is a score in the 1-5 range. Then I compute a business value as the result of a calculation, where each number is weighted by a preset weight. I can sort my stories by Business Value to help me prioritize my backlog: that's the first step, and it works. Now what I want to do is to make my freeform grid editable: I am extracting each of my digits as a separate column, but those columns are display-only. How can I turn them into something editable? What I want to do of course is update back the score field based on the values input in each custom column. Here's an example: I have a record with score "15254", which means Business Value criteria 1 scores 1 out of 5, Business Value criteria 2 scores 5 out of 5, and so on... In the end my Business Value is computed as "1*1 + 5*2 + 2*3 + 5*4 + 4*5 = 57". So far this is the part that works. Now let's say I found that the third criteria should not score 2 but 3, I want to be able to edit the value in the corresponding column and have my score field updated to "15354", and my Business Value to display 60 instead of 57. Here is my current code, I'll be really grateful if you can help me with turning that grid into something editable :)  <script type="text/javascript" src="https://rally1.rallydev.com/apps/2.0p2/sdk-debug.js"></script>  <script type="text/javascript"> Rally.onReady(function() { Ext.define('BVApp', { extend: 'Rally.app.App', componentCls: 'app', launch: function() { Ext.create('Rally.data.WsapiDataStore', { model: 'UserStory', autoLoad: true, listeners: { load: this._onDataLoaded, scope: this } }); }, _onDataLoaded: function(store, data) { var records = []; var li_score; var li_bv1, li_bv2, li_bv3, li_bv4, li_bv5, li_bvtotal; var weights = new Array(1, 2, 3, 4, 5); Ext.Array.each(data, function(record) { //Let's fetch score and compute the business values... li_score = record.get('Score'); if (li_score) { li_bv1 = li_score.toString().substring(0,1); li_bv2 = li_score.toString().substring(1,2); li_bv3 = li_score.toString().substring(2,3); li_bv4 = li_score.toString().substring(3,4); li_bv5 = li_score.toString().substring(4,5); li_bvtotal = li_bv1*weights[0] + li_bv2*weights[1] + li_bv3*weights[2] + li_bv4*weights[3] + li_bv5*weights[4]; } records.push({ FormattedID: record.get('FormattedID'), ref: record.get('_ref'), Name: record.get('Name'), Score: record.get('Score'), Bv1: li_bv1, Bv2: li_bv2, Bv3: li_bv3, Bv4: li_bv4, Bv5: li_bv5, BvTotal: li_bvtotal }); }); this.add({ xtype: 'rallygrid', store: Ext.create('Rally.data.custom.Store', { data: records, pageSize: 5 }), columnCfgs: [ { text: 'FormattedID', dataIndex: 'FormattedID' }, { text: 'ref', dataIndex: 'ref' }, { text: 'Name', dataIndex: 'Name', flex: 1 }, { text: 'Score', dataIndex: 'Score' }, { text: 'BusVal 1', dataIndex: 'Bv1' }, { text: 'BusVal 2', dataIndex: 'Bv2' }, { text: 'BusVal 3', dataIndex: 'Bv3' }, { text: 'BusVal 4', dataIndex: 'Bv4' }, { text: 'BusVal 5', dataIndex: 'Bv5' }, { text: 'BusVal Total', dataIndex: 'BvTotal' } ] }); } }); Rally.launchApp('BVApp', { name: 'Business Values App' }); var exampleHtml = '<div id="example-intro"><h1>Business Values App</h1>' + '<div>Own sample app for Business Values</div>' + '</div>'; // Default app viewport uses layout: 'fit', // so we need to insert a container into the viewport var viewport = Ext.ComponentQuery.query('viewport')[0]; var appComponent = viewport.items.getAt(0); var viewportContainerItems = [{ html: exampleHtml, border: 0 }]; //hide advanced cardboard live previews in examples for now viewportContainerItems.push({ xtype: 'container', items: [appComponent] }); viewport.remove(appComponent, false); viewport.add({ xtype: 'container', layout: 'vbox', items: viewportContainerItems }); }); </script>  <style type="text/css"> .app { /* Add app styles here */ } </style>

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Record audio via MediaRecorder

- by Isuru Madusanka

I am trying to record audio by MediaRecorder, and I get an error, I tried to change everything and nothing works. Last two hours I try to find the error, I used Log class too and I found out that error occurred when it call recorder.start() method. What could be the problem? public class AudioRecorderActivity extends Activity { MediaRecorder recorder; File audioFile = null; private static final String TAG = "AudioRecorderActivity"; private View startButton; private View stopButton; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); startButton = findViewById(R.id.start); stopButton = findViewById(R.id.stop); setContentView(R.layout.main); } public void startRecording(View view) throws IOException{ startButton.setEnabled(false); stopButton.setEnabled(true); File sampleDir = Environment.getExternalStorageDirectory(); try{ audioFile = File.createTempFile("sound", ".3gp", sampleDir); }catch(IOException e){ Toast.makeText(getApplicationContext(), "SD Card Access Error", Toast.LENGTH_LONG).show(); Log.e(TAG, "Sdcard access error"); return; } recorder = new MediaRecorder(); recorder.setAudioSource(MediaRecorder.AudioSource.MIC); recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); recorder.setAudioEncodingBitRate(16); recorder.setAudioSamplingRate(44100); recorder.setOutputFile(audioFile.getAbsolutePath()); recorder.prepare(); recorder.start(); } public void stopRecording(View view){ startButton.setEnabled(true); stopButton.setEnabled(false); recorder.stop(); recorder.release(); addRecordingToMediaLibrary(); } protected void addRecordingToMediaLibrary(){ ContentValues values = new ContentValues(4); long current = System.currentTimeMillis(); values.put(MediaStore.Audio.Media.TITLE, "audio" + audioFile.getName()); values.put(MediaStore.Audio.Media.DATE_ADDED, (int)(current/1000)); values.put(MediaStore.Audio.Media.MIME_TYPE, "audio/3gpp"); values.put(MediaStore.Audio.Media.DATA, audioFile.getAbsolutePath()); ContentResolver contentResolver = getContentResolver(); Uri base = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; Uri newUri = contentResolver.insert(base, values); sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, newUri)); Toast.makeText(this, "Added File" + newUri, Toast.LENGTH_LONG).show(); } } And here is the xml layout. <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/RelativeLayout1" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <Button android:id="@+id/start" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:layout_marginTop="146dp" android:onClick="startRecording" android:text="Start Recording" /> <Button android:id="@+id/stop" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/start" android:layout_below="@+id/start" android:layout_marginTop="41dp" android:enabled="false" android:onClick="stopRecording" android:text="Stop Recording" /> </RelativeLayout> And I added permission to AndroidManifest file. <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="in.isuru.audiorecorder" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".AudioRecorderActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <uses-permission android:name="android.permission.RECORD_AUDIO" /> </manifest> I need to record high quality audio. Thanks!

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Help with understanding why UAC dialog pops up on Win7 for our application

- by Tim

We have a C++ unmanaged application that appears to cause a UAC prompt. It seems to happen on Win7 and NOT on Vista Unfortunately the UAC dlg is system modal so I can't attach a debugger to check in the code where it is, and running under msdev (we're using 2008) runs in elevated mode. We put a message box at the start of our program/winmain but it doesn't even get that far, so apparently this is in the startup code. What can cause a UAC notification so early and what other things can I do to track down the cause? EDIT Apparently the manifest is an important issue here, but it seems not to be helping me - or perhaps I am not configuring the manifest file correctly. Can someone provide a sample manifest? Also, does the linker/UAC magic figure out that the program "might" write to the registry and set its UAC requirements based on that? There are code paths that might trigger UAC, but we are not even at that point when the UAC dlg comes up. An additional oddity is that this does not seem to happen on Vista with UAC turned on. Here is a manifest (that I think is/was generated automatically): <?xml version='1.0' encoding='UTF-8' standalone='yes'?> <assembly xmlns='urn:schemas-microsoft-com:asm.v1' manifestVersion='1.0'> <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3"> <security> <requestedPrivileges> <requestedExecutionLevel level='asInvoker' uiAccess='false' /> </requestedPrivileges> </security> </trustInfo> <dependency> <dependentAssembly> <assemblyIdentity type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*' /> </dependentAssembly> </dependency> <dependency> <dependentAssembly> <assemblyIdentity type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='x86' publicKeyToken='6595b64144ccf1df' language='*' /> </dependentAssembly> </dependency> </assembly> And then this one was added to the manifest list to see if it would help <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0"> <assemblyIdentity version="1.0.0.0" processorArchitecture="x86" name="[removed for anonymity]" type="win32" /> <description> [removed for anonymity] </description> <dependency> <dependentAssembly> <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="x86" publicKeyToken="6595b64144ccf1df" language="*" /> </dependentAssembly> </dependency> <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2"> <security> <requestedPrivileges> <requestedExecutionLevel level="asInvoker" uiAccess="false"/> </requestedPrivileges> </security> </trustInfo> </assembly> The following is from the actual EXE using the ManifestViewer tool - <assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0"> <assemblyIdentity version="1.0.0.0" processorArchitecture="x86" name="[removed]" type="win32" /> <description>[removed]</description> - <dependency> - <dependentAssembly> <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="x86" publicKeyToken="6595b64144ccf1df" language="*" /> </dependentAssembly> </dependency> - <dependency> - <dependentAssembly> <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*" /> </dependentAssembly> </dependency> - <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2"> - <security> - <requestedPrivileges> <requestedExecutionLevel level="asInvoker" uiAccess="false" /> </requestedPrivileges> </security> </trustInfo> </assembly> It appears that it might be due to the xp compatibility setting on our app. I'll have to test that. (we set that in the installer I found out because some sound drivers don't work correctly on win7)

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Windows Phone 7: Making ListBox items change dynamically

- by Chad La Guardia

I am working on creating a Windows Phone app that will play a series of sound clips selected from a list. I am using the MVVM (Model View View-Model) Design pattern and have designed a model for my data, along with a view model for my page. Here is what the XAML for the ListBox looks like: <ListBox x:Name="MediaListBox" Margin="0,0,-12,0" ItemsSource="{Binding Media}" SelectionChanged="MediaListBox_SelectionChanged" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch"> <ListBox.ItemTemplate > <DataTemplate> <StackPanel Margin="0,0,0,17" Width="432" Orientation="Horizontal"> <Image Source="../Media/Images/play.png" /> <StackPanel > <TextBlock Text="{Binding Title}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}"/> <TextBlock Text="{Binding ShortDescription}" TextWrapping="Wrap" Margin="12,-6,12,0" Visibility="{Binding ShortDescriptionVisibility}" Style="{StaticResource PhoneTextSubtleStyle}"/> <TextBlock Text="{Binding LongDescription}" TextWrapping="Wrap" Visibility="{Binding LongDescriptionVisibility}" /> <StackPanel> <Slider HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" Visibility="{Binding LongDescriptionVisibility}" ValueChanged="Slider_ValueChanged" LargeChange="0.25" SmallChange="0.05" /> </StackPanel> </StackPanel> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> My question is this: I want to be able to expand and collapse part of the items in the ListBox. As you can see, I have a binding for the visibility. That binding is coming from the MediaModel. However, when I change this property in the ObservableCollection, the page is not updated to reflect this. The ViewModel for this page looks like this: public class ListenPageViewModel : INotifyPropertyChanged { public ListenPageViewModel() { this.Media = new ObservableCollection<MediaModel>; } /// <summary> /// A collection for MediaModel objects. /// </summary> public ObservableCollection<MediaModel> Media { get; private set; } public bool IsDataLoaded { get; private set; } /// <summary> /// Creates and adds the media to their respective collections. /// </summary> public void LoadData() { this.Media.Clear(); this.Media.Add(new MediaModel() { Title = "Media 1", ShortDescription = "Short here.", LongDescription = "Long here.", MediaSource = "/Media/test.mp3", LongDescriptionVisibility = Visibility.Collapsed, ShortDescriptionVisibility = Visibility.Visible }); this.Media.Add(new MediaModel() { Title = "Media 2", ShortDescription = "Short here.", LongDescription = "Long here.", MediaSource = "/Media/test2.mp3", LongDescriptionVisibility = Visibility.Collapsed, ShortDescriptionVisibility = Visibility.Visible }); this.IsDataLoaded = true; } public event PropertyChangedEventHandler PropertyChanged; private void NotifyPropertyChanged(String propertyName) { PropertyChangedEventHandler handler = PropertyChanged; if (null != handler) { handler(this, new PropertyChangedEventArgs(propertyName)); } } } The bindings work correctly and I am seeing the data displayed; however, when I change the properties, the list does not update. I believe that this may be because when I change things inside the observable collection, the property changed event is not firing. What can I do to remedy this? I have poked around for some info on this, but many of the tutorials don't cover this kind of behavior. Any help would be greatly appreciated! Thanks Edit: As requested, I have added the MediaModel code: public class MediaModel : INotifyPropertyChanged { public string Title { get; set; } public string ShortDescription { get; set; } public string LongDescription { get; set; } public string MediaSource { get; set; } public Visibility LongDescriptionVisibility { get; set; } public Visibility ShortDescriptionVisibility { get; set; } public MediaModel() { } public MediaModel(string Title, string ShortDescription, string LongDescription, string MediaSource, Visibility LongDescriptionVisibility, Visibility ShortDescriptionVisibility) { this.Title = Title; this.ShortDescription = ShortDescription; this.LongDescription = LongDescription; this.MediaSource = MediaSource; this.LongDescriptionVisibility = LongDescriptionVisibility; this.ShortDescriptionVisibility = ShortDescriptionVisibility; } public event PropertyChangedEventHandler PropertyChanged; private void NotifyPropertyChanged(String propertyName) { PropertyChangedEventHandler handler = PropertyChanged; if (null != handler) { handler(this, new PropertyChangedEventArgs(propertyName)); } } } Originally, I did not have this class implement the INotifyPropertyChanged. I did this to see if it would solve the problem. I was hoping this could just be a data object.

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My computer freezes irregularly

- by Manhim

My computer started to freeze at irregular times for 3 weeks now. Please note that this question change with each things that i try. (For additional details) What happens My computer freezes, the video stops. (No graphic glitches, it just stops) Sound keeps playing up to some time (Usually 10-30 seconds) then stops playing. Sometimes, randomly, the screen on my G-15 keyboard flickers and I see caracters not at the right places. Usually happens for about 1-2 seconds and a bit before my computer freezes. I have to keep the power button pressed for 4 seconds to shut my computer down. I still hear my hard drives and fans working. Sometimes it works with no problems for a full day, some other times it just keeps freezing each time I restart my computer and I have to leave it for the rest of the day. Sometimes my mouse freezes for a fraction of a second (Like 0.01 to 0.2 seconds) quite randomly, usually before it freezes. No errors spotted by the "Action center" unlike when I had problems with my last video card on this system (Driver errors). My G-15 LCD screen also freezes. Sometimes my G-15 LCD screen flickers and caracters gets caried around temporary under heavy load. Now, most of the times, the BIOS hard disks boot order gets reversed for some reason and I have to put it to the right one and save each times I boot. (Might be unrelated, not sure, but it first started yesterday) Sometimes the BIOS doesn't detect my 750GB hard drive plugged in SATA1. What I did so far I have had similar problems in the past and I had changed my hard drive (It was faulty), so I tested my software RAID-0 array and it was faulty so I changed it. (I reinstalled Windows 7 with this part). I also tested with unplugging my secondary hard drive. My CPU was running at about 100 degree Celsius, I removed the dust between the fans and the heatsink and it's now between 45-55. I ran a CPU stress-test and it didn't freeze during the tests (using Prime95 on all cores) Ran a memory test (using memtest86+) for a single pass and there were no errors. Ran a GPU stress test with ati-tools and furmark and it didn't freeze during the tests. (No artefacts either) I had troubles with my graphic card when I got it, but I think that it got fixed with a driver update. I checked the voltages in my BIOS setup and they all seemed ok (±0.2 I think). I have ran on the computer without problems with Fedora 15 on an external hard drive (Appart that it couldn't load Gnome 3 and was reverting to Gnome 2, didn't want to install drivers since I use it on multiple computers) I used it to backup my files from the raid array to my 1TB hard drive for the reinstallation of Windows. (So the crashes only happenned on Windows) [The external hard drive is plugged directly on a SATA port] I contacted EVGA (My graphic card vendor) and pointed them on this question, I'm looking for an answer. Ran sensors on Fedora 15 and got this output: http://pastebin.com/0BHJnAvu Ran 6 short different CPU stress test on Fedora 15 (Haven't found any complete stress testers for Linux) and it didn't crash. Changed the thermal paste to some Artic Silver 5 for my CPU and stress tested the CPU, temperature was at 50 idle, then 64 highest and slowly went down to 62 during the test. Ran some stress testing with a temporary graphic card and it went ok. Ran furmark stress test with my original graphic card and it freezed again. GPU had a temp of 74C, a CPU temp of 58C and a mobo temp of 40C or 45C (Dunno which one it is from SpeedFan). Ran a furmark stress test and a CPU stress test at the same time, results: http://pastebin.com/2t6PLpdJ I have been using my computer without stressing it for about 2 hours now and no crashes yet. I also have disabled the AMD Cool'n'quiet function on the BIOS for a more regular power to the CPU. When I ran Furmark without C'n'q my computer didn't freeze but I had a "Driver Kernel Error" that have recovered (And Furmark crashed) all that while running a CPU stress test. The computer eventually frozed without me being at it, but this time my screen just went on sleep and I couldn't wake it. Using the stability tester in nTune my computer freezed again (In the same manner as before). I notived that Speedfan gives me a -12V of -16.97V and a -5V of -8.78V. I wonder if these numbers are reliable and if they are good or bad. I have swapped my G-15 with another basic USB keyboard (HP) and I have ran furmark for about 10 minutes with a CPU stability test running each 60 seconds for 30 seconds and my computer haven't crashed yet. Ran some more extended tests without my G-15 and it freezed like it usually do. Removed the nForce Hard disk controler. Disabled command queuing in the NVIDIA nForce SATA Controller for both port 0 and port 1 (Errors from the logs) Used CPUID HwMonitor, here are the voltages: http://pastebin.com/dfM7p4jV Changed some configurations in the motherboard BIOS: Disabled PEG Link Mode, Changed AI Tuning to Standard, Disabled the 1394 Controller, Disabled HD Audio, Disabled JMicron RAID controller and Disabled SATA Raid. When it happens When I play video games (Mostly) When I play flash games (Second most) When I'm looking at my desktop background (It rarely happens when I have a window open, but it does, sometimes) When my Graphic card and my CPU are stressed. Sometimes when my Graphic card is stressed. Never happenned while stressing only the CPU. Sometimes when my CPU is stressed. Specs Windows Seven x64 Home Premium Motherboard: M2N-SLI Deluxe CPU: AMD Phenom 9950 x2 @ 2.6GHz Memory: Kingston 4x2GB Dual Channel (Pretty basic memory sticks) Hard drives: Was 2x250GB (Western digital caviar) in raid-0 + 1TB (WD caviar black), I replaced the raid array with a 750GB (WD caviar black) [Yes I removed the array from the raid configurations] 750W Power supply No overcloking. Ever. There have been some power-downs like 4-5 weeks ago, but the problem didn't start immediately after. (I wasn't home, so my computer got shut-down) Event logs (Warnings, errors and critical errors) for the last 24 hours: http://pastebin.com/Bvvk31T7 My current to-try list Reinstall the drivers and software 1 by 1 and do extensive stress testing between each. Update the BIOS firmware to the most recent stable one. Change my motherboard. Status updates Keeping only the last 3 (28/06 04pm) More stress testing and still pass the tests. (28/06 03pm) Been stress testing for 10 minute straight now and 5 minutes with both CPU and GPU being stressed at the same time. (28/06 03pm) Stress-testing right now, so far no problems. A little hope Tests with Furmark and Prime95. Testing Windows bare-bone: 30 Minutes stress, no freeze. Installing an Anti-virus and some software, restarting computer. Testing with Anti-virus and some software (No drivers installed): 30 Minutes stress, no freeze. Installing audio drivers, restarting computer. Testing with the audio drivers: 30 Minutes stress, no freeze. Installing the latest graphic drivers from EVGA's website (without 3d vision since I don't use it), restarting computer. Testing with the graphic drivers: 30 Minutes stress, no freeze. Configuring Windows to my liking and installing more softwares. In this situation, how can I successfully pin-point the current hardware problem? (If it's a hardware problem) Because I don't really have the budget to just forget and replace everything. I also don't really have hardware to test-replace current hardware.

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Connect ps/2->usb keyboard to linux?

- by Daniel

I have a lovely ancient ergonomic keyboard (no name SK - 6000) connected via a DIN-ps/2 adapter to a ps/2-usb adapter to my docking station. After Grub it stops working. It takes either suspending and waking up or replugging it while Linux is running to get it to work. No extra kernel modules get loaded for this. When it works and I restart without power off, it will work immediately. Even when it does not work, it is visible (lsusb device number varies but output is identical whether working or not): $ lsusb -v -s 001:006 Bus 001 Device 006: ID 0a81:0205 Chesen Electronics Corp. PS/2 Keyboard+Mouse Adapter Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 8 idVendor 0x0a81 Chesen Electronics Corp. idProduct 0x0205 PS/2 Keyboard+Mouse Adapter bcdDevice 0.10 iManufacturer 1 CHESEN iProduct 2 PS2 to USB Converter iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 59 bNumInterfaces 2 bConfigurationValue 1 iConfiguration 2 PS2 to USB Converter bmAttributes 0xa0 (Bus Powered) Remote Wakeup MaxPower 100mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 1 Boot Interface Subclass bInterfaceProtocol 1 Keyboard iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.10 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 64 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 10 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 1 Boot Interface Subclass bInterfaceProtocol 2 Mouse iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.10 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 148 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 10 Device Status: 0x0000 (Bus Powered) $ ll -R /sys/bus/hid/drivers/ /sys/bus/hid/drivers/: total 0 drwxr-xr-x 2 root root 0 Jul 8 2012 generic-usb/ /sys/bus/hid/drivers/generic-usb: total 0 lrwxrwxrwx 1 root root 0 Jul 7 23:33 0003:046D:C03D.0003 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.2/1-1.2.2:1.0/0003:046D:C03D.0003/ lrwxrwxrwx 1 root root 0 Jul 7 23:33 0003:0A81:0205.0001 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/0003:0A81:0205.0001/ lrwxrwxrwx 1 root root 0 Jul 7 23:33 0003:0A81:0205.0002 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.1/0003:0A81:0205.0002/ --w------- 1 root root 4096 Jul 7 23:32 bind lrwxrwxrwx 1 root root 0 Jul 7 23:33 module -> ../../../../module/usbhid/ --w------- 1 root root 4096 Jul 7 23:32 new_id --w------- 1 root root 4096 Jul 8 2012 uevent --w------- 1 root root 4096 Jul 7 23:32 unbind When replugging, dmesg shows this (which except for the 1st line and different input numbers already came at boot time): [ 1583.295385] usb 1-1.2.1: new low-speed USB device number 6 using ehci_hcd [ 1583.446514] input: CHESEN PS2 to USB Converter as /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/input/input17 [ 1583.446817] generic-usb 0003:0A81:0205.0001: input,hidraw0: USB HID v1.10 Keyboard [CHESEN PS2 to USB Converter] on usb-0000:00:1a.0-1.2.1/input0 [ 1583.454764] input: CHESEN PS2 to USB Converter as /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.1/input/input18 [ 1583.455534] generic-usb 0003:0A81:0205.0002: input,hidraw1: USB HID v1.10 Mouse [CHESEN PS2 to USB Converter] on usb-0000:00:1a.0-1.2.1/input1 [ 1583.455578] usbcore: registered new interface driver usbhid [ 1583.455584] usbhid: USB HID core driver So I tried $ sudo udevadm test /sys/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/0003:0A81:0205.0001/hidraw/hidraw0 run_command: calling: test adm_test: version 175 This program is for debugging only, it does not run any program, specified by a RUN key. It may show incorrect results, because some values may be different, or not available at a simulation run. parse_file: reading '/lib/udev/rules.d/40-crda.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-fuse.rules' as rules file ... parse_file: reading '/lib/udev/rules.d/40-usb-media-players.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-usb_modeswitch.rules' as rules file ... parse_file: reading '/lib/udev/rules.d/42-qemu-usb.rules' as rules file ... parse_file: reading '/lib/udev/rules.d/69-cd-sensors.rules' as rules file add_rule: IMPORT found builtin 'usb_id', replacing /lib/udev/rules.d/69-cd-sensors.rules:76 ... parse_file: reading '/lib/udev/rules.d/77-mm-usb-device-blacklist.rules' as rules file ... parse_file: reading '/lib/udev/rules.d/85-usbmuxd.rules' as rules file ... parse_file: reading '/lib/udev/rules.d/95-upower-hid.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-wup.rules' as rules file parse_file: reading '/lib/udev/rules.d/97-bluetooth-hid2hci.rules' as rules file udev_rules_new: rules use 271500 bytes tokens (22625 * 12 bytes), 44331 bytes buffer udev_rules_new: temporary index used 76320 bytes (3816 * 20 bytes) udev_device_new_from_syspath: device 0x7f78a5e4d2d0 has devpath '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/0003:0A81:0205.0001/hidraw/hidraw0' udev_device_new_from_syspath: device 0x7f78a5e5f820 has devpath '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/0003:0A81:0205.0001/hidraw/hidraw0' udev_device_read_db: device 0x7f78a5e5f820 filled with db file data udev_device_new_from_syspath: device 0x7f78a5e60270 has devpath '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/0003:0A81:0205.0001' udev_device_new_from_syspath: device 0x7f78a5e609c0 has devpath '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0' udev_device_new_from_syspath: device 0x7f78a5e61160 has devpath '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1' udev_device_new_from_syspath: device 0x7f78a5e61960 has devpath '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2' udev_device_new_from_syspath: device 0x7f78a5e62150 has devpath '/devices/pci0000:00/0000:00:1a.0/usb1/1-1' udev_device_new_from_syspath: device 0x7f78a5e62940 has devpath '/devices/pci0000:00/0000:00:1a.0/usb1' udev_device_new_from_syspath: device 0x7f78a5e630f0 has devpath '/devices/pci0000:00/0000:00:1a.0' udev_device_new_from_syspath: device 0x7f78a5e638a0 has devpath '/devices/pci0000:00' udev_event_execute_rules: no node name set, will use kernel supplied name 'hidraw0' udev_node_add: creating device node '/dev/hidraw0', devnum=251:0, mode=0600, uid=0, gid=0 udev_node_mknod: preserve file '/dev/hidraw0', because it has correct dev_t udev_node_mknod: preserve permissions /dev/hidraw0, 020600, uid=0, gid=0 node_symlink: preserve already existing symlink '/dev/char/251:0' to '../hidraw0' udev_device_update_db: created empty file '/run/udev/data/c251:0' for '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/0003:0A81:0205.0001/hidraw/hidraw0' ACTION=add DEVNAME=/dev/hidraw0 DEVPATH=/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/0003:0A81:0205.0001/hidraw/hidraw0 MAJOR=251 MINOR=0 SUBSYSTEM=hidraw UDEV_LOG=6 USEC_INITIALIZED=969079051 The later lines sound like it's already there. And none of these awakes the keyboard: $ sudo udevadm trigger --verbose --sysname-match=usb* /sys/devices/pci0000:00/0000:00:1a.0/usb1 /sys/devices/pci0000:00/0000:00:1a.0/usbmon/usbmon1 /sys/devices/pci0000:00/0000:00:1d.0/usb2 /sys/devices/pci0000:00/0000:00:1d.0/usbmon/usbmon2 /sys/devices/virtual/usbmon/usbmon0 $ sudo udevadm trigger --verbose --sysname-match=hidraw0 /sys/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1:1.0/0003:0A81:0205.0001/hidraw/hidraw0 $ sudo udevadm trigger I also tried this to no avail: # echo -n 0003:0A81:0205.0001 > /sys/bus/hid/drivers/generic-usb/bind ksh: echo: write to 1 failed [No such device] # echo -n 0003:0A81:0205.0001 > /sys/bus/hid/drivers/generic-usb/unbind # echo -n 0003:0A81:0205.0001 > /sys/bus/hid/drivers/generic-usb/bind # echo usb1 >/sys/bus/usb/drivers/usb/unbind # echo usb1 >/sys/bus/usb/drivers/usb/bind What else should I try to get the same result as replugging or suspending, by just issuing a command?

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Why are my hard drives failing?

- by WishCow

I have a small Ubuntu server running at home, with 2 HDDs. There are two software raids (raid1) on the disks, managed by mdadm, which I believe is irrelevant, but mentioning it anyway. Both of the HDDs are Western Digital, and have been used for around 2 years, when one of them started making clicking noises, and died. I figured that maybe it's natural after 2 years, so I bought a new one, and resynced the raid arrays. After about a month, the other drive also died. I didn't get suspicious, since both drives have been bought at the same time, it's not that surprising to see both of them near each other, so I bought another one. So far, 2 old drives failed, and 2 brand new in the system. After one month, one of the new drives died. This is when it started getting suspicious. Since the PC was put together from some really old parts (think AthlonXP), I figured that maybe the motherboard's SATA controller is the culprit. Of course you can't switch parts easily in an old PC like this, so I bought a whole system, new MB, new CPU, new RAM. Took the just failed drive back, since it was under warranty, and got it replaced. So it is up to 2 failed drives from the old ones, and 1 failed drive from the new ones. No problems, for 1 month. After that errors were creeping up again in /var/log/messages, and mdadm was reporting raid array failures. I started tearing my hair out. Everything is new in the system, it's up to the third brand new HDD, it's simply not possible that all of the new drives that I bought were faulty. Let's see what is still common... the cables. Okay, long shot, let's replace the SATA cables. Take HDD back, smile to the guy at the counter and say that I'm really unlucky. He replaces the HDD. I come home, one month passes and one of HDDs fails, again. I'm not joking. Two of the brand new HDDs have failed. Maybe it's a bug in the OS. Let's see what the manufacturer's testing tool says. Download testing tool, burn it to a CD, reboot, leave HDD testing overnight. Test says that the drive is faulty, and I should back up everything, if I still can. I don't know what's happening, but it does not look like a software problem, something is definitely thrashing the HDDs. I should mention now, that the whole system is in a shoebox. Since there are a load of "build your own ikea case" stuff, I thought there shouldn't be any problems throwing the thing in a box, and stuffing it away somewhere. The box is well ventilated, but I thought that just maybe the drives were overheating. There is no other possible answer to this. So I took the HDD back, and got it replaced (for the 3rd time), and bought HDD coolers. And just now, I have heard the sound of doom. click click whizzzzzzzzz. SSH into the box: You have new mail! mail r 1 DegradedArrayEvent on /dev/md0 ... dmesg output: [47128.000051] ata3: lost interrupt (Status 0x50) [47128.000097] end_request: I/O error, dev sda, sector 58588863 [47128.000134] md: super_written gets error=-5, uptodate=0 [48043.976054] ata3: lost interrupt (Status 0x50) [48043.976086] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen [48043.976132] ata3.00: cmd c8/00:18:bf:40:52/00:00:00:00:00/e1 tag 0 dma 12288 in [48043.976135] res 40/00:00:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout) [48043.976208] ata3.00: status: { DRDY } [48043.976241] ata3: soft resetting link [48044.148446] ata3.00: configured for UDMA/133 [48044.148457] ata3.00: device reported invalid CHS sector 0 [48044.148477] ata3: EH complete Recap: No possibility of overheating 6 drives have failed, 4 of those have been brand new. I'm not sure now that the original two have been faulty, or suffered the same thing that the new ones. There is nothing common in the system, apart from the OS which is Ubuntu Karmic now (started with Jaunty). New MB, new CPU, new RAM, new SATA cables. No, the little holes on the HDD are not covered I'm crying. Really. I don't have the face to return to the store now, it's not possible for 4 drives to fail under 4 months. A few ideas that I have been thinking: Is it possible that I fuck up something when I partition and resync the drives? Can it be so bad that it physicaly wrecks the drive? (since the vendor supplied tool says that the drive is damaged) I do the partitoning with fdisk, and use the same block size for the raid1 partitions (I check the exact block sizes with fdisk -lu) Is it possible that the linux kernel or mdadm, or something is not compatible with this exact brand of HDDs, and thrashes them? Is it possible that it may be the shoebox? Try placing it somewhere else? It's under a shelf now, so humidity is not a problem either. Is it possible that a normal PC case will solve my problem (I'm going to shoot myself then)? I will get a picture tomorrow. Am I just simply cursed? Any help or speculation is greatly appreciated. Edit: The power strip is guarded against overvoltage. Edit2: I have moved inbetween these 4 months, so the possibility of the cause being "dirty" electricity in both places, is very low. Edit3: I have checked the voltages in the BIOS (couldn't borrow a multimeter), and they are all seem correct, the biggest discrepancy is in the 12V, because it's supplying 11.3. Should I be worried about that? Edit4: I put my desktop PC's PSU into the server. The BIOS reported much more accurate voltage readings, and also it has successfully rebuilt the raid1 array, which took some 3-4 hours, so I feel a little positive now. Will get a new PSU tomorrow to test with that. Also, attaching the picture about the box: (disregard the 3rd drive)

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Improving Partitioned Table Join Performance

- by Paul White

The query optimizer does not always choose an optimal strategy when joining partitioned tables. This post looks at an example, showing how a manual rewrite of the query can almost double performance, while reducing the memory grant to almost nothing. Test Data The two tables in this example use a common partitioning partition scheme. The partition function uses 41 equal-size partitions: CREATE PARTITION FUNCTION PFT (integer) AS RANGE RIGHT FOR VALUES ( 125000, 250000, 375000, 500000, 625000, 750000, 875000, 1000000, 1125000, 1250000, 1375000, 1500000, 1625000, 1750000, 1875000, 2000000, 2125000, 2250000, 2375000, 2500000, 2625000, 2750000, 2875000, 3000000, 3125000, 3250000, 3375000, 3500000, 3625000, 3750000, 3875000, 4000000, 4125000, 4250000, 4375000, 4500000, 4625000, 4750000, 4875000, 5000000 ); GO CREATE PARTITION SCHEME PST AS PARTITION PFT ALL TO ([PRIMARY]); There two tables are: CREATE TABLE dbo.T1 ( TID integer NOT NULL IDENTITY(0,1), Column1 integer NOT NULL, Padding binary(100) NOT NULL DEFAULT 0x, CONSTRAINT PK_T1 PRIMARY KEY CLUSTERED (TID) ON PST (TID) ); CREATE TABLE dbo.T2 ( TID integer NOT NULL, Column1 integer NOT NULL, Padding binary(100) NOT NULL DEFAULT 0x, CONSTRAINT PK_T2 PRIMARY KEY CLUSTERED (TID, Column1) ON PST (TID) ); The next script loads 5 million rows into T1 with a pseudo-random value between 1 and 5 for Column1. The table is partitioned on the IDENTITY column TID: INSERT dbo.T1 WITH (TABLOCKX) (Column1) SELECT (ABS(CHECKSUM(NEWID())) % 5) + 1 FROM dbo.Numbers AS N WHERE n BETWEEN 1 AND 5000000; In case you don’t already have an auxiliary table of numbers lying around, here’s a script to create one with 10 million rows: CREATE TABLE dbo.Numbers (n bigint PRIMARY KEY); WITH L0 AS(SELECT 1 AS c UNION ALL SELECT 1), L1 AS(SELECT 1 AS c FROM L0 AS A CROSS JOIN L0 AS B), L2 AS(SELECT 1 AS c FROM L1 AS A CROSS JOIN L1 AS B), L3 AS(SELECT 1 AS c FROM L2 AS A CROSS JOIN L2 AS B), L4 AS(SELECT 1 AS c FROM L3 AS A CROSS JOIN L3 AS B), L5 AS(SELECT 1 AS c FROM L4 AS A CROSS JOIN L4 AS B), Nums AS(SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS n FROM L5) INSERT dbo.Numbers WITH (TABLOCKX) SELECT TOP (10000000) n FROM Nums ORDER BY n OPTION (MAXDOP 1); Table T1 contains data like this: Next we load data into table T2. The relationship between the two tables is that table 2 contains ‘n’ rows for each row in table 1, where ‘n’ is determined by the value in Column1 of table T1. There is nothing particularly special about the data or distribution, by the way. INSERT dbo.T2 WITH (TABLOCKX) (TID, Column1) SELECT T.TID, N.n FROM dbo.T1 AS T JOIN dbo.Numbers AS N ON N.n >= 1 AND N.n <= T.Column1; Table T2 ends up containing about 15 million rows: The primary key for table T2 is a combination of TID and Column1. The data is partitioned according to the value in column TID alone. Partition Distribution The following query shows the number of rows in each partition of table T1: SELECT PartitionID = CA1.P, NumRows = COUNT_BIG(*) FROM dbo.T1 AS T CROSS APPLY (VALUES ($PARTITION.PFT(TID))) AS CA1 (P) GROUP BY CA1.P ORDER BY CA1.P; There are 40 partitions containing 125,000 rows (40 * 125k = 5m rows). The rightmost partition remains empty. The next query shows the distribution for table 2: SELECT PartitionID = CA1.P, NumRows = COUNT_BIG(*) FROM dbo.T2 AS T CROSS APPLY (VALUES ($PARTITION.PFT(TID))) AS CA1 (P) GROUP BY CA1.P ORDER BY CA1.P; There are roughly 375,000 rows in each partition (the rightmost partition is also empty): Ok, that’s the test data done. Test Query and Execution Plan The task is to count the rows resulting from joining tables 1 and 2 on the TID column: SET STATISTICS IO ON; DECLARE @s datetime2 = SYSUTCDATETIME(); SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID; SELECT DATEDIFF(Millisecond, @s, SYSUTCDATETIME()); SET STATISTICS IO OFF; The optimizer chooses a plan using parallel hash join, and partial aggregation: The Plan Explorer plan tree view shows accurate cardinality estimates and an even distribution of rows across threads (click to enlarge the image): With a warm data cache, the STATISTICS IO output shows that no physical I/O was needed, and all 41 partitions were touched: Running the query without actual execution plan or STATISTICS IO information for maximum performance, the query returns in around 2600ms. Execution Plan Analysis The first step toward improving on the execution plan produced by the query optimizer is to understand how it works, at least in outline. The two parallel Clustered Index Scans use multiple threads to read rows from tables T1 and T2. Parallel scan uses a demand-based scheme where threads are given page(s) to scan from the table as needed. This arrangement has certain important advantages, but does result in an unpredictable distribution of rows amongst threads. The point is that multiple threads cooperate to scan the whole table, but it is impossible to predict which rows end up on which threads. For correct results from the parallel hash join, the execution plan has to ensure that rows from T1 and T2 that might join are processed on the same thread. For example, if a row from T1 with join key value ‘1234’ is placed in thread 5’s hash table, the execution plan must guarantee that any rows from T2 that also have join key value ‘1234’ probe thread 5’s hash table for matches. The way this guarantee is enforced in this parallel hash join plan is by repartitioning rows to threads after each parallel scan. The two repartitioning exchanges route rows to threads using a hash function over the hash join keys. The two repartitioning exchanges use the same hash function so rows from T1 and T2 with the same join key must end up on the same hash join thread. Expensive Exchanges This business of repartitioning rows between threads can be very expensive, especially if a large number of rows is involved. The execution plan selected by the optimizer moves 5 million rows through one repartitioning exchange and around 15 million across the other. As a first step toward removing these exchanges, consider the execution plan selected by the optimizer if we join just one partition from each table, disallowing parallelism: SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = 1 AND $PARTITION.PFT(T2.TID) = 1 OPTION (MAXDOP 1); The optimizer has chosen a (one-to-many) merge join instead of a hash join. The single-partition query completes in around 100ms. If everything scaled linearly, we would expect that extending this strategy to all 40 populated partitions would result in an execution time around 4000ms. Using parallelism could reduce that further, perhaps to be competitive with the parallel hash join chosen by the optimizer. This raises a question. If the most efficient way to join one partition from each of the tables is to use a merge join, why does the optimizer not choose a merge join for the full query? Forcing a Merge Join Let’s force the optimizer to use a merge join on the test query using a hint: SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID OPTION (MERGE JOIN); This is the execution plan selected by the optimizer: This plan results in the same number of logical reads reported previously, but instead of 2600ms the query takes 5000ms. The natural explanation for this drop in performance is that the merge join plan is only using a single thread, whereas the parallel hash join plan could use multiple threads. Parallel Merge Join We can get a parallel merge join plan using the same query hint as before, and adding trace flag 8649: SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID OPTION (MERGE JOIN, QUERYTRACEON 8649); The execution plan is: This looks promising. It uses a similar strategy to distribute work across threads as seen for the parallel hash join. In practice though, performance is disappointing. On a typical run, the parallel merge plan runs for around 8400ms; slower than the single-threaded merge join plan (5000ms) and much worse than the 2600ms for the parallel hash join. We seem to be going backwards! The logical reads for the parallel merge are still exactly the same as before, with no physical IOs. The cardinality estimates and thread distribution are also still very good (click to enlarge): A big clue to the reason for the poor performance is shown in the wait statistics (captured by Plan Explorer Pro): CXPACKET waits require careful interpretation, and are most often benign, but in this case excessive waiting occurs at the repartitioning exchanges. Unlike the parallel hash join, the repartitioning exchanges in this plan are order-preserving ‘merging’ exchanges (because merge join requires ordered inputs): Parallelism works best when threads can just grab any available unit of work and get on with processing it. Preserving order introduces inter-thread dependencies that can easily lead to significant waits occurring. In extreme cases, these dependencies can result in an intra-query deadlock, though the details of that will have to wait for another time to explore in detail. The potential for waits and deadlocks leads the query optimizer to cost parallel merge join relatively highly, especially as the degree of parallelism (DOP) increases. This high costing resulted in the optimizer choosing a serial merge join rather than parallel in this case. The test results certainly confirm its reasoning. Collocated Joins In SQL Server 2008 and later, the optimizer has another available strategy when joining tables that share a common partition scheme. This strategy is a collocated join, also known as as a per-partition join. It can be applied in both serial and parallel execution plans, though it is limited to 2-way joins in the current optimizer. Whether the optimizer chooses a collocated join or not depends on cost estimation. The primary benefits of a collocated join are that it eliminates an exchange and requires less memory, as we will see next. Costing and Plan Selection The query optimizer did consider a collocated join for our original query, but it was rejected on cost grounds. The parallel hash join with repartitioning exchanges appeared to be a cheaper option. There is no query hint to force a collocated join, so we have to mess with the costing framework to produce one for our test query. Pretending that IOs cost 50 times more than usual is enough to convince the optimizer to use collocated join with our test query: -- Pretend IOs are 50x cost temporarily DBCC SETIOWEIGHT(50); -- Co-located hash join SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID OPTION (RECOMPILE); -- Reset IO costing DBCC SETIOWEIGHT(1); Collocated Join Plan The estimated execution plan for the collocated join is: The Constant Scan contains one row for each partition of the shared partitioning scheme, from 1 to 41. The hash repartitioning exchanges seen previously are replaced by a single Distribute Streams exchange using Demand partitioning. Demand partitioning means that the next partition id is given to the next parallel thread that asks for one. My test machine has eight logical processors, and all are available for SQL Server to use. As a result, there are eight threads in the single parallel branch in this plan, each processing one partition from each table at a time. Once a thread finishes processing a partition, it grabs a new partition number from the Distribute Streams exchange…and so on until all partitions have been processed. It is important to understand that the parallel scans in this plan are different from the parallel hash join plan. Although the scans have the same parallelism icon, tables T1 and T2 are not being co-operatively scanned by multiple threads in the same way. Each thread reads a single partition of T1 and performs a hash match join with the same partition from table T2. The properties of the two Clustered Index Scans show a Seek Predicate (unusual for a scan!) limiting the rows to a single partition: The crucial point is that the join between T1 and T2 is on TID, and TID is the partitioning column for both tables. A thread that processes partition ‘n’ is guaranteed to see all rows that can possibly join on TID for that partition. In addition, no other thread will see rows from that partition, so this removes the need for repartitioning exchanges. CPU and Memory Efficiency Improvements The collocated join has removed two expensive repartitioning exchanges and added a single exchange processing 41 rows (one for each partition id). Remember, the parallel hash join plan exchanges had to process 5 million and 15 million rows. The amount of processor time spent on exchanges will be much lower in the collocated join plan. In addition, the collocated join plan has a maximum of 8 threads processing single partitions at any one time. The 41 partitions will all be processed eventually, but a new partition is not started until a thread asks for it. Threads can reuse hash table memory for the new partition. The parallel hash join plan also had 8 hash tables, but with all 5,000,000 build rows loaded at the same time. The collocated plan needs memory for only 8 * 125,000 = 1,000,000 rows at any one time. Collocated Hash Join Performance The collated join plan has disappointing performance in this case. The query runs for around 25,300ms despite the same IO statistics as usual. This is much the worst result so far, so what went wrong? It turns out that cardinality estimation for the single partition scans of table T1 is slightly low. The properties of the Clustered Index Scan of T1 (graphic immediately above) show the estimation was for 121,951 rows. This is a small shortfall compared with the 125,000 rows actually encountered, but it was enough to cause the hash join to spill to physical tempdb: A level 1 spill doesn’t sound too bad, until you realize that the spill to tempdb probably occurs for each of the 41 partitions. As a side note, the cardinality estimation error is a little surprising because the system tables accurately show there are 125,000 rows in every partition of T1. Unfortunately, the optimizer uses regular column and index statistics to derive cardinality estimates here rather than system table information (e.g. sys.partitions). Collocated Merge Join We will never know how well the collocated parallel hash join plan might have worked without the cardinality estimation error (and the resulting 41 spills to tempdb) but we do know: Merge join does not require a memory grant; and Merge join was the optimizer’s preferred join option for a single partition join Putting this all together, what we would really like to see is the same collocated join strategy, but using merge join instead of hash join. Unfortunately, the current query optimizer cannot produce a collocated merge join; it only knows how to do collocated hash join. So where does this leave us? CROSS APPLY sys.partitions We can try to write our own collocated join query. We can use sys.partitions to find the partition numbers, and CROSS APPLY to get a count per partition, with a final step to sum the partial counts. The following query implements this idea: SELECT row_count = SUM(Subtotals.cnt) FROM ( -- Partition numbers SELECT p.partition_number FROM sys.partitions AS p WHERE p.[object_id] = OBJECT_ID(N'T1', N'U') AND p.index_id = 1 ) AS P CROSS APPLY ( -- Count per collocated join SELECT cnt = COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = p.partition_number AND $PARTITION.PFT(T2.TID) = p.partition_number ) AS SubTotals; The estimated plan is: The cardinality estimates aren’t all that good here, especially the estimate for the scan of the system table underlying the sys.partitions view. Nevertheless, the plan shape is heading toward where we would like to be. Each partition number from the system table results in a per-partition scan of T1 and T2, a one-to-many Merge Join, and a Stream Aggregate to compute the partial counts. The final Stream Aggregate just sums the partial counts. Execution time for this query is around 3,500ms, with the same IO statistics as always. This compares favourably with 5,000ms for the serial plan produced by the optimizer with the OPTION (MERGE JOIN) hint. This is another case of the sum of the parts being less than the whole – summing 41 partial counts from 41 single-partition merge joins is faster than a single merge join and count over all partitions. Even so, this single-threaded collocated merge join is not as quick as the original parallel hash join plan, which executed in 2,600ms. On the positive side, our collocated merge join uses only one logical processor and requires no memory grant. The parallel hash join plan used 16 threads and reserved 569 MB of memory: Using a Temporary Table Our collocated merge join plan should benefit from parallelism. The reason parallelism is not being used is that the query references a system table. We can work around that by writing the partition numbers to a temporary table (or table variable): SET STATISTICS IO ON; DECLARE @s datetime2 = SYSUTCDATETIME(); CREATE TABLE #P ( partition_number integer PRIMARY KEY); INSERT #P (partition_number) SELECT p.partition_number FROM sys.partitions AS p WHERE p.[object_id] = OBJECT_ID(N'T1', N'U') AND p.index_id = 1; SELECT row_count = SUM(Subtotals.cnt) FROM #P AS p CROSS APPLY ( SELECT cnt = COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = p.partition_number AND $PARTITION.PFT(T2.TID) = p.partition_number ) AS SubTotals; DROP TABLE #P; SELECT DATEDIFF(Millisecond, @s, SYSUTCDATETIME()); SET STATISTICS IO OFF; Using the temporary table adds a few logical reads, but the overall execution time is still around 3500ms, indistinguishable from the same query without the temporary table. The problem is that the query optimizer still doesn’t choose a parallel plan for this query, though the removal of the system table reference means that it could if it chose to: In fact the optimizer did enter the parallel plan phase of query optimization (running search 1 for a second time): Unfortunately, the parallel plan found seemed to be more expensive than the serial plan. This is a crazy result, caused by the optimizer’s cost model not reducing operator CPU costs on the inner side of a nested loops join. Don’t get me started on that, we’ll be here all night. In this plan, everything expensive happens on the inner side of a nested loops join. Without a CPU cost reduction to compensate for the added cost of exchange operators, candidate parallel plans always look more expensive to the optimizer than the equivalent serial plan. Parallel Collocated Merge Join We can produce the desired parallel plan using trace flag 8649 again: SELECT row_count = SUM(Subtotals.cnt) FROM #P AS p CROSS APPLY ( SELECT cnt = COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = p.partition_number AND $PARTITION.PFT(T2.TID) = p.partition_number ) AS SubTotals OPTION (QUERYTRACEON 8649); The actual execution plan is: One difference between this plan and the collocated hash join plan is that a Repartition Streams exchange operator is used instead of Distribute Streams. The effect is similar, though not quite identical. The Repartition uses round-robin partitioning, meaning the next partition id is pushed to the next thread in sequence. The Distribute Streams exchange seen earlier used Demand partitioning, meaning the next partition id is pulled across the exchange by the next thread that is ready for more work. There are subtle performance implications for each partitioning option, but going into that would again take us too far off the main point of this post. Performance The important thing is the performance of this parallel collocated merge join – just 1350ms on a typical run. The list below shows all the alternatives from this post (all timings include creation, population, and deletion of the temporary table where appropriate) from quickest to slowest: Collocated parallel merge join: 1350ms Parallel hash join: 2600ms Collocated serial merge join: 3500ms Serial merge join: 5000ms Parallel merge join: 8400ms Collated parallel hash join: 25,300ms (hash spill per partition) The parallel collocated merge join requires no memory grant (aside from a paltry 1.2MB used for exchange buffers). This plan uses 16 threads at DOP 8; but 8 of those are (rather pointlessly) allocated to the parallel scan of the temporary table. These are minor concerns, but it turns out there is a way to address them if it bothers you. Parallel Collocated Merge Join with Demand Partitioning This final tweak replaces the temporary table with a hard-coded list of partition ids (dynamic SQL could be used to generate this query from sys.partitions): SELECT row_count = SUM(Subtotals.cnt) FROM ( VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10), (11),(12),(13),(14),(15),(16),(17),(18),(19),(20), (21),(22),(23),(24),(25),(26),(27),(28),(29),(30), (31),(32),(33),(34),(35),(36),(37),(38),(39),(40),(41) ) AS P (partition_number) CROSS APPLY ( SELECT cnt = COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = p.partition_number AND $PARTITION.PFT(T2.TID) = p.partition_number ) AS SubTotals OPTION (QUERYTRACEON 8649); The actual execution plan is: The parallel collocated hash join plan is reproduced below for comparison: The manual rewrite has another advantage that has not been mentioned so far: the partial counts (per partition) can be computed earlier than the partial counts (per thread) in the optimizer’s collocated join plan. The earlier aggregation is performed by the extra Stream Aggregate under the nested loops join. The performance of the parallel collocated merge join is unchanged at around 1350ms. Final Words It is a shame that the current query optimizer does not consider a collocated merge join (Connect item closed as Won’t Fix). The example used in this post showed an improvement in execution time from 2600ms to 1350ms using a modestly-sized data set and limited parallelism. In addition, the memory requirement for the query was almost completely eliminated – down from 569MB to 1.2MB. The problem with the parallel hash join selected by the optimizer is that it attempts to process the full data set all at once (albeit using eight threads). It requires a large memory grant to hold all 5 million rows from table T1 across the eight hash tables, and does not take advantage of the divide-and-conquer opportunity offered by the common partitioning. The great thing about the collocated join strategies is that each parallel thread works on a single partition from both tables, reading rows, performing the join, and computing a per-partition subtotal, before moving on to a new partition. From a thread’s point of view… If you have trouble visualizing what is happening from just looking at the parallel collocated merge join execution plan, let’s look at it again, but from the point of view of just one thread operating between the two Parallelism (exchange) operators. Our thread picks up a single partition id from the Distribute Streams exchange, and starts a merge join using ordered rows from partition 1 of table T1 and partition 1 of table T2. By definition, this is all happening on a single thread. As rows join, they are added to a (per-partition) count in the Stream Aggregate immediately above the Merge Join. Eventually, either T1 (partition 1) or T2 (partition 1) runs out of rows and the merge join stops. The per-partition count from the aggregate passes on through the Nested Loops join to another Stream Aggregate, which is maintaining a per-thread subtotal. Our same thread now picks up a new partition id from the exchange (say it gets id 9 this time). The count in the per-partition aggregate is reset to zero, and the processing of partition 9 of both tables proceeds just as it did for partition 1, and on the same thread. Each thread picks up a single partition id and processes all the data for that partition, completely independently from other threads working on other partitions. One thread might eventually process partitions (1, 9, 17, 25, 33, 41) while another is concurrently processing partitions (2, 10, 18, 26, 34) and so on for the other six threads at DOP 8. The point is that all 8 threads can execute independently and concurrently, continuing to process new partitions until the wider job (of which the thread has no knowledge!) is done. This divide-and-conquer technique can be much more efficient than simply splitting the entire workload across eight threads all at once. Related Reading Understanding and Using Parallelism in SQL Server Parallel Execution Plans Suck © 2013 Paul White – All Rights Reserved Twitter: @SQL_Kiwi

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C#/.NET Little Wonders: The Concurrent Collections (1 of 3)

- by James Michael Hare

Once again we consider some of the lesser known classes and keywords of C#. In the next few weeks, we will discuss the concurrent collections and how they have changed the face of concurrent programming. This week’s post will begin with a general introduction and discuss the ConcurrentStack<T> and ConcurrentQueue<T>. Then in the following post we’ll discuss the ConcurrentDictionary<T> and ConcurrentBag<T>. Finally, we shall close on the third post with a discussion of the BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. A brief history of collections In the beginning was the .NET 1.0 Framework. And out of this framework emerged the System.Collections namespace, and it was good. It contained all the basic things a growing programming language needs like the ArrayList and Hashtable collections. The main problem, of course, with these original collections is that they held items of type object which means you had to be disciplined enough to use them correctly or you could end up with runtime errors if you got an object of a type you weren't expecting. Then came .NET 2.0 and generics and our world changed forever! With generics the C# language finally got an equivalent of the very powerful C++ templates. As such, the System.Collections.Generic was born and we got type-safe versions of all are favorite collections. The List<T> succeeded the ArrayList and the Dictionary<TKey,TValue> succeeded the Hashtable and so on. The new versions of the library were not only safer because they checked types at compile-time, in many cases they were more performant as well. So much so that it's Microsoft's recommendation that the System.Collections original collections only be used for backwards compatibility. So we as developers came to know and love the generic collections and took them into our hearts and embraced them. The problem is, thread safety in both the original collections and the generic collections can be problematic, for very different reasons. Now, if you are only doing single-threaded development you may not care – after all, no locking is required. Even if you do have multiple threads, if a collection is “load-once, read-many” you don’t need to do anything to protect that container from multi-threaded access, as illustrated below: 1: public static class OrderTypeTranslator 2: { 3: // because this dictionary is loaded once before it is ever accessed, we don't need to synchronize 4: // multi-threaded read access 5: private static readonly Dictionary<string, char> _translator = new Dictionary<string, char> 6: { 7: {"New", 'N'}, 8: {"Update", 'U'}, 9: {"Cancel", 'X'} 10: }; 11: 12: // the only public interface into the dictionary is for reading, so inherently thread-safe 13: public static char? Translate(string orderType) 14: { 15: char charValue; 16: if (_translator.TryGetValue(orderType, out charValue)) 17: { 18: return charValue; 19: } 20: 21: return null; 22: } 23: } Unfortunately, most of our computer science problems cannot get by with just single-threaded applications or with multi-threading in a load-once manner. Looking at today's trends, it's clear to see that computers are not so much getting faster because of faster processor speeds -- we've nearly reached the limits we can push through with today's technologies -- but more because we're adding more cores to the boxes. With this new hardware paradigm, it is even more important to use multi-threaded applications to take full advantage of parallel processing to achieve higher application speeds. So let's look at how to use collections in a thread-safe manner. Using historical collections in a concurrent fashion The early .NET collections (System.Collections) had a Synchronized() static method that could be used to wrap the early collections to make them completely thread-safe. This paradigm was dropped in the generic collections (System.Collections.Generic) because having a synchronized wrapper resulted in atomic locks for all operations, which could prove overkill in many multithreading situations. Thus the paradigm shifted to having the user of the collection specify their own locking, usually with an external object: 1: public class OrderAggregator 2: { 3: private static readonly Dictionary<string, List<Order>> _orders = new Dictionary<string, List<Order>>(); 4: private static readonly _orderLock = new object(); 5: 6: public void Add(string accountNumber, Order newOrder) 7: { 8: List<Order> ordersForAccount; 9: 10: // a complex operation like this should all be protected 11: lock (_orderLock) 12: { 13: if (!_orders.TryGetValue(accountNumber, out ordersForAccount)) 14: { 15: _orders.Add(accountNumber, ordersForAccount = new List<Order>()); 16: } 17: 18: ordersForAccount.Add(newOrder); 19: } 20: } 21: } Notice how we’re performing several operations on the dictionary under one lock. With the Synchronized() static methods of the early collections, you wouldn’t be able to specify this level of locking (a more macro-level). So in the generic collections, it was decided that if a user needed synchronization, they could implement their own locking scheme instead so that they could provide synchronization as needed. The need for better concurrent access to collections Here’s the problem: it’s relatively easy to write a collection that locks itself down completely for access, but anything more complex than that can be difficult and error-prone to write, and much less to make it perform efficiently! For example, what if you have a Dictionary that has frequent reads but in-frequent updates? Do you want to lock down the entire Dictionary for every access? This would be overkill and would prevent concurrent reads. In such cases you could use something like a ReaderWriterLockSlim which allows for multiple readers in a lock, and then once a writer grabs the lock it blocks all further readers until the writer is done (in a nutshell). This is all very complex stuff to consider. Fortunately, this is where the Concurrent Collections come in. The Parallel Computing Platform team at Microsoft went through great pains to determine how to make a set of concurrent collections that would have the best performance characteristics for general case multi-threaded use. Now, as in all things involving threading, you should always make sure you evaluate all your container options based on the particular usage scenario and the degree of parallelism you wish to acheive. This article should not be taken to understand that these collections are always supperior to the generic collections. Each fills a particular need for a particular situation. Understanding what each container is optimized for is key to the success of your application whether it be single-threaded or multi-threaded. General points to consider with the concurrent collections The MSDN points out that the concurrent collections all support the ICollection interface. However, since the collections are already synchronized, the IsSynchronized property always returns false, and SyncRoot always returns null. Thus you should not attempt to use these properties for synchronization purposes. Note that since the concurrent collections also may have different operations than the traditional data structures you may be used to. Now you may ask why they did this, but it was done out of necessity to keep operations safe and atomic. For example, in order to do a Pop() on a stack you have to know the stack is non-empty, but between the time you check the stack’s IsEmpty property and then do the Pop() another thread may have come in and made the stack empty! This is why some of the traditional operations have been changed to make them safe for concurrent use. In addition, some properties and methods in the concurrent collections achieve concurrency by creating a snapshot of the collection, which means that some operations that were traditionally O(1) may now be O(n) in the concurrent models. I’ll try to point these out as we talk about each collection so you can be aware of any potential performance impacts. Finally, all the concurrent containers are safe for enumeration even while being modified, but some of the containers support this in different ways (snapshot vs. dirty iteration). Once again I’ll highlight how thread-safe enumeration works for each collection. ConcurrentStack<T>: The thread-safe LIFO container The ConcurrentStack<T> is the thread-safe counterpart to the System.Collections.Generic.Stack<T>, which as you may remember is your standard last-in-first-out container. If you think of algorithms that favor stack usage (for example, depth-first searches of graphs and trees) then you can see how using a thread-safe stack would be of benefit. The ConcurrentStack<T> achieves thread-safe access by using System.Threading.Interlocked operations. This means that the multi-threaded access to the stack requires no traditional locking and is very, very fast! For the most part, the ConcurrentStack<T> behaves like it’s Stack<T> counterpart with a few differences: Pop() was removed in favor of TryPop() Returns true if an item existed and was popped and false if empty. PushRange() and TryPopRange() were added Allows you to push multiple items and pop multiple items atomically. Count takes a snapshot of the stack and then counts the items. This means it is a O(n) operation, if you just want to check for an empty stack, call IsEmpty instead which is O(1). ToArray() and GetEnumerator() both also take snapshots. This means that iteration over a stack will give you a static view at the time of the call and will not reflect updates. Pushing on a ConcurrentStack<T> works just like you’d expect except for the aforementioned PushRange() method that was added to allow you to push a range of items concurrently. 1: var stack = new ConcurrentStack<string>(); 2: 3: // adding to stack is much the same as before 4: stack.Push("First"); 5: 6: // but you can also push multiple items in one atomic operation (no interleaves) 7: stack.PushRange(new [] { "Second", "Third", "Fourth" }); For looking at the top item of the stack (without removing it) the Peek() method has been removed in favor of a TryPeek(). This is because in order to do a peek the stack must be non-empty, but between the time you check for empty and the time you execute the peek the stack contents may have changed. Thus the TryPeek() was created to be an atomic check for empty, and then peek if not empty: 1: // to look at top item of stack without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (stack.TryPeek(out item)) 5: { 6: Console.WriteLine("Top item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Stack was empty."); 11: } Finally, to remove items from the stack, we have the TryPop() for single, and TryPopRange() for multiple items. Just like the TryPeek(), these operations replace Pop() since we need to ensure atomically that the stack is non-empty before we pop from it: 1: // to remove items, use TryPop or TryPopRange to get multiple items atomically (no interleaves) 2: if (stack.TryPop(out item)) 3: { 4: Console.WriteLine("Popped " + item); 5: } 6: 7: // TryPopRange will only pop up to the number of spaces in the array, the actual number popped is returned. 8: var poppedItems = new string[2]; 9: int numPopped = stack.TryPopRange(poppedItems); 10: 11: foreach (var theItem in poppedItems.Take(numPopped)) 12: { 13: Console.WriteLine("Popped " + theItem); 14: } Finally, note that as stated before, GetEnumerator() and ToArray() gets a snapshot of the data at the time of the call. That means if you are enumerating the stack you will get a snapshot of the stack at the time of the call. This is illustrated below: 1: var stack = new ConcurrentStack<string>(); 2: 3: // adding to stack is much the same as before 4: stack.Push("First"); 5: 6: var results = stack.GetEnumerator(); 7: 8: // but you can also push multiple items in one atomic operation (no interleaves) 9: stack.PushRange(new [] { "Second", "Third", "Fourth" }); 10: 11: while(results.MoveNext()) 12: { 13: Console.WriteLine("Stack only has: " + results.Current); 14: } The only item that will be printed out in the above code is "First" because the snapshot was taken before the other items were added. This may sound like an issue, but it’s really for safety and is more correct. You don’t want to enumerate a stack and have half a view of the stack before an update and half a view of the stack after an update, after all. In addition, note that this is still thread-safe, whereas iterating through a non-concurrent collection while updating it in the old collections would cause an exception. ConcurrentQueue<T>: The thread-safe FIFO container The ConcurrentQueue<T> is the thread-safe counterpart of the System.Collections.Generic.Queue<T> class. The concurrent queue uses an underlying list of small arrays and lock-free System.Threading.Interlocked operations on the head and tail arrays. Once again, this allows us to do thread-safe operations without the need for heavy locks! The ConcurrentQueue<T> (like the ConcurrentStack<T>) has some departures from the non-concurrent counterpart. Most notably: Dequeue() was removed in favor of TryDequeue(). Returns true if an item existed and was dequeued and false if empty. Count does not take a snapshot It subtracts the head and tail index to get the count. This results overall in a O(1) complexity which is quite good. It’s still recommended, however, that for empty checks you call IsEmpty instead of comparing Count to zero. ToArray() and GetEnumerator() both take snapshots. This means that iteration over a queue will give you a static view at the time of the call and will not reflect updates. The Enqueue() method on the ConcurrentQueue<T> works much the same as the generic Queue<T>: 1: var queue = new ConcurrentQueue<string>(); 2: 3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: queue.Enqueue("Second"); 6: queue.Enqueue("Third"); For front item access, the TryPeek() method must be used to attempt to see the first item if the queue. There is no Peek() method since, as you’ll remember, we can only peek on a non-empty queue, so we must have an atomic TryPeek() that checks for empty and then returns the first item if the queue is non-empty. 1: // to look at first item in queue without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (queue.TryPeek(out item)) 5: { 6: Console.WriteLine("First item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Queue was empty."); 11: } Then, to remove items you use TryDequeue(). Once again this is for the same reason we have TryPeek() and not Peek(): 1: // to remove items, use TryDequeue. If queue is empty returns false. 2: if (queue.TryDequeue(out item)) 3: { 4: Console.WriteLine("Dequeued first item " + item); 5: } Just like the concurrent stack, the ConcurrentQueue<T> takes a snapshot when you call ToArray() or GetEnumerator() which means that subsequent updates to the queue will not be seen when you iterate over the results. Thus once again the code below will only show the first item, since the other items were added after the snapshot. 1: var queue = new ConcurrentQueue<string>(); 2: 3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: 6: var iterator = queue.GetEnumerator(); 7: 8: queue.Enqueue("Second"); 9: queue.Enqueue("Third"); 10: 11: // only shows First 12: while (iterator.MoveNext()) 13: { 14: Console.WriteLine("Dequeued item " + iterator.Current); 15: } Using collections concurrently You’ll notice in the examples above I stuck to using single-threaded examples so as to make them deterministic and the results obvious. Of course, if we used these collections in a truly multi-threaded way the results would be less deterministic, but would still be thread-safe and with no locking on your part required! For example, say you have an order processor that takes an IEnumerable<Order> and handles each other in a multi-threaded fashion, then groups the responses together in a concurrent collection for aggregation. This can be done easily with the TPL’s Parallel.ForEach(): 1: public static IEnumerable<OrderResult> ProcessOrders(IEnumerable<Order> orderList) 2: { 3: var proxy = new OrderProxy(); 4: var results = new ConcurrentQueue<OrderResult>(); 5: 6: // notice that we can process all these in parallel and put the results 7: // into our concurrent collection without needing any external locking! 8: Parallel.ForEach(orderList, 9: order => 10: { 11: var result = proxy.PlaceOrder(order); 12: 13: results.Enqueue(result); 14: }); 15: 16: return results; 17: } Summary Obviously, if you do not need multi-threaded safety, you don’t need to use these collections, but when you do need multi-threaded collections these are just the ticket! The plethora of features (I always think of the movie The Three Amigos when I say plethora) built into these containers and the amazing way they acheive thread-safe access in an efficient manner is wonderful to behold. Stay tuned next week where we’ll continue our discussion with the ConcurrentBag<T> and the ConcurrentDictionary<TKey,TValue>. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here. Tweet Technorati Tags: C#,.NET,Concurrent Collections,Collections,Multi-Threading,Little Wonders,BlackRabbitCoder,James Michael Hare

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E: Sub-process /usr/bin/dpkg returned an error code (1) seems to be choking on kde-runtime-data version issue

- by BMT

12.04 LTS, on a dell mini 10. Install stable until about a week ago. Updated about 1x a week, sometimes more often. Several days ago, I booted up and the system was no longer working correctly. All these symptoms occurred simultaneously: Cannot run (exit on opening, every time): Update manager, software center, ubuntuOne, libreOffice. Vinagre autostarts on boot, no explanation, not set to startup with Ubuntu. Using apt-get to fix install results in the following: maura@pandora:~$ sudo apt-get -f install Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following package was automatically installed and is no longer required: libtelepathy-farstream2 Use 'apt-get autoremove' to remove them. The following extra packages will be installed: gwibber gwibber-service kde-runtime-data software-center Suggested packages: gwibber-service-flickr gwibber-service-digg gwibber-service-statusnet gwibber-service-foursquare gwibber-service-friendfeed gwibber-service-pingfm gwibber-service-qaiku unity-lens-gwibber The following packages will be upgraded: gwibber gwibber-service kde-runtime-data software-center 4 upgraded, 0 newly installed, 0 to remove and 39 not upgraded. 20 not fully installed or removed. Need to get 0 B/5,682 kB of archives. After this operation, 177 kB of additional disk space will be used. Do you want to continue [Y/n]? debconf: Perl may be unconfigured (Can't locate Scalar/Util.pm in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.14.2 /usr/local/share/perl/5.14.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.14 /usr/share/perl/5.14 /usr/local/lib/site_perl .) at /usr/lib/perl/5.14/Hash/Util.pm line 9. BEGIN failed--compilation aborted at /usr/lib/perl/5.14/Hash/Util.pm line 9. Compilation failed in require at /usr/share/perl/5.14/fields.pm line 122. Compilation failed in require at /usr/share/perl5/Debconf/Log.pm line 10. Compilation failed in require at (eval 1) line 4. BEGIN failed--compilation aborted at (eval 1) line 4. ) -- aborting (Reading database ... 242672 files and directories currently installed.) Preparing to replace gwibber 3.4.1-0ubuntu1 (using .../gwibber_3.4.2-0ubuntu1_i386.deb) ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: warning: subprocess old pre-removal script returned error exit status 1 dpkg - trying script from the new package instead ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: error processing /var/cache/apt/archives/gwibber_3.4.2-0ubuntu1_i386.deb (--unpack): subprocess new pre-removal script returned error exit status 1 Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging dpkg: error while cleaning up: subprocess installed post-installation script returned error exit status 1 Preparing to replace gwibber-service 3.4.1-0ubuntu1 (using .../gwibber-service_3.4.2-0ubuntu1_all.deb) ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: warning: subprocess old pre-removal script returned error exit status 1 dpkg - trying script from the new package instead ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: error processing /var/cache/apt/archives/gwibber-service_3.4.2-0ubuntu1_all.deb (--unpack): subprocess new pre-removal script returned error exit status 1 Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging dpkg: error while cleaning up: subprocess installed post-installation script returned error exit status 1 Preparing to replace kde-runtime-data 4:4.8.3-0ubuntu0.1 (using .../kde-runtime-data_4%3a4.8.4-0ubuntu0.1_all.deb) ... Unpacking replacement kde-runtime-data ... dpkg: error processing /var/cache/apt/archives/kde-runtime-data_4%3a4.8.4-0ubuntu0.1_all.deb (--unpack): trying to overwrite '/usr/share/sounds', which is also in package sound-theme-freedesktop 0.7.pristine-2 dpkg-deb (subprocess): subprocess data was killed by signal (Broken pipe) dpkg-deb: error: subprocess <decompress> returned error exit status 2 Preparing to replace python-crypto 2.4.1-1 (using .../python-crypto_2.4.1-1_i386.deb) ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: warning: subprocess old pre-removal script returned error exit status 1 dpkg - trying script from the new package instead ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: error processing /var/cache/apt/archives/python-crypto_2.4.1-1_i386.deb (--unpack): subprocess new pre-removal script returned error exit status 1 No apport report written because MaxReports is reached already Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging dpkg: error while cleaning up: subprocess installed post-installation script returned error exit status 1 Preparing to replace software-center 5.2.2.2 (using .../software-center_5.2.4_all.deb) ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: warning: subprocess old pre-removal script returned error exit status 1 dpkg - trying script from the new package instead ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: error processing /var/cache/apt/archives/software-center_5.2.4_all.deb (--unpack): subprocess new pre-removal script returned error exit status 1 No apport report written because MaxReports is reached already Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging dpkg: error while cleaning up: subprocess installed post-installation script returned error exit status 1 Preparing to replace xdiagnose 2.5 (using .../archives/xdiagnose_2.5_all.deb) ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: warning: subprocess old pre-removal script returned error exit status 1 dpkg - trying script from the new package instead ... Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pyclean", line 25, in <module> import logging ImportError: No module named logging dpkg: error processing /var/cache/apt/archives/xdiagnose_2.5_all.deb (--unpack): subprocess new pre-removal script returned error exit status 1 No apport report written because MaxReports is reached already Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook from apport.fileutils import likely_packaged, get_recent_crashes File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module> from apport.report import Report File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module> from xml.parsers.expat import ExpatError File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module> from pyexpat import * ImportError: No module named pyexpat Original exception was: Traceback (most recent call last): File "/usr/bin/pycompile", line 27, in <module> import logging ImportError: No module named logging dpkg: error while cleaning up: subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: /var/cache/apt/archives/gwibber_3.4.2-0ubuntu1_i386.deb /var/cache/apt/archives/gwibber-service_3.4.2-0ubuntu1_all.deb /var/cache/apt/archives/kde-runtime-data_4%3a4.8.4-0ubuntu0.1_all.deb /var/cache/apt/archives/python-crypto_2.4.1-1_i386.deb /var/cache/apt/archives/software-center_5.2.4_all.deb /var/cache/apt/archives/xdiagnose_2.5_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1) maura@pandora:~$ ^C maura@pandora:~$

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High CPU usage with Team Speak 3.0.0-rc2

- by AlexTheBird

The CPU usage is always around 40 percent. I use push-to-talk and I had uninstalled pulseaudio. Now I use Alsa. I don't even have to connect to a Server. By simply starting TS the cpu usage goes up 40 percent and stays there. The CPU usage of 3.0.0-rc1 [Build: 14468] is constantly 14 percent. This is the output of top, mpstat and ps aux while I am running TS3 ... of course: alexandros@alexandros-laptop:~$ top top - 18:20:07 up 2:22, 3 users, load average: 1.02, 0.85, 0.77 Tasks: 163 total, 1 running, 162 sleeping, 0 stopped, 0 zombie Cpu(s): 5.3%us, 1.9%sy, 0.1%ni, 91.8%id, 0.7%wa, 0.1%hi, 0.1%si, 0.0%st Mem: 2061344k total, 964028k used, 1097316k free, 69116k buffers Swap: 3997688k total, 0k used, 3997688k free, 449032k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2714 alexandr 20 0 206m 31m 24m S 37 1.6 0:12.78 ts3client_linux 868 root 20 0 47564 27m 10m S 8 1.4 3:21.73 Xorg 1 root 20 0 2804 1660 1204 S 0 0.1 0:00.53 init 2 root 20 0 0 0 0 S 0 0.0 0:00.00 kthreadd 3 root RT 0 0 0 0 S 0 0.0 0:00.01 migration/0 4 root 20 0 0 0 0 S 0 0.0 0:00.45 ksoftirqd/0 5 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/0 6 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/1 7 root 20 0 0 0 0 S 0 0.0 0:00.08 ksoftirqd/1 8 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/1 9 root 20 0 0 0 0 S 0 0.0 0:01.17 events/0 10 root 20 0 0 0 0 S 0 0.0 0:00.81 events/1 11 root 20 0 0 0 0 S 0 0.0 0:00.00 cpuset 12 root 20 0 0 0 0 S 0 0.0 0:00.00 khelper 13 root 20 0 0 0 0 S 0 0.0 0:00.00 async/mgr 14 root 20 0 0 0 0 S 0 0.0 0:00.00 pm 16 root 20 0 0 0 0 S 0 0.0 0:00.00 sync_supers 17 root 20 0 0 0 0 S 0 0.0 0:00.00 bdi-default 18 root 20 0 0 0 0 S 0 0.0 0:00.00 kintegrityd/0 19 root 20 0 0 0 0 S 0 0.0 0:00.00 kintegrityd/1 20 root 20 0 0 0 0 S 0 0.0 0:00.05 kblockd/0 21 root 20 0 0 0 0 S 0 0.0 0:00.02 kblockd/1 22 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpid 23 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpi_notify 24 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpi_hotplug 25 root 20 0 0 0 0 S 0 0.0 0:00.99 ata/0 26 root 20 0 0 0 0 S 0 0.0 0:00.92 ata/1 27 root 20 0 0 0 0 S 0 0.0 0:00.00 ata_aux 28 root 20 0 0 0 0 S 0 0.0 0:00.00 ksuspend_usbd 29 root 20 0 0 0 0 S 0 0.0 0:00.00 khubd alexandros@alexandros-laptop:~$ mpstat Linux 2.6.32-32-generic (alexandros-laptop) 16.06.2011 _i686_ (2 CPU) 18:20:15 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle 18:20:15 all 5,36 0,09 1,91 0,68 0,07 0,06 0,00 0,00 91,83 alexandros@alexandros-laptop:~$ ps aux USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 1 0.0 0.0 2804 1660 ? Ss 15:58 0:00 /sbin/init root 2 0.0 0.0 0 0 ? S 15:58 0:00 [kthreadd] root 3 0.0 0.0 0 0 ? S 15:58 0:00 [migration/0] root 4 0.0 0.0 0 0 ? S 15:58 0:00 [ksoftirqd/0] root 5 0.0 0.0 0 0 ? S 15:58 0:00 [watchdog/0] root 6 0.0 0.0 0 0 ? S 15:58 0:00 [migration/1] root 7 0.0 0.0 0 0 ? S 15:58 0:00 [ksoftirqd/1] root 8 0.0 0.0 0 0 ? S 15:58 0:00 [watchdog/1] root 9 0.0 0.0 0 0 ? S 15:58 0:01 [events/0] root 10 0.0 0.0 0 0 ? S 15:58 0:00 [events/1] root 11 0.0 0.0 0 0 ? S 15:58 0:00 [cpuset] root 12 0.0 0.0 0 0 ? S 15:58 0:00 [khelper] root 13 0.0 0.0 0 0 ? S 15:58 0:00 [async/mgr] root 14 0.0 0.0 0 0 ? S 15:58 0:00 [pm] root 16 0.0 0.0 0 0 ? S 15:58 0:00 [sync_supers] root 17 0.0 0.0 0 0 ? S 15:58 0:00 [bdi-default] root 18 0.0 0.0 0 0 ? S 15:58 0:00 [kintegrityd/0] root 19 0.0 0.0 0 0 ? S 15:58 0:00 [kintegrityd/1] root 20 0.0 0.0 0 0 ? S 15:58 0:00 [kblockd/0] root 21 0.0 0.0 0 0 ? S 15:58 0:00 [kblockd/1] root 22 0.0 0.0 0 0 ? S 15:58 0:00 [kacpid] root 23 0.0 0.0 0 0 ? S 15:58 0:00 [kacpi_notify] root 24 0.0 0.0 0 0 ? S 15:58 0:00 [kacpi_hotplug] root 25 0.0 0.0 0 0 ? S 15:58 0:00 [ata/0] root 26 0.0 0.0 0 0 ? S 15:58 0:00 [ata/1] root 27 0.0 0.0 0 0 ? S 15:58 0:00 [ata_aux] root 28 0.0 0.0 0 0 ? S 15:58 0:00 [ksuspend_usbd] root 29 0.0 0.0 0 0 ? S 15:58 0:00 [khubd] root 30 0.0 0.0 0 0 ? S 15:58 0:00 [kseriod] root 31 0.0 0.0 0 0 ? S 15:58 0:00 [kmmcd] root 34 0.0 0.0 0 0 ? S 15:58 0:00 [khungtaskd] root 35 0.0 0.0 0 0 ? S 15:58 0:00 [kswapd0] root 36 0.0 0.0 0 0 ? SN 15:58 0:00 [ksmd] root 37 0.0 0.0 0 0 ? S 15:58 0:00 [aio/0] root 38 0.0 0.0 0 0 ? S 15:58 0:00 [aio/1] root 39 0.0 0.0 0 0 ? S 15:58 0:00 [ecryptfs-kthrea] root 40 0.0 0.0 0 0 ? S 15:58 0:00 [crypto/0] root 41 0.0 0.0 0 0 ? S 15:58 0:00 [crypto/1] root 48 0.0 0.0 0 0 ? S 15:58 0:03 [scsi_eh_0] root 50 0.0 0.0 0 0 ? S 15:58 0:00 [scsi_eh_1] root 53 0.0 0.0 0 0 ? S 15:58 0:00 [kstriped] root 54 0.0 0.0 0 0 ? S 15:58 0:00 [kmpathd/0] root 55 0.0 0.0 0 0 ? S 15:58 0:00 [kmpathd/1] root 56 0.0 0.0 0 0 ? S 15:58 0:00 [kmpath_handlerd] root 57 0.0 0.0 0 0 ? S 15:58 0:00 [ksnapd] root 58 0.0 0.0 0 0 ? S 15:58 0:03 [kondemand/0] root 59 0.0 0.0 0 0 ? S 15:58 0:02 [kondemand/1] root 60 0.0 0.0 0 0 ? S 15:58 0:00 [kconservative/0] root 61 0.0 0.0 0 0 ? S 15:58 0:00 [kconservative/1] root 213 0.0 0.0 0 0 ? S 15:58 0:00 [scsi_eh_2] root 222 0.0 0.0 0 0 ? S 15:58 0:00 [scsi_eh_3] root 234 0.0 0.0 0 0 ? S 15:58 0:00 [scsi_eh_4] root 235 0.0 0.0 0 0 ? S 15:58 0:01 [usb-storage] root 255 0.0 0.0 0 0 ? S 15:58 0:00 [jbd2/sda5-8] root 256 0.0 0.0 0 0 ? S 15:58 0:00 [ext4-dio-unwrit] root 257 0.0 0.0 0 0 ? S 15:58 0:00 [ext4-dio-unwrit] root 290 0.0 0.0 0 0 ? S 15:58 0:00 [flush-8:0] root 318 0.0 0.0 2316 888 ? S 15:58 0:00 upstart-udev-bridge --daemon root 321 0.0 0.0 2616 1024 ? S<s 15:58 0:00 udevd --daemon root 526 0.0 0.0 0 0 ? S 15:58 0:00 [kpsmoused] root 528 0.0 0.0 0 0 ? S 15:58 0:00 [led_workqueue] root 650 0.0 0.0 0 0 ? S 15:58 0:00 [radeon/0] root 651 0.0 0.0 0 0 ? S 15:58 0:00 [radeon/1] root 652 0.0 0.0 0 0 ? S 15:58 0:00 [ttm_swap] root 654 0.0 0.0 2612 984 ? S< 15:58 0:00 udevd --daemon root 656 0.0 0.0 0 0 ? S 15:58 0:00 [hd-audio0] root 657 0.0 0.0 2612 916 ? S< 15:58 0:00 udevd --daemon root 674 0.6 0.0 0 0 ? S 15:58 0:57 [phy0] syslog 715 0.0 0.0 34812 1776 ? Sl 15:58 0:00 rsyslogd -c4 102 731 0.0 0.0 3236 1512 ? Ss 15:58 0:02 dbus-daemon --system --fork root 740 0.0 0.1 19088 3380 ? Ssl 15:58 0:00 gdm-binary root 744 0.0 0.1 18900 4032 ? Ssl 15:58 0:01 NetworkManager avahi 749 0.0 0.0 2928 1520 ? S 15:58 0:00 avahi-daemon: running [alexandros-laptop.local] avahi 752 0.0 0.0 2928 544 ? Ss 15:58 0:00 avahi-daemon: chroot helper root 753 0.0 0.1 4172 2300 ? S 15:58 0:00 /usr/sbin/modem-manager root 762 0.0 0.1 20584 3152 ? Sl 15:58 0:00 /usr/sbin/console-kit-daemon --no-daemon root 836 0.0 0.1 20856 3864 ? Sl 15:58 0:00 /usr/lib/gdm/gdm-simple-slave --display-id /org/gnome/DisplayManager/Display1 root 856 0.0 0.1 4836 2388 ? S 15:58 0:00 /sbin/wpa_supplicant -u -s root 868 2.3 1.3 36932 27924 tty7 Rs+ 15:58 3:22 /usr/bin/X :0 -nr -verbose -auth /var/run/gdm/auth-for-gdm-a46T4j/database -nolisten root 891 0.0 0.0 1792 564 tty4 Ss+ 15:58 0:00 /sbin/getty -8 38400 tty4 root 901 0.0 0.0 1792 564 tty5 Ss+ 15:58 0:00 /sbin/getty -8 38400 tty5 root 908 0.0 0.0 1792 564 tty2 Ss+ 15:58 0:00 /sbin/getty -8 38400 tty2 root 910 0.0 0.0 1792 568 tty3 Ss+ 15:58 0:00 /sbin/getty -8 38400 tty3 root 913 0.0 0.0 1792 564 tty6 Ss+ 15:58 0:00 /sbin/getty -8 38400 tty6 root 917 0.0 0.0 2180 1072 ? Ss 15:58 0:00 acpid -c /etc/acpi/events -s /var/run/acpid.socket daemon 924 0.0 0.0 2248 432 ? Ss 15:58 0:00 atd root 927 0.0 0.0 2376 900 ? Ss 15:58 0:00 cron root 950 0.0 0.0 11736 1372 ? Ss 15:58 0:00 /usr/sbin/winbindd root 958 0.0 0.0 11736 1184 ? S 15:58 0:00 /usr/sbin/winbindd root 974 0.0 0.1 6832 2580 ? Ss 15:58 0:00 /usr/sbin/cupsd -C /etc/cups/cupsd.conf root 1078 0.0 0.0 1792 564 tty1 Ss+ 15:58 0:00 /sbin/getty -8 38400 tty1 gdm 1097 0.0 0.0 3392 772 ? S 15:58 0:00 /usr/bin/dbus-launch --exit-with-session root 1112 0.0 0.1 19216 3292 ? Sl 15:58 0:00 /usr/lib/gdm/gdm-session-worker root 1116 0.0 0.1 5540 2932 ? S 15:58 0:01 /usr/lib/upower/upowerd root 1131 0.0 0.1 6308 3824 ? S 15:58 0:00 /usr/lib/policykit-1/polkitd 108 1163 0.0 0.2 16788 4360 ? Ssl 15:58 0:01 /usr/sbin/hald root 1164 0.0 0.0 3536 1300 ? S 15:58 0:00 hald-runner root 1188 0.0 0.0 3612 1256 ? S 15:58 0:00 hald-addon-input: Listening on /dev/input/event6 /dev/input/event5 /dev/input/event2 root 1194 0.0 0.0 3612 1224 ? S 15:58 0:00 /usr/lib/hal/hald-addon-rfkill-killswitch root 1200 0.0 0.0 3608 1240 ? S 15:58 0:00 /usr/lib/hal/hald-addon-generic-backlight root 1202 0.0 0.0 3616 1236 ? S 15:58 0:02 hald-addon-storage: polling /dev/sr0 (every 2 sec) root 1204 0.0 0.0 3616 1236 ? S 15:58 0:00 hald-addon-storage: polling /dev/sdb (every 2 sec) root 1211 0.0 0.0 3624 1220 ? S 15:58 0:00 /usr/lib/hal/hald-addon-cpufreq 108 1212 0.0 0.0 3420 1200 ? S 15:58 0:00 hald-addon-acpi: listening on acpid socket /var/run/acpid.socket 1000 1222 0.0 0.1 24196 2816 ? Sl 15:58 0:00 /usr/bin/gnome-keyring-daemon --daemonize --login 1000 1240 0.0 0.3 28228 7312 ? Ssl 15:58 0:00 gnome-session 1000 1274 0.0 0.0 3284 356 ? Ss 15:58 0:00 /usr/bin/ssh-agent /usr/bin/dbus-launch --exit-with-session gnome-session 1000 1277 0.0 0.0 3392 772 ? S 15:58 0:00 /usr/bin/dbus-launch --exit-with-session gnome-session 1000 1278 0.0 0.0 3160 1652 ? Ss 15:58 0:00 /bin/dbus-daemon --fork --print-pid 5 --print-address 7 --session 1000 1281 0.0 0.2 8172 4636 ? S 15:58 0:00 /usr/lib/libgconf2-4/gconfd-2 1000 1287 0.0 0.5 24228 10896 ? Ss 15:58 0:03 /usr/lib/gnome-settings-daemon/gnome-settings-daemon 1000 1290 0.0 0.1 6468 2364 ? S 15:58 0:00 /usr/lib/gvfs/gvfsd 1000 1293 0.0 0.6 38104 13004 ? S 15:58 0:03 metacity 1000 1296 0.0 0.1 30280 2628 ? Ssl 15:58 0:00 /usr/lib/gvfs//gvfs-fuse-daemon /home/alexandros/.gvfs 1000 1301 0.0 0.0 3344 988 ? S 15:58 0:03 syndaemon -i 0.5 -k 1000 1303 0.0 0.1 8060 3488 ? S 15:58 0:00 /usr/lib/gvfs/gvfs-gdu-volume-monitor root 1306 0.0 0.1 15692 3104 ? Sl 15:58 0:00 /usr/lib/udisks/udisks-daemon 1000 1307 0.4 1.0 50748 21684 ? S 15:58 0:34 python -u /usr/share/screenlets/DigiClock/DigiClockScreenlet.py 1000 1308 0.0 0.9 35608 18564 ? S 15:58 0:00 python /usr/share/screenlets-manager/screenlets-daemon.py 1000 1309 0.0 0.3 19524 6468 ? S 15:58 0:00 /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1 1000 1311 0.0 0.5 37412 11788 ? S 15:58 0:01 gnome-power-manager 1000 1312 0.0 1.0 50772 22628 ? S 15:58 0:03 gnome-panel 1000 1313 0.1 1.5 102648 31184 ? Sl 15:58 0:10 nautilus root 1314 0.0 0.0 5188 996 ? S 15:58 0:02 udisks-daemon: polling /dev/sdb /dev/sr0 1000 1315 0.0 0.6 51948 12464 ? SL 15:58 0:01 nm-applet --sm-disable 1000 1317 0.0 0.1 16956 2364 ? Sl 15:58 0:00 /usr/lib/gvfs/gvfs-afc-volume-monitor 1000 1318 0.0 0.3 20164 7792 ? S 15:58 0:00 bluetooth-applet 1000 1321 0.0 0.1 7260 2384 ? S 15:58 0:00 /usr/lib/gvfs/gvfs-gphoto2-volume-monitor 1000 1323 0.0 0.5 37436 12124 ? S 15:58 0:00 /usr/lib/notify-osd/notify-osd 1000 1324 0.0 1.9 197928 40456 ? Ssl 15:58 0:06 /home/alexandros/.dropbox-dist/dropbox 1000 1329 0.0 0.3 20136 7968 ? S 15:58 0:00 /usr/bin/gnome-screensaver --no-daemon 1000 1331 0.0 0.1 7056 3112 ? S 15:58 0:00 /usr/lib/gvfs/gvfsd-trash --spawner :1.6 /org/gtk/gvfs/exec_spaw/0 root 1340 0.0 0.0 2236 1008 ? S 15:58 0:00 /sbin/dhclient -d -sf /usr/lib/NetworkManager/nm-dhcp-client.action -pf /var/run/dhcl 1000 1348 0.0 0.1 42252 3680 ? Ssl 15:58 0:00 /usr/lib/bonobo-activation/bonobo-activation-server --ac-activate --ior-output-fd=19 1000 1384 0.0 1.7 80244 35480 ? Sl 15:58 0:02 /usr/bin/python /usr/lib/deskbar-applet/deskbar-applet/deskbar-applet --oaf-activate- 1000 1388 0.0 0.5 26196 11804 ? S 15:58 0:01 /usr/lib/gnome-panel/wnck-applet --oaf-activate-iid=OAFIID:GNOME_Wncklet_Factory --oa 1000 1393 0.1 0.5 25876 11548 ? S 15:58 0:08 /usr/lib/gnome-applets/multiload-applet-2 --oaf-activate-iid=OAFIID:GNOME_MultiLoadAp 1000 1394 0.0 0.5 25600 11140 ? S 15:58 0:03 /usr/lib/gnome-applets/cpufreq-applet --oaf-activate-iid=OAFIID:GNOME_CPUFreqApplet_F 1000 1415 0.0 0.5 39192 11156 ? S 15:58 0:01 /usr/lib/gnome-power-manager/gnome-inhibit-applet --oaf-activate-iid=OAFIID:GNOME_Inh 1000 1417 0.0 0.7 53544 15488 ? Sl 15:58 0:00 /usr/lib/gnome-applets/mixer_applet2 --oaf-activate-iid=OAFIID:GNOME_MixerApplet_Fact 1000 1419 0.0 0.4 23816 9068 ? S 15:58 0:00 /usr/lib/gnome-panel/notification-area-applet --oaf-activate-iid=OAFIID:GNOME_Notific 1000 1488 0.0 0.3 20964 7548 ? S 15:58 0:00 /usr/lib/gnome-disk-utility/gdu-notification-daemon 1000 1490 0.0 0.1 6608 2484 ? S 15:58 0:00 /usr/lib/gvfs/gvfsd-burn --spawner :1.6 /org/gtk/gvfs/exec_spaw/1 1000 1510 0.0 0.1 6348 2084 ? S 15:58 0:00 /usr/lib/gvfs/gvfsd-metadata 1000 1531 0.0 0.3 19472 6616 ? S 15:58 0:00 /usr/lib/gnome-user-share/gnome-user-share 1000 1535 0.0 0.4 77128 8392 ? Sl 15:58 0:00 /usr/lib/evolution/evolution-data-server-2.28 --oaf-activate-iid=OAFIID:GNOME_Evoluti 1000 1601 0.0 0.5 69576 11800 ? Sl 15:59 0:00 /usr/lib/evolution/2.28/evolution-alarm-notify 1000 1604 0.0 0.7 33924 15888 ? S 15:59 0:00 python /usr/share/system-config-printer/applet.py 1000 1701 0.0 0.5 37116 11968 ? S 15:59 0:00 update-notifier 1000 1892 4.5 7.0 406720 145312 ? Sl 17:11 3:09 /opt/google/chrome/chrome 1000 1896 0.0 0.1 69812 3680 ? S 17:11 0:02 /opt/google/chrome/chrome 1000 1898 0.0 0.6 91420 14080 ? S 17:11 0:00 /opt/google/chrome/chrome --type=zygote 1000 1916 0.2 1.3 140780 27220 ? Sl 17:11 0:12 /opt/google/chrome/chrome --type=extension --disable-client-side-phishing-detection - 1000 1918 0.7 1.8 155720 37912 ? Sl 17:11 0:31 /opt/google/chrome/chrome --type=extension --disable-client-side-phishing-detection - 1000 1921 0.0 1.0 135904 21052 ? Sl 17:11 0:02 /opt/google/chrome/chrome --type=extension --disable-client-side-phishing-detection - 1000 1927 6.5 3.6 194604 74960 ? Sl 17:11 4:32 /opt/google/chrome/chrome --type=renderer --disable-client-side-phishing-detection -- 1000 2156 0.4 0.7 48344 14896 ? Rl 18:03 0:04 gnome-terminal 1000 2157 0.0 0.0 1988 712 ? S 18:03 0:00 gnome-pty-helper 1000 2158 0.0 0.1 6504 3860 pts/0 Ss 18:03 0:00 bash 1000 2564 0.2 0.1 6624 3984 pts/1 Ss+ 18:17 0:00 bash 1000 2711 0.0 0.0 4208 1352 ? S 18:19 0:00 /bin/bash /home/alexandros/Programme/TeamSpeak3-Client-linux_x86_back/ts3client_runsc 1000 2714 36.5 1.5 210872 31960 ? SLl 18:19 0:18 ./ts3client_linux_x86 1000 2743 0.0 0.0 2716 1068 pts/0 R+ 18:20 0:00 ps aux Output of vmstat: alexandros@alexandros-laptop:~$ vmstat procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 0 1093324 69840 449496 0 0 27 10 476 667 6 2 91 1 Output of lsusb alexandros@alexandros-laptop:~$ lspci 00:00.0 Host bridge: Silicon Integrated Systems [SiS] 671MX 00:01.0 PCI bridge: Silicon Integrated Systems [SiS] PCI-to-PCI bridge 00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS968 [MuTIOL Media IO] (rev 01) 00:02.5 IDE interface: Silicon Integrated Systems [SiS] 5513 [IDE] (rev 01) 00:03.0 USB Controller: Silicon Integrated Systems [SiS] USB 1.1 Controller (rev 0f) 00:03.1 USB Controller: Silicon Integrated Systems [SiS] USB 1.1 Controller (rev 0f) 00:03.3 USB Controller: Silicon Integrated Systems [SiS] USB 2.0 Controller 00:05.0 IDE interface: Silicon Integrated Systems [SiS] SATA Controller / IDE mode (rev 03) 00:06.0 PCI bridge: Silicon Integrated Systems [SiS] PCI-to-PCI bridge 00:07.0 PCI bridge: Silicon Integrated Systems [SiS] PCI-to-PCI bridge 00:0d.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10) 00:0f.0 Audio device: Silicon Integrated Systems [SiS] Azalia Audio Controller 01:00.0 VGA compatible controller: ATI Technologies Inc Mobility Radeon X2300 02:00.0 Ethernet controller: Atheros Communications Inc. AR5001 Wireless Network Adapter (rev 01) The Team Speak log file : 2011-06-19 19:04:04.223522|INFO | | | Logging started, clientlib version: 3.0.0-rc2 [Build: 14642] 2011-06-19 19:04:04.761149|ERROR |SoundBckndIntf| | /home/alexandros/Programme/TeamSpeak3-Client-linux_x86_back/soundbackends/libpulseaudio_linux_x86.so error: NOT_CONNECTED 2011-06-19 19:04:05.871770|INFO |ClientUI | | Failed to init text to speech engine 2011-06-19 19:04:05.894623|INFO |ClientUI | | TeamSpeak 3 client version: 3.0.0-rc2 [Build: 14642] 2011-06-19 19:04:05.895421|INFO |ClientUI | | Qt version: 4.7.2 2011-06-19 19:04:05.895571|INFO |ClientUI | | Using configuration location: /home/alexandros/.ts3client/ts3clientui_qt.conf 2011-06-19 19:04:06.559596|INFO |ClientUI | | Last update check was: Sa. Jun 18 00:08:43 2011 2011-06-19 19:04:06.560506|INFO | | | Checking for updates... 2011-06-19 19:04:07.357869|INFO | | | Update check, my version: 14642, latest version: 14642 2011-06-19 19:05:52.978481|INFO |PreProSpeex | 1| Speex version: 1.2rc1 2011-06-19 19:05:54.055347|INFO |UIHelpers | | setClientVolumeModifier: 10 -8 2011-06-19 19:05:54.057196|INFO |UIHelpers | | setClientVolumeModifier: 11 2 Thanks for taking the time to read my message. UPDATE: Thanks to nickguletskii's link I googled for "alsa cpu usage" (without quotes) and it brought me to a forum. A user wrote that by directly selecting the hardware with "plughw:x.x" won't impact the performance of the system. I have selected it in the TS 3 configuration and it worked. But this solution is not optimal because now no other program can access the sound output. If you need any further information or my question is unclear than please tell me.

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C#/.NET Little Wonders: The ConcurrentDictionary

- by James Michael Hare

Once again we consider some of the lesser known classes and keywords of C#. In this series of posts, we will discuss how the concurrent collections have been developed to help alleviate these multi-threading concerns. Last week’s post began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>. Today's post discusses the ConcurrentDictionary<T> (originally I had intended to discuss ConcurrentBag this week as well, but ConcurrentDictionary had enough information to create a very full post on its own!). Finally next week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. Recap As you'll recall from the previous post, the original collections were object-based containers that accomplished synchronization through a Synchronized member. While these were convenient because you didn't have to worry about writing your own synchronization logic, they were a bit too finely grained and if you needed to perform multiple operations under one lock, the automatic synchronization didn't buy much. With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization. This cuts both ways in that you have a lot more control as a developer over when and how fine-grained you want to synchronize, but on the other hand if you just want simple synchronization it creates more work. With .NET 4.0, we get the best of both worlds in generic collections. A new breed of collections was born called the concurrent collections in the System.Collections.Concurrent namespace. These amazing collections are fine-tuned to have best overall performance for situations requiring concurrent access. They are not meant to replace the generic collections, but to simply be an alternative to creating your own locking mechanisms. Among those concurrent collections were the ConcurrentStack<T> and ConcurrentQueue<T> which provide classic LIFO and FIFO collections with a concurrent twist. As we saw, some of the traditional methods that required calls to be made in a certain order (like checking for not IsEmpty before calling Pop()) were replaced in favor of an umbrella operation that combined both under one lock (like TryPop()). Now, let's take a look at the next in our series of concurrent collections!For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentDictionary – the fully thread-safe dictionary The ConcurrentDictionary<TKey,TValue> is the thread-safe counterpart to the generic Dictionary<TKey, TValue> collection. Obviously, both are designed for quick – O(1) – lookups of data based on a key. If you think of algorithms where you need lightning fast lookups of data and don’t care whether the data is maintained in any particular ordering or not, the unsorted dictionaries are generally the best way to go. Note: as a side note, there are sorted implementations of IDictionary, namely SortedDictionary and SortedList which are stored as an ordered tree and a ordered list respectively. While these are not as fast as the non-sorted dictionaries – they are O(log2 n) – they are a great combination of both speed and ordering -- and still greatly outperform a linear search. Now, once again keep in mind that if all you need to do is load a collection once and then allow multi-threaded reading you do not need any locking. Examples of this tend to be situations where you load a lookup or translation table once at program start, then keep it in memory for read-only reference. In such cases locking is completely non-productive. However, most of the time when we need a concurrent dictionary we are interleaving both reads and updates. This is where the ConcurrentDictionary really shines! It achieves its thread-safety with no common lock to improve efficiency. It actually uses a series of locks to provide concurrent updates, and has lockless reads! This means that the ConcurrentDictionary gets even more efficient the higher the ratio of reads-to-writes you have. ConcurrentDictionary and Dictionary differences For the most part, the ConcurrentDictionary<TKey,TValue> behaves like it’s Dictionary<TKey,TValue> counterpart with a few differences. Some notable examples of which are: Add() does not exist in the concurrent dictionary. This means you must use TryAdd(), AddOrUpdate(), or GetOrAdd(). It also means that you can’t use a collection initializer with the concurrent dictionary. TryAdd() replaced Add() to attempt atomic, safe adds. Because Add() only succeeds if the item doesn’t already exist, we need an atomic operation to check if the item exists, and if not add it while still under an atomic lock. TryUpdate() was added to attempt atomic, safe updates. If we want to update an item, we must make sure it exists first and that the original value is what we expected it to be. If all these are true, we can update the item under one atomic step. TryRemove() was added to attempt atomic, safe removes. To safely attempt to remove a value we need to see if the key exists first, this checks for existence and removes under an atomic lock. AddOrUpdate() was added to attempt an thread-safe “upsert”. There are many times where you want to insert into a dictionary if the key doesn’t exist, or update the value if it does. This allows you to make a thread-safe add-or-update. GetOrAdd() was added to attempt an thread-safe query/insert. Sometimes, you want to query for whether an item exists in the cache, and if it doesn’t insert a starting value for it. This allows you to get the value if it exists and insert if not. Count, Keys, Values properties take a snapshot of the dictionary. Accessing these properties may interfere with add and update performance and should be used with caution. ToArray() returns a static snapshot of the dictionary. That is, the dictionary is locked, and then copied to an array as a O(n) operation. GetEnumerator() is thread-safe and efficient, but allows dirty reads. Because reads require no locking, you can safely iterate over the contents of the dictionary. The only downside is that, depending on timing, you may get dirty reads. Dirty reads during iteration The last point on GetEnumerator() bears some explanation. Picture a scenario in which you call GetEnumerator() (or iterate using a foreach, etc.) and then, during that iteration the dictionary gets updated. This may not sound like a big deal, but it can lead to inconsistent results if used incorrectly. The problem is that items you already iterated over that are updated a split second after don’t show the update, but items that you iterate over that were updated a split second before do show the update. Thus you may get a combination of items that are “stale” because you iterated before the update, and “fresh” because they were updated after GetEnumerator() but before the iteration reached them. Let’s illustrate with an example, let’s say you load up a concurrent dictionary like this: 1: // load up a dictionary. 2: var dictionary = new ConcurrentDictionary<string, int>(); 3: 4: dictionary["A"] = 1; 5: dictionary["B"] = 2; 6: dictionary["C"] = 3; 7: dictionary["D"] = 4; 8: dictionary["E"] = 5; 9: dictionary["F"] = 6; Then you have one task (using the wonderful TPL!) to iterate using dirty reads: 1: // attempt iteration in a separate thread 2: var iterationTask = new Task(() => 3: { 4: // iterates using a dirty read 5: foreach (var pair in dictionary) 6: { 7: Console.WriteLine(pair.Key + ":" + pair.Value); 8: } 9: }); And one task to attempt updates in a separate thread (probably): 1: // attempt updates in a separate thread 2: var updateTask = new Task(() => 3: { 4: // iterates, and updates the value by one 5: foreach (var pair in dictionary) 6: { 7: dictionary[pair.Key] = pair.Value + 1; 8: } 9: }); Now that we’ve done this, we can fire up both tasks and wait for them to complete: 1: // start both tasks 2: updateTask.Start(); 3: iterationTask.Start(); 4: 5: // wait for both to complete. 6: Task.WaitAll(updateTask, iterationTask); Now, if I you didn’t know about the dirty reads, you may have expected to see the iteration before the updates (such as A:1, B:2, C:3, D:4, E:5, F:6). However, because the reads are dirty, we will quite possibly get a combination of some updated, some original. My own run netted this result: 1: F:6 2: E:6 3: D:5 4: C:4 5: B:3 6: A:2 Note that, of course, iteration is not in order because ConcurrentDictionary, like Dictionary, is unordered. Also note that both E and F show the value 6. This is because the output task reached F before the update, but the updates for the rest of the items occurred before their output (probably because console output is very slow, comparatively). If we want to always guarantee that we will get a consistent snapshot to iterate over (that is, at the point we ask for it we see precisely what is in the dictionary and no subsequent updates during iteration), we should iterate over a call to ToArray() instead: 1: // attempt iteration in a separate thread 2: var iterationTask = new Task(() => 3: { 4: // iterates using a dirty read 5: foreach (var pair in dictionary.ToArray()) 6: { 7: Console.WriteLine(pair.Key + ":" + pair.Value); 8: } 9: }); The atomic Try…() methods As you can imagine TryAdd() and TryRemove() have few surprises. Both first check the existence of the item to determine if it can be added or removed based on whether or not the key currently exists in the dictionary: 1: // try add attempts an add and returns false if it already exists 2: if (dictionary.TryAdd("G", 7)) 3: Console.WriteLine("G did not exist, now inserted with 7"); 4: else 5: Console.WriteLine("G already existed, insert failed."); TryRemove() also has the virtue of returning the value portion of the removed entry matching the given key: 1: // attempt to remove the value, if it exists it is removed and the original is returned 2: int removedValue; 3: if (dictionary.TryRemove("C", out removedValue)) 4: Console.WriteLine("Removed C and its value was " + removedValue); 5: else 6: Console.WriteLine("C did not exist, remove failed."); Now TryUpdate() is an interesting creature. You might think from it’s name that TryUpdate() first checks for an item’s existence, and then updates if the item exists, otherwise it returns false. Well, note quite... It turns out when you call TryUpdate() on a concurrent dictionary, you pass it not only the new value you want it to have, but also the value you expected it to have before the update. If the item exists in the dictionary, and it has the value you expected, it will update it to the new value atomically and return true. If the item is not in the dictionary or does not have the value you expected, it is not modified and false is returned. 1: // attempt to update the value, if it exists and if it has the expected original value 2: if (dictionary.TryUpdate("G", 42, 7)) 3: Console.WriteLine("G existed and was 7, now it's 42."); 4: else 5: Console.WriteLine("G either didn't exist, or wasn't 7."); The composite Add methods The ConcurrentDictionary also has composite add methods that can be used to perform updates and gets, with an add if the item is not existing at the time of the update or get. The first of these, AddOrUpdate(), allows you to add a new item to the dictionary if it doesn’t exist, or update the existing item if it does. For example, let’s say you are creating a dictionary of counts of stock ticker symbols you’ve subscribed to from a market data feed: 1: public sealed class SubscriptionManager 2: { 3: private readonly ConcurrentDictionary<string, int> _subscriptions = new ConcurrentDictionary<string, int>(); 4: 5: // adds a new subscription, or increments the count of the existing one. 6: public void AddSubscription(string tickerKey) 7: { 8: // add a new subscription with count of 1, or update existing count by 1 if exists 9: var resultCount = _subscriptions.AddOrUpdate(tickerKey, 1, (symbol, count) => count + 1); 10: 11: // now check the result to see if we just incremented the count, or inserted first count 12: if (resultCount == 1) 13: { 14: // subscribe to symbol... 15: } 16: } 17: } Notice the update value factory Func delegate. If the key does not exist in the dictionary, the add value is used (in this case 1 representing the first subscription for this symbol), but if the key already exists, it passes the key and current value to the update delegate which computes the new value to be stored in the dictionary. The return result of this operation is the value used (in our case: 1 if added, existing value + 1 if updated). Likewise, the GetOrAdd() allows you to attempt to retrieve a value from the dictionary, and if the value does not currently exist in the dictionary it will insert a value. This can be handy in cases where perhaps you wish to cache data, and thus you would query the cache to see if the item exists, and if it doesn’t you would put the item into the cache for the first time: 1: public sealed class PriceCache 2: { 3: private readonly ConcurrentDictionary<string, double> _cache = new ConcurrentDictionary<string, double>(); 4: 5: // adds a new subscription, or increments the count of the existing one. 6: public double QueryPrice(string tickerKey) 7: { 8: // check for the price in the cache, if it doesn't exist it will call the delegate to create value. 9: return _cache.GetOrAdd(tickerKey, symbol => GetCurrentPrice(symbol)); 10: } 11: 12: private double GetCurrentPrice(string tickerKey) 13: { 14: // do code to calculate actual true price. 15: } 16: } There are other variations of these two methods which vary whether a value is provided or a factory delegate, but otherwise they work much the same. Oddities with the composite Add methods The AddOrUpdate() and GetOrAdd() methods are totally thread-safe, on this you may rely, but they are not atomic. It is important to note that the methods that use delegates execute those delegates outside of the lock. This was done intentionally so that a user delegate (of which the ConcurrentDictionary has no control of course) does not take too long and lock out other threads. This is not necessarily an issue, per se, but it is something you must consider in your design. The main thing to consider is that your delegate may get called to generate an item, but that item may not be the one returned! Consider this scenario: A calls GetOrAdd and sees that the key does not currently exist, so it calls the delegate. Now thread B also calls GetOrAdd and also sees that the key does not currently exist, and for whatever reason in this race condition it’s delegate completes first and it adds its new value to the dictionary. Now A is done and goes to get the lock, and now sees that the item now exists. In this case even though it called the delegate to create the item, it will pitch it because an item arrived between the time it attempted to create one and it attempted to add it. Let’s illustrate, assume this totally contrived example program which has a dictionary of char to int. And in this dictionary we want to store a char and it’s ordinal (that is, A = 1, B = 2, etc). So for our value generator, we will simply increment the previous value in a thread-safe way (perhaps using Interlocked): 1: public static class Program 2: { 3: private static int _nextNumber = 0; 4: 5: // the holder of the char to ordinal 6: private static ConcurrentDictionary<char, int> _dictionary 7: = new ConcurrentDictionary<char, int>(); 8: 9: // get the next id value 10: public static int NextId 11: { 12: get { return Interlocked.Increment(ref _nextNumber); } 13: } Then, we add a method that will perform our insert: 1: public static void Inserter() 2: { 3: for (int i = 0; i < 26; i++) 4: { 5: _dictionary.GetOrAdd((char)('A' + i), key => NextId); 6: } 7: } Finally, we run our test by starting two tasks to do this work and get the results… 1: public static void Main() 2: { 3: // 3 tasks attempting to get/insert 4: var tasks = new List<Task> 5: { 6: new Task(Inserter), 7: new Task(Inserter) 8: }; 9: 10: tasks.ForEach(t => t.Start()); 11: Task.WaitAll(tasks.ToArray()); 12: 13: foreach (var pair in _dictionary.OrderBy(p => p.Key)) 14: { 15: Console.WriteLine(pair.Key + ":" + pair.Value); 16: } 17: } If you run this with only one task, you get the expected A:1, B:2, ..., Z:26. But running this in parallel you will get something a bit more complex. My run netted these results: 1: A:1 2: B:3 3: C:4 4: D:5 5: E:6 6: F:7 7: G:8 8: H:9 9: I:10 10: J:11 11: K:12 12: L:13 13: M:14 14: N:15 15: O:16 16: P:17 17: Q:18 18: R:19 19: S:20 20: T:21 21: U:22 22: V:23 23: W:24 24: X:25 25: Y:26 26: Z:27 Notice that B is 3? This is most likely because both threads attempted to call GetOrAdd() at roughly the same time and both saw that B did not exist, thus they both called the generator and one thread got back 2 and the other got back 3. However, only one of those threads can get the lock at a time for the actual insert, and thus the one that generated the 3 won and the 3 was inserted and the 2 got discarded. This is why on these methods your factory delegates should be careful not to have any logic that would be unsafe if the value they generate will be pitched in favor of another item generated at roughly the same time. As such, it is probably a good idea to keep those generators as stateless as possible. Summary The ConcurrentDictionary is a very efficient and thread-safe version of the Dictionary generic collection. It has all the benefits of type-safety that it’s generic collection counterpart does, and in addition is extremely efficient especially when there are more reads than writes concurrently. Tweet Technorati Tags: C#, .NET, Concurrent Collections, Collections, Little Wonders, Black Rabbit Coder,James Michael Hare

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Ubuntu missing from the Grub menu

- by varevarao

Recently I've had some audio issues with Ubuntu (using precise), and in the process of trying to resolve that I ran a dist-upgrade. Everything went just fine, and the sound seemed good, until I rebooted my machine for the first time since the dist-upgrade. All I see now in the Grub menu at startup is memtest86+, another memtest variant, and Windows 7. It's not showing any of the linux kernels that Ubuntu is running on. I am attaching my bootinfoscript: Boot Info Script 0.61.full + Boot-Repair extra info [Boot-Info November 20th 2012] ============================= Boot Info Summary: =============================== => Grub2 (v1.99) is installed in the MBR of /dev/sda and looks at sector 1 of the same hard drive for core.img. core.img is at this location and looks for (,msdos6)/boot/grub on this drive. sda1: __________________________________________________________________________ File system: vfat Boot sector type: Dell Utility: FAT16 Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: sda2: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: sda3: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: No errors found in the Boot Parameter Block. Operating System: Windows 7 Boot files: sda4: __________________________________________________________________________ File system: Extended Partition Boot sector type: Unknown Boot sector info: sda5: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: According to the info in the boot sector, sda5 starts at sector 2048. Operating System: Boot files: sda6: __________________________________________________________________________ File system: ext4 Boot sector type: Grub2 (v1.99-2.00) Boot sector info: Grub2 (v1.99) is installed in the boot sector of sda6 and looks at sector 220046240 of the same hard drive for core.img. core.img is at this location and looks for (,msdos6)/boot/grub on this drive. Operating System: Ubuntu 12.04.1 LTS Boot files: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img sda7: __________________________________________________________________________ File system: swap Boot sector type: - Boot sector info: ============================ Drive/Partition Info: ============================= Drive: sda _____________________________________________________________________ Disk /dev/sda: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes Partition Boot Start Sector End Sector # of Sectors Id System /dev/sda1 63 273,104 273,042 de Dell Utility /dev/sda2 * 274,432 19,406,847 19,132,416 7 NTFS / exFAT / HPFS /dev/sda3 19,406,848 218,274,364 198,867,517 7 NTFS / exFAT / HPFS /dev/sda4 218,275,838 625,139,711 406,863,874 f W95 Extended (LBA) /dev/sda5 328,630,272 625,139,711 296,509,440 7 NTFS / exFAT / HPFS /dev/sda6 218,275,840 324,030,463 105,754,624 83 Linux /dev/sda7 324,032,512 328,626,175 4,593,664 82 Linux swap / Solaris "blkid" output: ________________________________________________________________ Device UUID TYPE LABEL /dev/loop0 squashfs /dev/sda1 07DA-0512 vfat DellUtility /dev/sda2 8834146034145392 ntfs RECOVERY /dev/sda3 48E2189DE21890F4 ntfs OS /dev/sda5 BC2A44C02A447982 ntfs Varshneya /dev/sda6 34731459-4b0f-46ac-a9bf-cb360a2c947c ext4 /dev/sda7 dcb9ce9b-799a-4c65-b008-887b01775670 swap /dev/sr0 iso9660 Ubuntu 12.04.1 LTS i386 ================================ Mount points: ================================= Device Mount_Point Type Options /dev/loop0 /rofs squashfs (ro,noatime) /dev/sda6 /mnt ext4 (rw) /dev/sr0 /cdrom iso9660 (ro,noatime) =========================== sda6/boot/grub/grub.cfg: =========================== -------------------------------------------------------------------------------- # # DO NOT EDIT THIS FILE # # It is automatically generated by grub-mkconfig using templates # from /etc/grub.d and settings from /etc/default/grub # ### BEGIN /etc/grub.d/00_header ### if [ -s $prefix/grubenv ]; then set have_grubenv=true load_env fi set default="0" if [ "${prev_saved_entry}" ]; then set saved_entry="${prev_saved_entry}" save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true fi function savedefault { if [ -z "${boot_once}" ]; then saved_entry="${chosen}" save_env saved_entry fi } function recordfail { set recordfail=1 if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi } function load_video { insmod vbe insmod vga insmod video_bochs insmod video_cirrus } insmod part_msdos insmod ext2 set root='(hd0,msdos6)' search --no-floppy --fs-uuid --set=root 34731459-4b0f-46ac-a9bf-cb360a2c947c if loadfont /boot/grub/unicode.pf2 ; then set gfxmode=auto load_video insmod gfxterm insmod part_msdos insmod ext2 set root='(hd0,msdos6)' search --no-floppy --fs-uuid --set=root 34731459-4b0f-46ac-a9bf-cb360a2c947c set locale_dir=($root)/boot/grub/locale set lang=en_US insmod gettext fi terminal_output gfxterm if [ "${recordfail}" = 1 ]; then set timeout=-1 else set timeout=10 fi ### END /etc/grub.d/00_header ### ### BEGIN /etc/grub.d/05_debian_theme ### set menu_color_normal=white/black set menu_color_highlight=black/light-gray ### END /etc/grub.d/05_debian_theme ### ### BEGIN /etc/grub.d/10_linux ### function gfxmode { set gfxpayload="${1}" if [ "${1}" = "keep" ]; then set vt_handoff=vt.handoff=7 else set vt_handoff= fi } if [ "${recordfail}" != 1 ]; then if [ -e ${prefix}/gfxblacklist.txt ]; then if hwmatch ${prefix}/gfxblacklist.txt 3; then if [ ${match} = 0 ]; then set linux_gfx_mode=keep else set linux_gfx_mode=text fi else set linux_gfx_mode=text fi else set linux_gfx_mode=keep fi else set linux_gfx_mode=text fi export linux_gfx_mode if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi ### END /etc/grub.d/10_linux ### ### BEGIN /etc/grub.d/20_linux_xen ### ### END /etc/grub.d/20_linux_xen ### ### BEGIN /etc/grub.d/20_memtest86+ ### menuentry "Memory test (memtest86+)" { insmod part_msdos insmod ext2 set root='(hd0,msdos6)' search --no-floppy --fs-uuid --set=root 34731459-4b0f-46ac-a9bf-cb360a2c947c linux16 /boot/memtest86+.bin } menuentry "Memory test (memtest86+, serial console 115200)" { insmod part_msdos insmod ext2 set root='(hd0,msdos6)' search --no-floppy --fs-uuid --set=root 34731459-4b0f-46ac-a9bf-cb360a2c947c linux16 /boot/memtest86+.bin console=ttyS0,115200n8 } ### END /etc/grub.d/20_memtest86+ ### ### BEGIN /etc/grub.d/30_os-prober ### menuentry "Windows 7 (loader) (on /dev/sda2)" --class windows --class os { insmod part_msdos insmod ntfs set root='(hd0,msdos2)' search --no-floppy --fs-uuid --set=root 8834146034145392 chainloader +1 } ### END /etc/grub.d/30_os-prober ### ### BEGIN /etc/grub.d/40_custom ### # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. ### END /etc/grub.d/40_custom ### ### BEGIN /etc/grub.d/41_custom ### if [ -f $prefix/custom.cfg ]; then source $prefix/custom.cfg; fi ### END /etc/grub.d/41_custom ### -------------------------------------------------------------------------------- =============================== sda6/etc/fstab: ================================ -------------------------------------------------------------------------------- # /etc/fstab: static file system information. # # Use 'blkid -o value -s UUID' to print the universally unique identifier # for a device; this may be used with UUID= as a more robust way to name # devices that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> proc /proc proc nodev,noexec,nosuid 0 0 # / was on /dev/sda6 during installation UUID=34731459-4b0f-46ac-a9bf-cb360a2c947c / ext4 errors=remount-ro,user_xattr 0 1 # swap was on /dev/sda7 during installation UUID=dcb9ce9b-799a-4c65-b008-887b01775670 none swap sw 0 0 -------------------------------------------------------------------------------- =================== sda6: Location of files loaded by Grub: ==================== GiB - GB File Fragment(s) 104.851909637 = 112.583880704 boot/grub/core.img 1 121.191410065 = 130.128285696 boot/grub/grub.cfg 1 ======================== Unknown MBRs/Boot Sectors/etc: ======================== Unknown BootLoader on sda4 00000000 eb 0f 2a 5d f4 b7 75 f2 e9 56 12 b8 50 b4 79 ec |..*]..u..V..P.y.| 00000010 89 91 ca c3 16 40 31 d0 ae c4 53 3d c7 dd d7 98 |[email protected]=....| 00000020 bd a4 f2 a4 e8 ab fc ea 36 30 1b 34 cf 8a 28 30 |........60.4..(0| 00000030 43 95 6c 31 3e 76 93 58 84 37 99 c3 ae 3a 88 a3 |C.l1>v.X.7...:..| 00000040 c2 a6 36 2a f8 e0 e1 03 91 8d a1 50 cd ad b0 b5 |..6*.......P....| 00000050 ad 69 3a 49 63 1f 4a 33 97 6e 0c 71 bf 7d bd 35 |.i:Ic.J3.n.q.}.5| 00000060 86 c5 17 93 b4 9f e5 af e0 c4 6f f4 6f f9 4b dd |..........o.o.K.| 00000070 14 39 e2 9e b9 36 ca b1 56 5b d9 b1 66 2c 05 b2 |.9...6..V[..f,..| 00000080 5d 5b 99 c0 db e6 81 27 ab c2 e1 55 00 ac 0b 2c |][.....'...U...,| 00000090 24 d3 8e 54 b0 3d ab 58 e4 23 fc 3a 79 93 fb 5e |$..T.=.X.#.:y..^| 000000a0 94 5a 3a c2 16 4e 56 cb 1b 7f 7e b3 4c 38 ca 5b |.Z:..NV...~.L8.[| 000000b0 ca ab c1 2c 2a 64 e7 77 fe 2a ba ee 08 33 b5 9b |...,*d.w.*...3..| 000000c0 d0 c2 b4 a8 fc 73 4f 01 fd 03 61 75 eb 6d 1a 74 |.....sO...au.m.t| 000000d0 5f 79 31 7f ed e6 f5 99 21 36 16 ed 25 d9 6d 2b |_y1.....!6..%.m+| 000000e0 5f f4 42 b8 9d 01 89 10 fe df a4 98 e7 ab ab ea |_.B.............| 000000f0 1d 1c 44 e1 49 d9 19 c9 ab f5 41 eb 4a 32 c2 39 |..D.I.....A.J2.9| 00000100 87 57 f6 f6 f3 b5 4d 17 72 f2 b1 16 19 aa ec 24 |.W....M.r......$| 00000110 39 bd e3 b1 68 b3 b0 7f fa 2a 3a 2e 99 ed db 8a |9...h....*:.....| 00000120 f8 61 b4 ef 9d 7d 85 95 ed ad eb 9e 71 f4 27 d3 |.a...}......q.'.| 00000130 f3 04 8b 8a 69 98 02 72 df e1 f9 83 27 5b 01 4c |....i..r....'[.L| 00000140 d4 9a b9 3b db ca 1e 40 35 db 6f c1 52 c0 7f 27 |...;[email protected]..'| 00000150 8a 1d bc 34 89 24 b6 e3 fd ec a1 2a e5 9e d1 8f |...4.$.....*....| 00000160 77 e0 d5 52 c0 4c c4 38 38 3c 28 19 bf 20 f0 03 |w..R.L.88<(.. ..| 00000170 38 a4 b1 b5 ed 6a b8 f7 a9 7b 65 b1 7b 64 4a 33 |8....j...{e.{dJ3| 00000180 66 1a 60 29 38 1d 5b 52 40 31 de a5 0c 0f cc 6f |f.`)8.[[email protected]| 00000190 dd 31 6d 3d f0 2a 32 85 67 66 ca 4f 02 aa 0d 30 |.1m=.*2.gf.O...0| 000001a0 66 c9 b2 33 c2 4b 8a fa 3c 7b 52 02 00 88 8e cf |f..3.K..<{R.....| 000001b0 67 1e d4 20 49 1d 1a b8 71 ad c2 d4 37 9d 00 fe |g.. I...q...7...| 000001c0 ff ff 07 fe ff ff 02 e0 93 06 00 60 ac 11 00 fe |...........`....| 000001d0 ff ff 05 fe ff ff 01 00 00 00 01 b0 4d 06 00 00 |............M...| 000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 ADDITIONAL INFORMATION : =================== log of boot-repair 2012-11-24__09h45 =================== boot-repair version : 3.195~ppa2~precise boot-sav version : 3.195~ppa2~precise glade2script version : 3.2.2~ppa45~precise boot-sav-extra version : 3.195~ppa2~precise boot-repair is executed in live-session (Ubuntu 12.04.1 LTS, precise, Ubuntu, i686) CPU op-mode(s): 32-bit, 64-bit file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash -- =================== os-prober: /dev/sda2:Windows 7 (loader):Windows:chain /dev/sda6:Ubuntu 12.04.1 LTS (12.04):Ubuntu:linux =================== blkid: /dev/sda1: SEC_TYPE="msdos" LABEL="DellUtility" UUID="07DA-0512" TYPE="vfat" /dev/sda2: LABEL="RECOVERY" UUID="8834146034145392" TYPE="ntfs" /dev/sda3: LABEL="OS" UUID="48E2189DE21890F4" TYPE="ntfs" /dev/sda5: LABEL="Varshneya" UUID="BC2A44C02A447982" TYPE="ntfs" /dev/loop0: TYPE="squashfs" /dev/sda6: UUID="34731459-4b0f-46ac-a9bf-cb360a2c947c" TYPE="ext4" /dev/sda7: UUID="dcb9ce9b-799a-4c65-b008-887b01775670" TYPE="swap" /dev/sr0: LABEL="Ubuntu 12.04.1 LTS i386" TYPE="iso9660" 1 disks with OS, 2 OS : 1 Linux, 0 MacOS, 1 Windows, 0 unknown type OS. Windows not detected by os-prober on sda3. Warning: extended partition does not start at a cylinder boundary. DOS and Linux will interpret the contents differently. =================== /mnt/etc/default/grub : # If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: # info -f grub -n 'Simple configuration' GRUB_DEFAULT=0 GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" GRUB_CMDLINE_LINUX="" # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true" # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1" =================== /mnt/etc/grub.d/ : drwxr-xr-x 2 root root 4096 Nov 22 16:15 grub.d total 56 -rwxr-xr-x 1 root root 6743 Sep 12 20:19 00_header -rwxr-xr-x 1 root root 5522 Sep 12 20:05 05_debian_theme -rwxr-xr-x 1 root root 7407 Sep 12 20:19 10_linux -rwxr-xr-x 1 root root 6335 Sep 12 20:19 20_linux_xen -rwxr-xr-x 1 root root 1588 Sep 24 2010 20_memtest86+ -rwxr-xr-x 1 root root 7603 Sep 12 20:19 30_os-prober -rwxr-xr-x 1 root root 214 Sep 12 20:19 40_custom -rwxr-xr-x 1 root root 95 Sep 12 20:19 41_custom -rw-r--r-- 1 root root 483 Sep 12 20:19 README =================== No kernel in /mnt/boot: grub memtest86+.bin memtest86+_multiboot.bin =================== UEFI/Legacy mode: This live-session is not EFI-compatible. SecureBoot maybe enabled. =================== PARTITIONS & DISKS: sda1 : sda, not-sepboot, no-grubenv nogrub, no-docgrub, no-update-grub, 32, no-boot, no-os, not--efi--part, part-has-no-fstab, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, nopakmgr, nogrubinstall, no---usr, part-has-no-fstab, not-sep-usr, standard, not-far, /mnt/boot-sav/sda1. sda2 : sda, not-sepboot, no-grubenv nogrub, no-docgrub, no-update-grub, 32, no-boot, is-os, not--efi--part, part-has-no-fstab, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, bootmgr, is-winboot, nopakmgr, nogrubinstall, no---usr, part-has-no-fstab, not-sep-usr, standard, not-far, /mnt/boot-sav/sda2. sda3 : sda, not-sepboot, no-grubenv nogrub, no-docgrub, no-update-grub, 32, no-boot, is-os, not--efi--part, part-has-no-fstab, part-has-no-fstab, no-nt, haswinload, no-recov-nor-hid, no-bmgr, notwinboot, nopakmgr, nogrubinstall, no---usr, part-has-no-fstab, not-sep-usr, standard, farbios, /mnt/boot-sav/sda3. sda5 : sda, not-sepboot, no-grubenv nogrub, no-docgrub, no-update-grub, 32, no-boot, no-os, not--efi--part, part-has-no-fstab, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, nopakmgr, nogrubinstall, no---usr, part-has-no-fstab, not-sep-usr, standard, farbios, /mnt/boot-sav/sda5. sda6 : sda, not-sepboot, grubenv-ok grub2, grub-pc, update-grub, 64, no-kernel, is-os, not--efi--part, fstab-without-boot, fstab-without-efi, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, apt-get, grub-install, with--usr, fstab-without-usr, not-sep-usr, standard, farbios, /mnt. sda : not-GPT, BIOSboot-not-needed, has-no-EFIpart, not-usb, has-os, 63 sectors * 512 bytes =================== parted -l: Model: ATA ST9320423AS (scsi) Disk /dev/sda: 320GB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 32.3kB 140MB 140MB primary fat16 diag 2 141MB 9936MB 9796MB primary ntfs boot 3 9936MB 112GB 102GB primary ntfs 4 112GB 320GB 208GB extended lba 6 112GB 166GB 54.1GB logical ext4 7 166GB 168GB 2352MB logical linux-swap(v1) 5 168GB 320GB 152GB logical ntfs Model: HL-DT-ST DVD+-RW GA31N (scsi) Disk /dev/sr0: 4700MB Sector size (logical/physical): 2048B/2048B Partition Table: msdos Number Start End Size Type File system Flags 1 131kB 2916MB 2916MB primary boot, hidden =================== parted -lm: BYT; /dev/sda:320GB:scsi:512:512:msdos:ATA ST9320423AS; 1:32.3kB:140MB:140MB:fat16::diag; 2:141MB:9936MB:9796MB:ntfs::boot; 3:9936MB:112GB:102GB:ntfs::; 4:112GB:320GB:208GB:::lba; 6:112GB:166GB:54.1GB:ext4::; 7:166GB:168GB:2352MB:linux-swap(v1)::; 5:168GB:320GB:152GB:ntfs::; BYT; /dev/sr0:4700MB:scsi:2048:2048:msdos:HL-DT-ST DVD+-RW GA31N; 1:131kB:2916MB:2916MB:::boot, hidden; =================== mount: /cow on / type overlayfs (rw) proc on /proc type proc (rw,noexec,nosuid,nodev) sysfs on /sys type sysfs (rw,noexec,nosuid,nodev) udev on /dev type devtmpfs (rw,mode=0755) devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620) tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755) /dev/sr0 on /cdrom type iso9660 (ro,noatime) /dev/loop0 on /rofs type squashfs (ro,noatime) none on /sys/fs/fuse/connections type fusectl (rw) none on /sys/kernel/debug type debugfs (rw) none on /sys/kernel/security type securityfs (rw) tmpfs on /tmp type tmpfs (rw,nosuid,nodev) none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880) none on /run/shm type tmpfs (rw,nosuid,nodev) gvfs-fuse-daemon on /home/ubuntu/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=ubuntu) /dev/sda6 on /mnt type ext4 (rw) /dev on /mnt/dev type none (rw,bind) /proc on /mnt/proc type none (rw,bind) /sys on /mnt/sys type none (rw,bind) /usr on /mnt/usr type none (rw,bind) /dev/sda1 on /mnt/boot-sav/sda1 type vfat (rw) /dev/sda2 on /mnt/boot-sav/sda2 type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) /dev/sda3 on /mnt/boot-sav/sda3 type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) /dev/sda5 on /mnt/boot-sav/sda5 type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) =================== ls: /sys/block/sda (filtered): alignment_offset bdi capability dev device discard_alignment events events_async events_poll_msecs ext_range holders inflight power queue range removable ro sda1 sda2 sda3 sda4 sda5 sda6 sda7 size slaves stat subsystem trace uevent /sys/block/sr0 (filtered): alignment_offset bdi capability dev device discard_alignment events events_async events_poll_msecs ext_range holders inflight power queue range removable ro size slaves stat subsystem trace uevent /dev (filtered): autofs block bsg btrfs-control bus cdrom cdrw char console core cpu cpu_dma_latency disk dri dvd dvdrw ecryptfs fb0 fd full fuse fw0 hidraw0 hpet input kmsg log mapper mcelog mei mem net network_latency network_throughput null oldmem port ppp psaux ptmx pts random rfkill rtc rtc0 sda sda1 sda2 sda3 sda4 sda5 sda6 sda7 sg0 sg1 shm snapshot snd sr0 stderr stdin stdout uinput urandom usbmon0 usbmon1 usbmon2 v4l vga_arbiter video0 zero ls /dev/mapper: control =================== df -Th: Filesystem Type Size Used Avail Use% Mounted on /cow overlayfs 1.9G 113M 1.8G 6% / udev devtmpfs 1.9G 12K 1.9G 1% /dev tmpfs tmpfs 777M 872K 776M 1% /run /dev/sr0 iso9660 696M 696M 0 100% /cdrom /dev/loop0 squashfs 667M 667M 0 100% /rofs tmpfs tmpfs 1.9G 20K 1.9G 1% /tmp none tmpfs 5.0M 0 5.0M 0% /run/lock none tmpfs 1.9G 176K 1.9G 1% /run/shm /dev/sda6 ext4 51G 27G 22G 56% /mnt /dev/sda1 vfat 134M 9.1M 125M 7% /mnt/boot-sav/sda1 /dev/sda2 fuseblk 9.2G 5.6G 3.6G 61% /mnt/boot-sav/sda2 /dev/sda3 fuseblk 95G 80G 16G 84% /mnt/boot-sav/sda3 /dev/sda5 fuseblk 142G 130G 12G 92% /mnt/boot-sav/sda5 =================== fdisk -l: Disk /dev/sda: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xb8000000 Device Boot Start End Blocks Id System /dev/sda1 63 273104 136521 de Dell Utility /dev/sda2 * 274432 19406847 9566208 7 HPFS/NTFS/exFAT /dev/sda3 19406848 218274364 99433758+ 7 HPFS/NTFS/exFAT /dev/sda4 218275838 625139711 203431937 f W95 Ext'd (LBA) /dev/sda5 328630272 625139711 148254720 7 HPFS/NTFS/exFAT /dev/sda6 218275840 324030463 52877312 83 Linux /dev/sda7 324032512 328626175 2296832 82 Linux swap / Solaris Partition table entries are not in disk order =================== Repair blockers 64bits detected. Please use this software in a 64bits session. (Please use Ubuntu-Secure-Remix-64bits (www.sourceforge.net/p/ubuntu-secured) which contains a 64bits-compatible version of this software.) This will enable this feature. =================== Final advice in case of recommended repair The boot files of [Ubuntu 12.04.1 LTS] are far from the start of the disk. Your BIOS may not detect them. You may want to retry after creating a /boot partition (EXT4, >200MB, start of the disk). This can be performed via tools such as gParted. Then select this partition via the [Separate /boot partition:] option of [Boot Repair]. (https://help.ubuntu.com/community/BootPartition) =================== Default settings Recommended-Repair This setting would reinstall the grub2 of sda6 into the MBR of sda, using the following options: kernel-purge Additional repair would be performed: unhide-bootmenu-10s fix-windows-boot =================== Settings chosen by the user Boot-Info This setting will not act on the MBR. No change has been performed on your computer. See you soon! pastebinit packages needed dpkg-preconfigure: unable to re-open stdin: No such file or directory pastebin.com ko (), using paste.ubuntu Please report this message to [email protected] Any help would be great, I'm really missing Ubuntu (hate being stuck in the Windows world).

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high load average, high wait, dmesg raid error messages (debian nfs server)

- by John Stumbles

Debian 6 on HP proliant (2 CPU) with raid (2*1.5T RAID1 + 2*2T RAID1 joined RAID0 to make 3.5T) running mainly nfs & imapd (plus samba for windows share & local www for previewing web pages); with local ubuntu desktop client mounting $HOME, laptops accessing imap & odd files (e.g. videos) via nfs/smb; boxes connected 100baseT or wifi via home router/switch uname -a Linux prole 2.6.32-5-686 #1 SMP Wed Jan 11 12:29:30 UTC 2012 i686 GNU/Linux Setup has been working for months but prone to intermittently going very slow (user experience on desktop mounting $HOME from server, or laptop playing videos) and now consistently so bad I've had to delve into it to try to find what's wrong(!) Server seems OK at low load e.g. (laptop) client (with $HOME on local disk) connecting to server's imapd and nfs mounting RAID to access 1 file: top shows load ~ 0.1 or less, 0 wait but when (desktop) client mounts $HOME and starts user KDE session (all accessing server) then top shows e.g. top - 13:41:17 up 3:43, 3 users, load average: 9.29, 9.55, 8.27 Tasks: 158 total, 1 running, 157 sleeping, 0 stopped, 0 zombie Cpu(s): 0.4%us, 0.4%sy, 0.0%ni, 49.0%id, 49.7%wa, 0.0%hi, 0.5%si, 0.0%st Mem: 903856k total, 851784k used, 52072k free, 171152k buffers Swap: 0k total, 0k used, 0k free, 476896k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3935 root 20 0 2456 1088 784 R 2 0.1 0:00.02 top 1 root 20 0 2028 680 584 S 0 0.1 0:01.14 init 2 root 20 0 0 0 0 S 0 0.0 0:00.00 kthreadd 3 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/0 4 root 20 0 0 0 0 S 0 0.0 0:00.12 ksoftirqd/0 5 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/0 6 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/1 7 root 20 0 0 0 0 S 0 0.0 0:00.16 ksoftirqd/1 8 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/1 9 root 20 0 0 0 0 S 0 0.0 0:00.42 events/0 10 root 20 0 0 0 0 S 0 0.0 0:02.26 events/1 11 root 20 0 0 0 0 S 0 0.0 0:00.00 cpuset 12 root 20 0 0 0 0 S 0 0.0 0:00.00 khelper 13 root 20 0 0 0 0 S 0 0.0 0:00.00 netns 14 root 20 0 0 0 0 S 0 0.0 0:00.00 async/mgr 15 root 20 0 0 0 0 S 0 0.0 0:00.00 pm 16 root 20 0 0 0 0 S 0 0.0 0:00.02 sync_supers 17 root 20 0 0 0 0 S 0 0.0 0:00.02 bdi-default 18 root 20 0 0 0 0 S 0 0.0 0:00.00 kintegrityd/0 19 root 20 0 0 0 0 S 0 0.0 0:00.00 kintegrityd/1 20 root 20 0 0 0 0 S 0 0.0 0:00.02 kblockd/0 21 root 20 0 0 0 0 S 0 0.0 0:00.08 kblockd/1 22 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpid 23 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpi_notify 24 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpi_hotplug 25 root 20 0 0 0 0 S 0 0.0 0:00.00 kseriod 28 root 20 0 0 0 0 S 0 0.0 0:04.19 kondemand/0 29 root 20 0 0 0 0 S 0 0.0 0:02.93 kondemand/1 30 root 20 0 0 0 0 S 0 0.0 0:00.00 khungtaskd 31 root 20 0 0 0 0 S 0 0.0 0:00.18 kswapd0 32 root 25 5 0 0 0 S 0 0.0 0:00.00 ksmd 33 root 20 0 0 0 0 S 0 0.0 0:00.00 aio/0 34 root 20 0 0 0 0 S 0 0.0 0:00.00 aio/1 35 root 20 0 0 0 0 S 0 0.0 0:00.00 crypto/0 36 root 20 0 0 0 0 S 0 0.0 0:00.00 crypto/1 203 root 20 0 0 0 0 S 0 0.0 0:00.00 ksuspend_usbd 204 root 20 0 0 0 0 S 0 0.0 0:00.00 khubd 205 root 20 0 0 0 0 S 0 0.0 0:00.00 ata/0 206 root 20 0 0 0 0 S 0 0.0 0:00.00 ata/1 207 root 20 0 0 0 0 S 0 0.0 0:00.14 ata_aux 208 root 20 0 0 0 0 S 0 0.0 0:00.01 scsi_eh_0 dmesg suggests there's a disk problem: .............. (previous episode) [13276.966004] raid1:md0: read error corrected (8 sectors at 489900360 on sdc7) [13276.966043] raid1: sdb7: redirecting sector 489898312 to another mirror [13279.569186] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13279.569211] ata4.00: irq_stat 0x40000008 [13279.569230] ata4.00: failed command: READ FPDMA QUEUED [13279.569257] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13279.569262] res 41/40:00:05:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13279.569306] ata4.00: status: { DRDY ERR } [13279.569321] ata4.00: error: { UNC } [13279.575362] ata4.00: configured for UDMA/133 [13279.575388] ata4: EH complete [13283.169224] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13283.169246] ata4.00: irq_stat 0x40000008 [13283.169263] ata4.00: failed command: READ FPDMA QUEUED [13283.169289] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13283.169294] res 41/40:00:07:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13283.169331] ata4.00: status: { DRDY ERR } [13283.169345] ata4.00: error: { UNC } [13283.176071] ata4.00: configured for UDMA/133 [13283.176104] ata4: EH complete [13286.224814] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13286.224837] ata4.00: irq_stat 0x40000008 [13286.224853] ata4.00: failed command: READ FPDMA QUEUED [13286.224879] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13286.224884] res 41/40:00:06:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13286.224922] ata4.00: status: { DRDY ERR } [13286.224935] ata4.00: error: { UNC } [13286.231277] ata4.00: configured for UDMA/133 [13286.231303] ata4: EH complete [13288.802623] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13288.802646] ata4.00: irq_stat 0x40000008 [13288.802662] ata4.00: failed command: READ FPDMA QUEUED [13288.802688] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13288.802693] res 41/40:00:05:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13288.802731] ata4.00: status: { DRDY ERR } [13288.802745] ata4.00: error: { UNC } [13288.808901] ata4.00: configured for UDMA/133 [13288.808927] ata4: EH complete [13291.380430] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13291.380453] ata4.00: irq_stat 0x40000008 [13291.380470] ata4.00: failed command: READ FPDMA QUEUED [13291.380496] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13291.380501] res 41/40:00:05:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13291.380577] ata4.00: status: { DRDY ERR } [13291.380594] ata4.00: error: { UNC } [13291.386517] ata4.00: configured for UDMA/133 [13291.386543] ata4: EH complete [13294.347147] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13294.347169] ata4.00: irq_stat 0x40000008 [13294.347186] ata4.00: failed command: READ FPDMA QUEUED [13294.347211] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13294.347217] res 41/40:00:06:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13294.347254] ata4.00: status: { DRDY ERR } [13294.347268] ata4.00: error: { UNC } [13294.353556] ata4.00: configured for UDMA/133 [13294.353583] sd 3:0:0:0: [sdc] Unhandled sense code [13294.353590] sd 3:0:0:0: [sdc] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [13294.353599] sd 3:0:0:0: [sdc] Sense Key : Medium Error [current] [descriptor] [13294.353610] Descriptor sense data with sense descriptors (in hex): [13294.353616] 72 03 11 04 00 00 00 0c 00 0a 80 00 00 00 00 00 [13294.353635] 23 05 6a 06 [13294.353644] sd 3:0:0:0: [sdc] Add. Sense: Unrecovered read error - auto reallocate failed [13294.353657] sd 3:0:0:0: [sdc] CDB: Read(10): 28 00 23 05 6a 00 00 00 08 00 [13294.353675] end_request: I/O error, dev sdc, sector 587557382 [13294.353726] ata4: EH complete [13294.366953] raid1:md0: read error corrected (8 sectors at 489900544 on sdc7) [13294.366992] raid1: sdc7: redirecting sector 489898496 to another mirror and they're happening quite frequently, which I guess is liable to account for the performance problem(?) # dmesg | grep mirror [12433.561822] raid1: sdc7: redirecting sector 489900464 to another mirror [12449.428933] raid1: sdb7: redirecting sector 489900504 to another mirror [12464.807016] raid1: sdb7: redirecting sector 489900512 to another mirror [12480.196222] raid1: sdb7: redirecting sector 489900520 to another mirror [12495.585413] raid1: sdb7: redirecting sector 489900528 to another mirror [12510.974424] raid1: sdb7: redirecting sector 489900536 to another mirror [12526.374933] raid1: sdb7: redirecting sector 489900544 to another mirror [12542.619938] raid1: sdc7: redirecting sector 489900608 to another mirror [12559.431328] raid1: sdc7: redirecting sector 489900616 to another mirror [12576.553866] raid1: sdc7: redirecting sector 489900624 to another mirror [12592.065265] raid1: sdc7: redirecting sector 489900632 to another mirror [12607.621121] raid1: sdc7: redirecting sector 489900640 to another mirror [12623.165856] raid1: sdc7: redirecting sector 489900648 to another mirror [12638.699474] raid1: sdc7: redirecting sector 489900656 to another mirror [12655.610881] raid1: sdc7: redirecting sector 489900664 to another mirror [12672.255617] raid1: sdc7: redirecting sector 489900672 to another mirror [12672.288746] raid1: sdc7: redirecting sector 489900680 to another mirror [12672.332376] raid1: sdc7: redirecting sector 489900688 to another mirror [12672.362935] raid1: sdc7: redirecting sector 489900696 to another mirror [12674.201177] raid1: sdc7: redirecting sector 489900704 to another mirror [12698.045050] raid1: sdc7: redirecting sector 489900712 to another mirror [12698.089309] raid1: sdc7: redirecting sector 489900720 to another mirror [12698.111999] raid1: sdc7: redirecting sector 489900728 to another mirror [12698.134006] raid1: sdc7: redirecting sector 489900736 to another mirror [12719.034376] raid1: sdc7: redirecting sector 489900744 to another mirror [12734.545775] raid1: sdc7: redirecting sector 489900752 to another mirror [12734.590014] raid1: sdc7: redirecting sector 489900760 to another mirror [12734.624050] raid1: sdc7: redirecting sector 489900768 to another mirror [12734.647308] raid1: sdc7: redirecting sector 489900776 to another mirror [12734.664657] raid1: sdc7: redirecting sector 489900784 to another mirror [12734.710642] raid1: sdc7: redirecting sector 489900792 to another mirror [12734.721919] raid1: sdc7: redirecting sector 489900800 to another mirror [12734.744732] raid1: sdc7: redirecting sector 489900808 to another mirror [12734.779330] raid1: sdc7: redirecting sector 489900816 to another mirror [12782.604564] raid1: sdb7: redirecting sector 1242934216 to another mirror [12798.264153] raid1: sdc7: redirecting sector 1242935080 to another mirror [13245.832193] raid1: sdb7: redirecting sector 489898296 to another mirror [13261.376929] raid1: sdb7: redirecting sector 489898304 to another mirror [13276.966043] raid1: sdb7: redirecting sector 489898312 to another mirror [13294.366992] raid1: sdc7: redirecting sector 489898496 to another mirror although the arrays are still running on all disks - they haven't given up on any yet: # cat /proc/mdstat Personalities : [raid1] [raid0] md10 : active raid0 md0[0] md1[1] 3368770048 blocks super 1.2 512k chunks md1 : active raid1 sde2[2] sdd2[1] 1464087824 blocks super 1.2 [2/2] [UU] md0 : active raid1 sdb7[0] sdc7[2] 1904684920 blocks super 1.2 [2/2] [UU] unused devices: <none> So I think I have some idea what the problem is but I am not a linux sysadmin expert by the remotest stretch of the imagination and would really appreciate some clue checking here with my diagnosis and what do I need to do: obviously I need to source another drive for sdc. (I'm guessing I could buy a larger drive if the price is right: I'm thinking that one day I'll need to grow the size of the array and that would be one less drive to replace with a larger one) then use mdadm to fail out the existing sdc, remove it and fit the new drive fdisk the new drive with the same size partition for the array as the old one had use mdadm to add the new drive into the array that sound OK?

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PC powers off at random times

- by Timo Huovinen

Short Version After experiencing some problems with Mobo batteries my PC started to power off at random times, the power off is instant and sudden and does not restart afterwards, need help figuring out the cause. Facts: Powers off when PC is playing games Powers off when PC is idle Powers off when PC is in safe mode Powers off when PC is in BIOS Powers off when PC is booted through a Windows installation USB Replaced the motherboard battery several times Replaced the 650W PSU with a 750W PSU Replaced the RAM Swapped the RAM between slots Re-applied thermal paste to the CPU Checked if the motherboard touches the case Nothing is overclocked PC Specs PC specs: OS: Windows 7 Ultimate SP1 RAM: klingston 1333MHz 4GB stick CPU: AMD Phenom II x4 955 Mobo: Gigabyte 88GMA-UD2H rev 2.2 Motherboard battery: CR2032 3v HDD: 500GB Seagate ST3500418AS ATA Device Graphics: ATI/AMD Radeon HD 6870 Very Long version Around 10 months ago I built a brand new gaming PC. Around 6 months ago it's time setting in windows started resetting to the year 2010. I swapped the Motherboard battery for a new one of the exact same size and shape and voltage, and the problems disappeared...for around 2 weeks. Then the same problem happened again, time gets reset, I swapped the battery again, and the problem was gone for good and everything was great for about 3 months.. then another problem started happening, the PC started to power off suddenly and without warning at completely random times, sometimes the PC works for and hour, sometimes 5 minutes. So I read on the forums that it might be either the PSU or the motherboard Battery or RAM or HDD or the Graphics card or the CPU or the motherboard or the drivers or a Virus or Grounding issues, or something short circuiting, basically it can be anything... I spent some days researching, and decided to remove the possibility of a virus. I reset the CMOS, cleared all BIOS settings and reinstalled windows 7 after a full format of the HDD, but the random power off kept happening. I then disabled the restart on error option in windows and looked at the event log for error events, but they did not help me figure out the problem. Network list service depends on network location awareness the dependency group failed to start Source Kernel Power Event 41 Task Category 63 Source Disk Event ID 11 Task Category None The driver detected a controller error on device disk I took apart the PC, every little piece, re-applied some expensive thermal paste to the CPU, and double checked that none of the pieces are touching the PC case. The problem was gone, the PC no longer powered off randomly I re-attached the graphics card and all was good for 4 months... then the power off problem appeared again, but was happening at high intervals, the PC would shutdown once in 2 days on average, at random points in time, sometimes when it's idle all day long, sometimes when it's running CRYSIS 2. I checked the CPU temperature, because I know that AMD CPU's have a built in protection mechanism that switches off the PC if the CPU gets too hot, and the Temp was 50C system temp, and 45C CPU after running the PC all day long (I did not do tests to see if there are any temperature spikes, don't know how to do them) Originally the PSU that powered the PC was 650Watts and had one 4 pin cable to power the CPU, I replaced it with a new 750Watts PSU which has two 4 pin cables for the CPU, but the problem remained. I removed the graphics card and let the motherboard use the built in one, but the PC kept suddenly powering off at random times. I took apart the PC completely again, and re-applied thermal paste to the CPU, added lots of insulation, and checked for any type of short-circuit possibility again and again, but the problem remained. The problem was like that for some months. I replaced the Battery a couple of times over the time, changed lots of options in windows, and tried everything I could, but it kept powering off, so I stopped using the PC as much as I used to, just living with the random power offs from time to time, until a couple of days ago, when the power off happens almost immediately after powering on the PC. I replaced the RAM with a brand new one, but that did not help. Took apart the PC again, checked for anything anywhere that might cause it, found some small scratches on the very edge of the motherboard to the left of the PCI express x16 slot. This might cause the problem, I thought, but the scratch looks very superficial, not deep at all, and if the scratch did harm the motherboard, wouldn't it cause it to not start at all? And why did it start to power off a while ago, and then suddenly stop powering off? The scratches could not have vanished??? did chkdsk \d but it powered off when it was at 75% I removed the hard disks, the graphics card, while I fiddled with the BIOS settings, and suddenly the PC shut down while I was looking at the BIOS version. This makes me realize, it is not caused by: HDD, Windows, Drivers or the Graphics card I cleared the CMOS again, updated the BIOS from F5 to F6f beta, but that did not help, it might even seem that the PC powers off even sooner. The shutdown even happened to me while I booted through a windows 7 installation USB and was in the repair console. I removed one of the cables powering the CPU, now only one 4pin cable powers it, and it worked for 30mins after doing that, which makes me think that it's the CPU overheating, and because it gets less power, it overheats slower? The things that I am still considering: CPU overheating (does not seem to overheat, maybe false readings?) Motherboard short circuiting (faulty motherboard?) I desperately need some advice in what is faulty, is it a faulty Motherboard or an overheating CPU? or maybe something else? I have been breaking my head over this problem over a span of 6 months. I'm not sure if this is a good place to ask this question, if it is not, then tell me where I can get some experienced help. More info I have also discovered a mysterious piece that seems to have fallen out of the motherboard i119.photobucket.com/albums/o126/yurikolovsky/strangepiece.jpg What is it? Looks like each time that it powers off the datetime gets reset I also found another forum post tomshardware.co.uk/forum/… except I don't have Integrated PeripheralsUSB Keyboard Function option in BIOS :S Comments summary (asked by Random moderator) Q. tell me, if the computer restarts, is it immediately? Does it take a second and then restarts? Do you see (BSOD) or hear (PSU, short circuit) any suspicious when it happens? After reading trough it, it remains the mainboard that is faulty. – JohannesM A. Immediate power off, all the fans stop instantly, all the light turn off instantly, no sound or anything, and it remains off until I turn it back on. Thanks for the feedback, faulty motherboard is what I fear. Q. Try stress-testing the system with Prime95 and see if errors or shutdowns occur when the CPU is under full load. – speakr A. Prime95 heat stress test peaked CPU heat at 60C after 5mins, it powered off after 30mins of testing in the middle of the test with no errors, Prime95 Heat test or the stress-testing with low RAM usage (small or in-place FFTs) do not report errors while testing for 10-60 mins. The power off does not seem like it is affected by Prime95 at all Makes me wonder if it's a CPU or Motherboard issue at all. Q. I had similar random/intermittent problems with my old board. It gave one of a few different symptoms: keyboard and/or mouse would die and/or the RAM wouldn't work and/or it would shut down. It was in bad shape. One problems was that my old PSU had literally burned the connector on it (browned around the pins), another was that a broken lead inside the layers of the PCB would work sometimes if it happened to be hot or if I bent the board—by jamming a hunk of wood behind it. I managed to keep the board alive for several years, but eventually nothing I did would make it work correctly anymore. – Synetech A. I will try that as the last resort, ok? ;) Q. Have you tried a different power cord, surge protector, outlet (on a different circuit). It's worth a shot just to ensure it's not subpar wiring or a week circuit (dips in power may cause shutdown if the PSU can't pull enough juice from the wall). – Kyle A. yes, I attached the PC to an entirely different outlet on a different circuit and the problem persists. After connecting it to a different outlet after starting the PC it gave me 3 long beeps and 1 short one, then the PC immediately proceeded to boot up normally. Q. Re-check your mainboard manual and all PSU connections to your mainboard to be sure that nothing is missing (e.g. 12V ATX 4-pin/6-pin connector). If you can provoke shutdowns with Prime95, then consider buying new hardware -- a stable system should run Prime95 for 24h without any errors. Prime95 mentions errors in the log when they occur and gives a summary after the stress test was stopped manually (e.g. "0 errors, 0 warnings", if all is fine) – speakr A. Re-checked, there are no more PSU connectors that I can physically connect, except the one ATX 4-pin (there are 2 that power the CPU) that I disconnected on purpose, I have reconnected it but the problem persists. Q. With one PC I had a short curcuit. The power button on the front plate had its cables soldered, but not isolated, and the contacts were very close to the metal case. A heavier touch was enough to cause a shutdown. The PC's vibration could be enough – ott-- A. yes, it seems to switch off with even the lightest touch, I switched on the PC, then pulled out the front panel power cable that connects to the motherboard so the power button does not work anymore, after 5 mins of working like that, with the power button completely disconnected, just sitting idle, the PC powered off again, I don't think it's the power button. Q. I wonder if you dare to operate components without the case, that is remove motherboard, power, disk ( just put the motherboard on a wooden desk). Don't bend the adapters when running like that. – ott-- A. yes, I do dare to do that, but only tomorrow, too tired/late right now.

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Impossible to do POSTs with appengine-jruby/RoR: Reflection is not allowed

- by Joel Cuevas

I'm trying to build a site with RoR on Google App Engine. I'm using the google-appengine gem (http://appengine-jruby.googlecode.com) and following the instructions in (http://gist.github.com/268192). The problem is that I can't submit ANY form! I've already tried this in two diferent clean Win 7 Pro envs and the result is the same. After install Ruby 1.8.6 (One-Click Installer): 1. gem update --system 2. gem install rails 3. gem install google-appengine 4. gem install rails_dm_datastore 5. gem install activerecord-nulldb-adapter 6. curl -O http://appengine-jruby.googlecode.com/hg/demos/rails2/rails2_appengine.rb 7. ruby rails2_appengine.rb (previously downloaded) 8. rails myproj 9. chmod myproj 10. ruby script/generate dd_model MyModel f1:string f2:float f3:float f4:float f5:integer f6:integer f7:integer -f 11. ruby script/generate scaffold MyModel f1:string f2:float f3:float f4:float f5:integer f6:integer f7:integer -f --skip-migration 12. dev_appserver.rb -p 3000 . At this point, I manually test the scaffold in (http://localhost:3000/my_models). The index is OK, then I create a new registry with the generated form, everything's fine, but when I try to create a second one, I get a "java.lang.RuntimeException: DummyDynamicScope should never be used for backref storage" in the console. As far as I read this is a won't-fix behavior in JRuby 1.4.1, but it's converted to a debug only warning in 1.5.0, so I proceed to install the pre release. 13. gem install appengine-jruby-jars --pre With this, that exception is solved and everything works great... until I move the project to the GAE server. 14. ruby appcfg.rb update . And now, in (http://myproj.appspot.com/my_models), again, the index is fine, also the new form, but in the moment that I submit it with valid data, I get a 500 error: "java.lang.IllegalAccessException: Reflection is not allowed on public int". As I said, this behavior is not present in the local SDK. In both cases, I'm completely unable to post anything. This is what I have right now in the GAE environment: Ruby version 1.8.7 (java) RubyGems disabled Rack version 1.1 Rails version 2.3.5 Action Pack version 2.3.5 Active Support version 2.3.5 DataMapper version 0.10.2 Environment production JRuby Runtime version 1.5.0.pre JRuby-Rack version 0.9.7 AppEngine SDK version Google App Engine/1.3.3 AppEngine APIs version 0.0.15 And this are my intalled gems: actionmailer (2.3.5) actionpack (2.3.5) activerecord (2.3.5) activerecord-nulldb-adapter (0.2.0) activeresource (2.3.5) activesupport (2.3.5) addressable (2.1.2) appengine-apis (0.0.15) appengine-jruby-jars (0.0.8.pre, 0.0.7) appengine-rack (0.0.8) appengine-sdk (1.3.3.1) appengine-tools (0.0.12) bundler08 (0.8.5) dm-appengine (0.0.8) dm-ar-finders (0.10.2) dm-core (0.10.2) dm-timestamps (0.10.2) dm-validations (0.10.2) extlib (0.9.14) fxri (0.3.7, 0.3.6) google-appengine (0.0.12) hpricot (0.8.2 x86-mswin32, 0.6 mswin32) jruby-rack (0.9.8, 0.9.7) log4r (1.1.7, 1.0.5) rack (1.1.0, 1.0.1) rails (2.3.5) rails_appengine (0.0.3) rails_dm_datastore (0.2.9) rake (0.8.7, 0.7.3) rubygems-update (1.3.7, 1.3.6) rubyzip (0.9.4) sources (0.0.1) win32-api (1.4.6 x86-mswin32-60, 1.0.4 mswin32) win32-clipboard (0.5.2, 0.4.3) win32-dir (0.3.6, 0.3.2) win32-eventlog (0.5.2, 0.4.6) win32-file (0.6.3, 0.5.4) win32-file-stat (1.3.4, 1.2.7) win32-process (0.6.2, 0.5.3) win32-sapi (0.1.5, 0.1.4) win32-sound (0.4.2, 0.4.1) windows-api (0.4.0, 0.2.0) windows-pr (1.0.9, 0.7.2) I'm unable to attach the full logs of the exceptions because of the character limits, but I can provide them under request. Here's an abstract of them: DummyDynamicScope (dev and prod envs): 14-may-2010 7:18:40 com.google.appengine.tools.development.ApiProxyLocalImpl log SEVERE: [1273821520195000] javax.servlet.ServletContext log: Application Error java.lang.RuntimeException: DummyDynamicScope should never be used for backref storage at org.jruby.runtime.scope.DummyDynamicScope.getBackRef(DummyDynamicScope.java:49) at org.jruby.RubyRegexp.updateBackRef(RubyRegexp.java:1404) at org.jruby.RubyRegexp.updateBackRef(RubyRegexp.java:1396) at org.jruby.RubyRegexp.search(RubyRegexp.java:1386) at org.jruby.RubyRegexp.op_match(RubyRegexp.java:1301) at org.jruby.RubyString.op_match(RubyString.java:1446) at org.jruby.RubyString$i_method_1_0$RUBYINVOKER$op_match.call(org/jruby/RubyString$i_method_1_0$RUBYINVOKER$op_match.gen) at org.jruby.internal.runtime.methods.JavaMethod$JavaMethodOneOrN.call(JavaMethod.java:721) at org.jruby.RubyClass.finvoke(RubyClass.java:472) at org.jruby.RubyObject.send(RubyObject.java:1442) at org.jruby.RubyObject$i_method_multi$RUBYINVOKER$send.call(org/jruby/RubyObject$i_method_multi$RUBYINVOKER$send.gen) at org.jruby.internal.runtime.methods.JavaMethod$JavaMethodZeroOrOneOrTwoOrNBlock.call(JavaMethod.java:276) at org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:330) at org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:189) at ruby.jit.ruby.C_3a_.Desarrollo.AppEngine.gorgory.WEB_minus_INF.lib.gems_dot_jar.bundler_gems.jruby.$1_dot_8.gems.dm_minus_validations_minus_0_dot_10_dot_2.lib.dm_minus_validations.validators.numeric_validator.validate_with_comparison at ruby.jit.ruby.C_3a_.Desarrollo.AppEngine.gorgory.WEB_minus_INF.lib.gems_dot_jar.bundler_gems.jruby.$1_dot_8.gems.dm_minus_validations_minus_0_dot_10_dot_2.lib.dm_minus_validations.validators.numeric_validator.validate_with_comparison at org.jruby.internal.runtime.methods.JittedMethod.call(JittedMethod.java:102) at org.jruby.internal.runtime.methods.DefaultMethod.call(DefaultMethod.java:144) at org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:280) at org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:69) at org.jruby.ast.FCallManyArgsNode.interpret(FCallManyArgsNode.java:60) at org.jruby.ast.NewlineNode.interpret(NewlineNode.java:104) at org.jruby.internal.runtime.methods.InterpretedMethod.call(InterpretedMethod.java:229) at org.jruby.internal.runtime.methods.DefaultMethod.call(DefaultMethod.java:193) at org.jruby.RubyClass.finvoke(RubyClass.java:491) at org.jruby.RubyObject.send(RubyObject.java:1448) at org.jruby.RubyObject$i_method_multi$RUBYINVOKER$send.call(org/jruby/RubyObject$i_method_multi$RUBYINVOKER$send.gen) at org.jruby.internal.runtime.methods.JavaMethod$JavaMethodZeroOrOneOrTwoOrThreeOrNBlock.call(JavaMethod.java:293) at org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:350) at org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:229) at ruby.jit.ruby.C_3a_.Desarrollo.AppEngine.gorgory.WEB_minus_INF.lib.gems_dot_jar.bundler_gems.jruby.$1_dot_8.gems.dm_minus_validations_minus_0_dot_10_dot_2.lib.dm_minus_validations.validators.numeric_validator.validate_with28985350_50 at ruby.jit.ruby.C_3a_.Desarrollo.AppEngine.gorgory.WEB_minus_INF.lib.gems_dot_jar.bundler_gems.jruby.$1_dot_8.gems.dm_minus_validations_minus_0_dot_10_dot_2.lib.dm_minus_validations.validators.numeric_validator.validate_with28985350_50 at org.jruby.internal.runtime.methods.JittedMethod.call(JittedMethod.java:221) at org.jruby.internal.runtime.methods.DefaultMethod.call(DefaultMethod.java:201) at org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:227) at org.jruby.ast.FCallThreeArgNode.interpret(FCallThreeArgNode.java:40) Reflection (only prod env): Java::JavaLang::SecurityException (java.lang.IllegalAccessException: Reflection is not allowed on public int java.lang.String$CaseInsensitiveComparator.compare(java.lang.String,java.lang.String)): com.google.appengine.runtime.Request.process-92563a0605f433ea(Request.java) java.lang.reflect.AccessibleObject.setAccessible(AccessibleObject.java:40) org.jruby.javasupport.JavaMethod.<init>(JavaMethod.java:176) org.jruby.javasupport.JavaMethod.create(JavaMethod.java:183) org.jruby.java.invokers.MethodInvoker.createCallable(MethodInvoker.java:23) org.jruby.java.invokers.RubyToJavaInvoker.<init>(RubyToJavaInvoker.java:63) org.jruby.java.invokers.MethodInvoker.<init>(MethodInvoker.java:13) org.jruby.java.invokers.InstanceMethodInvoker.<init>(InstanceMethodInvoker.java:15) org.jruby.javasupport.JavaClass$InstanceMethodInvokerInstaller.install(JavaClass.java:339) org.jruby.javasupport.JavaClass.installClassMethods(JavaClass.java:723) org.jruby.javasupport.JavaClass.setupProxy(JavaClass.java:586) org.jruby.javasupport.Java.createProxyClass(Java.java:506) org.jruby.javasupport.Java.getProxyClass(Java.java:445) org.jruby.javasupport.Java.getInstance(Java.java:354) org.jruby.javasupport.JavaUtil.convertJavaToUsableRubyObject(JavaUtil.java:143) org.jruby.javasupport.JavaClass$ConstantField.install(JavaClass.java:360) org.jruby.javasupport.JavaClass.installClassFields(JavaClass.java:711) org.jruby.javasupport.JavaClass.setupProxy(JavaClass.java:585) org.jruby.javasupport.Java.createProxyClass(Java.java:506) org.jruby.javasupport.Java.getProxyClass(Java.java:445) org.jruby.javasupport.Java.getProxyOrPackageUnderPackage(Java.java:885) org.jruby.javasupport.Java.get_proxy_or_package_under_package(Java.java:918) org.jruby.javasupport.JavaUtilities.get_proxy_or_package_under_package(JavaUtilities.java:54) org.jruby.javasupport.JavaUtilities$s_method_2_0$RUBYINVOKER$get_proxy_or_package_under_package.call(org/jruby/javasupport/JavaUtilities$s_method_2_0$RUBYINVOKER$get_proxy_or_package_under_package.gen:65535) org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:329) org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:188) org.jruby.ast.CallTwoArgNode.interpret(CallTwoArgNode.java:59) org.jruby.ast.NewlineNode.interpret(NewlineNode.java:104) org.jruby.ast.BlockNode.interpret(BlockNode.java:71) org.jruby.internal.runtime.methods.InterpretedMethod.call(InterpretedMethod.java:113) org.jruby.internal.runtime.methods.DefaultMethod.call(DefaultMethod.java:138) org.jruby.javasupport.util.RuntimeHelpers$MethodMissingMethod.call(RuntimeHelpers.java:389) org.jruby.internal.runtime.methods.DynamicMethod.call(DynamicMethod.java:182) What should I do now? Any hint would be wellcome. Thanks!

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scrolling lags in emacs 23.2 with GTK

- by mefiX

Hey there, I am using emacs 23.2 with the GTK toolkit. I built emacs from source using the following configure-params: ./configure --prefix=/usr --without-makeinfo --without-sound Which builds emacs with the following configuration: Where should the build process find the source code? /home/****/incoming/emacs-23.2 What operating system and machine description files should Emacs use? `s/gnu-linux.h' and `m/intel386.h' What compiler should emacs be built with? gcc -g -O2 -Wdeclaration-after-statement -Wno-pointer-sign Should Emacs use the GNU version of malloc? yes (Using Doug Lea's new malloc from the GNU C Library.) Should Emacs use a relocating allocator for buffers? yes Should Emacs use mmap(2) for buffer allocation? no What window system should Emacs use? x11 What toolkit should Emacs use? GTK Where do we find X Windows header files? Standard dirs Where do we find X Windows libraries? Standard dirs Does Emacs use -lXaw3d? no Does Emacs use -lXpm? yes Does Emacs use -ljpeg? yes Does Emacs use -ltiff? yes Does Emacs use a gif library? yes -lgif Does Emacs use -lpng? yes Does Emacs use -lrsvg-2? no Does Emacs use -lgpm? yes Does Emacs use -ldbus? yes Does Emacs use -lgconf? no Does Emacs use -lfreetype? yes Does Emacs use -lm17n-flt? no Does Emacs use -lotf? yes Does Emacs use -lxft? yes Does Emacs use toolkit scroll bars? yes When I'm scrolling within files of a common size (about 1000 lines) holding the up/down-keys, emacs almost hangs and produces about 50% CPU-load. I use the following plugins: ido linum tabbar auto-complete-config Starting emacs with -q fixes the problem, but then I don't have any plugins. I can't figure out, which part of my .emacs is responsible for this behaviour. Here's an excerpt of my .emacs-file: (require 'ido) (ido-mode 1) (require 'linum) (global-linum-mode 1) (require 'tabbar) (tabbar-mode 1) (tabbar-local-mode 0) (tabbar-mwheel-mode 0) (setq tabbar-buffer-groups-function (lambda () (list "All"))) (global-set-key [M-left] 'tabbar-backward) (global-set-key [M-right] 'tabbar-forward) ;; hide the toolbar (gtk etc.) (tool-bar-mode -1) ;; Mouse scrolling enhancements (setq mouse-wheel-progressive-speed nil) (setq mouse-wheel-scroll-amount '(5 ((shift) . 5) ((control) . nil))) ;; Smart-HOME (defun smart-beginning-of-line () "Forces the cursor to jump to the first none whitespace char of the current line when pressing HOME" (interactive) (let ((oldpos (point))) (back-to-indentation) (and (= oldpos (point)) (beginning-of-line)))) (put 'smart-beginning-of-line 'CUA 'move) (global-set-key [home] 'smart-beginning-of-line) (custom-set-variables ;; custom-set-variables was added by Custom. ;; If you edit it by hand, you could mess it up, so be careful. ;; Your init file should contain only one such instance. ;; If there is more than one, they won't work right. '(column-number-mode t) '(cua-mode t nil (cua-base)) '(custom-buffer-indent 4) '(delete-selection-mode nil) '(display-time-24hr-format t) '(display-time-day-and-date 1) '(display-time-mode t) '(global-font-lock-mode t nil (font-lock)) '(inhibit-startup-buffer-menu t) '(inhibit-startup-screen t) '(pc-select-meta-moves-sexps t) '(pc-select-selection-keys-only t) '(pc-selection-mode t nil (pc-select)) '(scroll-bar-mode (quote right)) '(show-paren-mode t) '(standard-indent 4) '(uniquify-buffer-name-style (quote forward) nil (uniquify))) (setq-default tab-width 4) (setq-default indent-tabs-mode t) (setq c-basic-offset 4) ;; Highlighting of the current line (global-hl-line-mode 1) (set-face-background 'hl-line "#E8F2FE") (defalias 'yes-or-no-p 'y-or-n-p) (display-time) (set-language-environment "Latin-1") ;; Change cursor color according to mode (setq djcb-read-only-color "gray") ;; valid values are t, nil, box, hollow, bar, (bar . WIDTH), hbar, ;; (hbar. HEIGHT); see the docs for set-cursor-type (setq djcb-read-only-cursor-type 'hbar) (setq djcb-overwrite-color "red") (setq djcb-overwrite-cursor-type 'box) (setq djcb-normal-color "black") (setq djcb-normal-cursor-type 'bar) (defun djcb-set-cursor-according-to-mode () "change cursor color and type according to some minor modes." (cond (buffer-read-only (set-cursor-color djcb-read-only-color) (setq cursor-type djcb-read-only-cursor-type)) (overwrite-mode (set-cursor-color djcb-overwrite-color) (setq cursor-type djcb-overwrite-cursor-type)) (t (set-cursor-color djcb-normal-color) (setq cursor-type djcb-normal-cursor-type)))) (add-hook 'post-command-hook 'djcb-set-cursor-according-to-mode) (define-key global-map '[C-right] 'forward-sexp) (define-key global-map '[C-left] 'backward-sexp) (define-key global-map '[s-left] 'windmove-left) (define-key global-map '[s-right] 'windmove-right) (define-key global-map '[s-up] 'windmove-up) (define-key global-map '[s-down] 'windmove-down) (define-key global-map '[S-down-mouse-1] 'mouse-stay-and-copy) (define-key global-map '[C-M-S-down-mouse-1] 'mouse-stay-and-swap) (define-key global-map '[S-mouse-2] 'mouse-yank-and-kill) (define-key global-map '[C-S-down-mouse-1] 'mouse-stay-and-kill) (define-key global-map "\C-a" 'mark-whole-buffer) (custom-set-faces ;; custom-set-faces was added by Custom. ;; If you edit it by hand, you could mess it up, so be careful. ;; Your init file should contain only one such instance. ;; If there is more than one, they won't work right. '(default ((t (:inherit nil :stipple nil :background "#f7f9fa" :foreground "#191919" :inverse-video nil :box nil :strike-through nil :overline nil :underline nil :slant normal :weight normal :height 98 :width normal :foundry "unknown" :family "DejaVu Sans Mono")))) '(font-lock-builtin-face ((((class color) (min-colors 88) (background light)) (:foreground "#642880" :weight bold)))) '(font-lock-comment-face ((((class color) (min-colors 88) (background light)) (:foreground "#3f7f5f")))) '(font-lock-constant-face ((((class color) (min-colors 88) (background light)) (:weight bold)))) '(font-lock-doc-face ((t (:inherit font-lock-string-face :foreground "#3f7f5f")))) '(font-lock-function-name-face ((((class color) (min-colors 88) (background light)) (:foreground "Black" :weight bold)))) '(font-lock-keyword-face ((((class color) (min-colors 88) (background light)) (:foreground "#7f0055" :weight bold)))) '(font-lock-preprocessor-face ((t (:inherit font-lock-builtin-face :foreground "#7f0055" :weight bold)))) '(font-lock-string-face ((((class color) (min-colors 88) (background light)) (:foreground "#0000c0")))) '(font-lock-type-face ((((class color) (min-colors 88) (background light)) (:foreground "#7f0055" :weight bold)))) '(font-lock-variable-name-face ((((class color) (min-colors 88) (background light)) (:foreground "Black")))) '(minibuffer-prompt ((t (:foreground "medium blue")))) '(mode-line ((t (:background "#222222" :foreground "White")))) '(tabbar-button ((t (:inherit tabbar-default :foreground "dark red")))) '(tabbar-button-highlight ((t (:inherit tabbar-default :background "white" :box (:line-width 2 :color "white"))))) '(tabbar-default ((t (:background "gray90" :foreground "gray50" :box (:line-width 3 :color "gray90") :height 100)))) '(tabbar-highlight ((t (:underline t)))) '(tabbar-selected ((t (:inherit tabbar-default :foreground "blue" :weight bold)))) '(tabbar-separator ((t nil))) '(tabbar-unselected ((t (:inherit tabbar-default))))) Any suggestions? Kind regards, mefiX

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XMLReader mysteriously fails when parsing document

- by Valrus

I have a php script that takes in some XML data and parses it, displaying various bits of information I pull out of it. This has been working fine for over 6 months, until recently it now fails mysteriously on a certain tag. The XML is generated from an outside source(a conferencing bridge), so I have no control over how it is built. I have put the xml through an online validator and it returned no errors. The code also works fine when I connect to another conferencing bridge and get the same output. I have been using XMLReader class so far and tried switching to SmipleXML, but it fails when I create the SimpleXML object using the data. Here is the snippet of where it fails while parsing: <CDR_SUMMARY> <FILE_VERSION>1001</FILE_VERSION> <NAME>Conference Title Hidden</NAME> <ID>10227</ID> <STATUS_STR>Auto_termination,_everybody_quit</STATUS_STR> <STATUS>4</STATUS> <GMT_OFFSET>-4</GMT_OFFSET> <START_TIME>2010-04-14T15:00:33</START_TIME> <DURATION> <HOUR>0</HOUR> <MINUTE>39</MINUTE> <SECOND>37</SECOND> </DURATION> <RESERVE_START_TIME>2010-04-14T15:00:33</RESERVE_START_TIME> <RESERVE_DURATION> <HOUR>12</HOUR> <MINUTE>0</MINUTE> <SECOND>0</SECOND> </RESERVE_DURATION> <MCU_FILE_NAME>c11</MCU_FILE_NAME> <FILE_SAVED>0</FILE_SAVED> <GMT_OFFSET_MINUTE>0</GMT_OFFSET_MINUTE> </CDR_SUMMARY> The <SOUND> opening tag is the last one read before failing. And this is my code: `public function processResponse($xml) { print "Processing List..."; $reader = new XMLReader($xml); try { $reader->setSchema("./schemas/response_trans_cdr_list.xsd"); } catch(Exception $e) { print "Exception:".$e->getMessage(); } //verify xml if($reader->xml($xml)) { while($reader->read()) { //$currentstring = $reader->readstring(); if($reader->name === "ACTION") { //into meat of resposnse while($reader->read()) { //print "Looping..."; //$currentstring = $reader->readInnerXML(); //print $currentstring; if($reader->nodeType == XMLReader::ELEMENT) { if($reader->name === "ID") { $this->conferenceIDs[$this->counter] = $reader->readString(); print "<BR>Conf ID found: ".$this->counter." ID: ".$this->conferenceIDs[$this->counter]; $this->counter += 1; } else if($reader->name === "START_TIME") { //conference start time. print "<BR>Start Time Found! "; $this->conferenceStarts[$this->counter-1] = $reader->readString(); } else if($reader->name === "NAME") { print "<BR> Name Found!"; $this->conferenceNames[$this->counter] = $reader->readString(); } else if($reader->name === "MCU_FILE_NAME") { print "<BR> MCU_FILE_NAME Found!"; //print $this->counter." File Name: ".$reader->readstring()."<BR>"; } else if($reader->name === "RESERVE_START_TIME") { print "<BR> RESERVE_START_TIME Found!"; } else if($reader->name === "FILE_VERSION") { print "<BR> FILE_VERSION Found!"; } else if($reader->name === "STATUS_STR") { print "<BR> STATUS_STR Found!"; } else if($reader->name === "STATUS") { print "<BR> STATUS Found!"; } else if($reader->name === "GMT_OFFSET") { print "<BR> GMT_OFFSET Found!"; } else if($reader->name === "DURATION") { print "<BR> DURATION Found!"; } else if($reader->name === "RESERVE_START_TIME") { print "<BR> RESERVE_START_TIME Found!"; } else if($reader->name === "RESERVE_DURATION") { print "<BR> RESERVE_DURATION Found!"; } else if($reader->name === "FILE_SAVED") { print "<BR> FILE_SAVED Found!"; } else if($reader->name === "GMT_OFFSET_MINUTE") { print "<BR> GMT_OFFSET_MINUTE Found!"; } else if($reader->name === "HOUR") { print "<BR> HOUR Found!"; } else if($reader->name === "MINUTE") { print "<BR> MINUTE Found!"; } else if($reader->name === "SECOND") { print "<BR> SECOND Found!"; } }else if($reader->nodeType == XMLReader::END_ELEMENT) { print "Close Element".$reader->name; } } print "End Action Loop"; } } } else { print "Error reading response: Bad XML returned"; } }` Anyone have any ideas what could be causing this failure? the code exits gracefully and I see the "End Action Loop" message in my output. It's like it just spontaneously exits the loop.

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A free standing ASP.NET Pager Web Control

- by Rick Strahl

Paging in ASP.NET has been relatively easy with stock controls supporting basic paging functionality. However, recently I built an MVC application and one of the things I ran into was that I HAD TO build manual paging support into a few of my pages. Dealing with list controls and rendering markup is easy enough, but doing paging is a little more involved. I ended up with a small but flexible component that can be dropped anywhere. As it turns out the task of creating a semi-generic Pager control for MVC was fairly easily. Now I’m back to working in Web Forms and thought to myself that the way I created the pager in MVC actually would also work in ASP.NET – in fact quite a bit easier since the whole thing can be conveniently wrapped up into an easily reusable control. A standalone pager would provider easier reuse in various pages and a more consistent pager display regardless of what kind of 'control’ the pager is associated with. Why a Pager Control? At first blush it might sound silly to create a new pager control – after all Web Forms has pretty decent paging support, doesn’t it? Well, sort of. Yes the GridView control has automatic paging built in and the ListView control has the related DataPager control. The built in ASP.NET paging has several issues though: Postback and JavaScript requirements If you look at paging links in ASP.NET they are always postback links with javascript:__doPostback() calls that go back to the server. While that works fine and actually has some benefit like the fact that paging saves changes to the page and post them back, it’s not very SEO friendly. Basically if you use javascript based navigation nosearch engine will follow the paging links which effectively cuts off list content on the first page. The DataPager control does support GET based links via the QueryStringParameter property, but the control is effectively tied to the ListView control (which is the only control that implements IPageableItemContainer). DataSource Controls required for Efficient Data Paging Retrieval The only way you can get paging to work efficiently where only the few records you display on the page are queried for and retrieved from the database you have to use a DataSource control - only the Linq and Entity DataSource controls support this natively. While you can retrieve this data yourself manually, there’s no way to just assign the page number and render the pager based on this custom subset. Other than that default paging requires a full resultset for ASP.NET to filter the data and display only a subset which can be very resource intensive and wasteful if you’re dealing with largish resultsets (although I’m a firm believer in returning actually usable sets :-}). If you use your own business layer that doesn’t fit an ObjectDataSource you’re SOL. That’s a real shame too because with LINQ based querying it’s real easy to retrieve a subset of data that is just the data you want to display but the native Pager functionality doesn’t support just setting properties to display just the subset AFAIK. DataPager is not Free Standing The DataPager control is the closest thing to a decent Pager implementation that ASP.NET has, but alas it’s not a free standing component – it works off a related control and the only one that it effectively supports from the stock ASP.NET controls is the ListView control. This means you can’t use the same data pager formatting for a grid and a list view or vice versa and you’re always tied to the control. Paging Events In order to handle paging you have to deal with paging events. The events fire at specific time instances in the page pipeline and because of this you often have to handle data binding in a way to work around the paging events or else end up double binding your data sources based on paging. Yuk. Styling The GridView pager is a royal pain to beat into submission for styled rendering. The DataPager control has many more options and template layout and it renders somewhat cleaner, but it too is not exactly easy to get a decent display for. Not a Generic Solution The problem with the ASP.NET controls too is that it’s not generic. GridView, DataGrid use their own internal paging, ListView can use a DataPager and if you want to manually create data layout – well you’re on your own. IOW, depending on what you use you likely have very different looking Paging experiences. So, I figured I’ve struggled with this once too many and finally sat down and built a Pager control. The Pager Control My goal was to create a totally free standing control that has no dependencies on other controls and certainly no requirements for using DataSource controls. The idea is that you should be able to use this pager control without any sort of data requirements at all – you should just be able to set properties and be able to display a pager. The Pager control I ended up with has the following features: Completely free standing Pager control – no control or data dependencies Complete manual control – Pager can render without any data dependency Easy to use: Only need to set PageSize, ActivePage and TotalItems Supports optional filtering of IQueryable for efficient queries and Pager rendering Supports optional full set filtering of IEnumerable<T> and DataTable Page links are plain HTTP GET href Links Control automatically picks up Page links on the URL and assigns them (automatic page detection no page index changing events to hookup) Full CSS Styling support On the downside there’s no templating support for the control so the layout of the pager is relatively fixed. All elements however are stylable and there are options to control the text, and layout options such as whether to display first and last pages and the previous/next buttons and so on. To give you an idea what the pager looks like, here are two differently styled examples (all via CSS): The markup for these two pagers looks like this: <ww:Pager runat="server" id="ItemPager" PageSize="5" PageLinkCssClass="gridpagerbutton" SelectedPageCssClass="gridpagerbutton-selected" PagesTextCssClass="gridpagertext" CssClass="gridpager" RenderContainerDiv="true" ContainerDivCssClass="gridpagercontainer" MaxPagesToDisplay="6" PagesText="Item Pages:" NextText="next" PreviousText="previous" /> <ww:Pager runat="server" id="ItemPager2" PageSize="5" RenderContainerDiv="true" MaxPagesToDisplay="6" /> The latter example uses default style settings so it there’s not much to set. The first example on the other hand explicitly assigns custom styles and overrides a few of the formatting options. Styling The styling is based on a number of CSS classes of which the the main pager, pagerbutton and pagerbutton-selected classes are the important ones. Other styles like pagerbutton-next/prev/first/last are based on the pagerbutton style. The default styling shown for the red outlined pager looks like this: .pagercontainer { margin: 20px 0; background: whitesmoke; padding: 5px; } .pager { float: right; font-size: 10pt; text-align: left; } .pagerbutton,.pagerbutton-selected,.pagertext { display: block; float: left; text-align: center; border: solid 2px maroon; min-width: 18px; margin-left: 3px; text-decoration: none; padding: 4px; } .pagerbutton-selected { font-size: 130%; font-weight: bold; color: maroon; border-width: 0px; background: khaki; } .pagerbutton-first { margin-right: 12px; } .pagerbutton-last,.pagerbutton-prev { margin-left: 12px; } .pagertext { border: none; margin-left: 30px; font-weight: bold; } .pagerbutton a { text-decoration: none; } .pagerbutton:hover { background-color: maroon; color: cornsilk; } .pagerbutton-prev { background-image: url(images/prev.png); background-position: 2px center; background-repeat: no-repeat; width: 35px; padding-left: 20px; } .pagerbutton-next { background-image: url(images/next.png); background-position: 40px center; background-repeat: no-repeat; width: 35px; padding-right: 20px; margin-right: 0px; } Yup that’s a lot of styling settings although not all of them are required. The key ones are pagerbutton, pager and pager selection. The others (which are implicitly created by the control based on the pagerbutton style) are for custom markup of the ‘special’ buttons. In my apps I tend to have two kinds of pages: Those that are associated with typical ‘grid’ displays that display purely tabular data and those that have a more looser list like layout. The two pagers shown above represent these two views and the pager and gridpager styles in my standard style sheet reflect these two styles. Configuring the Pager with Code Finally lets look at what it takes to hook up the pager. As mentioned in the highlights the Pager control is completely independent of other controls so if you just want to display a pager on its own it’s as simple as dropping the control and assigning the PageSize, ActivePage and either TotalPages or TotalItems. So for this markup: <ww:Pager runat="server" id="ItemPagerManual" PageSize="5" MaxPagesToDisplay="6" /> I can use code as simple as: ItemPagerManual.PageSize = 3; ItemPagerManual.ActivePage = 4;ItemPagerManual.TotalItems = 20; Note that ActivePage is not required - it will automatically use any Page=x query string value and assign it, although you can override it as I did above. TotalItems can be any value that you retrieve from a result set or manually assign as I did above. A more realistic scenario based on a LINQ to SQL IQueryable result is even easier. In this example, I have a UserControl that contains a ListView control that renders IQueryable data. I use a User Control here because there are different views the user can choose from with each view being a different user control. This incidentally also highlights one of the nice features of the pager: Because the pager is independent of the control I can put the pager on the host page instead of into each of the user controls. IOW, there’s only one Pager control, but there are potentially many user controls/listviews that hold the actual display data. The following code demonstrates how to use the Pager with an IQueryable that loads only the records it displays: protected voidPage_Load(objectsender, EventArgs e) { Category = Request.Params["Category"] ?? string.Empty; IQueryable<wws_Item> ItemList = ItemRepository.GetItemsByCategory(Category); // Update the page and filter the list down ItemList = ItemPager.FilterIQueryable<wws_Item>(ItemList); // Render user control with a list view Control ulItemList = LoadControl("~/usercontrols/" + App.Configuration.ItemListType + ".ascx"); ((IInventoryItemListControl)ulItemList).InventoryItemList = ItemList; phItemList.Controls.Add(ulItemList); // placeholder } The code uses a business object to retrieve Items by category as an IQueryable which means that the result is only an expression tree that hasn’t execute SQL yet and can be further filtered. I then pass this IQueryable to the FilterIQueryable() helper method of the control which does two main things: Filters the IQueryable to retrieve only the data displayed on the active page Sets the Totaltems property and calculates TotalPages on the Pager and that’s it! When the Pager renders it uses those values, plus the PageSize and ActivePage properties to render the Pager. In addition to IQueryable there are also filter methods for IEnumerable<T> and DataTable, but these versions just filter the data by removing rows/items from the entire already retrieved data. Output Generated and Paging Links The output generated creates pager links as plain href links. Here’s what the output looks like: <div id="ItemPager" class="pagercontainer"> <div class="pager"> <span class="pagertext">Pages: </span><a href="http://localhost/WestWindWebStore/itemlist.aspx?Page=1" class="pagerbutton" />1</a> <a href="http://localhost/WestWindWebStore/itemlist.aspx?Page=2" class="pagerbutton" />2</a> <a href="http://localhost/WestWindWebStore/itemlist.aspx?Page=3" class="pagerbutton" />3</a> <span class="pagerbutton-selected">4</span> <a href="http://localhost/WestWindWebStore/itemlist.aspx?Page=5" class="pagerbutton" />5</a> <a href="http://localhost/WestWindWebStore/itemlist.aspx?Page=6" class="pagerbutton" />6</a> <a href="http://localhost/WestWindWebStore/itemlist.aspx?Page=20" class="pagerbutton pagerbutton-last" />20</a> <a href="http://localhost/WestWindWebStore/itemlist.aspx?Page=3" class="pagerbutton pagerbutton-prev" />Prev</a> <a href="http://localhost/WestWindWebStore/itemlist.aspx?Page=5" class="pagerbutton pagerbutton-next" />Next</a></div> <br clear="all" /> </div> </div> The links point back to the current page and simply append a Page= page link into the page. When the page gets reloaded with the new page number the pager automatically detects the page number and automatically assigns the ActivePage property which results in the appropriate page to be displayed. The code shown in the previous section is all that’s needed to handle paging. Note that HTTP GET based paging is different than the Postback paging ASP.NET uses by default. Postback paging preserves modified page content when clicking on pager buttons, but this control will simply load a new page – no page preservation at this time. The advantage of not using Postback paging is that the URLs generated are plain HTML links that a search engine can follow where __doPostback() links are not. Pager with a Grid The pager also works in combination with grid controls so it’s easy to bypass the grid control’s paging features if desired. In the following example I use a gridView control and binds it to a DataTable result which is also filterable by the Pager control. The very basic plain vanilla ASP.NET grid markup looks like this: <div style="width: 600px; margin: 0 auto;padding: 20px; "> <asp:DataGrid runat="server" AutoGenerateColumns="True" ID="gdItems" CssClass="blackborder" style="width: 600px;"> <AlternatingItemStyle CssClass="gridalternate" /> <HeaderStyle CssClass="gridheader" /> </asp:DataGrid> <ww:Pager runat="server" ID="Pager" CssClass="gridpager" ContainerDivCssClass="gridpagercontainer" PageLinkCssClass="gridpagerbutton" SelectedPageCssClass="gridpagerbutton-selected" PageSize="8" RenderContainerDiv="true" MaxPagesToDisplay="6" /> </div> and looks like this when rendered: using custom set of CSS styles. The code behind for this code is also very simple: protected void Page_Load(object sender, EventArgs e) { string category = Request.Params["category"] ?? ""; busItem itemRep = WebStoreFactory.GetItem(); var items = itemRep.GetItemsByCategory(category) .Select(itm => new {Sku = itm.Sku, Description = itm.Description}); // run query into a DataTable for demonstration DataTable dt = itemRep.Converter.ToDataTable(items,"TItems"); // Remove all items not on the current page dt = Pager.FilterDataTable(dt,0); // bind and display gdItems.DataSource = dt; gdItems.DataBind(); } A little contrived I suppose since the list could already be bound from the list of elements, but this is to demonstrate that you can also bind against a DataTable if your business layer returns those. Unfortunately there’s no way to filter a DataReader as it’s a one way forward only reader and the reader is required by the DataSource to perform the bindings. However, you can still use a DataReader as long as your business logic filters the data prior to rendering and provides a total item count (most likely as a second query). Control Creation The control itself is a pretty brute force ASP.NET control. Nothing clever about this other than some basic rendering logic and some simple calculations and update routines to determine which buttons need to be shown. You can take a look at the full code from the West Wind Web Toolkit’s Repository (note there are a few dependencies). To give you an idea how the control works here is the Render() method: /// <summary> /// overridden to handle custom pager rendering for runtime and design time /// </summary> /// <param name="writer"></param> protected override void Render(HtmlTextWriter writer) { base.Render(writer); if (TotalPages == 0 && TotalItems > 0) TotalPages = CalculateTotalPagesFromTotalItems(); if (DesignMode) TotalPages = 10; // don't render pager if there's only one page if (TotalPages < 2) return; if (RenderContainerDiv) { if (!string.IsNullOrEmpty(ContainerDivCssClass)) writer.AddAttribute("class", ContainerDivCssClass); writer.RenderBeginTag("div"); } // main pager wrapper writer.WriteBeginTag("div"); writer.AddAttribute("id", this.ClientID); if (!string.IsNullOrEmpty(CssClass)) writer.WriteAttribute("class", this.CssClass); writer.Write(HtmlTextWriter.TagRightChar + "\r\n"); // Pages Text writer.WriteBeginTag("span"); if (!string.IsNullOrEmpty(PagesTextCssClass)) writer.WriteAttribute("class", PagesTextCssClass); writer.Write(HtmlTextWriter.TagRightChar); writer.Write(this.PagesText); writer.WriteEndTag("span"); // if the base url is empty use the current URL FixupBaseUrl(); // set _startPage and _endPage ConfigurePagesToRender(); // write out first page link if (ShowFirstAndLastPageLinks && _startPage != 1) { writer.WriteBeginTag("a"); string pageUrl = StringUtils.SetUrlEncodedKey(BaseUrl, QueryStringPageField, (1).ToString()); writer.WriteAttribute("href", pageUrl); if (!string.IsNullOrEmpty(PageLinkCssClass)) writer.WriteAttribute("class", PageLinkCssClass + " " + PageLinkCssClass + "-first"); writer.Write(HtmlTextWriter.SelfClosingTagEnd); writer.Write("1"); writer.WriteEndTag("a"); writer.Write(" "); } // write out all the page links for (int i = _startPage; i < _endPage + 1; i++) { if (i == ActivePage) { writer.WriteBeginTag("span"); if (!string.IsNullOrEmpty(SelectedPageCssClass)) writer.WriteAttribute("class", SelectedPageCssClass); writer.Write(HtmlTextWriter.TagRightChar); writer.Write(i.ToString()); writer.WriteEndTag("span"); } else { writer.WriteBeginTag("a"); string pageUrl = StringUtils.SetUrlEncodedKey(BaseUrl, QueryStringPageField, i.ToString()).TrimEnd('&'); writer.WriteAttribute("href", pageUrl); if (!string.IsNullOrEmpty(PageLinkCssClass)) writer.WriteAttribute("class", PageLinkCssClass); writer.Write(HtmlTextWriter.SelfClosingTagEnd); writer.Write(i.ToString()); writer.WriteEndTag("a"); } writer.Write("\r\n"); } // write out last page link if (ShowFirstAndLastPageLinks && _endPage < TotalPages) { writer.WriteBeginTag("a"); string pageUrl = StringUtils.SetUrlEncodedKey(BaseUrl, QueryStringPageField, TotalPages.ToString()); writer.WriteAttribute("href", pageUrl); if (!string.IsNullOrEmpty(PageLinkCssClass)) writer.WriteAttribute("class", PageLinkCssClass + " " + PageLinkCssClass + "-last"); writer.Write(HtmlTextWriter.SelfClosingTagEnd); writer.Write(TotalPages.ToString()); writer.WriteEndTag("a"); } // Previous link if (ShowPreviousNextLinks && !string.IsNullOrEmpty(PreviousText) && ActivePage > 1) { writer.Write(" "); writer.WriteBeginTag("a"); string pageUrl = StringUtils.SetUrlEncodedKey(BaseUrl, QueryStringPageField, (ActivePage - 1).ToString()); writer.WriteAttribute("href", pageUrl); if (!string.IsNullOrEmpty(PageLinkCssClass)) writer.WriteAttribute("class", PageLinkCssClass + " " + PageLinkCssClass + "-prev"); writer.Write(HtmlTextWriter.SelfClosingTagEnd); writer.Write(PreviousText); writer.WriteEndTag("a"); } // Next link if (ShowPreviousNextLinks && !string.IsNullOrEmpty(NextText) && ActivePage < TotalPages) { writer.Write(" "); writer.WriteBeginTag("a"); string pageUrl = StringUtils.SetUrlEncodedKey(BaseUrl, QueryStringPageField, (ActivePage + 1).ToString()); writer.WriteAttribute("href", pageUrl); if (!string.IsNullOrEmpty(PageLinkCssClass)) writer.WriteAttribute("class", PageLinkCssClass + " " + PageLinkCssClass + "-next"); writer.Write(HtmlTextWriter.SelfClosingTagEnd); writer.Write(NextText); writer.WriteEndTag("a"); } writer.WriteEndTag("div"); if (RenderContainerDiv) { if (RenderContainerDivBreak) writer.Write("<br clear=\"all\" />\r\n"); writer.WriteEndTag("div"); } } As I said pretty much brute force rendering based on the control’s property settings of which there are quite a few: You can also see the pager in the designer above. unfortunately the VS designer (both 2010 and 2008) fails to render the float: left CSS styles properly and starts wrapping after margins are applied in the special buttons. Not a big deal since VS does at least respect the spacing (the floated elements overlay). Then again I’m not using the designer anyway :-}. Filtering Data What makes the Pager easy to use is the filter methods built into the control. While this functionality is clearly not the most politically correct design choice as it violates separation of concerns, it’s very useful for typical pager operation. While I actually have filter methods that do something similar in my business layer, having it exposed on the control makes the control a lot more useful for typical databinding scenarios. Of course these methods are optional – if you have a business layer that can provide filtered page queries for you can use that instead and assign the TotalItems property manually. There are three filter method types available for IQueryable, IEnumerable and for DataTable which tend to be the most common use cases in my apps old and new. The IQueryable version is pretty simple as it can simply rely on on .Skip() and .Take() with LINQ: /// <summary> /// <summary> /// Queries the database for the ActivePage applied manually /// or from the Request["page"] variable. This routine /// figures out and sets TotalPages, ActivePage and /// returns a filtered subset IQueryable that contains /// only the items from the ActivePage. /// </summary> /// <param name="query"></param> /// <param name="activePage"> /// The page you want to display. Sets the ActivePage property when passed. /// Pass 0 or smaller to use ActivePage setting. /// </param> /// <returns></returns> public IQueryable<T> FilterIQueryable<T>(IQueryable<T> query, int activePage) where T : class, new() { ActivePage = activePage < 1 ? ActivePage : activePage; if (ActivePage < 1) ActivePage = 1; TotalItems = query.Count(); if (TotalItems <= PageSize) { ActivePage = 1; TotalPages = 1; return query; } int skip = ActivePage - 1; if (skip > 0) query = query.Skip(skip * PageSize); _TotalPages = CalculateTotalPagesFromTotalItems(); return query.Take(PageSize); } The IEnumerable<T> version simply converts the IEnumerable to an IQuerable and calls back into this method for filtering. The DataTable version requires a little more work to manually parse and filter records (I didn’t want to add the Linq DataSetExtensions assembly just for this): /// <summary> /// Filters a data table for an ActivePage. /// /// Note: Modifies the data set permanently by remove DataRows /// </summary> /// <param name="dt">Full result DataTable</param> /// <param name="activePage">Page to display. 0 to use ActivePage property </param> /// <returns></returns> public DataTable FilterDataTable(DataTable dt, int activePage) { ActivePage = activePage < 1 ? ActivePage : activePage; if (ActivePage < 1) ActivePage = 1; TotalItems = dt.Rows.Count; if (TotalItems <= PageSize) { ActivePage = 1; TotalPages = 1; return dt; } int skip = ActivePage - 1; if (skip > 0) { for (int i = 0; i < skip * PageSize; i++ ) dt.Rows.RemoveAt(0); } while(dt.Rows.Count > PageSize) dt.Rows.RemoveAt(PageSize); return dt; } Using the Pager Control The pager as it is is a first cut I built a couple of weeks ago and since then have been tweaking a little as part of an internal project I’m working on. I’ve replaced a bunch of pagers on various older pages with this pager without any issues and have what now feels like a more consistent user interface where paging looks and feels the same across different controls. As a bonus I’m only loading the data from the database that I need to display a single page. With the preset class tags applied too adding a pager is now as easy as dropping the control and adding the style sheet for styling to be consistent – no fuss, no muss. Schweet. Hopefully some of you may find this as useful as I have or at least as a baseline to build ontop of… Resources The Pager is part of the West Wind Web & Ajax Toolkit Pager.cs Source Code (some toolkit dependencies) Westwind.css base stylesheet with .pager and .gridpager styles Pager Example Page © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET

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The Incremental Architect’s Napkin - #5 - Design functions for extensibility and readability

- by Ralf Westphal

Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/08/24/the-incremental-architectrsquos-napkin---5---design-functions-for.aspx The functionality of programs is entered via Entry Points. So what we´re talking about when designing software is a bunch of functions handling the requests represented by and flowing in through those Entry Points. Designing software thus consists of at least three phases: Analyzing the requirements to find the Entry Points and their signatures Designing the functionality to be executed when those Entry Points get triggered Implementing the functionality according to the design aka coding I presume, you´re familiar with phase 1 in some way. And I guess you´re proficient in implementing functionality in some programming language. But in my experience developers in general are not experienced in going through an explicit phase 2. “Designing functionality? What´s that supposed to mean?” you might already have thought. Here´s my definition: To design functionality (or functional design for short) means thinking about… well, functions. You find a solution for what´s supposed to happen when an Entry Point gets triggered in terms of functions. A conceptual solution that is, because those functions only exist in your head (or on paper) during this phase. But you may have guess that, because it´s “design” not “coding”. And here is, what functional design is not: It´s not about logic. Logic is expressions (e.g. +, -, && etc.) and control statements (e.g. if, switch, for, while etc.). Also I consider calling external APIs as logic. It´s equally basic. It´s what code needs to do in order to deliver some functionality or quality. Logic is what´s doing that needs to be done by software. Transformations are either done through expressions or API-calls. And then there is alternative control flow depending on the result of some expression. Basically it´s just jumps in Assembler, sometimes to go forward (if, switch), sometimes to go backward (for, while, do). But calling your own function is not logic. It´s not necessary to produce any outcome. Functionality is not enhanced by adding functions (subroutine calls) to your code. Nor is quality increased by adding functions. No performance gain, no higher scalability etc. through functions. Functions are not relevant to functionality. Strange, isn´t it. What they are important for is security of investment. By introducing functions into our code we can become more productive (re-use) and can increase evolvability (higher unterstandability, easier to keep code consistent). That´s no small feat, however. Evolvable code can hardly be overestimated. That´s why to me functional design is so important. It´s at the core of software development. To sum this up: Functional design is on a level of abstraction above (!) logical design or algorithmic design. Functional design is only done until you get to a point where each function is so simple you are very confident you can easily code it. Functional design an logical design (which mostly is coding, but can also be done using pseudo code or flow charts) are complementary. Software needs both. If you start coding right away you end up in a tangled mess very quickly. Then you need back out through refactoring. Functional design on the other hand is bloodless without actual code. It´s just a theory with no experiments to prove it. But how to do functional design? An example of functional design Let´s assume a program to de-duplicate strings. The user enters a number of strings separated by commas, e.g. a, b, a, c, d, b, e, c, a. And the program is supposed to clear this list of all doubles, e.g. a, b, c, d, e. There is only one Entry Point to this program: the user triggers the de-duplication by starting the program with the string list on the command line C:\>deduplicate "a, b, a, c, d, b, e, c, a" a, b, c, d, e …or by clicking on a GUI button. This leads to the Entry Point function to get called. It´s the program´s main function in case of the batch version or a button click event handler in the GUI version. That´s the physical Entry Point so to speak. It´s inevitable. What then happens is a three step process: Transform the input data from the user into a request. Call the request handler. Transform the output of the request handler into a tangible result for the user. Or to phrase it a bit more generally: Accept input. Transform input into output. Present output. This does not mean any of these steps requires a lot of effort. Maybe it´s just one line of code to accomplish it. Nevertheless it´s a distinct step in doing the processing behind an Entry Point. Call it an aspect or a responsibility - and you will realize it most likely deserves a function of its own to satisfy the Single Responsibility Principle (SRP). Interestingly the above list of steps is already functional design. There is no logic, but nevertheless the solution is described - albeit on a higher level of abstraction than you might have done yourself. But it´s still on a meta-level. The application to the domain at hand is easy, though: Accept string list from command line De-duplicate Present de-duplicated strings on standard output And this concrete list of processing steps can easily be transformed into code:static void Main(string[] args) { var input = Accept_string_list(args); var output = Deduplicate(input); Present_deduplicated_string_list(output); } Instead of a big problem there are three much smaller problems now. If you think each of those is trivial to implement, then go for it. You can stop the functional design at this point. But maybe, just maybe, you´re not so sure how to go about with the de-duplication for example. Then just implement what´s easy right now, e.g.private static string Accept_string_list(string[] args) { return args[0]; } private static void Present_deduplicated_string_list( string[] output) { var line = string.Join(", ", output); Console.WriteLine(line); } Accept_string_list() contains logic in the form of an API-call. Present_deduplicated_string_list() contains logic in the form of an expression and an API-call. And then repeat the functional design for the remaining processing step. What´s left is the domain logic: de-duplicating a list of strings. How should that be done? Without any logic at our disposal during functional design you´re left with just functions. So which functions could make up the de-duplication? Here´s a suggestion: De-duplicate Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Processing step 2 obviously was the core of the solution. That´s where real creativity was needed. That´s the core of the domain. But now after this refinement the implementation of each step is easy again:private static string[] Parse_string_list(string input) { return input.Split(',') .Select(s => s.Trim()) .ToArray(); } private static Dictionary<string,object> Compile_unique_strings(string[] strings) { return strings.Aggregate( new Dictionary<string, object>(), (agg, s) => { agg[s] = null; return agg; }); } private static string[] Serialize_unique_strings( Dictionary<string,object> dict) { return dict.Keys.ToArray(); } With these three additional functions Main() now looks like this:static void Main(string[] args) { var input = Accept_string_list(args); var strings = Parse_string_list(input); var dict = Compile_unique_strings(strings); var output = Serialize_unique_strings(dict); Present_deduplicated_string_list(output); } I think that´s very understandable code: just read it from top to bottom and you know how the solution to the problem works. It´s a mirror image of the initial design: Accept string list from command line Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Present de-duplicated strings on standard output You can even re-generate the design by just looking at the code. Code and functional design thus are always in sync - if you follow some simple rules. But about that later. And as a bonus: all the functions making up the process are small - which means easy to understand, too. So much for an initial concrete example. Now it´s time for some theory. Because there is method to this madness ;-) The above has only scratched the surface. Introducing Flow Design Functional design starts with a given function, the Entry Point. Its goal is to describe the behavior of the program when the Entry Point is triggered using a process, not an algorithm. An algorithm consists of logic, a process on the other hand consists just of steps or stages. Each processing step transforms input into output or a side effect. Also it might access resources, e.g. a printer, a database, or just memory. Processing steps thus can rely on state of some sort. This is different from Functional Programming, where functions are supposed to not be stateful and not cause side effects.[1] In its simplest form a process can be written as a bullet point list of steps, e.g. Get data from user Output result to user Transform data Parse data Map result for output Such a compilation of steps - possibly on different levels of abstraction - often is the first artifact of functional design. It can be generated by a team in an initial design brainstorming. Next comes ordering the steps. What should happen first, what next etc.? Get data from user Parse data Transform data Map result for output Output result to user That´s great for a start into functional design. It´s better than starting to code right away on a given function using TDD. Please get me right: TDD is a valuable practice. But it can be unnecessarily hard if the scope of a functionn is too large. But how do you know beforehand without investing some thinking? And how to do this thinking in a systematic fashion? My recommendation: For any given function you´re supposed to implement first do a functional design. Then, once you´re confident you know the processing steps - which are pretty small - refine and code them using TDD. You´ll see that´s much, much easier - and leads to cleaner code right away. For more information on this approach I call “Informed TDD” read my book of the same title. Thinking before coding is smart. And writing down the solution as a bunch of functions possibly is the simplest thing you can do, I´d say. It´s more according to the KISS (Keep It Simple, Stupid) principle than returning constants or other trivial stuff TDD development often is started with. So far so good. A simple ordered list of processing steps will do to start with functional design. As shown in the above example such steps can easily be translated into functions. Moving from design to coding thus is simple. However, such a list does not scale. Processing is not always that simple to be captured in a list. And then the list is just text. Again. Like code. That means the design is lacking visuality. Textual representations need more parsing by your brain than visual representations. Plus they are limited in their “dimensionality”: text just has one dimension, it´s sequential. Alternatives and parallelism are hard to encode in text. In addition the functional design using numbered lists lacks data. It´s not visible what´s the input, output, and state of the processing steps. That´s why functional design should be done using a lightweight visual notation. No tool is necessary to draw such designs. Use pen and paper; a flipchart, a whiteboard, or even a napkin is sufficient. Visualizing processes The building block of the functional design notation is a functional unit. I mostly draw it like this: Something is done, it´s clear what goes in, it´s clear what comes out, and it´s clear what the processing step requires in terms of state or hardware. Whenever input flows into a functional unit it gets processed and output is produced and/or a side effect occurs. Flowing data is the driver of something happening. That´s why I call this approach to functional design Flow Design. It´s about data flow instead of control flow. Control flow like in algorithms is of no concern to functional design. Thinking about control flow simply is too low level. Once you start with control flow you easily get bogged down by tons of details. That´s what you want to avoid during design. Design is supposed to be quick, broad brush, abstract. It should give overview. But what about all the details? As Robert C. Martin rightly said: “Programming is abot detail”. Detail is a matter of code. Once you start coding the processing steps you designed you can worry about all the detail you want. Functional design does not eliminate all the nitty gritty. It just postpones tackling them. To me that´s also an example of the SRP. Function design has the responsibility to come up with a solution to a problem posed by a single function (Entry Point). And later coding has the responsibility to implement the solution down to the last detail (i.e. statement, API-call). TDD unfortunately mixes both responsibilities. It´s just coding - and thereby trying to find detailed implementations (green phase) plus getting the design right (refactoring). To me that´s one reason why TDD has failed to deliver on its promise for many developers. Using functional units as building blocks of functional design processes can be depicted very easily. Here´s the initial process for the example problem: For each processing step draw a functional unit and label it. Choose a verb or an “action phrase” as a label, not a noun. Functional design is about activities, not state or structure. Then make the output of an upstream step the input of a downstream step. Finally think about the data that should flow between the functional units. Write the data above the arrows connecting the functional units in the direction of the data flow. Enclose the data description in brackets. That way you can clearly see if all flows have already been specified. Empty brackets mean “no data is flowing”, but nevertheless a signal is sent. A name like “list” or “strings” in brackets describes the data content. Use lower case labels for that purpose. A name starting with an upper case letter like “String” or “Customer” on the other hand signifies a data type. If you like, you also can combine descriptions with data types by separating them with a colon, e.g. (list:string) or (strings:string[]). But these are just suggestions from my practice with Flow Design. You can do it differently, if you like. Just be sure to be consistent. Flows wired-up in this manner I call one-dimensional (1D). Each functional unit just has one input and/or one output. A functional unit without an output is possible. It´s like a black hole sucking up input without producing any output. Instead it produces side effects. A functional unit without an input, though, does make much sense. When should it start to work? What´s the trigger? That´s why in the above process even the first processing step has an input. If you like, view such 1D-flows as pipelines. Data is flowing through them from left to right. But as you can see, it´s not always the same data. It get´s transformed along its passage: (args) becomes a (list) which is turned into (strings). The Principle of Mutual Oblivion A very characteristic trait of flows put together from function units is: no functional units knows another one. They are all completely independent of each other. Functional units don´t know where their input is coming from (or even when it´s gonna arrive). They just specify a range of values they can process. And they promise a certain behavior upon input arriving. Also they don´t know where their output is going. They just produce it in their own time independent of other functional units. That means at least conceptually all functional units work in parallel. Functional units don´t know their “deployment context”. They now nothing about the overall flow they are place in. They are just consuming input from some upstream, and producing output for some downstream. That makes functional units very easy to test. At least as long as they don´t depend on state or resources. I call this the Principle of Mutual Oblivion (PoMO). Functional units are oblivious of others as well as an overall context/purpose. They are just parts of a whole focused on a single responsibility. How the whole is built, how a larger goal is achieved, is of no concern to the single functional units. By building software in such a manner, functional design interestingly follows nature. Nature´s building blocks for organisms also follow the PoMO. The cells forming your body do not know each other. Take a nerve cell “controlling” a muscle cell for example:[2] The nerve cell does not know anything about muscle cells, let alone the specific muscel cell it is “attached to”. Likewise the muscle cell does not know anything about nerve cells, let a lone a specific nerve cell “attached to” it. Saying “the nerve cell is controlling the muscle cell” thus only makes sense when viewing both from the outside. “Control” is a concept of the whole, not of its parts. Control is created by wiring-up parts in a certain way. Both cells are mutually oblivious. Both just follow a contract. One produces Acetylcholine (ACh) as output, the other consumes ACh as input. Where the ACh is going, where it´s coming from neither cell cares about. Million years of evolution have led to this kind of division of labor. And million years of evolution have produced organism designs (DNA) which lead to the production of these different cell types (and many others) and also to their co-location. The result: the overall behavior of an organism. How and why this happened in nature is a mystery. For our software, though, it´s clear: functional and quality requirements needs to be fulfilled. So we as developers have to become “intelligent designers” of “software cells” which we put together to form a “software organism” which responds in satisfying ways to triggers from it´s environment. My bet is: If nature gets complex organisms working by following the PoMO, who are we to not apply this recipe for success to our much simpler “machines”? So my rule is: Wherever there is functionality to be delivered, because there is a clear Entry Point into software, design the functionality like nature would do it. Build it from mutually oblivious functional units. That´s what Flow Design is about. In that way it´s even universal, I´d say. Its notation can also be applied to biology: Never mind labeling the functional units with nouns. That´s ok in Flow Design. You´ll do that occassionally for functional units on a higher level of abstraction or when their purpose is close to hardware. Getting a cockroach to roam your bedroom takes 1,000,000 nerve cells (neurons). Getting the de-duplication program to do its job just takes 5 “software cells” (functional units). Both, though, follow the same basic principle. Translating functional units into code Moving from functional design to code is no rocket science. In fact it´s straightforward. There are two simple rules: Translate an input port to a function. Translate an output port either to a return statement in that function or to a function pointer visible to that function. The simplest translation of a functional unit is a function. That´s what you saw in the above example. Functions are mutually oblivious. That why Functional Programming likes them so much. It makes them composable. Which is the reason, nature works according to the PoMO. Let´s be clear about one thing: There is no dependency injection in nature. For all of an organism´s complexity no DI container is used. Behavior is the result of smooth cooperation between mutually oblivious building blocks. Functions will often be the adequate translation for the functional units in your designs. But not always. Take for example the case, where a processing step should not always produce an output. Maybe the purpose is to filter input. Here the functional unit consumes words and produces words. But it does not pass along every word flowing in. Some words are swallowed. Think of a spell checker. It probably should not check acronyms for correctness. There are too many of them. Or words with no more than two letters. Such words are called “stop words”. In the above picture the optionality of the output is signified by the astrisk outside the brackets. It means: Any number of (word) data items can flow from the functional unit for each input data item. It might be none or one or even more. This I call a stream of data. Such behavior cannot be translated into a function where output is generated with return. Because a function always needs to return a value. So the output port is translated into a function pointer or continuation which gets passed to the subroutine when called:[3]void filter_stop_words( string word, Action<string> onNoStopWord) { if (...check if not a stop word...) onNoStopWord(word); } If you want to be nitpicky you might call such a function pointer parameter an injection. And technically you´re right. Conceptually, though, it´s not an injection. Because the subroutine is not functionally dependent on the continuation. Firstly continuations are procedures, i.e. subroutines without a return type. Remember: Flow Design is about unidirectional data flow. Secondly the name of the formal parameter is chosen in a way as to not assume anything about downstream processing steps. onNoStopWord describes a situation (or event) within the functional unit only. Translating output ports into function pointers helps keeping functional units mutually oblivious in cases where output is optional or produced asynchronically. Either pass the function pointer to the function upon call. Or make it global by putting it on the encompassing class. Then it´s called an event. In C# that´s even an explicit feature.class Filter { public void filter_stop_words( string word) { if (...check if not a stop word...) onNoStopWord(word); } public event Action<string> onNoStopWord; } When to use a continuation and when to use an event dependens on how a functional unit is used in flows and how it´s packed together with others into classes. You´ll see examples further down the Flow Design road. Another example of 1D functional design Let´s see Flow Design once more in action using the visual notation. How about the famous word wrap kata? Robert C. Martin has posted a much cited solution including an extensive reasoning behind his TDD approach. So maybe you want to compare it to Flow Design. The function signature given is:string WordWrap(string text, int maxLineLength) {...} That´s not an Entry Point since we don´t see an application with an environment and users. Nevertheless it´s a function which is supposed to provide a certain functionality. The text passed in has to be reformatted. The input is a single line of arbitrary length consisting of words separated by spaces. The output should consist of one or more lines of a maximum length specified. If a word is longer than a the maximum line length it can be split in multiple parts each fitting in a line. Flow Design Let´s start by brainstorming the process to accomplish the feat of reformatting the text. What´s needed? Words need to be assembled into lines Words need to be extracted from the input text The resulting lines need to be assembled into the output text Words too long to fit in a line need to be split Does sound about right? I guess so. And it shows a kind of priority. Long words are a special case. So maybe there is a hint for an incremental design here. First let´s tackle “average words” (words not longer than a line). Here´s the Flow Design for this increment: The the first three bullet points turned into functional units with explicit data added. As the signature requires a text is transformed into another text. See the input of the first functional unit and the output of the last functional unit. In between no text flows, but words and lines. That´s good to see because thereby the domain is clearly represented in the design. The requirements are talking about words and lines and here they are. But note the asterisk! It´s not outside the brackets but inside. That means it´s not a stream of words or lines, but lists or sequences. For each text a sequence of words is output. For each sequence of words a sequence of lines is produced. The asterisk is used to abstract from the concrete implementation. Like with streams. Whether the list of words gets implemented as an array or an IEnumerable is not important during design. It´s an implementation detail. Does any processing step require further refinement? I don´t think so. They all look pretty “atomic” to me. And if not… I can always backtrack and refine a process step using functional design later once I´ve gained more insight into a sub-problem. Implementation The implementation is straightforward as you can imagine. The processing steps can all be translated into functions. Each can be tested easily and separately. Each has a focused responsibility. And the process flow becomes just a sequence of function calls: Easy to understand. It clearly states how word wrapping works - on a high level of abstraction. And it´s easy to evolve as you´ll see. Flow Design - Increment 2 So far only texts consisting of “average words” are wrapped correctly. Words not fitting in a line will result in lines too long. Wrapping long words is a feature of the requested functionality. Whether it´s there or not makes a difference to the user. To quickly get feedback I decided to first implement a solution without this feature. But now it´s time to add it to deliver the full scope. Fortunately Flow Design automatically leads to code following the Open Closed Principle (OCP). It´s easy to extend it - instead of changing well tested code. How´s that possible? Flow Design allows for extension of functionality by inserting functional units into the flow. That way existing functional units need not be changed. The data flow arrow between functional units is a natural extension point. No need to resort to the Strategy Pattern. No need to think ahead where extions might need to be made in the future. I just “phase in” the remaining processing step: Since neither Extract words nor Reformat know of their environment neither needs to be touched due to the “detour”. The new processing step accepts the output of the existing upstream step and produces data compatible with the existing downstream step. Implementation - Increment 2 A trivial implementation checking the assumption if this works does not do anything to split long words. The input is just passed on: Note how clean WordWrap() stays. The solution is easy to understand. A developer looking at this code sometime in the future, when a new feature needs to be build in, quickly sees how long words are dealt with. Compare this to Robert C. Martin´s solution:[4] How does this solution handle long words? Long words are not even part of the domain language present in the code. At least I need considerable time to understand the approach. Admittedly the Flow Design solution with the full implementation of long word splitting is longer than Robert C. Martin´s. At least it seems. Because his solution does not cover all the “word wrap situations” the Flow Design solution handles. Some lines would need to be added to be on par, I guess. But even then… Is a difference in LOC that important as long as it´s in the same ball park? I value understandability and openness for extension higher than saving on the last line of code. Simplicity is not just less code, it´s also clarity in design. But don´t take my word for it. Try Flow Design on larger problems and compare for yourself. What´s the easier, more straightforward way to clean code? And keep in mind: You ain´t seen all yet ;-) There´s more to Flow Design than described in this chapter. In closing I hope I was able to give you a impression of functional design that makes you hungry for more. To me it´s an inevitable step in software development. Jumping from requirements to code does not scale. And it leads to dirty code all to quickly. Some thought should be invested first. Where there is a clear Entry Point visible, it´s functionality should be designed using data flows. Because with data flows abstraction is possible. For more background on why that´s necessary read my blog article here. For now let me point out to you - if you haven´t already noticed - that Flow Design is a general purpose declarative language. It´s “programming by intention” (Shalloway et al.). Just write down how you think the solution should work on a high level of abstraction. This breaks down a large problem in smaller problems. And by following the PoMO the solutions to those smaller problems are independent of each other. So they are easy to test. Or you could even think about getting them implemented in parallel by different team members. Flow Design not only increases evolvability, but also helps becoming more productive. All team members can participate in functional design. This goes beyon collective code ownership. We´re talking collective design/architecture ownership. Because with Flow Design there is a common visual language to talk about functional design - which is the foundation for all other design activities. PS: If you like what you read, consider getting my ebook “The Incremental Architekt´s Napkin”. It´s where I compile all the articles in this series for easier reading. I like the strictness of Function Programming - but I also find it quite hard to live by. And it certainly is not what millions of programmers are used to. Also to me it seems, the real world is full of state and side effects. So why give them such a bad image? That´s why functional design takes a more pragmatic approach. State and side effects are ok for processing steps - but be sure to follow the SRP. Don´t put too much of it into a single processing step. ? Image taken from www.physioweb.org ? My code samples are written in C#. C# sports typed function pointers called delegates. Action is such a function pointer type matching functions with signature void someName(T t). Other languages provide similar ways to work with functions as first class citizens - even Java now in version 8. I trust you find a way to map this detail of my translation to your favorite programming language. I know it works for Java, C++, Ruby, JavaScript, Python, Go. And if you´re using a Functional Programming language it´s of course a no brainer. ? Taken from his blog post “The Craftsman 62, The Dark Path”. ?

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Using HTML 5 SessionState to save rendered Page Content

- by Rick Strahl

HTML 5 SessionState and LocalStorage are very useful and super easy to use to manage client side state. For building rich client side or SPA style applications it's a vital feature to be able to cache user data as well as HTML content in order to swap pages in and out of the browser's DOM. What might not be so obvious is that you can also use the sessionState and localStorage objects even in classic server rendered HTML applications to provide caching features between pages. These APIs have been around for a long time and are supported by most relatively modern browsers and even all the way back to IE8, so you can use them safely in your Web applications. SessionState and LocalStorage are easy The APIs that make up sessionState and localStorage are very simple. Both object feature the same API interface which is a simple, string based key value store that has getItem, setItem, removeitem, clear and key methods. The objects are also pseudo array objects and so can be iterated like an array with a length property and you have array indexers to set and get values with. Basic usage for storing and retrieval looks like this (using sessionStorage, but the syntax is the same for localStorage - just switch the objects):// set var lastAccess = new Date().getTime(); if (sessionStorage) sessionStorage.setItem("myapp_time", lastAccess.toString()); // retrieve in another page or on a refresh var time = null; if (sessionStorage) time = sessionStorage.getItem("myapp_time"); if (time) time = new Date(time * 1); else time = new Date(); sessionState stores data that is browser session specific and that has a liftetime of the active browser session or window. Shut down the browser or tab and the storage goes away. localStorage uses the same API interface, but the lifetime of the data is permanently stored in the browsers storage area until deleted via code or by clearing out browser cookies (not the cache). Both sessionStorage and localStorage space is limited. The spec is ambiguous about this - supposedly sessionStorage should allow for unlimited size, but it appears that most WebKit browsers support only 2.5mb for either object. This means you have to be careful what you store especially since other applications might be running on the same domain and also use the storage mechanisms. That said 2.5mb worth of character data is quite a bit and would go a long way. The easiest way to get a feel for how sessionState and localStorage work is to look at a simple example. You can go check out the following example online in Plunker: http://plnkr.co/edit/0ICotzkoPjHaWa70GlRZ?p=preview which looks like this: Plunker is an online HTML/JavaScript editor that lets you write and run Javascript code and similar to JsFiddle, but a bit cleaner to work in IMHO (thanks to John Papa for turning me on to it). The sample has two text boxes with counts that update session/local storage every time you click the related button. The counts are 'cached' in Session and Local storage. The point of these examples is that both counters survive full page reloads, and the LocalStorage counter survives a complete browser shutdown and restart. Go ahead and try it out by clicking the Reload button after updating both counters and then shutting down the browser completely and going back to the same URL (with the same browser). What you should see is that reloads leave both counters intact at the counted values, while a browser restart will leave only the local storage counter intact. The code to deal with the SessionStorage (and LocalStorage not shown here) in the example is isolated into a couple of wrapper methods to simplify the code: function getSessionCount() { var count = 0; if (sessionStorage) { var count = sessionStorage.getItem("ss_count"); count = !count ? 0 : count * 1; } $("#txtSession").val(count); return count; } function setSessionCount(count) { if (sessionStorage) sessionStorage.setItem("ss_count", count.toString()); } These two functions essentially load and store a session counter value. The two key methods used here are: sessionStorage.getItem(key); sessionStorage.setItem(key,stringVal); Note that the value given to setItem and return by getItem has to be a string. If you pass another type you get an error. Don't let that limit you though - you can easily enough store JSON data in a variable so it's quite possible to pass complex objects and store them into a single sessionStorage value:var user = { name: "Rick", id="ricks", level=8 } sessionStorage.setItem("app_user",JSON.stringify(user)); to retrieve it:var user = sessionStorage.getItem("app_user"); if (user) user = JSON.parse(user); Simple! If you're using the Chrome Developer Tools (F12) you can also check out the session and local storage state on the Resource tab: You can also use this tool to refresh or remove entries from storage. What we just looked at is a purely client side implementation where a couple of counters are stored. For rich client centric AJAX applications sessionStorage and localStorage provide a very nice and simple API to store application state while the application is running. But you can also use these storage mechanisms to manage server centric HTML applications when you combine server rendering with some JavaScript to perform client side data caching. You can both store some state information and data on the client (ie. store a JSON object and carry it forth between server rendered HTML requests) or you can use it for good old HTTP based caching where some rendered HTML is saved and then restored later. Let's look at the latter with a real life example. Why do I need Client-side Page Caching for Server Rendered HTML? I don't know about you, but in a lot of my existing server driven applications I have lists that display a fair amount of data. Typically these lists contain links to then drill down into more specific data either for viewing or editing. You can then click on a link and go off to a detail page that provides more concise content. So far so good. But now you're done with the detail page and need to get back to the list, so you click on a 'bread crumbs trail' or an application level 'back to list' button and… …you end up back at the top of the list - the scroll position, the current selection in some cases even filters conditions - all gone with the wind. You've left behind the state of the list and are starting from scratch in your browsing of the list from the top. Not cool! Sound familiar? This a pretty common scenario with server rendered HTML content where it's so common to display lists to drill into, only to lose state in the process of returning back to the original list. Look at just about any traditional forums application, or even StackOverFlow to see what I mean here. Scroll down a bit to look at a post or entry, drill in then use the bread crumbs or tab to go back… In some cases returning to the top of a list is not a big deal. On StackOverFlow that sort of works because content is turning around so quickly you probably want to actually look at the top posts. Not always though - if you're browsing through a list of search topics you're interested in and drill in there's no way back to that position. Essentially anytime you're actively browsing the items in the list, that's when state becomes important and if it's not handled the user experience can be really disrupting. Content Caching If you're building client centric SPA style applications this is a fairly easy to solve problem - you tend to render the list once and then update the page content to overlay the detail content, only hiding the list temporarily until it's used again later. It's relatively easy to accomplish this simply by hiding content on the page and later making it visible again. But if you use server rendered content, hanging on to all the detail like filters, selections and scroll position is not quite as easy. Or is it??? This is where sessionStorage comes in handy. What if we just save the rendered content of a previous page, and then restore it when we return to this page based on a special flag that tells us to use the cached version? Let's see how we can do this. A real World Use Case Recently my local ISP asked me to help out with updating an ancient classifieds application. They had a very busy, local classifieds app that was originally an ASP classic application. The old app was - wait for it: frames based - and even though I lobbied against it, the decision was made to keep the frames based layout to allow rapid browsing of the hundreds of posts that are made on a daily basis. The primary reason they wanted this was precisely for the ability to quickly browse content item by item. While I personally hate working with Frames, I have to admit that the UI actually works well with the frames layout as long as you're running on a large desktop screen. You can check out the frames based desktop site here: http://classifieds.gorge.net/ However when I rebuilt the app I also added a secondary view that doesn't use frames. The main reason for this of course was for mobile displays which work horribly with frames. So there's a somewhat mobile friendly interface to the interface, which ditches the frames and uses some responsive design tweaking for mobile capable operation: http://classifeds.gorge.net/mobile (or browse the base url with your browser width under 800px) Here's what the mobile, non-frames view looks like: As you can see this means that the list of classifieds posts now is a list and there's a separate page for drilling down into the item. And of course… originally we ran into that usability issue I mentioned earlier where the browse, view detail, go back to the list cycle resulted in lost list state. Originally in mobile mode you scrolled through the list, found an item to look at and drilled in to display the item detail. Then you clicked back to the list and BAM - you've lost your place. Because there are so many items added on a daily basis the full list is never fully loaded, but rather there's a "Load Additional Listings" entry at the button. Not only did we originally lose our place when coming back to the list, but any 'additionally loaded' items are no longer there because the list was now rendering as if it was the first page hit. The additional listings, and any filters, the selection of an item all were lost. Major Suckage! Using Client SessionStorage to cache Server Rendered Content To work around this problem I decided to cache the rendered page content from the list in SessionStorage. Anytime the list renders or is updated with Load Additional Listings, the page HTML is cached and stored in Session Storage. Any back links from the detail page or the login or write entry forms then point back to the list page with a back=true query string parameter. If the server side sees this parameter it doesn't render the part of the page that is cached. Instead the client side code retrieves the data from the sessionState cache and simply inserts it into the page. It sounds pretty simple, and the overall the process is really easy, but there are a few gotchas that I'll discuss in a minute. But first let's look at the implementation. Let's start with the server side here because that'll give a quick idea of the doc structure. As I mentioned the server renders data from an ASP.NET MVC view. On the list page when returning to the list page from the display page (or a host of other pages) looks like this: https://classifieds.gorge.net/list?back=True The query string value is a flag, that indicates whether the server should render the HTML. Here's what the top level MVC Razor view for the list page looks like:@model MessageListViewModel @{ ViewBag.Title = "Classified Listing"; bool isBack = !string.IsNullOrEmpty(Request.QueryString["back"]); } <form method="post" action="@Url.Action("list")"> <div id="SizingContainer"> @if (!isBack) { @Html.Partial("List_CommandBar_Partial", Model) <div id="PostItemContainer" class="scrollbox" xstyle="-webkit-overflow-scrolling: touch;"> @Html.Partial("List_Items_Partial", Model) @if (Model.RequireLoadEntry) { <div class="postitem loadpostitems" style="padding: 15px;"> <div id="LoadProgress" class="smallprogressright"></div> <div class="control-progress"> Load additional listings... </div> </div> } </div> } </div> </form> As you can see the query string triggers a conditional block that if set is simply not rendered. The content inside of #SizingContainer basically holds the entire page's HTML sans the headers and scripts, but including the filter options and menu at the top. In this case this makes good sense - in other situations the fact that the menu or filter options might be dynamically updated might make you only cache the list rather than essentially the entire page. In this particular instance all of the content works and produces the proper result as both the list along with any filter conditions in the form inputs are restored. Ok, let's move on to the client. On the client there are two page level functions that deal with saving and restoring state. Like the counter example I showed earlier, I like to wrap the logic to save and restore values from sessionState into a separate function because they are almost always used in several places.page.saveData = function(id) { if (!sessionStorage) return; var data = { id: id, scroll: $("#PostItemContainer").scrollTop(), html: $("#SizingContainer").html() }; sessionStorage.setItem("list_html",JSON.stringify(data)); }; page.restoreData = function() { if (!sessionStorage) return; var data = sessionStorage.getItem("list_html"); if (!data) return null; return JSON.parse(data); }; The data that is saved is an object which contains an ID which is the selected element when the user clicks and a scroll position. These two values are used to reset the scroll position when the data is used from the cache. Finally the html from the #SizingContainer element is stored, which makes for the bulk of the document's HTML. In this application the HTML captured could be a substantial bit of data. If you recall, I mentioned that the server side code renders a small chunk of data initially and then gets more data if the user reads through the first 50 or so items. The rest of the items retrieved can be rather sizable. Other than the JSON deserialization that's Ok. Since I'm using SessionStorage the storage space has no immediate limits. Next is the core logic to handle saving and restoring the page state. At first though this would seem pretty simple, and in some cases it might be, but as the following code demonstrates there are a few gotchas to watch out for. Here's the relevant code I use to save and restore:$( function() { … var isBack = getUrlEncodedKey("back", location.href); if (isBack) { // remove the back key from URL setUrlEncodedKey("back", "", location.href); var data = page.restoreData(); // restore from sessionState if (!data) { // no data - force redisplay of the server side default list window.location = "list"; return; } $("#SizingContainer").html(data.html); var el = $(".postitem[data-id=" + data.id + "]"); $(".postitem").removeClass("highlight"); el.addClass("highlight"); $("#PostItemContainer").scrollTop(data.scroll); setTimeout(function() { el.removeClass("highlight"); }, 2500); } else if (window.noFrames) page.saveData(null); // save when page loads $("#SizingContainer").on("click", ".postitem", function() { var id = $(this).attr("data-id"); if (!id) return true; if (window.noFrames) page.saveData(id); var contentFrame = window.parent.frames["Content"]; if (contentFrame) contentFrame.location.href = "show/" + id; else window.location.href = "show/" + id; return false; }); … The code starts out by checking for the back query string flag which triggers restoring from the client cache. If cached the cached data structure is read from sessionStorage. It's important here to check if data was returned. If the user had back=true on the querystring but there is no cached data, he likely bookmarked this page or otherwise shut down the browser and came back to this URL. In that case the server didn't render any detail and we have no cached data, so all we can do is redirect to the original default list view using window.location. If we continued the page would render no data - so make sure to always check the cache retrieval result. Always! If there is data the it's loaded and the data.html data is restored back into the document by simply injecting the HTML back into the document's #SizingContainer element:$("#SizingContainer").html(data.html); It's that simple and it's quite quick even with a fully loaded list of additional items and on a phone. The actual HTML data is stored to the cache on every page load initially and then again when the user clicks on an element to navigate to a particular listing. The former ensures that the client cache always has something in it, and the latter updates with additional information for the selected element. For the click handling I use a data-id attribute on the list item (.postitem) in the list and retrieve the id from that. That id is then used to navigate to the actual entry as well as storing that Id value in the saved cached data. The id is used to reset the selection by searching for the data-id value in the restored elements. The overall process of this save/restore process is pretty straight forward and it doesn't require a bunch of code, yet it yields a huge improvement in the usability of the site on mobile devices (or anybody who uses the non-frames view). Some things to watch out for As easy as it conceptually seems to simply store and retrieve cached content, you have to be quite aware what type of content you are caching. The code above is all that's specific to cache/restore cycle and it works, but it took a few tweaks to the rest of the script code and server code to make it all work. There were a few gotchas that weren't immediately obvious. Here are a few things to pay attention to: Event Handling Logic Timing of manipulating DOM events Inline Script Code Bookmarking to the Cache Url when no cache exists Do you have inline script code in your HTML? That script code isn't going to run if you restore from cache and simply assign or it may not run at the time you think it would normally in the DOM rendering cycle. JavaScript Event Hookups The biggest issue I ran into with this approach almost immediately is that originally I had various static event handlers hooked up to various UI elements that are now cached. If you have an event handler like:$("#btnSearch").click( function() {…}); that works fine when the page loads with server rendered HTML, but that code breaks when you now load the HTML from cache. Why? Because the elements you're trying to hook those events to may not actually be there - yet. Luckily there's an easy workaround for this by using deferred events. With jQuery you can use the .on() event handler instead:$("#SelectionContainer").on("click","#btnSearch", function() {…}); which monitors a parent element for the events and checks for the inner selector elements to handle events on. This effectively defers to runtime event binding, so as more items are added to the document bindings still work. For any cached content use deferred events. Timing of manipulating DOM Elements Along the same lines make sure that your DOM manipulation code follows the code that loads the cached content into the page so that you don't manipulate DOM elements that don't exist just yet. Ideally you'll want to check for the condition to restore cached content towards the top of your script code, but that can be tricky if you have components or other logic that might not all run in a straight line. Inline Script Code Here's another small problem I ran into: I use a DateTime Picker widget I built a while back that relies on the jQuery date time picker. I also created a helper function that allows keyboard date navigation into it that uses JavaScript logic. Because MVC's limited 'object model' the only way to embed widget content into the page is through inline script. This code broken when I inserted the cached HTML into the page because the script code was not available when the component actually got injected into the page. As the last bullet - it's a matter of timing. There's no good work around for this - in my case I pulled out the jQuery date picker and relied on native <input type="date" /> logic instead - a better choice these days anyway, especially since this view is meant to be primarily to serve mobile devices which actually support date input through the browser (unlike desktop browsers of which only WebKit seems to support it). Bookmarking Cached Urls When you cache HTML content you have to make a decision whether you cache on the client and also not render that same content on the server. In the Classifieds app I didn't render server side content so if the user comes to the page with back=True and there is no cached content I have to a have a Plan B. Typically this happens when somebody ends up bookmarking the back URL. The easiest and safest solution for this scenario is to ALWAYS check the cache result to make sure it exists and if not have a safe URL to go back to - in this case to the plain uncached list URL which amounts to effectively redirecting. This seems really obvious in hindsight, but it's easy to overlook and not see a problem until much later, when it's not obvious at all why the page is not rendering anything. Don't use <body> to replace Content Since we're practically replacing all the HTML in the page it may seem tempting to simply replace the HTML content of the <body> tag. Don't. The body tag usually contains key things that should stay in the page and be there when it loads. Specifically script tags and elements and possibly other embedded content. It's best to create a top level DOM element specifically as a placeholder container for your cached content and wrap just around the actual content you want to replace. In the app above the #SizingContainer is that container. Other Approaches The approach I've used for this application is kind of specific to the existing server rendered application we're running and so it's just one approach you can take with caching. However for server rendered content caching this is a pattern I've used in a few apps to retrofit some client caching into list displays. In this application I took the path of least resistance to the existing server rendering logic. Here are a few other ways that come to mind: Using Partial HTML Rendering via AJAXInstead of rendering the page initially on the server, the page would load empty and the client would render the UI by retrieving the respective HTML and embedding it into the page from a Partial View. This effectively makes the initial rendering and the cached rendering logic identical and removes the server having to decide whether this request needs to be rendered or not (ie. not checking for a back=true switch). All the logic related to caching is made on the client in this case. Using JSON Data and Client RenderingThe hardcore client option is to do the whole UI SPA style and pull data from the server and then use client rendering or databinding to pull the data down and render using templates or client side databinding with knockout/angular et al. As with the Partial Rendering approach the advantage is that there's no difference in the logic between pulling the data from cache or rendering from scratch other than the initial check for the cache request. Of course if the app is a full on SPA app, then caching may not be required even - the list could just stay in memory and be hidden and reactivated. I'm sure there are a number of other ways this can be handled as well especially using AJAX. AJAX rendering might simplify the logic, but it also complicates search engine optimization since there's no content loaded initially. So there are always tradeoffs and it's important to look at all angles before deciding on any sort of caching solution in general. State of the Session SessionState and LocalStorage are easy to use in client code and can be integrated even with server centric applications to provide nice caching features of content and data. In this post I've shown a very specific scenario of storing HTML content for the purpose of remembering list view data and state and making the browsing experience for lists a bit more friendly, especially if there's dynamically loaded content involved. If you haven't played with sessionStorage or localStorage I encourage you to give it a try. There's a lot of cool stuff that you can do with this beyond the specific scenario I've covered here… Resources Overview of localStorage (also applies to sessionStorage) Web Storage Compatibility Modernizr Test Suite© Rick Strahl, West Wind Technologies, 2005-2013Posted in JavaScript HTML5 ASP.NET MVC Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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