Search Results

Search found 8144 results on 326 pages for 'thread'.

Page 224/326 | < Previous Page | 220 221 222 223 224 225 226 227 228 229 230 231 | Next Page >

Using static variable in function vs passing variable from caller

- by Patrick

I have a function which spawns various types of threads, one of the thread types needs to be spawned every x seconds. I currently have it like this: bool isTime( Time t ) { return t >= now(); } void spawner() { while( 1 ) { Time t = now(); if( isTime( t ) )//is time is called in more than one place in the real function { launchthread() t = now() + offset; } } } but I'm thinking of changing it to: bool isTime() { static Time t = now(); if( t >= now() ) { t = now() + offset; return true; } return false; } void spawner() { if( isTime() ) launchthread(); } I think the second way is neater but I generally avoid statics in much the same way I avoid global data; anyone have any thoughts on the different styles?

Read the article
Django database caching

- by hekevintran

I have a Django form that uses an integer field to lookup a model object by its primary key. The form has a save() method that uses the model object referred to by the integer field. The model's manager's get() method is called twice, once in the clean method and once in the save() method: class MyForm(forms.Form): id_a = fields.IntegerField() def clean_id_a(user_id): id_a = self.cleaned_data['id_a'] try: # here is the first call to get MyModel.objects.get(id=id_a) except User.DoesNotExist: raise ValidationError('Object does not exist') def save(self): id_a = self.cleaned_data['id_a'] # here is the second call to get my_model_object = MyModel.objects.get(id=id_a) # do other stuff I wasn't sure whether this hits the database two times or one time so I returned the object itself in the clean method so that I could avoid a second get() call. Does calling get() hit the database two times? Or is the object cached in the thread? class MyForm(forms.Form): id_a = fields.IntegerField() def clean_id_a(user_id): id_a = self.cleaned_data['id_a'] try: # here is my workaround return MyModel.objects.get(id=id_a) except User.DoesNotExist: raise ValidationError('Object does not exist') def save(self): # looking up the cleaned value returns the model object my_model_object = self.cleaned_data['id_a'] # do other stuff

Read the article
UITableView via NSFetchedResultsControllerDelegate, select first record by default?

- by deafgreatdane

I have a UITableView that gets populated from CoreData via a controller that implements NSFetchedResultsControllerDelegate. How can I have it automatically select the first row (and fire the tableView:didSelectRowAtIndexPath message)? The tableview is used for a variety of predicate queries, so I'm suspicious of solutions that work on the UIViewController lifecycle (viewDidLoad, etc), but I'm new to the platform, so I'm open. I've tried a variety of things, but I'm not sure where in the call stack to put it. I've tried calling cell.selected = true inside tableView:cellForRowAtIndex: method, but that just ends up turning the cell black (and doesn't fire the selected callback method) A tagent question, with all the delegating and core data protocols, does it imply asynchronous data fetch (multiple threads)? Or is the NSFetchedResultsController calling all its related methods in the same thread? Maybe I'm just scared that if it is async, there would be race conditions that would be tough to troubleshoot later.

Read the article
Alternative approach to OpenGL View on top of Camera

- by Mr. Roland

Hi, the traditional way of doing a camera preview background with OpenGL on the front is to take two SurfaceViews(one for the camera another for OpenGL) and stack them on top of each other. The problem is that stacking SurfaceViews is discouraged: http://groups.google.com/group/android-developers/browse_thread/thread/4850fe5c314a3dc6 So what alternatives are there? I was considering the following: Subclass GlSurfaceView, and then call set the Camera preview onto the holder of this subclass: Camera.setPreviewDisplay(mHolder); Don't use GLSurfaceView, instead create your own SurfaceView subclass where you display the Camera preview onto the holder and also draw your openGL. This would require to use OpenGL without GLSurfaceView, has anyone done this before? I'm not sure if this even is possible or makes sense, since it implies displaying the camera preview onto the holder of the surface and at the same time drawing OpenGL on the same surface. Is there any other sensible alternative to solving the problem without using two SurfaceViews? Thanks!

Read the article
OpenGL: Textured Primitives + High Framerate

- by James D

Short version: What's the best practice going forward for efficiently rendering large numbers of independent texture-mapped, lighted 2D/3D primitives (circles, rects, etc.) in OpenGL? For example: a typical particle system using billboarded quads/triangles, point sprites, or whatever other technique, with blending. Because after reading this thread on the messiness of OpenGL versioning/deprecation I'm starting to have my doubts. My specific question is not the ABCs of displaying primitives in OpenGL, but rather how to do so efficiently in post-deprecation (or pre-deprecation) OpenGL, in a way that's going to be compatible with a wide range of commodity hardware and in a way that's not going to break or itself get deprecated, five years down the line. Thanks!

Read the article
Using ManualResetEvent to wait for multiple Image.ImageOpened events

- by umlgorithm

Dictionary<Image, ManualResetEvent> waitHandleMap = new Dictionary<Image, ManualResetEvent>(); List<Image> images = GetImagesWhichAreAlreadyInVisualTree(); foreach (var image in images) { image.Source = new BitmapImage(new Uri("some_valid_image_url")); waitHandleMap.Add(image, new ManualResetEvent(false)); image.ImageOpened += delegate { waitHandleMap[image].Set(); }; image.ImageFailed += delegate { waitHandleMap[image].Set(); }; } WaitHandle.WaitAll(waitHandleMap.Values.ToArray()); WaitHandle.WaitAll blocks the current UI thread, so ImageOpened/ImageFailed events would never get fired. Could you suggest me an easy workaround to wait for the multiple ui events?

Read the article
Map the physical file path in asp.net mvc

- by rmassart

Hi, I am trying to read an XSLT file from disk in my ASP.Net MVC controller. What I am doing is the following: string filepath = HttpContext.Request.PhysicalApplicationPath; filepath += "/Content/Xsl/pubmed.xslt"; string xsl = System.IO.File.ReadAllText(filepath); However, half way down this thread on forums.asp.net there is the following quote HttpContext.Current is evil and if you use it anywhere in your mvc app you are doing something wrong because you do not need it. Whilst I am not using "Current", I am wondering what is the best way to determine the absolute physical path of a file in MVC? For some reason (I don't know why!) HttpContext doesn't feel right for me. Is there a better (or recommended/best practice) way of reading files from disk in ASP.Net MVC? Thanks for your help, Robin

Read the article
Sharing Jinja2 templates between Pylons and Django applications

- by Joe Holloway

I'm writing a couple of Jinja2 templates that basically implement some common grid layouts. I'd like to be able to share this 'library' of templates between a Pylons app and Django app. I've hit a minor stumbling block in that Django's template context is accessible from the "top-level" of the template, whereas Pylons wraps your context inside the thread local c (or tmpl_context) variable. Here are some analogous examples that demonstrate this. Django from django.shortcuts import render_to_response ctx = {} ctx['name'] = 'John' return render_to_response('hello.html', ctx) hello.html: Hello {{ name }} Pylons from pylons import tmpl_context as c from myapp.lib.base import render c.name = 'John' return render('hello.html') hello.html: Hello {{ c.name }} What I'm trying to do is make it so that hello.html is the same across both frameworks. One way I see to do it is by wrapping the Django render_to_response and do something like this: ctx['c'] = ctx But that just doesn't feel right. Anybody see other alternatives to this? Thanks

Read the article
multiple occurences of HandleCreated for a single control

- by Asher

I’m using control that needs to be register to asynchronous events. The events will be raised in the UI thread using the ISynchronizeInvoke interface implemented by WinForms controls I can’t register to the event at the constructor because it will allow calling the event handler before the control is fully created. during which calls to ISynchronizeInvoke are not allowed. Solution to that problem is to use the perform the asynchronous event registration from an event handler to the HandleCreated instead of registering from the constructor. however, this poses another issue, in some scenations the HandleCreated event is raised multiple times as result of change at the control state. For example, each changing of the “RightToLeft” property causes a WMCreate message that cause raising the “HandleCreated” event. How can I prevent the multiply times of event rising? Is there is another way to know when the control is created and display for the first time? I can keep a boolean flag in the HandleCreated, however it feels like a hack and I am wondering if there is a better way to handle this issue.

Read the article
.NET JAXB equivalent?

- by Dan

Is there an equivalent library for JAXB in .NET? I am trying to convert an XML I get to a .NET class. I have the XSD, but not sure how to convert the XML received into a concrete Class? I used the XSD tool to generate a class from the schema, but what I want to to convert the XML I receive on the fly to a object that I can work with in code. I've seen the thread here that deals with this, but my query is - I want the object created to contain the data that I receive in the XML (i.e. the field values must be populated).

Read the article
Java and gstreamer-java initialisation error

- by Mark

I am building a small app which will play streaming audio from the internet in java (mainly internet radio stations). I have decided to use the gstreamer-java library for the sound, which uses JNA. I would like to include a check in the code, to see whether the gstreamer library has been initialised. When I have left the "Gst.init()" code out (to mimic when the library has not been initialised correctly), the application throws out the following messages: (process:21888): GLib-GObject-CRITICAL **: /build/buildd/glib2.0-2.22.3/gobject/gtype.c:2458: initialization assertion failed, use IA__g_type_init() prior to this function (process:21888): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed The app calls the gstreamer-java library. The error messages appear but the thread continues to run, hogging the CPU. Is there any way to catch the error or to add a check to prevent it from happening? An alternative would be to put the "Gst.init()" in the main class, but I am not sure if this would always guarantee the gstreamer library is initialised.

Read the article
Perl throws an error message about syntax

- by Ben Dauphinee

So, building off a question about string matching (this thread), I am working on implementing that info in solution 3 into a working solution to the problem I am working on. However, I am getting errors, specifically about this line of the below function: next if @$args->{search_in} !~ /@$cur[1]/; syntax error at ./db_index.pl line 16, near "next " My question as a perl newbie is what am I doing wrong here? sub search_for_key { my ($args) = @_; foreach $row(@{$args->{search_ary}}){ print "@$row[0] : @$row[1]\n"; } my $thiskey = NULL; foreach $cur (@{$args->{search_ary}}){ print "\n" . @$cur[1] . "\n" next if @$args->{search_in} !~ /@$cur[1]/; $thiskey = @$cur[0]; last; } return $thiskey; }

Read the article
In TCPServer (Ruby) how can i get the IP/MAC from the client?

- by a0rtega

Hi, i want to get the IP Address of the client in a TCPServer in Ruby. And (if it is possible) the MAC Address. For example, a Time Server in Ruby, see the comment. tcpserver = TCPServer.new("", 80) if tcpserver puts "Listening" loop do socket = tcpserver.accept if socket Thread.new do puts "Connected from" + # HERE! How can i get the IP Address from the client? socket.write(Time.now.to_s) socket.close end end end end Thank you very much!

Read the article
Git. Remote HEAD is ambiguous.

- by Siegfried

I checked the relevant thread but still can't solve this problem. When I typed "git remote show origin", I got * remote origin Fetch URL: xxxx Push URL: xxxx HEAD branch (remote HEAD is ambiguous, may be one of the following): development master Remote branches: development tracked master tracked Local branches configured for 'git pull': development merges with remote development master merges with remote master Local ref configured for 'git push': master pushes to master (up to date) I also checked "git show-ref", and I got: 3f8f4292e31cb8fa5938dbdd406b2f357764205b refs/heads/development 3f8f4292e31cb8fa5938dbdd406b2f357764205b refs/heads/master 3f8f4292e31cb8fa5938dbdd406b2f357764205b refs/remotes/origin/development 3f8f4292e31cb8fa5938dbdd406b2f357764205b refs/remotes/origin/master Here is the list of all branches I have by executing "git branch -a" development * master remotes/origin/development remotes/origin/master And this is what is in the .git/config: [core] repositoryformatversion = 0 filemode = false bare = false logallrefupdates = true ignorecase = true hideDotFiles = dotGitOnly autocrlf = false [remote "origin"] fetch = +refs/heads/*:refs/remotes/origin/* url = xxxx push = refs/heads/master:refs/heads/master [branch "master"] remote = origin merge = refs/heads/master [branch "development"] remote = origin merge = refs/heads/development I and it seems that the remote development and master branch share the same node. How to solve this ambiguity problem? Thank you!

Read the article
JTable Boolean cell .. how to read it

- by dimitar

Hello guys, i have a table with a column that contains Boolean type. now when i try to run a program i have a problem: System.out.println(table.getColumnClass(5)); b= (Boolean)table.getValueAt(row, 5); It prints class java.lang.Boolean but also: Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Boolean and i even try with b= (Boolean)table.getValueAt(row, 5); b= Boolean.parseBoolean((String)table.getValueAt(row, 5)); b= table.getValueAt(row, 5); but those show error too. So how to fix this guys?

Read the article
Eclipse Problems View doesn't show Errors

- by Jack

[Note: There is another thread about this problem but it did not answer the question.] For one specific project in Eclipse, the problems view does not show errors. It shows warnings but it does not show errors. The other projects do show errors (and everything else). For that problematic project, I can see the red squiggly error line in the files. However, the directory structure does not show an error icon and the error is not populated in the Problems View. Any ideas?

Read the article
NSThread running a class

- by Thomas Joulin

Hi, Every the example I find on the internet (including Apple doc) sets the target to self like this : [NSThread detachNewThreadSelector:@selector(threadedTask) toTarget:self withObject:nil]; Since i would like to do a more complex task in background (involving multiple methods), I thought of creating a class Task called like this : Task *task = [[Task alloc] init]; [NSThread detachNewThreadSelector:@selector(main) toTarget:task withObject:nil]; but I wonder, how will be handled the instance variables of my class Task ? in my method main can I safely call methods of my class Task using [self myMethod] and modifying members variables assuming I'm the only thread accessing it ? This way of handling threads seems weird to me, sorry if my question is stupid ^^ Thanks in advance

Read the article
Python: Traffic-Simulation (cars on a road)

- by kame

Hello! I want to create a traffic simulator like here: http://www.doobybrain.com/wp-content/uploads/2008/03/traffic-simulation.gif But I didn't thougt very deep about this. I would create the class car. Every car has his own color, position and so on. And I could create the road with an array. But how to tell the car where to go? Could I hear your ideas? EDIT: Is it forbidden to get new ideas from good programmers? Why do some people want to close this thread? Or were to ask such questions? I dont understand them. :(

Read the article
C# String Resource Values as Enum String Part values?

- by JL

Using VS2010 and .net V4.0 I would like to achieve the following: I already have 2 resource files in my project for 2 languages - English and Czech. I must say Resource Management in .net is excellent, I am suprised even to get code completion when implementing a String for example: string desc = Strings.ResourceManagerDesc This gets the string associated with the current culture of the thread. Now I am trying to create an Enum that can have the String portion of the Enum interpreted from the Strings resources. In the following way (This code DOES NOT WORK): public enum DownloadStatus { 1 = Strings.DownloadState_Complete, 2 = Strings.DownloadState_Failed, 3 = Strings.DownloadState_InProgress } This is a made up example, but you can see the point here. Since the above code won't work, is there a best practice way to achieve what I want?

Read the article
cannot access localhost using ip

- by Robert

I have done a small web development project using eclipse. It runs well when I try running it on browser with url localhost:8080/myproject/home.html. But if I want to access it on another machine (laptop, mobile, etc. using the same wifi) it is not possible; it is not able to connect. After Googling for a while found out that I have to use the IP address instead of 'localhost'. So I tried 10.0.0.4:8080/myproject/home.html, but still does not work. In fact i am unable to open that url on the same machine (where localhost:8080/myproject/home.html works fine). I also added a new Inbound rule in control panel firewall settings, allowing access to all ports for protocol TCP. Still have problem in running application with the url 10.0.0.4:8080/myproject/home.html (both on same machine as well as laptop and mobile). FYI i am using Eclipse Indigo, Apache tomcat 6.0 and server.xml file contents is as below: <?xml version="1.0" encoding="UTF-8"?> <Server port="8005" shutdown="SHUTDOWN">  <Listener SSLEngine="on" className="org.apache.catalina.core.AprLifecycleListener"/>  <Listener className="org.apache.catalina.core.JasperListener"/>  <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener"/>  <Listener className="org.apache.catalina.mbeans.ServerLifecycleListener"/> <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"/>  <GlobalNamingResources>  <Resource auth="Container" description="User database that can be updated and saved" factory="org.apache.catalina.users.MemoryUserDatabaseFactory" name="UserDatabase" pathname="conf/tomcat-users.xml" type="org.apache.catalina.UserDatabase"/> </GlobalNamingResources>  <Service name="Catalina">    <Connector port="8080" protocol="HTTP/1.1" address="10.0.0.4" connectionTimeout="20000" redirectPort="8443" />      <Connector port="8009" protocol="AJP/1.3" redirectPort="8443"/>   <Engine defaultHost="localhost" name="Catalina">      <Realm className="org.apache.catalina.realm.UserDatabaseRealm" resourceName="UserDatabase"/>  <Host appBase="webapps" autoDeploy="true" name="localhost" unpackWARs="true" xmlNamespaceAware="false" xmlValidation="false">     <Context docBase="myproject" path="/myproject" reloadable="true" source="org.eclipse.jst.jee.server:myproject"/></Host> </Engine> </Service> </Server>

Read the article
not getting output from parmiko/ssh command

- by Matt

I am using paramiko/ssh/python to attempt to run a command on a remote server. When I ssh manually and run the command in question, I get the results I want. But if I use the python (co-opted from another thread on this site) below, there is no returned data. If I modify the command to be something more basic like 'pwd' or 'ls' I can then get the output. Any help is appreciated. Thanks, Matt import paramiko import time import sys, os, select import select username='medelman' password='Ru5h21iz' hostname='10.15.27.166' hostport=22 cmd='tail -f /x/web/mlog.txt' #works cmd='' #doesn't work client = paramiko.SSHClient() client.load_system_host_keys() client.connect(hostname=hostname, username=username, password=password) transport = client.get_transport() channel = transport.open_session() channel.exec_command(cmd) while True: rl, wl, xl = select.select([channel],[],[],0.0) if len(rl) 0: # Must be stdout print channel.recv(1024) time.sleep(1)

Read the article
How do I wait until a console application is idle?

- by Anthony Mastrean

I have a console application that starts up, hosts a bunch of services (long-running startup), and then waits for clients to call into it. I have integration tests that start this console application and make "client" calls. How do I wait for the console application to complete its startup before making the client calls? I want to avoid doing Thread.Sleep(int) because that's dependent on the startup time (which may change) and I waste time if the startup is faster. Process.WaitForInputIdle works only on applications with a UI (and I confirmed that it does throw an exception in this case). I'm open to awkward solutions like, have the console application write a temp file when it's ready.

Read the article
How can I safely raise events in an AsyncCallback?

- by cyclotis04

I'm writing a wrapper class around a TcpClient which raises an event when data arrives. I'm using BeginRead and EndRead, but when the parent form handles the event, it's not running on the UI thread. I do I need to use delegates and pass the context into the callback? I thought that callbacks were a way to avoid this... void ReadCallback(IAsyncResult ar) { int length = _tcpClient.GetStream().EndRead(ar); _stringBuilder.Append(ByteArrayToString(_buffer, length)); BeginRead(); OnStringArrival(EventArgs.Empty); }

Read the article
How to make a mutable ItemizedOverlay

- by Hamy

Hey all, I would like to make a Google map overlay with changable pins. An easy way to visualize this would be to think of a near real time overlay, where the pins are constantly changing location. However, I can't seem to think of a safe way to do this with the ItemizedOverlay. The problem seems to be the call to populate - If size() is called by some maps thread, and then my data changes, then the result when the maps call accesses getItem() can be an IndexOutOfBoundsException. Can anyone think of a better solution than overloading populate and wrapping super.populate in a synchronized block? Perhaps I could get better luck using a normal Overlay? The Itemized one seems to exist to manage the data for you, perhaps I am making a fundamental mistake by using it? Thanks for any help, my brain is hurting! Hamy

Read the article
Python threads all executing on a single core

- by Rob Lourens

I have a Python program that spawns many threads, runs 4 at a time, and each performs an expensive operation. Pseudocode: for object in list: t = Thread(target=process, args=(object)) # if fewer than 4 threads are currently running, t.start(). Otherwise, add t to queue But when the program is run, Activity Monitor in OS X shows that 1 of the 4 logical cores is at 100% and the others are at nearly 0. Obviously I can't force the OS to do anything but I've never had to pay attention to performance in multi-threaded code like this before so I was wondering if I'm just missing or misunderstanding something. Thanks.

Read the article

< Previous Page | 220 221 222 223 224 225 226 227 228 229 230 231 | Next Page >