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  • Communicate progress from local Service

    - by kpdvx
    An application I'm building uses a local Service for downloading files from the web to the phone's SD card. In this app users can browse lists of books, and read them while online. A user can also download a pdf copy of a book for offline viewing. To handle downloads I'm using a locally bound Service. I do not want this Service to run all the time, only when downloading files. So that the Service can shut itself down when its tasks are complete, I am not binding to the service, rather I'm sending an "enqueue for download" command through the Intent passed to Context.startService. Books available for download are shown in a list. A user can choose to download a book by clicking on its row in the list. On download, I need to show download progress using a ProgressBar on the actual book list row. I need to also show, on the rows, if a book is enqueued for download, or if its download has completed or failed. The books can be shown in different activities throughout the application--in search, or in the user's list of favorite books, for example. When the books are shown in different places, these are not the same objects, but they are uniquely identified by their bookId. Because I do not want to bind to the service from every Activity, my tentative plan was to use a public static final HashMap on the Service class itself to contain a mapping of bookId to download status, an enum of enqueued, downloading, cancelled, etc. Each book view, when displayed, would check this static HashMap, and if the bookId is in the map, retrieve and display its status. I don't particularly like this idea, but at the moment it's the only way I can think of to retrieve status from the Service without having to bind to it and start it. Additionally I need to retrieve download progress percent from the Service, for a given bookId, if it is the active download. Again I'd rather not bind to the service from every activity, so I'm not sure how to go about retrieving current progress from the Service. My current plan is to use some sort of singleton mediator, that the Service will push updates to, and the views can read from. But I'm not terribly happy with this idea. The reason I'd like to avoid binding to the Service from each Activity is 1.) I'm already running another Service and 2.) binding is verbose and I'd like to avoid needing to pass around a reference to the Service (but admittedly this isn't too much of a problem). Perhaps binding to the local Service isn't expensive enough to warrant this other setup? Should I not be concerned about binding to it from each Activity? Maybe this is a non-issue?

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  • newbie in Jquery (including but no result)

    - by Negin
    I have this code: <html> <head> </head> <body> <form method='post'> <link type="text/css" href="css/themename/jquery-ui-1.8.14.custom.css" rel="Stylesheet" /> <script type="text/javascript" src="js/jquery-1.4.4.min.js"></script> <script type="text/javascript" src="js/jquery-ui-1.8.14.custom.min.js"></script> <style> #feedback { font-size: 1.4em; } #selectable .ui-selecting { background: #FECA40; } #selectable .ui-selected { background: #F39814; color: white; } #selectable { list-style-type: none; margin: 0; padding: 0; width: 60%; } #selectable li { margin: 3px; padding: 0.4em; font-size: 1.4em; height: 18px; } </style> <script> $(function() { $( "#selectable" ).selectable(); }); </script> <div class="demo"> <ol id="selectable"> <li class="ui-widget-content">Item 1</li> <li class="ui-widget-content">Item 2</li> <li class="ui-widget-content">Item 3</li> </ol> </div><!-- End demo --> <div class="demo-description" style="display: none; "> <p>Enable a DOM element (or group of elements) to be selectable. Draw a box with your cursor to select items. Hold down the Ctrl key to make multiple non-adjacent selections. </p> </div><!-- End demo-description --> </form> </body> </html> I downloaded the jquery but it has no result I used this site: http://jqueryui.com/demos/selectable/#event-create what is wrong here?

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  • Is it possible to use CSS to align these divs/spans in a table-like manner? (While still retaining continuity)

    - by Justin L.
    I have <div class='line'> <div class='chord_line'> <span class='chord_block'></span> <span class='chord_block'>E</span> <span class='chord_block'>B</span> <span class='chord_block'>C#m</span> <span class='chord_block'>A</span> </div> <div class='lyric_line'> <span class='lyric_block'></span> <span class='lyric_block'>Just a</span> <span class='lyric_block'>small-town girl</span> <span class='lyric_block'>living in a</span> <span class='lyric_block'>lonely world</span> </div> </div> (Excuse me for not being too familiar with proper css conventions for when to use div/spans) I want to be able to display them so that each chord_block span and lyric_block span is aligned vertically, as if they were left-aligned and on the same row of a table. For example: E B C#m A Just a small-town girl living in a lonely world (There will often be cases where an empty chord block is matched up to non-empty lyric block, and vice-versa.) I'm completely new to using CSS to align things, and have had no real understanding/experience of CSS aside from changing background colors and link styles. Is this possible in CSS? If not, how could the div/class nesting structure be revised to make this possible? I could change the spans to divs if necessary. Some things I cannot use: I can't change the structure to group things by a chord_and_lyric_block div (and have their width stretch to the length of the lyric, and stack them horizontally), because I couldn't really copy/select the lyrical lines continuously in their entirety, which is extremely critical. I'm trying to avoid a table-like solution, because this data is not tabular at all. The chord line and the lyric line are meant to be read as one continuous line, not a set of cells. Also, apart from the design philosophy reasons, I think it might have the same problems as the previous thing bullet point. If this is possible, what div/span attributes should I be using? Can you provide sample css? If this is not possible, can it be done with javascript? EDIT: I'm sorry I wasn't clear at the start, but I would like a solution that allows both the chord line and the lyric line to be "selectable" and continuous.

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  • Wake up thread blocked on accept() call

    - by selbie
    Sockets on Linux question I have a worker thread that is blocked on an accept() call. It simply waits for an incoming network connection, handles it, and then returns to listening for the next connection. When it is time for the program to exit, how do I signal this network worker thread (from the main thread) to return from the accept() call while still being able to gracefully exit its loop and handle it's cleanup code. Some things I tried: 1. pthread_kill to send a signal. Feels kludgy to do this, plus it doesn't reliably allow the thread to do it's shutdown logic. Also makes the program terminate as well. I'd like to avoid signals if at all possible. pthread_cancel. Same as above. It's a harsh kill on the thread. That, and the thread may be doing something else. Closing the listen socket from the main thread in order to make accept() abort. This doesn't reliably work. Some constraints: If the solution involves making the listen socket non-blocking, that is fine. But I don't want to accept a solution that involves the thread waking up via a select call every few seconds to check the exit condition. The thread condition to exit may not be tied to the process exiting. Essentially, the logic I am going for looks like this. void* WorkerThread(void* args) { DoSomeImportantInitialization(); // initialize listen socket and some thread specific stuff while (HasExitConditionBeenSet()==false) { listensize = sizeof(listenaddr); int sock = accept(listensocket, &listenaddr, &listensize); // check if exit condition has been set using thread safe semantics if (HasExitConditionBeenSet()) { break; } if (sock < 0) { printf("accept returned %d (errno==%d)\n", sock, errno); } else { HandleNewNetworkCondition(sock, &listenaddr); } } DoSomeImportantCleanup(); // close listen socket, close connections, cleanup etc.. return NULL; } void SignalHandler(int sig) { printf("Caught CTRL-C\n"); } void NotifyWorkerThreadToExit(pthread_t thread_handle) { // signal thread to exit } int main() { void* ptr_ret= NULL; pthread_t workerthread_handle = 0; pthread_create(&workerthread, NULL, WorkerThread, NULL); signal(SIGINT, SignalHandler); sleep((unsigned int)-1); // sleep until the user hits ctrl-c printf("Returned from sleep call...\n"); SetThreadExitCondition(); // sets global variable with barrier that worker thread checks on // this is the function I'm stalled on writing NotifyWorkerThreadToExit(workerthread_handle); // wait for thread to exit cleanly pthread_join(workerthread_handle, &ptr_ret); DoProcessCleanupStuff(); }

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  • iOS dynamic object creation

    - by Abdul Ahmad
    I've worked with Xcode and iOS on a few personal projects and have always used non-object-oriented designs for everything... just because I've been doing mostly learning/experimenting with things. Now I've been trying to implement some object oriented design into one game I've made previously. The idea is, I have a space ship that can shoot bullets. In the past I basically added the UIImageView to the storyboard and then connected it to the .h file and from there did things on it like move it around or whatever (using CGPointMake). The idea now is to make a method (and a whole other class soon) that will create a UIImageView programmatically, allocate it, add it to the superview etc... I've got this working so far, easy stuff, but the next part is a bit harder. Where do I store this local variable "bullet"? I've been saving it to an NSMutableArray and doing the following: (actually here are the methods that I have) -(void)movement { for (int i = 0; i < [array1 count]; i ++) { UIImageView *a = [array1 objectAtIndex:i]; a.center = CGPointMake(a.center.x + 2, a.center.y); if (a.center.x > 500) { [array1 removeObjectAtIndex:i]; [a removeFromSuperview]; } } } -(void)getBullet { UIImageView *bullet = [[UIImageView alloc] initWithFrame:CGRectMake(ship.center.x + 20, ship.center.y - 2, 15, 3)]; bullet.image = [UIImage imageNamed:@"bullet2.png"]; bullet.hidden = NO; [self.view addSubview:bullet]; [array1 addObject:bullet]; } (by the way, array1 is declared in the .h file) and theres a timer that controls the movement method timer = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(movement) userInfo:nil repeats:YES]; first question is: what is the correct way of doing this? Storing a bullet for example until it is removed from the superview, should I store it another way? and another question is, when I remove a UIImageView from the superview, does that remove it from memory so its not using up system resources? Thank you for the help! (will update if I Think of other questions

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  • A versioning workflow for multiple similar (but not identical) deployments

    - by rs77
    I'm currently employed at a small non-tech organisation and have been given the role of coding the organisations' website. While I have enjoyed the task and have learnt much with web dev I've encountered a few issues that I'm hoping someone will be able to help with me or at least point me in the right direction on. A little background: The site I work on has subdomains that each have their own separate WordPress installation on - as this has been the easiest "backend" admin panel for the type of user who will be responsible for updating content (etc). Within the organisation I work under the Marketing Manager (MM) and I code according to his style guide and wire frames. While we have been working with only one subdomain since the beginning of the year the project has been relatively simple and straightforward. However, lately the workflow is becoming a little more complicated as our original subdomain has been copied over to the other subdomains. Each of the new subdomains receives minor edits to their stylesheets (eg. different pictures for background, slightly different colours here and there, etc). The issue: At the moment managing all the different subdomains has been "bearable", but the straw that's braking the camel's back at the moment has been the slight reversions the MM has required now that the CEO has seen the final product. The problem I'm having with reversions in stylesheets is that the CEO will one week state that he likes change "X" and then as the MM and I continue to modify the site (to now "Z"), will another week state that he wants us to change "X" to "W" but keeping most of the changes made in "Y". What I'm looking for is something that allows for: tracking file changes reverting changes made (or reverting back to 'a' from 'e' but including changes 'b' & 'c') easily upload necessary files to their respective WP-theme installation Does anything out there come close to addressing these issues? If so, what? Thanks for any help! PS - I'm learning Git at the moment and it seems to do the "tracking file changes" quite nicely. Haven't learnt about the reverting changes bit yet, though. Maybe for my final point I'm thinking of creating a shell script to automatically upload the files to their folders. Does Git do this too though? Addendum (alexbbrown) I had a similar problem: I ran a custom version of mediawiki where I installed various extensions in the versioned core (with svn). Each of the extensions required an section in the confit file, but the confit file also needed local configuration for each of several deployments. I could have implemented it using includes, but they would not be versioned; and rebasing branches each time is a chore. +50 experience points for a good answer in git.

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  • No warning from gcc when function definition in linked source different from function prototype in h

    - by c_c
    Hi, I had a problem with a part of my code, which after some iterations seemed to read NaN as value of a int of a struct. I think I found the error, but am still wondering why gcc (version 3.2.3 on a embedded Linux with busybox) did not warn me. Here are the important parts of the code: A c file and its header for functions to acquire data over USB: // usb_control.h typedef struct{ double mean; short *values; } DATA_POINTS; typedef struct{ int size; DATA_POINTS *channel1; //....7 more channels } DATA_STRUCT; DATA_STRUCT *create_data_struct(int N); // N values per channel int free_data_struct(DATA_STRUCT *data); int aqcu_data(DATA_STRUCT *data, int N); A c and header file with helper function (math, bitshift,etc...): // helper.h int mean(DATA_STRUCT *data); // helper.c (this is where the error is obviously) double mean(DATA_STRUCT *data) { // sum in for loop data->channel1->mean = sum/data->N; // ...7 more channels // a printf here displayed the mean values corretly } The main file // main.c #include "helper.h" #include "usb_control.h" // Allocate space for data struct DATA_STRUCT *data = create_data_struct(N); // get data for different delays for (delay = 0; delay < 500; delay += pw){ acqu_data(data, N); mean(data); // printf of the mean values first is correct. Than after 5 iterations // it is always NaN for channel1. The other channels are displayed correctly; } There were no segfaults nor any other missbehavior, just the NaN for channel1 in the main file. After finding the error, which was not easy, it was of course east to fix. The return type of mean(){} was wrong in the definition. Instead of double mean() it has to be int mean() as the prototype defines. When all the functions are put into one file, gcc warns me that there is a redefinition of the function mean(). But as I compile each c file seperately and link them afterwards gcc seems to miss that. So my questions would be. Why didn't I get any warnings, even non with gcc -Wall? Or is there still another error hidden which is just not causing problems now? Regards, christian

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  • mvc partial views loses track of the images folder when using jquery

    - by jvelez
    This is what I have and it works: $(function(){ $('.slide-out-div').tabSlideOut({ tabHandle: '.handle', //class of the element that will become your tab pathToTabImage: 'http://mhmiisdev2/images/contact_tab.gif', //path to the image for the tab //Optionally can be set using css imageHeight: '122px', //height of tab image //Optionally can be set using css imageWidth: '40px', //width of tab image //Optionally can be set using css tabLocation: 'right', //side of screen where tab lives, top, right, bottom, or left speed: 300, //speed of animation action: 'click', //options: 'click' or 'hover', action to trigger animation topPos: '200px', //position from the top/ use if tabLocation is left or right leftPos: '20px', //position from left/ use if tabLocation is bottom or top fixedPosition: true //options: true makes it stick(fixed position) on scroll }); }); This is what I want and it doesnt work when I change from one controller to another controller. NOTICE THE IMAGE PATH IS NOT ABSOLUTE $(function(){ $('.slide-out-div').tabSlideOut({ tabHandle: '.handle', //class of the element that will become your tab pathToTabImage: '/images/contact_tab.gif', //path to the image for the tab //Optionally can be set using css imageHeight: '122px', //height of tab image //Optionally can be set using css imageWidth: '40px', //width of tab image //Optionally can be set using css tabLocation: 'right', //side of screen where tab lives, top, right, bottom, or left speed: 300, //speed of animation action: 'click', //options: 'click' or 'hover', action to trigger animation topPos: '200px', //position from the top/ use if tabLocation is left or right leftPos: '20px', //position from left/ use if tabLocation is bottom or top fixedPosition: true //options: true makes it stick(fixed position) on scroll }); }); the html for completeness.... <div class="slide-out-div"> <a class="handle" href="http://link-for-non-js-users.html">Content</a> <h3>Medical Variance Reports</h3> <div> <ul> <li><a href="http://mhmssrs2/Reports/Pages/Report.aspx?" target="_blank">Individual Medicines</a></li> </ul> </div> </div> I suspect somehow pathToTabImage: /images/contact_tab.gif' loses its context when browsing throught controllers. Help me understand...

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  • JQuery, Load() contents with plugins

    - by Galas
    I know this is not a completely new question, but none of the answers solved my problem... I have built a little menu that uses load() to load image galleries (as external html files) into a specified div ("content"). The said galleries make use of a JQuery plugin (SlideJS). Now I know that load() does not work for script tags and that I need to use $.getscript in the callback function in order to run the scripts, but it does not work. I have two .js files that need to be loaded: one is the plugin itself and another one is a smaller script with a preloader and the animations for the captions. I can't seem to merge them together; if I put them into the same document, the script won't run. So I tried just using $.getscript to load the two files. I tried using two callbacks as suggested in other answer (I know it's not ideal...): $("#proposal").click(function(){ $(this).addClass('selected'); $("a:not(:#proposal)").removeClass('selected'); $("#content").load("works/proposal/proposal.html", function(){ $.getScript("js/slide.js", function (){ $.getScript("js/slidepage.js"); }); }); }); and I tried a variable (read about it in some other faq, not sure if the syntax is correct) $("#proposal").click(function(){ $(this).addClass('selected'); $("a:not(:#proposal)").removeClass('selected'); $("#content").load("works/proposal/proposal.html", function(){ var scripts = ['js/slide.js','js/slidepage.js']; $.getScript(scripts); }); }); So none of these work. What am I doing wrong? I'm just starting on jquery and my js knowledge is very limited. Should I just merge the two .js files together using minify or something? One of them is already minified, but I've tried with a non-minified version and it does not work either. Can anyone suggest any other solution around this problem? I thought of just having the div embedded in the main document and just showing it on click, but I'll have at least 4 galleries with about 8 to 10 images each... its a lot of images to load in the main page, so I don't think its the best way. if you need me to post any more code, please ask! Thanks in advance for all your help!

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  • Handling Model Inheritance in ASP.NET MVC2

    - by enth
    I've gotten myself stuck on how to handle inheritance in my model when it comes to my controllers/views. Basic Model: public class Procedure : Entity { public Procedure() { } public int Id { get; set; } public DateTime ProcedureDate { get; set; } public ProcedureType Type { get; set; } } public ProcedureA : Procedure { public double VariableA { get; set; } public int VariableB { get; set; } public int Total { get; set; } } public ProcedureB : Procedure { public int Score { get; set; } } etc... many of different procedures eventually. So, I do things like list all the procedures: public class ProcedureController : Controller { public virtual ActionResult List() { IEnumerable<Procedure> procedures = _repository.GetAll(); return View(procedures); } } but now I'm kinda stuck. Basically, from the list page, I need to link to pages where the specific subclass details can be viewed/edited and I'm not sure what the best strategy is. I thought I could add an action on the ProcedureController that would conjure up the right subclass by dynamically figuring out what repository to use and loading the subclass to pass to the view. I had to store the class in the ProcedureType object. I had to create/implement a non-generic IRepository since I can't dynamically cast to a generic one. public virtual ActionResult Details(int procedureID) { Procedure procedure = _repository.GetById(procedureID, false); string className = procedure.Type.Class; Type type = Type.GetType(className, true); Type repositoryType = typeof (IRepository<>).MakeGenericType(type); var repository = (IRepository)DependencyRegistrar.Resolve(repositoryType); Entity procedure = repository.GetById(procedureID, false); return View(procedure); } I haven't even started sorting out how the view is going to determine which partial to load to display the subclass details. I'm wondering if this is a good approach? This makes determining the URL easy. It makes reusing the Procedure display code easy. Another approach is specific controllers for each subclass. It simplifies the controller code, but also means many simple controllers for the many procedure subclasses. Can work out the shared Procedure details with a partial view. How to get to construct the URL to get to the controller/action in the first place? Time to not think about it. Hopefully someone can show me the light. Thanks in advance.

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  • IntentService android download and return file to Activity

    - by Andrew G
    I have a fairly tricky situation that I'm trying to determine the best design for. The basics are this: I'm designing a messaging system with a similar interface to email. When a user clicks a message that has an attachment, an activity is spawned that shows the text of that message along with a paper clip signaling that there is an additional attachment. At this point, I begin preloading the attachment so that when the user clicks on it - it loads more quickly. currently, when the user clicks the attachment, it prompts with a loading dialog until the download is complete at which point it loads a separate attachment viewer activity, passing in the bmp byte array. I don't ever want to save attachments to persistent storage. The difficulty I have is in supporting rotation as well as home button presses etc. The download is currently done with a thread and handler setup. Instead of this, I'd like the flow to be the following: User loads message as before, preloading begins of attachment as before (invisible to user). When the user clicks on the attachment link, the attachment viewer activity is spawned right away. If the download was done, the image is displayed. If not, a dialog is shown in THIS activity until it is done and can be displayed. Note that ideally the download never restarts or else I've wasted cycles on the preload. Obviously I need some persistent background process that is able to keep downloading and is able to call back to arbitrarily bonded Activities. It seems like the IntentService almost fits my needs as it does its work in a background thread and has the Service (non UI) lifecycle. However, will it work for my other needs? I notice that common implementations for what I want to do get a Messenger from the caller Activity so that a Message object can be sent back to a Handler in the caller's thread. This is all well and good but what happens in my case when the caller Activity is Stopped or Destroyed and the currently active Activity (the attachment viewer) is showing? Is there some way to dynamically bind a new Activity to a running IntentService so that I can send a Message back to the new Activity? The other question is on the Message object. Can I send arbitrarily large data back in this package? For instance, rather than send back that "The file was downloaded", I need to send back the byte array of the downloaded file itself since I never want to write it to disk (and yes this needs to be the case). Any advice on achieving the behavior I want is greatly appreciated. I've not been working with Android for that long and I often get confused with how to best handle asynchronous processes over the course of the Activity lifecycle especially when it comes to orientation changes and home button presses...

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  • How to merge two test into one RSpec

    - by thefonso
    Both the last two test work individually...but when both are set to run (non pending) I get problems. question: can I create a test that merges the two into one? How would this look?(yes, I am new to rspec) require_relative '../spec_helper' # the universe is vast and infinite....and...it is empty describe "tic tac toe game" do context "the game class" do before (:each) do player_h = Player.new("X") player_c = Player.new("O") @game = Game.new(player_h, player_c) end it "method drawgrid must return a 3x3 game grid" do @game.drawgrid.should eq("\na #{$thegrid[:a1]}|#{$thegrid[:a2]}|#{$thegrid[:a3]} \n----------\nb #{$thegrid[:b1]}|#{$thegrid[:b2]}|#{$thegrid[:b3]} \n----------\nc #{$thegrid[:c1]}|#{$thegrid[:c2]}|#{$thegrid[:c3]} \n----------\n 1 2 3 \n") @game.drawgrid end #FIXME - last two test here - how to merge into one? it "play method must display 3x3 game grid" do STDOUT.should_receive(:puts).and_return("\na #{$thegrid[:a1]}|#{$thegrid[:a2]}|#{$thegrid[:a3]} \n----------\nb #{$thegrid[:b1]}|#{$thegrid[:b2]}|#{$thegrid[:b3]} \n----------\nc #{$thegrid[:c1]}|#{$thegrid[:c2]}|#{$thegrid[:c3]} \n----------\n 1 2 3 \n").with("computer move") @game.play end it "play method must display 3x3 game grid" do STDOUT.should_receive(:puts).with("computer move") @game.play end end end just for info here is the code containing the play method require_relative "player" # #Just a Tic Tac Toe game class class Game #create players def initialize(player_h, player_c) #bring into existence the board and the players @player_h = player_h @player_c = player_c #value hash for the grid lives here $thegrid = { :a1=>" ", :a2=>" ", :a3=>" ", :b1=>" ", :b2=>" ", :b3=>" ", :c1=>" ", :c2=>" ", :c3=>" " } #make a global var for drawgrid which is used by external player class $gamegrid = drawgrid end #display grid on console def drawgrid board = "\n" board << "a #{$thegrid[:a1]}|#{$thegrid[:a2]}|#{$thegrid[:a3]} \n" board << "----------\n" board << "b #{$thegrid[:b1]}|#{$thegrid[:b2]}|#{$thegrid[:b3]} \n" board << "----------\n" board << "c #{$thegrid[:c1]}|#{$thegrid[:c2]}|#{$thegrid[:c3]} \n" board << "----------\n" board << " 1 2 3 \n" return board end #start the game def play #draw the board puts drawgrid #external call to player class @player = @player_c.move_computer("O") end end player_h = Player.new("X") player_c = Player.new("O") game = Game.new(player_h, player_c) game.play

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  • Have main thread wait for a boost thread complete a task (but not finish).

    - by JAKE6459
    I have found plenty on making one thread wait for another to finish executing before continuing, but that is not what I wanted to do. I am not very familiar with using any multi-threading apis but right now I'm trying to learn boost. My situation is that I am using my main thread (the starting one from int main()) to create an instance of a class that is in charge of interacting with the main GUI. A class function is then called that creates a boost thread which in turn creates the GUI and runs the message pump. The thing I want to do is when my main thread calls the classes member function to create the GUI, I don't want that function to return until I tell it to from the newly created thread. This way my main thread can't continue and call more functions from the GUI class that interact with the GUI thread until that thread has completed GUI creation and entered the message loop. I think I may be able to figure it out if it was multiple boost thread objects interacting with each other, but when it is the main thread (non-boost object) interacting with a boost thread object, I get lost. Eventually I want a loop in my main thread to call a class function (among other tasks) to check if the user as entered any new input into the GUI (buy any changes detected by the message loop being updated into a struct and changing a bool to tell the main thread in the class function a change has occurred). Any suggestions for any of this would be greatly appreciated. This is the member function called by the main thread. int ANNGUI::CreateGUI() { GUIMain = new Main(); GUIThread = new boost::thread(boost::bind(&Main::MainThreadFunc, GUIMain)); return 0; }; This is the boost thread starting function. void Main::MainThreadFunc() { ANNVariables = new GUIVariables; WndProc = new WindowProcedure; ANNWindowsClass = new WindowsClass(ANNVariables, WndProc); ANNWindow = new MainWindow(ANNVariables); GUIMessagePump = new MessagePump; ANNWindow-ShowWindows(); while(true) { GUIMessagePump-ProcessMessage(); } }; BTW, everything compiles fine and when I run it, it works I just put a sleep() in the main thread so I can play with the GUI a little.

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  • Where can I find "canonical" sample programs that give quick refreshers for any given language? [on hold]

    - by acheong87
    Note to those close-voting this question: I understand this isn't a conventional programming question and I can agree with the reasoning that it's in the subjective domain (like best-of lists). In other ways though I think it's appropriate because, though it's not a "a specific programming problem," nor concerning "a software algorithm", nor (strictly) concerning "software tools commonly used by programmers", I think it is a "practical, answerable [problem that is] unique to the programming profession," and I think it is "based on an actual [problem I] face." I've been wanting this for some time now, because both approaches of (a) Googling for samples as I write every other line of code and (b) just winging it and seeing what errors crop up, distract me from coding efficiently. This note will be removed if the question gains popularity; this question will be deleted otherwise. I spend most of my time developing in C++, PHP, or Javascript, and every once in a while I have to do something in, say, VBA. In those times, it'd be convenient if I could just put up some sample code on a second monitor, something in between a cheat sheet (often too compact; and doesn't resemble anything that could actually compile/run), and a language reference (often too verbose, or segmented; requires extra steps to search or click through an index), so I can just glance at it and recall things, like how to loop through non-empty cells in a column. I think there's a hidden benefit to seeing formed code, that triggers the right spots in our brains to get back into a language we only need to brush up on. Similar in spirit is how http://ideone.com lets you click "Template" in any given language so you can get started without even doing a search. That template alone tells a lot, sometimes! Case-sensitivity, whitespace conventions, identifier conventions, the spelling of certain types, etc. I couldn't find a resource that pulled together such samples, so if there indeed doesn't exist such a repository, I was hoping this question would inspire professionals and experts to contribute links to the most useful sample code they've used for just this purpose: a keep-on-the-side, form-as-well-as-content, compilable/executable, reminder of a language's basic and oft-used features. Personally I am interested in seeing "samplers" for: VBA, Perl, Python, Java, C# (though for some of these autocompleters in Eclipse, Visual Studio, etc. help enough), awk, and sed. I'm tagging c++, php, and javascript because these are languages for which I'd best be able to evaluate whether proffered sample code matches what I had in mind.

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  • Data extract from website URL

    - by user2522395
    From this below script I am able to extract all links of particular website, But i need to know how I can generate data from extracted links especially like eMail, Phone number if its there Please help how i will modify the existing script and get the result or if you have full sample script please provide me. Private Sub btnGo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGo.Click 'url must be in this format: http://www.example.com/ Dim aList As ArrayList = Spider("http://www.qatarliving.com", 1) For Each url As String In aList lstUrls.Items.Add(url) Next End Sub Private Function Spider(ByVal url As String, ByVal depth As Integer) As ArrayList 'aReturn is used to hold the list of urls Dim aReturn As New ArrayList 'aStart is used to hold the new urls to be checked Dim aStart As ArrayList = GrabUrls(url) 'temp array to hold data being passed to new arrays Dim aTemp As ArrayList 'aNew is used to hold new urls before being passed to aStart Dim aNew As New ArrayList 'add the first batch of urls aReturn.AddRange(aStart) 'if depth is 0 then only return 1 page If depth < 1 Then Return aReturn 'loops through the levels of urls For i = 1 To depth 'grabs the urls from each url in aStart For Each tUrl As String In aStart 'grabs the urls and returns non-duplicates aTemp = GrabUrls(tUrl, aReturn, aNew) 'add the urls to be check to aNew aNew.AddRange(aTemp) Next 'swap urls to aStart to be checked aStart = aNew 'add the urls to the main list aReturn.AddRange(aNew) 'clear the temp array aNew = New ArrayList Next Return aReturn End Function Private Overloads Function GrabUrls(ByVal url As String) As ArrayList 'will hold the urls to be returned Dim aReturn As New ArrayList Try 'regex string used: thanks google Dim strRegex As String = "<a.*?href=""(.*?)"".*?>(.*?)</a>" 'i used a webclient to get the source 'web requests might be faster Dim wc As New WebClient 'put the source into a string Dim strSource As String = wc.DownloadString(url) Dim HrefRegex As New Regex(strRegex, RegexOptions.IgnoreCase Or RegexOptions.Compiled) 'parse the urls from the source Dim HrefMatch As Match = HrefRegex.Match(strSource) 'used later to get the base domain without subdirectories or pages Dim BaseUrl As New Uri(url) 'while there are urls While HrefMatch.Success = True 'loop through the matches Dim sUrl As String = HrefMatch.Groups(1).Value 'if it's a page or sub directory with no base url (domain) If Not sUrl.Contains("http://") AndAlso Not sUrl.Contains("www") Then 'add the domain plus the page Dim tURi As New Uri(BaseUrl, sUrl) sUrl = tURi.ToString End If 'if it's not already in the list then add it If Not aReturn.Contains(sUrl) Then aReturn.Add(sUrl) 'go to the next url HrefMatch = HrefMatch.NextMatch End While Catch ex As Exception 'catch ex here. I left it blank while debugging End Try Return aReturn End Function Private Overloads Function GrabUrls(ByVal url As String, ByRef aReturn As ArrayList, ByRef aNew As ArrayList) As ArrayList 'overloads function to check duplicates in aNew and aReturn 'temp url arraylist Dim tUrls As ArrayList = GrabUrls(url) 'used to return the list Dim tReturn As New ArrayList 'check each item to see if it exists, so not to grab the urls again For Each item As String In tUrls If Not aReturn.Contains(item) AndAlso Not aNew.Contains(item) Then tReturn.Add(item) End If Next Return tReturn End Function

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  • Why is the page still caching even after the no-cache headers have been sent?

    - by Matthew Grasinger
    I've done a ton of research on this and have asked many people with help and still no success. Here are the details... I'm involved in developing a website that pulls data from various data files, combines them in a temp .csv file, and then is graphed using a popular graphing library: dygraphs. The bulk of the website is written in PHP. The parameters that determine the data that is graphed are stored in the users session, the .csv is named after the users session and available for download, and then the .csv file is written in a script that passes it to the dygraphs object. And we've found, even with the no-cache headers sent: header("Cache-Control: no-cache, must-revalidate"); header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); Many users experience in the middle of a session, (if enough different graphs are generated) the page displaying an older, static rendering of the page (data they had graphed earlier in the session) as if it were cached and loaded instead of getting a new request. It only gets weirder though: I've checked using developer tools in both Firefox and Chrome and both browsers are receiving the no-cache headers just fine; Even when the problem occurs if you view the page source, the source is the correct content (a table/legend is also dynamically created using php, the source shows the correct table, but what is rendered is older content); the page begins to render correctly until the graph is about to be display, and then shows the older content; the older content displays as if it were a completely static overlay--the cached graph does not have the same dynamic features (roll over data point display, zoom and pan, etc.) And it is as if the correct page were somewhere beneath it (the download button for the csv file moves depending on how large the table is. The older, static page does nothing if you click the download .csv button, but if you can manage to find the one in the page beneath it you can click and still download the .csv. The data in the .csv is correct) It is one of the strangest things I've seen in development thus far. Some other relevant facts are that all the problems I've personally experience occurred while I was using Chrome. Non of these symptoms have been reported by Firefox users. IE users have had the same problems (IE users are forced to use chrome frame). I'm at my wits end at this point. We've sent the php headers; we've tried setting the cache profile for php on IIS as "DisableCache" (or whatever); we've tried sending a random query string to the results page; we've tried all the appropriate meta tags--all with no success.

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  • VB.Net 2008 IDE hanging - MSVB7.dll eating 100% CPU when editing code

    - by Andrew Backer
    I am having a problem with msvb7.dll eating 50%+ cpu on my dual core system. This usually lasts 10-30 seconds or so, during which time the IDE is non-responsive. This occurs when I do pretty much anything in the text editor, and can be replicated by simply adding blank lines to a function, and then deleting them. Or pasting some code. Or... lotsa stuff. SP1 installed I had DevExpress' refactor/coderush, components, and codeit.right installed, but have removed all 3 of them. (I had installed the latest version of Refactor Pro! (9.3.4), perhaps the day before) I have tried a VS.NET Repair. There is a kb that referenced some cpu destroying with vb, but it was included in SP1 Also: The solution consists of ~30 VB projects and 2 C# projects 8 other developers aren't having any issues with this (or at least not the SAME issues, we all have em) Clean get from TFS was done Project builds properly, can can even debug. This doesn't seem to happen on really small solutions, but perhaps it does and it just goes away super quick. Any clues at all as to what might be causing this, or how to fix it? I REALLY don't want to lose another day uninstalling and reinstalling and patching and so on =) If that even fixes it. Here is the stack trace (process explorer) that I get from the threads window when the msvb7.dll is churning. --- title in process explorer [threads] tab for process -------- cpu:49.28% cswitch delta: 300 to 3500 startaddress: [msvb7.dll+0x4218c] msvb7.dll version: 9.0.30729.1 --- actual stack trace ------- ntkrnlpa.exe!KiUnexpectedInterrupt+0x121 ntkrnlpa.exe!ZwYieldExecution+0x1c56 ntkrnlpa.exe!KiDispatchInterrupt+0x72e NDIS.sys!NdisFreeToBlockPool+0x15e1 // shortened stack trace. all of these are from msvb7, msvb7.dll+0x46ce7 <- 0x2676a <- 0x2698e <- 0x38031 <- 0x2659f <- 0x26644 msvb7.dll+0x25f29 <- 0x2ac7a <- 0x27522 <- 0x274a0 <- 0x2b5ce <- 0x2b6e4 msvb7.dll+0x67d0a <- 0x68551 <- 0x6817b <- 0x681f0 <- 0x67c38 <- 0x65fa8 msvb7.dll+0x666c6 <- 0x6672c <- 0x6673d <- 0x6677c <- 0x667b4 <- 0x63c77 msvb7.dll+0x63e97 <- 0x42c3a <- 0x42bc1 <- 0x41bd7 kernel32.dll!GetModuleFileNameA+0x1b4 This is the list of stuff from "copy info" in help-about, shortened to a resonable length. Microsoft Visual Studio 2008 | Version 9.0.30729.1 SP Microsoft Visual Studio 2008 Professional Edition - ENU Service Pack 1 (KB945140) KB945140 Microsoft .NET Framework | Version 3.5 SP1 Microsoft Visual Basic 2008 Microsoft Visual C# 2008 Microsoft Visual F# for Visual Studio 2008 Microsoft Visual Studio 2008 Team Explorer | Version 9.0.30729.1 Microsoft Visual Studio 2008 Tools for Office Microsoft Visual Web Developer 2008 Hotfix for Microsoft Visual Studio 2008 Professional Edition - ENU KB944899, KB945282, KB946040, KB946308, KB946344, KB946581, KB947171 KB947173, KB947180, KB947540, KB947789, KB948127, KB946260, KB946458, KB948816 Microsoft Recipe Framework Package 8.0 Process Editor WIT Designer 1.4.0.0 Process Editor for Microsoft Visual Studio Team Foundation Server, Version 1.4.0.0 tangible T4 Editor 9.0 tangible T4 Text Template Editor - T4 Editor tangibleprojectsystem 1.0 Team Foundation Server Power Tools October 2008 SQL Prompt 4.0 (disabled)

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  • XNA 4.0 draw a cube with DrawUserIndexedPrimitives method [on hold]

    - by Leggy7
    EDIT Since I read what Mark H suggested (thanks a lot, I found it very useful) I think my question can become clearer structured this way: Using XNA 4.0, I'm trying to draw a cube. Im using this method: GraphicsDevice.DrawUserIndexedPrimitives<VertexPositionColor>( PrimitiveType.LineList, primitiveList, 0, // vertex buffer offset to add to each element of the index buffer 8, // number of vertices in pointList lineListIndices, // the index buffer 0, // first index element to read 7 // number of primitives to draw ); I got the code sample from this page which simply draw a serie of triangles. I want to modify this code in order to draw a cube. I was able to slitghly move the camera so I can have the perception of solidity, I set the vertex array to contain the 8 points defining a cube. But I can't fully understand how many primitives I have to draw (last parameter) for each of PrimitiveType. So, I wasn't able to draw the cube (just some of the edges in a non-defined order). More in detail: to build the vertex index list, the sample used // Initialize an array of indices of type short. lineListIndices = new short[(points * 2) - 2]; // Populate the array with references to indices in the vertex buffer for (int i = 0; i < points - 1; i++) { lineListIndices[i * 2] = (short)(i); lineListIndices[(i * 2) + 1] = (short)(i + 1); } I'm ashamed to say I cannot do the same in the case of a cube. what has to be the size of the lineListIndices? how should I populate it? In which order? And how do these things change when I use a different PrimitiveType? In the code sample there are also another couple of calls which I cannot fully understand, which are: // Initialize the vertex buffer, allocating memory for each vertex. vertexBuffer = new VertexBuffer(graphics.GraphicsDevice, vertexDeclaration, points, BufferUsage.None); // Set the vertex buffer data to the array of vertices. vertexBuffer.SetData<VertexPositionColor>(pointList); and vertexDeclaration = new VertexDeclaration(new VertexElement[] { new VertexElement(0, VertexElementFormat.Vector3, VertexElementUsage.Position, 0), new VertexElement(12, VertexElementFormat.Color, VertexElementUsage.Color, 0) } ); that is, for VertexBuffer and VertexDeclaration I could not find and significant (monkey-like) guide. I reported them too because I think they could be involded in understanding things. I think I also have to understand something related to the order the vertexes are stored in the array. But actually I have no clue of what I should learn to have this function drawing a cube. So, if anybody could point me to the right direction, it wil be appreciated. Hope to have made myself clear this time

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  • Bug Triage

    In this blog post brain dump, I'll attempt to describe the process my team tries to follow when dealing with new bug reports (specifically, code defect reports). This is not official Microsoft policy, just the way we do things… if you do things differently and want to share, you can do so at the bottom in the comments (or on your blog).Feature Triage TeamA subset of the feature crew, the triage team (which has representations from the PM, Dev and QA disciplines), looks at all unassigned bugs at regular intervals. This can be weekly or daily (or other frequency) dependent on which part of the product cycle we are in and what the untriaged bug load looks like. They discuss each bug considering the evidence and make a decision of whether the bug goes from Not Yet Assigned to Assigned (plus the name of the DEV to fix this) or whether it goes from Active to Resolved (which means it gets assigned back to the requestor for closure or further debate if they were not present at the triage meeting). Close to critical milestones, the feature triage team needs to further justify bugs they take to additional higher-level triage teams.Bug Opened = Not Yet AssignedSomeone (typically an SDET from the QA team) creates the bug item (e.g. in TFS), ensuring they populate all the relevant fields including: Title, Description, Repro Steps (including the Actual Result at the end of the steps), attachments of code and/or screenshots, Build number that they observed the issue in, regression details if applicable, how it was found, if a test case exists or needs to be created etc. They also indicate their opinion on the Priority and Severity. The bug status is left as Not Yet Assigned."Issue" versus "Fix for issue"The solution to some bugs is easy to determine, e.g. "bug: the column name is misspelled". Obviously the fix is to correct the spelling – still, the triage team should be explicit and enter the correct spelling in the bug's Description. Note that a bad bug name here would be "bug: fix the spelling of the column" (it describes the solution, rather than the problem).Other solutions are trickier to establish, e.g. "bug: the column header is not accessible (can only be clicked on with the mouse, not reached via keyboard)". What is the correct solution here? The last thing to do is leave this undetermined and just assign it to a developer. The solution has to be entered in the description. Behind this type of a bug usually hides a spec defect or a new feature request.The person opening the bug should focus on describing the issue, rather than the solution. The person indicates what the fix is in their opinion by stating the Expected Result (immediately after stating the Actual Result). If they have a complex suggested solution, that should be split out in a separate part, but the triage team has the final say before assigning it. If the solution is lengthy/complicated to describe, the bug can be assigned to the PM. Note: the strict interpretation suggests that any bug with no clear, obvious solution is always a hole in the spec and should always go to the PM. This also ensures the spec gets updated.Not Yet Assigned - Not Yet Assigned (on someone else's plate)If the bug is observed in our feature, but the cause is actually another team, we change the Area Path (which is the way we identify teams in TFS) and leave it as Not Yet Assigned. The triage team may add more comments as appropriate including potentially changing the repro steps. In some cases, we may even resolve the bug in our area path and open a new bug in the area path of the other team.Even though there is no action on a dev on the team, the bug still needs to be tracked. One way of doing this is to implement some notification system that informs the team when the tracked bug changed status; another way is to occasionally run a global query (against all area paths) for bugs that have been opened by a member of the team and follow up with the current owners for stale bugs.Not Yet Assigned - ResolvedThis state transition can only be made by the Feature Triage Team.0. Sometimes the bug description is not clear and in that case it gets Resolved as More Information Needed, so the original requestor can provide it.After understanding what the bug item is about, the first decision is to determine whether it needs to go to a dev.1. If it is a known bug, it gets resolved as "Duplicate" and linked to the existing bug.2. If it is "By Design" it gets resolved as such, indicating that the triage team does not think this is a bug.3. If the bug does not repro on latest bits, it is resolved as "No Repro"4. The most painful: If it is decided that we cannot fix it for this release it gets resolved as "Postponed" or "Won't Fix". The former is typically due to resources and time constraints, while the latter is due to deciding that it is not important enough to consume our resources in any release (yes, not all bugs must be fixed!). For both cases, there are other factors that contribute to the decision such as: existence of a reasonable workaround, frequency we expect users to encounter the issue, dependencies on other team to offer a solution, whether it breaks a core scenario, whether it prohibits customer feedback on a major feature, is it a regression from a previous release, impact of the fix on other partner teams (e.g. User Education, User Experience, Localization/Globalization), whether this is the right fix, does the fix impact performance goals, and last but not least, severity of bug (e.g. loss of customer data, security threat, crash, hang). The bar for fixing a bug goes up as the release date approaches. The triage team becomes hardnosed about which bugs to take, while the developers are busy resolving assigned bugs thus everyone drives for Zero Bug Bounce (ZBB). ZBB is when you have 0 active bugs older than 48 hours.Not Yet Assigned - AssignedIf the bug is something we decide to fix in this release and the solution is known, then it is assigned to a DEV. This is either the developer that will do the work, or a Lead that can further assign it to one of his developer team based on a load balancing algorithm of their choosing.Sometimes, the triage team needs the dev to do some investigation work before deciding whether to take the fix; similarly, the checkin for the fix may be gated on code review by the triage team. In these cases, these instructions are provided in the comments section of the bug and when the developer is done they notify the triage team for final decision.Additionally, a Priority and Severity (from 0 to 4) has to be entered, e.g. a P0 means "drop anything you are doing and fix this now" whereas a P4 is something you get to after all P0,1,2,3 bugs are fixed.From a testing perspective, if the bug was found through ad-hoc testing or an external team, the decision is made whether test cases should be added to avoid future regressions. This is communicated to the QA team.Assigned - ResolvedWhen the developer receives the bug (they should be checking daily for new bugs on their plate looking at bugs in order of priority and from older to newer) they can send it back to triage if the information is not clear. Otherwise, they investigate the bug, setting the Sub Status to "Investigating"; if they cannot make progress, they set the Sub Status to "Blocked" and discuss this with triage or whoever else can help them get unblocked. Once they are unblocked, they set the Sub Status to "Working on Solution"; once they are code complete they send a code review request, setting the Sub Status to "Fix Available". After the iterative code review process is over and everyone is happy with the fix, the developer checks it in and changes the state of the bug from Active (and Assigned to them) to Resolved (and Assigned to someone else).The developer needs to ensure that when the status is changed to Resolved that it is assigned to a QA person. For example, maybe the PM opened the bug, but it should be a QA person that will verify the fix - the developer needs to manually change the assignee in that case. Typically the QA person will send an email to the original requestor notifying them that the fix is verified.Resolved - ??In all cases above, note that the final state was Resolved. What happens after that? The final step should be Closed. The bug is closed once the QA person verifying the fix is happy with it. If the person is not happy, then they change the state from Resolved to Active, thus sending it back to the developer. If the developer and QA person cannot reach agreement, then triage can be brought into it. An easy way to do that is change the status back to Not Yet Assigned with appropriate comments so the triage team can re-review.It is important to note that only QA can close a bug. That means that if the opener of the bug was a PM, when the bug gets resolved by the dev it may land on the PM's plate and after a quick review, the PM would re-assign to an SDET, which is the only role that can close bugs. One exception to this is if the person that filed the bug is external: in that case, we leave it Resolved and assigned to them and also send them a notification that they need to verify the fix. Another exception is if specialized developer knowledge is needed for verifying the bug fix (e.g. it was a refactoring suggestion bug typically not observable by the user) in which case it is fine to have a developer verify the fix, and ideally a different developer to the one that opened the bug.Other links on bug triageA quick search reveals that others have talked about this subject, e.g. here, here, here, here and here.Your take?If you have other best practices your team uses to deal with incoming bug reports, feel free to share in the comments below or on your blog. Comments about this post welcome at the original blog.

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  • Parallelism in .NET – Part 11, Divide and Conquer via Parallel.Invoke

    - by Reed
    Many algorithms are easily written to work via recursion.  For example, most data-oriented tasks where a tree of data must be processed are much more easily handled by starting at the root, and recursively “walking” the tree.  Some algorithms work this way on flat data structures, such as arrays, as well.  This is a form of divide and conquer: an algorithm design which is based around breaking up a set of work recursively, “dividing” the total work in each recursive step, and “conquering” the work when the remaining work is small enough to be solved easily. Recursive algorithms, especially ones based on a form of divide and conquer, are often a very good candidate for parallelization. This is apparent from a common sense standpoint.  Since we’re dividing up the total work in the algorithm, we have an obvious, built-in partitioning scheme.  Once partitioned, the data can be worked upon independently, so there is good, clean isolation of data. Implementing this type of algorithm is fairly simple.  The Parallel class in .NET 4 includes a method suited for this type of operation: Parallel.Invoke.  This method works by taking any number of delegates defined as an Action, and operating them all in parallel.  The method returns when every delegate has completed: Parallel.Invoke( () => { Console.WriteLine("Action 1 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); }, () => { Console.WriteLine("Action 2 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); }, () => { Console.WriteLine("Action 3 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); } ); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Running this simple example demonstrates the ease of using this method.  For example, on my system, I get three separate thread IDs when running the above code.  By allowing any number of delegates to be executed directly, concurrently, the Parallel.Invoke method provides us an easy way to parallelize any algorithm based on divide and conquer.  We can divide our work in each step, and execute each task in parallel, recursively. For example, suppose we wanted to implement our own quicksort routine.  The quicksort algorithm can be designed based on divide and conquer.  In each iteration, we pick a pivot point, and use that to partition the total array.  We swap the elements around the pivot, then recursively sort the lists on each side of the pivot.  For example, let’s look at this simple, sequential implementation of quicksort: public static void QuickSort<T>(T[] array) where T : IComparable<T> { QuickSortInternal(array, 0, array.Length - 1); } private static void QuickSortInternal<T>(T[] array, int left, int right) where T : IComparable<T> { if (left >= right) { return; } SwapElements(array, left, (left + right) / 2); int last = left; for (int current = left + 1; current <= right; ++current) { if (array[current].CompareTo(array[left]) < 0) { ++last; SwapElements(array, last, current); } } SwapElements(array, left, last); QuickSortInternal(array, left, last - 1); QuickSortInternal(array, last + 1, right); } static void SwapElements<T>(T[] array, int i, int j) { T temp = array[i]; array[i] = array[j]; array[j] = temp; } Here, we implement the quicksort algorithm in a very common, divide and conquer approach.  Running this against the built-in Array.Sort routine shows that we get the exact same answers (although the framework’s sort routine is slightly faster).  On my system, for example, I can use framework’s sort to sort ten million random doubles in about 7.3s, and this implementation takes about 9.3s on average. Looking at this routine, though, there is a clear opportunity to parallelize.  At the end of QuickSortInternal, we recursively call into QuickSortInternal with each partition of the array after the pivot is chosen.  This can be rewritten to use Parallel.Invoke by simply changing it to: // Code above is unchanged... SwapElements(array, left, last); Parallel.Invoke( () => QuickSortInternal(array, left, last - 1), () => QuickSortInternal(array, last + 1, right) ); } This routine will now run in parallel.  When executing, we now see the CPU usage across all cores spike while it executes.  However, there is a significant problem here – by parallelizing this routine, we took it from an execution time of 9.3s to an execution time of approximately 14 seconds!  We’re using more resources as seen in the CPU usage, but the overall result is a dramatic slowdown in overall processing time. This occurs because parallelization adds overhead.  Each time we split this array, we spawn two new tasks to parallelize this algorithm!  This is far, far too many tasks for our cores to operate upon at a single time.  In effect, we’re “over-parallelizing” this routine.  This is a common problem when working with divide and conquer algorithms, and leads to an important observation: When parallelizing a recursive routine, take special care not to add more tasks than necessary to fully utilize your system. This can be done with a few different approaches, in this case.  Typically, the way to handle this is to stop parallelizing the routine at a certain point, and revert back to the serial approach.  Since the first few recursions will all still be parallelized, our “deeper” recursive tasks will be running in parallel, and can take full advantage of the machine.  This also dramatically reduces the overhead added by parallelizing, since we’re only adding overhead for the first few recursive calls.  There are two basic approaches we can take here.  The first approach would be to look at the total work size, and if it’s smaller than a specific threshold, revert to our serial implementation.  In this case, we could just check right-left, and if it’s under a threshold, call the methods directly instead of using Parallel.Invoke. The second approach is to track how “deep” in the “tree” we are currently at, and if we are below some number of levels, stop parallelizing.  This approach is a more general-purpose approach, since it works on routines which parse trees as well as routines working off of a single array, but may not work as well if a poor partitioning strategy is chosen or the tree is not balanced evenly. This can be written very easily.  If we pass a maxDepth parameter into our internal routine, we can restrict the amount of times we parallelize by changing the recursive call to: // Code above is unchanged... SwapElements(array, left, last); if (maxDepth < 1) { QuickSortInternal(array, left, last - 1, maxDepth); QuickSortInternal(array, last + 1, right, maxDepth); } else { --maxDepth; Parallel.Invoke( () => QuickSortInternal(array, left, last - 1, maxDepth), () => QuickSortInternal(array, last + 1, right, maxDepth)); } We no longer allow this to parallelize indefinitely – only to a specific depth, at which time we revert to a serial implementation.  By starting the routine with a maxDepth equal to Environment.ProcessorCount, we can restrict the total amount of parallel operations significantly, but still provide adequate work for each processing core. With this final change, my timings are much better.  On average, I get the following timings: Framework via Array.Sort: 7.3 seconds Serial Quicksort Implementation: 9.3 seconds Naive Parallel Implementation: 14 seconds Parallel Implementation Restricting Depth: 4.7 seconds Finally, we are now faster than the framework’s Array.Sort implementation.

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  • ASP.NET MVC ‘Extendable-hooks’ – ControllerActionInvoker class

    - by nmarun
    There’s a class ControllerActionInvoker in ASP.NET MVC. This can be used as one of an hook-points to allow customization of your application. Watching Brad Wilsons’ Advanced MP3 from MVC Conf inspired me to write about this class. What MSDN says: “Represents a class that is responsible for invoking the action methods of a controller.” Well if MSDN says it, I think I can instill a fair amount of confidence into what the class does. But just to get to the details, I also looked into the source code for MVC. Seems like the base class Controller is where an IActionInvoker is initialized: 1: protected virtual IActionInvoker CreateActionInvoker() { 2: return new ControllerActionInvoker(); 3: } In the ControllerActionInvoker (the O-O-B behavior), there are different ‘versions’ of InvokeActionMethod() method that actually call the action method in question and return an instance of type ActionResult. 1: protected virtual ActionResult InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary<string, object> parameters) { 2: object returnValue = actionDescriptor.Execute(controllerContext, parameters); 3: ActionResult result = CreateActionResult(controllerContext, actionDescriptor, returnValue); 4: return result; 5: } I guess that’s enough on the ‘behind-the-screens’ of this class. Let’s see how we can use this class to hook-up extensions. Say I have a requirement that the user should be able to get different renderings of the same output, like html, xml, json, csv and so on. The user will type-in the output format in the url and should the get result accordingly. For example: http://site.com/RenderAs/ – renders the default way (the razor view) http://site.com/RenderAs/xml http://site.com/RenderAs/csv … and so on where RenderAs is my controller. There are many ways of doing this and I’m using a custom ControllerActionInvoker class (even though this might not be the best way to accomplish this). For this, my one and only route in the Global.asax.cs is: 1: routes.MapRoute("RenderAsRoute", "RenderAs/{outputType}", 2: new {controller = "RenderAs", action = "Index", outputType = ""}); Here the controller name is ‘RenderAsController’ and the action that’ll get called (always) is the Index action. The outputType parameter will map to the type of output requested by the user (xml, csv…). I intend to display a list of food items for this example. 1: public class Item 2: { 3: public int Id { get; set; } 4: public string Name { get; set; } 5: public Cuisine Cuisine { get; set; } 6: } 7:  8: public class Cuisine 9: { 10: public int CuisineId { get; set; } 11: public string Name { get; set; } 12: } Coming to my ‘RenderAsController’ class. I generate an IList<Item> to represent my model. 1: private static IList<Item> GetItems() 2: { 3: Cuisine cuisine = new Cuisine { CuisineId = 1, Name = "Italian" }; 4: Item item = new Item { Id = 1, Name = "Lasagna", Cuisine = cuisine }; 5: IList<Item> items = new List<Item> { item }; 6: item = new Item {Id = 2, Name = "Pasta", Cuisine = cuisine}; 7: items.Add(item); 8: //... 9: return items; 10: } My action method looks like 1: public IList<Item> Index(string outputType) 2: { 3: return GetItems(); 4: } There are two things that stand out in this action method. The first and the most obvious one being that the return type is not of type ActionResult (or one of its derivatives). Instead I’m passing the type of the model itself (IList<Item> in this case). We’ll convert this to some type of an ActionResult in our custom controller action invoker class later. The second thing (a little subtle) is that I’m not doing anything with the outputType value that is passed on to this action method. This value will be in the RouteData dictionary and we’ll use this in our custom invoker class as well. It’s time to hook up our invoker class. First, I’ll override the Initialize() method of my RenderAsController class. 1: protected override void Initialize(RequestContext requestContext) 2: { 3: base.Initialize(requestContext); 4: string outputType = string.Empty; 5:  6: // read the outputType from the RouteData dictionary 7: if (requestContext.RouteData.Values["outputType"] != null) 8: { 9: outputType = requestContext.RouteData.Values["outputType"].ToString(); 10: } 11:  12: // my custom invoker class 13: ActionInvoker = new ContentRendererActionInvoker(outputType); 14: } Coming to the main part of the discussion – the ContentRendererActionInvoker class: 1: public class ContentRendererActionInvoker : ControllerActionInvoker 2: { 3: private readonly string _outputType; 4:  5: public ContentRendererActionInvoker(string outputType) 6: { 7: _outputType = outputType.ToLower(); 8: } 9: //... 10: } So the outputType value that was read from the RouteData, which was passed in from the url, is being set here in  a private field. Moving to the crux of this article, I now override the CreateActionResult method. 1: protected override ActionResult CreateActionResult(ControllerContext controllerContext, ActionDescriptor actionDescriptor, object actionReturnValue) 2: { 3: if (actionReturnValue == null) 4: return new EmptyResult(); 5:  6: ActionResult result = actionReturnValue as ActionResult; 7: if (result != null) 8: return result; 9:  10: // This is where the magic happens 11: // Depending on the value in the _outputType field, 12: // return an appropriate ActionResult 13: switch (_outputType) 14: { 15: case "json": 16: { 17: JavaScriptSerializer serializer = new JavaScriptSerializer(); 18: string json = serializer.Serialize(actionReturnValue); 19: return new ContentResult { Content = json, ContentType = "application/json" }; 20: } 21: case "xml": 22: { 23: XmlSerializer serializer = new XmlSerializer(actionReturnValue.GetType()); 24: using (StringWriter writer = new StringWriter()) 25: { 26: serializer.Serialize(writer, actionReturnValue); 27: return new ContentResult { Content = writer.ToString(), ContentType = "text/xml" }; 28: } 29: } 30: case "csv": 31: controllerContext.HttpContext.Response.AddHeader("Content-Disposition", "attachment; filename=items.csv"); 32: return new ContentResult 33: { 34: Content = ToCsv(actionReturnValue as IList<Item>), 35: ContentType = "application/ms-excel" 36: }; 37: case "pdf": 38: string filePath = controllerContext.HttpContext.Server.MapPath("~/items.pdf"); 39: controllerContext.HttpContext.Response.AddHeader("content-disposition", 40: "attachment; filename=items.pdf"); 41: ToPdf(actionReturnValue as IList<Item>, filePath); 42: return new FileContentResult(StreamFile(filePath), "application/pdf"); 43:  44: default: 45: controllerContext.Controller.ViewData.Model = actionReturnValue; 46: return new ViewResult 47: { 48: TempData = controllerContext.Controller.TempData, 49: ViewData = controllerContext.Controller.ViewData 50: }; 51: } 52: } A big method there! The hook I was talking about kinda above actually is here. This is where different kinds / formats of output get returned based on the output type requested in the url. When the _outputType is not set (string.Empty as set in the Global.asax.cs file), the razor view gets rendered (lines 45-50). This is the default behavior in most MVC applications where-in a view (webform/razor) gets rendered on the browser. As you see here, this gets returned as a ViewResult. But then, for an outputType of json/xml/csv, a ContentResult gets returned, while for pdf, a FileContentResult is returned. Here are how the different kinds of output look like: This is how we can leverage this feature of ASP.NET MVC to developer a better application. I’ve used the iTextSharp library to convert to a pdf format. Mike gives quite a bit of detail regarding this library here. You can download the sample code here. (You’ll get an option to download once you open the link). Verdict: Hot chocolate: $3; Reebok shoes: $50; Your first car: $3000; Being able to extend a web application: Priceless.

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  • Connecting Linux to WatchGuard Firebox SSL (OpenVPN client)

    Recently, I got a new project assignment that requires to connect permanently to the customer's network through VPN. They are using a so-called SSL VPN. As I am using OpenVPN since more than 5 years within my company's network I was quite curious about their solution and how it would actually be different from OpenVPN. Well, short version: It is a disguised version of OpenVPN. Unfortunately, the company only offers a client for Windows and Mac OS which shouldn't bother any Linux user after all. OpenVPN is part of every recent distribution and can be activated in a couple of minutes - both client as well as server (if necessary). WatchGuard Firebox SSL - About dialog Borrowing some files from a Windows client installation Initially, I didn't know about the product, so therefore I went through the installation on Windows 8. No obstacles (and no restart despite installation of TAP device drivers!) here and the secured VPN channel was up and running in less than 2 minutes or so. Much appreciated from both parties - customer and me. Of course, this whole client package and my long year approved and stable installation ignited my interest to have a closer look at the WatchGuard client. Compared to the original OpenVPN client (okay, I have to admit this is years ago) this commercial product is smarter in terms of file locations during installation. You'll be able to access the configuration and key files below your roaming application data folder. To get there, simply enter '%AppData%\WatchGuard\Mobile VPN' in your Windows/File Explorer and confirm with Enter/Return. This will display the following files: Application folder below user profile with configuration and certificate files From there we are going to borrow four files, namely: ca.crt client.crt client.ovpn client.pem and transfer them to the Linux system. You might also be able to isolate those four files from a Mac OS client. Frankly, I'm just too lazy to run the WatchGuard client installation on a Mac mini only to find the folder location, and I'm going to describe why a little bit further down this article. I know that you can do that! Feedback in the comment section is appreciated. Configuration of OpenVPN (console) Depending on your distribution the following steps might be a little different but in general you should be able to get the important information from it. I'm going to describe the steps in Ubuntu 13.04 (Raring Ringtail). As usual, there are two possibilities to achieve your goal: console and UI. Let's what it is necessary to be done. First of all, you should ensure that you have OpenVPN installed on your system. Open your favourite terminal application and run the following statement: $ sudo apt-get install openvpn network-manager-openvpn network-manager-openvpn-gnome Just to be on the safe side. The four above mentioned files from your Windows machine could be copied anywhere but either you place them below your own user directory or you put them (as root) below the default directory: /etc/openvpn At this stage you would be able to do a test run already. Just in case, run the following command and check the output (it's the similar information you would get from the 'View Logs...' context menu entry in Windows: $ sudo openvpn --config client.ovpn Pay attention to the correct path to your configuration and certificate files. OpenVPN will ask you to enter your Auth Username and Auth Password in order to establish the VPN connection, same as the Windows client. Remote server and user authentication to establish the VPN Please complete the test run and see whether all went well. You can disconnect pressing Ctrl+C. Simplifying your life - authentication file In my case, I actually set up the OpenVPN client on my gateway/router. This establishes a VPN channel between my network and my client's network and allows me to switch machines easily without having the necessity to install the WatchGuard client on each and every machine. That's also very handy for my various virtualised Windows machines. Anyway, as the client configuration, key and certificate files are located on a headless system somewhere under the roof, it is mandatory to have an automatic connection to the remote site. For that you should first change the file extension '.ovpn' to '.conf' which is the default extension on Linux systems for OpenVPN, and then open the client configuration file in order to extend an existing line. $ sudo mv client.ovpn client.conf $ sudo nano client.conf You should have a similar content to this one here: dev tunclientproto tcp-clientca ca.crtcert client.crtkey client.pemtls-remote "/O=WatchGuard_Technologies/OU=Fireware/CN=Fireware_SSLVPN_Server"remote-cert-eku "TLS Web Server Authentication"remote 1.2.3.4 443persist-keypersist-tunverb 3mute 20keepalive 10 60cipher AES-256-CBCauth SHA1float 1reneg-sec 3660nobindmute-replay-warningsauth-user-pass auth.txt Note: I changed the IP address of the remote directive above (which should be obvious, right?). Anyway, the required change is marked in red and we have to create a new authentication file 'auth.txt'. You can give the directive 'auth-user-pass' any file name you'd like to. Due to my existing OpenVPN infrastructure my setup differs completely from the above written content but for sake of simplicity I just keep it 'as-is'. Okay, let's create this file 'auth.txt' $ sudo nano auth.txt and just put two lines of information in it - username on the first, and password on the second line, like so: myvpnusernameverysecretpassword Store the file, change permissions, and call openvpn with your configuration file again: $ sudo chmod 0600 auth.txt $ sudo openvpn --config client.conf This should now work without being prompted to enter username and password. In case that you placed your files below the system-wide location /etc/openvpn you can operate your VPNs also via service command like so: $ sudo service openvpn start client $ sudo service openvpn stop client Using Network Manager For newer Linux users or the ones with 'console-phobia' I'm going to describe now how to use Network Manager to setup the OpenVPN client. For this move your mouse to the systray area and click on Network Connections => VPN Connections => Configure VPNs... which opens your Network Connections dialog. Alternatively, use the HUD and enter 'Network Connections'. Network connections overview in Ubuntu Click on 'Add' button. On the next dialog select 'Import a saved VPN configuration...' from the dropdown list and click on 'Create...' Choose connection type to import VPN configuration Now you navigate to your folder where you put the client files from the Windows system and you open the 'client.ovpn' file. Next, on the tab 'VPN' proceed with the following steps (directives from the configuration file are referred): General Check the IP address of Gateway ('remote' - we used 1.2.3.4 in this setup) Authentication Change Type to 'Password with Certificates (TLS)' ('auth-pass-user') Enter User name to access your client keys (Auth Name: myvpnusername) Enter Password (Auth Password: verysecretpassword) and choose your password handling Browse for your User Certificate ('cert' - should be pre-selected with client.crt) Browse for your CA Certificate ('ca' - should be filled as ca.crt) Specify your Private Key ('key' - here: client.pem) Then click on the 'Advanced...' button and check the following values: Use custom gateway port: 443 (second value of 'remote' directive) Check the selected value of Cipher ('cipher') Check HMAC Authentication ('auth') Enter the Subject Match: /O=WatchGuard_Technologies/OU=Fireware/CN=Fireware_SSLVPN_Server ('tls-remote') Finally, you have to confirm and close all dialogs. You should be able to establish your OpenVPN-WatchGuard connection via Network Manager. For that, click on the 'VPN Connections => client' entry on your Network Manager in the systray. It is advised that you keep an eye on the syslog to see whether there are any problematic issues that would require some additional attention. Advanced topic: routing As stated above, I'm running the 'WatchGuard client for Linux' on my head-less server, and since then I'm actually establishing a secure communication channel between two networks. In order to enable your network clients to get access to machines on the remote side there are two possibilities to enable that: Proper routing on both sides of the connection which enables both-direction access, or Network masquerading on the 'client side' of the connection Following, I'm going to describe the second option a little bit more in detail. The Linux system that I'm using is already configured as a gateway to the internet. I won't explain the necessary steps to do that, and will only focus on the additional tweaks I had to do. You can find tons of very good instructions and tutorials on 'How to setup a Linux gateway/router' - just use Google. OK, back to the actual modifications. First, we need to have some information about the network topology and IP address range used on the 'other' side. We can get this very easily from /var/log/syslog after we established the OpenVPN channel, like so: $ sudo tail -n20 /var/log/syslog Or if your system is quite busy with logging, like so: $ sudo less /var/log/syslog | grep ovpn The output should contain PUSH received message similar to the following one: Jul 23 23:13:28 ios1 ovpn-client[789]: PUSH: Received control message: 'PUSH_REPLY,topology subnet,route 192.168.1.0 255.255.255.0,dhcp-option DOMAIN ,route-gateway 192.168.6.1,topology subnet,ping 10,ping-restart 60,ifconfig 192.168.6.2 255.255.255.0' The interesting part for us is the route command which I highlighted already in the sample PUSH_REPLY. Depending on your remote server there might be multiple networks defined (172.16.x.x and/or 10.x.x.x). Important: The IP address range on both sides of the connection has to be different, otherwise you will have to shuffle IPs or increase your the netmask. {loadposition content_adsense} After the VPN connection is established, we have to extend the rules for iptables in order to route and masquerade IP packets properly. I created a shell script to take care of those steps: #!/bin/sh -eIPTABLES=/sbin/iptablesDEV_LAN=eth0DEV_VPNS=tun+VPN=192.168.1.0/24 $IPTABLES -A FORWARD -i $DEV_LAN -o $DEV_VPNS -d $VPN -j ACCEPT$IPTABLES -A FORWARD -i $DEV_VPNS -o $DEV_LAN -s $VPN -j ACCEPT$IPTABLES -t nat -A POSTROUTING -o $DEV_VPNS -d $VPN -j MASQUERADE I'm using the wildcard interface 'tun+' because I have multiple client configurations for OpenVPN on my server. In your case, it might be sufficient to specify device 'tun0' only. Simplifying your life - automatic connect on boot Now, that the client connection works flawless, configuration of routing and iptables is okay, we might consider to add another 'laziness' factor into our setup. Due to kernel updates or other circumstances it might be necessary to reboot your system. Wouldn't it be nice that the VPN connections are established during the boot procedure? Yes, of course it would be. To achieve this, we have to configure OpenVPN to automatically start our VPNs via init script. Let's have a look at the responsible 'default' file and adjust the settings accordingly. $ sudo nano /etc/default/openvpn Which should have a similar content to this: # This is the configuration file for /etc/init.d/openvpn## Start only these VPNs automatically via init script.# Allowed values are "all", "none" or space separated list of# names of the VPNs. If empty, "all" is assumed.# The VPN name refers to the VPN configutation file name.# i.e. "home" would be /etc/openvpn/home.conf#AUTOSTART="all"#AUTOSTART="none"#AUTOSTART="home office"## ... more information which remains unmodified ... With the OpenVPN client configuration as described above you would either set AUTOSTART to "all" or to "client" to enable automatic start of your VPN(s) during boot. You should also take care that your iptables commands are executed after the link has been established, too. You can easily test this configuration without reboot, like so: $ sudo service openvpn restart Enjoy stable VPN connections between your Linux system(s) and a WatchGuard Firebox SSL remote server. Cheers, JoKi

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  • Revisiting ANTS Performance Profiler 7.4

    - by James Michael Hare
    Last year, I did a small review on the ANTS Performance Profiler 6.3, now that it’s a year later and a major version number higher, I thought I’d revisit the review and revise my last post. This post will take the same examples as the original post and update them to show what’s new in version 7.4 of the profiler. Background A performance profiler’s main job is to keep track of how much time is typically spent in each unit of code. This helps when we have a program that is not running at the performance we expect, and we want to know where the program is experiencing issues. There are many profilers out there of varying capabilities. Red Gate’s typically seem to be the very easy to “jump in” and get started with very little training required. So let’s dig into the Performance Profiler. I’ve constructed a very crude program with some obvious inefficiencies. It’s a simple program that generates random order numbers (or really could be any unique identifier), adds it to a list, sorts the list, then finds the max and min number in the list. Ignore the fact it’s very contrived and obviously inefficient, we just want to use it as an example to show off the tool: 1: // our test program 2: public static class Program 3: { 4: // the number of iterations to perform 5: private static int _iterations = 1000000; 6: 7: // The main method that controls it all 8: public static void Main() 9: { 10: var list = new List<string>(); 11: 12: for (int i = 0; i < _iterations; i++) 13: { 14: var x = GetNextId(); 15: 16: AddToList(list, x); 17: 18: var highLow = GetHighLow(list); 19: 20: if ((i % 1000) == 0) 21: { 22: Console.WriteLine("{0} - High: {1}, Low: {2}", i, highLow.Item1, highLow.Item2); 23: Console.Out.Flush(); 24: } 25: } 26: } 27: 28: // gets the next order id to process (random for us) 29: public static string GetNextId() 30: { 31: var random = new Random(); 32: var num = random.Next(1000000, 9999999); 33: return num.ToString(); 34: } 35: 36: // add it to our list - very inefficiently! 37: public static void AddToList(List<string> list, string item) 38: { 39: list.Add(item); 40: list.Sort(); 41: } 42: 43: // get high and low of order id range - very inefficiently! 44: public static Tuple<int,int> GetHighLow(List<string> list) 45: { 46: return Tuple.Create(list.Max(s => Convert.ToInt32(s)), list.Min(s => Convert.ToInt32(s))); 47: } 48: } So let’s run it through the profiler and see what happens! Visual Studio Integration First, let’s look at how the ANTS profilers integrate with Visual Studio’s menu system. Once you install the ANTS profilers, you will get an ANTS menu item with several options: Notice that you can either Profile Performance or Launch ANTS Performance Profiler. These sound similar but achieve two slightly different actions: Profile Performance: this immediately launches the profiler with all defaults selected to profile the active project in Visual Studio. Launch ANTS Performance Profiler: this launches the profiler much the same way as starting it from the Start Menu. The profiler will pre-populate the application and path information, but allow you to change the settings before beginning the profile run. So really, the main difference is that Profile Performance immediately begins profiling with the default selections, where Launch ANTS Performance Profiler allows you to change the defaults and attach to an already-running application. Let’s Fire it Up! So when you fire up ANTS either via Start Menu or Launch ANTS Performance Profiler menu in Visual Studio, you are presented with a very simple dialog to get you started: Notice you can choose from many different options for application type. You can profile executables, services, web applications, or just attach to a running process. In fact, in version 7.4 we see two new options added: ASP.NET Web Application (IIS Express) SharePoint web application (IIS) So this gives us an additional way to profile ASP.NET applications and the ability to profile SharePoint applications as well. You can also choose your level of detail in the Profiling Mode drop down. If you choose Line-Level and method-level timings detail, you will get a lot more detail on the method durations, but this will also slow down profiling somewhat. If you really need the profiler to be as unintrusive as possible, you can change it to Sample method-level timings. This is performing very light profiling, where basically the profiler collects timings of a method by examining the call-stack at given intervals. Which method you choose depends a lot on how much detail you need to find the issue and how sensitive your program issues are to timing. So for our example, let’s just go with the line and method timing detail. So, we check that all the options are correct (if you launch from VS2010, the executable and path are filled in already), and fire it up by clicking the [Start Profiling] button. Profiling the Application Once you start profiling the application, you will see a real-time graph of CPU usage that will indicate how much your application is using the CPU(s) on your system. During this time, you can select segments of the graph and bookmark them, giving them mnemonic names. This can be useful if you want to compare performance in one part of the run to another part of the run. Notice that once you select a block, it will give you the call tree breakdown for that selection only, and the relative performance of those calls. Once you feel you have collected enough information, you can click [Stop Profiling] to stop the application run and information collection and begin a more thorough analysis. Analyzing Method Timings So now that we’ve halted the run, we can look around the GUI and see what we can see. By default, the times are shown in terms of percentage of time of the total run of the application, though you can change it in the View menu item to milliseconds, ticks, or seconds as well. This won’t affect the percentages of methods, it only affects what units the times are shown. Notice also that the major hotspot seems to be in a method without source, ANTS Profiler will filter these out by default, but you can right-click on the line and remove the filter to see more detail. This proves especially handy when a bottleneck is due to a method in the BCL. So now that we’ve removed the filter, we see a bit more detail: In addition, ANTS Performance Profiler gives you the ability to decompile the methods without source so that you can dive even deeper, though typically this isn’t necessary for our purposes. When looking at timings, there are generally two types of timings for each method call: Time: This is the time spent ONLY in this method, not including calls this method makes to other methods. Time With Children: This is the total of time spent in both this method AND including calls this method makes to other methods. In other words, the Time tells you how much work is being done exclusively in this method, and the Time With Children tells you how much work is being done inclusively in this method and everything it calls. You can also choose to display the methods in a tree or in a grid. The tree view is the default and it shows the method calls arranged in terms of the tree representing all method calls and the parent method that called them, etc. This is useful for when you find a hot-spot method, you can see who is calling it to determine if the problem is the method itself, or if it is being called too many times. The grid method represents each method only once with its totals and is useful for quickly seeing what method is the trouble spot. In addition, you can choose to display Methods with source which are generally the methods you wrote (as opposed to native or BCL code), or Any Method which shows not only your methods, but also native calls, JIT overhead, synchronization waits, etc. So these are just two ways of viewing the same data, and you’re free to choose the organization that best suits what information you are after. Analyzing Method Source If we look at the timings above, we see that our AddToList() method (and in particular, it’s call to the List<T>.Sort() method in the BCL) is the hot-spot in this analysis. If ANTS sees a method that is consuming the most time, it will flag it as a hot-spot to help call out potential areas of concern. This doesn’t mean the other statistics aren’t meaningful, but that the hot-spot is most likely going to be your biggest bang-for-the-buck to concentrate on. So let’s select the AddToList() method, and see what it shows in the source window below: Notice the source breakout in the bottom pane when you select a method (from either tree or grid view). This shows you the timings in this method per line of code. This gives you a major indicator of where the trouble-spot in this method is. So in this case, we see that performing a Sort() on the List<T> after every Add() is killing our performance! Of course, this was a very contrived, duh moment, but you’d be surprised how many performance issues become duh moments. Note that this one line is taking up 86% of the execution time of this application! If we eliminate this bottleneck, we should see drastic improvement in the performance. So to fix this, if we still wanted to maintain the List<T> we’d have many options, including: delay Sort() until after all Add() methods, using a SortedSet, SortedList, or SortedDictionary depending on which is most appropriate, or forgoing the sorting all together and using a Dictionary. Rinse, Repeat! So let’s just change all instances of List<string> to SortedSet<string> and run this again through the profiler: Now we see the AddToList() method is no longer our hot-spot, but now the Max() and Min() calls are! This is good because we’ve eliminated one hot-spot and now we can try to correct this one as well. As before, we can then optimize this part of the code (possibly by taking advantage of the fact the list is now sorted and returning the first and last elements). We can then rinse and repeat this process until we have eliminated as many bottlenecks as possible. Calls by Web Request Another feature that was added recently is the ability to view .NET methods grouped by the HTTP requests that caused them to run. This can be helpful in determining which pages, web services, etc. are causing hot spots in your web applications. Summary If you like the other ANTS tools, you’ll like the ANTS Performance Profiler as well. It is extremely easy to use with very little product knowledge required to get up and running. There are profilers built into the higher product lines of Visual Studio, of course, which are also powerful and easy to use. But for quickly jumping in and finding hot spots rapidly, Red Gate’s Performance Profiler 7.4 is an excellent choice. Technorati Tags: Influencers,ANTS,Performance Profiler,Profiler

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  • Ada and 'The Book'

    - by Phil Factor
    The long friendship between Charles Babbage and Ada Lovelace created one of the most exciting and mysterious of collaborations ever to have resulted in a technological breakthrough. The fireworks that created by the collision of two prodigious mathematical and creative talents resulted in an invention, the Analytical Engine, which went on to change society fundamentally. However, beyond that, we just don't know what the bulk of their collaborative work was about:;  it was done in strictest secrecy. Even the known outcome of their friendship, the first programmable computer, was shrouded in mystery. At the time, nobody, except close friends and family, had any idea of Ada Byron's contribution to the invention of the ‘Engine’, and how to program it. Her great insight was published in August 1843, under the initials AAL, standing for Ada Augusta Lovelace, her title then being the Countess of Lovelace. It was contained in a lengthy ‘note’ to her translation of a publication that remains the best description of Babbage's amazing Analytical Engine. The secret identity of the person behind those enigmatic initials was finally revealed by Prince de Polignac who, seventy years later, wrote to Ada's daughter to seek confirmation that her mother had, indeed, been the author of the brilliant sentences that described so accurately how Babbage's mechanical computer could be programmed with punch-cards. L.F. Menabrea's paper on the Analytical Engine first appeared in the 'Bibliotheque Universelle de Geneve' in October 1842, and Ada translated it anonymously for Taylor's 'Scientific Memoirs'. Charles Babbage was surprised that she had not written an original paper as she already knew a surprising amount about the way the machine worked. He persuaded her to at least write some explanatory notes. These notes ended up extending to four times the length of the original article and represented the first published account of how a machine could be programmed to perform any calculation. Her example of programming the Bernoulli sequence would have worked on the Analytical engine had the device’s construction been completed, and gave Ada an unassailable claim to have invented the art of programming. What was the reason for Ada's secrecy? She was the only legitimate child of Lord Byron, who was probably the best known celebrity of the age, so she was already famous. She was a senior aristocrat, with titles, a fortune in money and vast estates in the Midlands. She had political influence, and was the cousin of Lord Melbourne, who was the Prime Minister at that time. She was friendly with the young Queen Victoria. Her mathematical activities were a pastime, and not one that would be considered by others to be in keeping with her roles and responsibilities. You wouldn't dare to dream up a fictional heroine like Ada. She was dazzlingly beautiful and talented. She could speak several languages fluently, and play some musical instruments with professional skill. Contemporary accounts refer to her being 'accomplished in science, art and literature'. On top of that, she was a brilliant mathematician, a talent inherited from her mother, Annabella Milbanke. In her mother's circle of literary and scientific friends was Charles Babbage, and Ada's friendship with him dates from her teenage zest for Mathematics. She was one of the first people he'd ever met who understood what he had attempted to achieve with the 'Difference Engine', and with whom he could converse as intellectual equals. He arranged for her to have an education from the most talented academics in the country. Ada melted the heart of the cantankerous genius to the point that he became a faithful and loyal father-figure to her. She was one of the very few who could grasp the principles of the later, and very different, ‘Analytical Engine’ which was designed from the start to tackle a variety of tasks. Sadly, Ada Byron's life ended less than a decade after completing the work that assured her long-term fame, in November 1852. She was dying of cancer, her gambling habits had caused her to run up huge debts, she'd had more than one affairs, and she was being blackmailed. Her brilliant but unempathic mother was nursing her in her final illness, destroying her personal letters and records, and repaying her debts. Her husband was distraught but helpless. Charles Babbage, however, maintained his steadfast paternalistic friendship to the end. She appointed her loyal friend to be her executor. For years, she and Babbage had been working together on a secret project, known only as 'The Book'. We have a clue to what it was in a letter written by her nine years earlier, on 11th August 1843. It was a joint project by herself and Lord Lovelace, her husband, and was intended to involve Babbage's 'undivided energies'. It involved 'consulting your Engine' (it required Babbage’s computer). The letter gives no hint about the project except for the high-minded nature of its purpose, and its highly mathematical nature.  From then on, the surviving correspondence between the two gives only veiled references to 'The Book'. There isn't much, since Babbage later destroyed any letters that could have damaged her reputation within the Establishment. 'I cannot spare the book today, which I am very sorry for. At the moment I want it for constant reference, but I think you can have it tomorrow' (Oct 1844)  And 'I will send you the book directly, and you can say, when you receive it, how long you will want to keep it'. (Nov 1844)  The two of them were obviously intent on the work: She writes, four years later, 'I have an engagement for Wednesday which will prevent me from attending to your wishes about the book' (Dec 1848). This was something that they both needed to work on, but could not do in parallel: 'I will send the book on Tuesday, and it can be left with you till Friday' (11 Feb 1849). After six years work, it had been so well-handled that it was beginning to fall apart: 'Don't forget the new cover you promised for the book. The poor book is very shabby and wants one' (20 Sept 1849). So what was going on? The word 'book' was not a code-word: it was a real book, probably a 'printer's blank', plain paper, but properly bound so printers and publishers could show off how the published work might look. The hints from the correspondence are of advanced mathematics. It is obvious that the book was travelling between them, back and forth, each one working on it for less than a week before passing it back. Ada and her husband were certainly involved in gambling large sums of money on the horses, and so most biographers have concluded that the three of them were trying to calculate the mathematical odds on the horses. This theory has three large problems. Firstly, Ada's original letter proposing the project refers to its high-minded nature. Babbage was temperamentally opposed to gambling and would scarcely have given so much time to the project, even though he was devoted to Ada. Secondly, Babbage would have very soon have realized the hopelessness of trying to beat the bookies. This sort of betting never attracts his type of intellectual background. The third problem is that any work on calculating the odds on horses would not need a well-thumbed book to pass back and forth between them; they would have not had to work in series. The original project was instigated by Ada, along with her husband, William King-Noel, 1st Earl of Lovelace. Charles Babbage was invited to join the project after the couple had come up with the idea. What could William have contributed? One might assume that William was a Bertie Wooster character, addicted only to the joys of the turf, but this was far from the truth. He was a scientist, a Cambridge graduate who was later elected to be a Fellow of the Royal Society. After Eton, he went to Trinity College, Cambridge. On graduation, he entered the diplomatic service and acted as secretary under Lord Nugent, who was Lord Commissioner of the Ionian Islands. William was very friendly with Babbage too, able to discuss scientific matters on equal terms. He was a capable engineer who invented a process for bending large timbers by the application of steam heat. He delivered a paper to the Institution of Civil Engineers in 1849, and received praise from the great engineer, Isambard Kingdom Brunel. As well as being Lord Lieutenant of the County of Surrey for most of Victoria's reign, he had time for a string of scientific and engineering achievements. Whatever the project was, it is unlikely that William was a junior partner. After Ada's death, the project disappeared. Then, two years later, Babbage, through one of his occasional outbursts of temper, demonstrated that he was able to decrypt one of the most powerful of secret codes, Vigenère's autokey cipher.  All contemporary diplomatic and military messages used a variant of this cipher. Babbage had made three important discoveries, namely, the mathematical law of this cipher, the principle of the key periodicity, and the technique of the symmetry of position. The technique is now known as the Kasiski examination, also called the Kasiski test, but Babbage got there first. At one time, he listed amongst his future projects, the writing of a book 'The Philosophy of Decyphering', but it never came to anything. This discovery was going to change the course of history, since it was used to decipher the Russians’ military dispatches in the Crimean war. Babbage himself played a role during the Crimean War as a cryptographical adviser to his friend, Rear-Admiral Sir Francis Beaufort of the Admiralty. This is as much as we can be certain about in trying to make sense of the bulk of the time that Charles Babbage and Ada Lovelace worked together. Nine years of intensive work, involving the 'Engine' and a great deal of mathematics and research seems to have been lost: or has it? I've argued in the past http://www.simple-talk.com/community/blogs/philfactor/archive/2008/06/13/59614.aspx that the cracking of the Vigenère autokey cipher, was a fundamental motive behind the British Government's support and funding of the 'Difference Engine'. The Duke of Wellington, whose understanding of the military significance of being able to read enemy dispatches, was the most steadfast advocate of the project. If the three friends were actually doing the work of cracking codes by mathematical techniques that used the techniques of key periodicity, and symmetry of position (the use of a book being passed quickly to and fro is very suggestive), intending to then use the 'Engine' to do the routine cracking of each dispatch, then this is a rather different story. The project was Ada and William's idea. (William had served in the diplomatic service and would be familiar with the use of codes). This makes Ada Lovelace the initiator of a project which, by giving both Britain, and probably the USA, a diplomatic and military advantage in the second part of the Nineteenth century, changed world history. Ada would never have wanted any credit for cracking the cipher, and developing the method that rendered all contemporary military and diplomatic ciphering techniques nugatory; quite the reverse. And it is clear from the gaps in the record of the letters between the collaborators that the evidence was destroyed, probably on her request by her irascible but intensely honorable executor, Charles Babbage. Charles Babbage toyed with the idea of going public, but the Crimean war put an end to that. The British Government had a valuable secret, and intended to keep it that way. Ada and Charles had quite often discussed possible moneymaking projects that would fund the development of the Analytic Engine, the first programmable computer, but their secret work was never in the running as a potential cash cow. I suspect that the British Government was, even then, working on the concealment of a discovery whose value to the nation depended on it remaining so. The success of code-breaking in the Crimean war, and the American Civil war, led to the British and Americans  subsequently giving much more weight and funding to the science of decryption. Paradoxically, this makes Ada's contribution even closer to the creation of Colossus, the first digital computer, at Bletchley Park, specifically to crack the Nazi’s secret codes.

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  • NINE Questions with Michelle Juett

    - by NINEQuestions
    Michelle Juett is one of the more interesting people I know, even though we’ve never met face to face. She’s part artist, part techie and all cool. We “met” via my good buddy George Clingerman and have plotting to take over the world, errr… I mean “collaborating” ever since. If you happen to live in the Seattle area, you can catch her and her work at Sakura Con on April 2-4, 2010 and various other gamer and art cons throughout the year. You can also find her on Twitter as @Shelldragon. Now that you know a little bit, I’ll let her tell you the rest of the story in these NINE Questions: 1. Where are you from? I was born in Clearwater, Florida. I like to tell people I'm from the Bermuda Triangle, it just makes explaining myself so much easier. My family moved to Washington when I was 5 and I've been in the Pacific Northwest ever since. We like to QQ about the rain but we really love the green trees and clean water. 2. What do you do? I fight evil by moonlight and win love by daylight.. or something like that.  I’ve been in quality assurance for games during the day since January 2008 and an artist for life. I currently work in QA for a really awesome game company in Bellevue.  At home, I work on personal digital art, making game assets as well as other random freelance projects as they pop up. 3. How did you get to where you are now? I'm still not where I want to be but I'm getting closer. The biggest piece of advice I can give is to work hard and never settle for the minimum required. I tend to overwork myself but I've never regretted it. You can want something really bad but if you aren't willing to work for it, then you can't expect it to just happen. I've always drawn and had an unhealthy love for video games that I was told I’d grow out of.  I knew I would not ‘grow out’ of games and that real adults make them and I could too. After I graduated, in searching for jobs, I discovered game testing. I figured this would be a good way to get my foot in the door and start networking. I’ve worked with consoles, websites and now, PC games.  I stuck with my journey, although it has been a rocky one, daylighting as a tester and moonlighting as an artist. I'm still on that journey but I wouldn't have it any other way. Test has given me a perspective that is difficult, if not impossible, to obtain any other way. It gives an unconditional respect for other hard working testers and an insight into creative problem solving. 4. So video game testing probably sounds WAY cooler than the reality. What's it like? What's a given day for you? Game testers don't get a lot of respect because of their stigmas and the fact most people don't actually know what we do.  People hear about the opening and closing disc trays all day. Many places do treat their testers like numbers. It all depends on where you work and how awesome your company is. I've had to deal with a lot of bad work situations to get to a really good one. QA exists to ensure the game is as flawless and enjoyable as it can be by the time it has to leave the nest and go out into the world. This includes everything obvious: “can I beat the level and save the princess?” to the more obscure: ‘What happens when I lose internet connection while trying to save right before falling into a pit to my death while holding the jump key then my cat pulls out my memory card and hides it in her litter box?” On the dev side, for developers, testers can be very scary people. Especially when the test team is not in house and you can’t see each other’s faces.  I've seen both sides. We don't mean to hurt your feelings. We really DO love you and want your game to be the best it can be! It can be some serious tough love. 5. You are also an accomplished artist. Got any major projects right now you'd like to talk about? LOL, I don't know if I’d say I'm an accomplished artist just yet. I’m still a long way from where I want to be. I figure that’s what makes you grow though: the desire to never stop improving. I like QA but I want to be a full time artist. I was lucky enough to register for a table at Sakura Con in the 11 second window that the tables sold out. As such, I’ll be selling my wares in the Artist Alley April 2-4th. Part of preparing for this is actually making the art to be sold there. Anime is a fun pass time but I don’t draw a whole lot of it so I’m making up for lost time. As I seem to enjoy burying myself in work, I’m an art lead for a secret project that’s so secret I might be killed tonight for even mentioning it. I also take on various freelance projects and do what I can to help out indie games. I discovered the XNA community a year and a half ago and developed a love for Indies when I was writing a weekly newsletter on XBLA news. I’m a little late to the party but I find myself in a unique position where I am an artist and also have technical skills in games. While not programmer myself, I have a lot of game sense and experience. I hope to make some awesome happen. Lastly, I have an ongoing web comic Shell’s Angels) that tends to get neglected when I get busy. I still love drawing comics and keep a little book with me to sketch down ideas as they pop into my head. I may pick it back up again as a larger project sometime in the future. 6. Can you talk about any of the other freelance projects you're doing or are you sworn to secrecy on those too? We wouldn't want a team of game developer ninjas to take you out or anything. All my projects are currently 2d. I have personal projects such as the ongoing comic as well as a graphic novel I've been picking at here and there. My main focus until April is Sakura Con, Sakura Con, Sakura Con.  I see it as a great way to get exposure and convention experience. I found out I love conventions a couple years ago and I want to get more involved in them. 7. As an artist, what is your weapon of choice? What do you use to get most of your stuff done? I am a Photoshop Hero and I have the hoodie to prove it. (http://www.pennyarcademerch.com/pah090011.html) I've dabbled in other paint programs but I always gravitate back to Photoshop. She is my one true love. I'd like to learn programs like Flash or Anime Studio when I get a bit more time because of their animation abilities. I've worked on frame by frame animation forever but I would love to learn 2d rigging. Still, nothing can compare to a simple sketchpad and a pencil. I always have one on me in case I come across or think of something interesting and can't get to a computer. If the Courier ever comes to exist it will be an ideal weapon for me. 8. You did some videos too, depicting the art creation process. What was the motivation behind those? The creative process is just as important as the final product, if not more so.  I've always loved watching speed paint videos and wanted to try it out myself. Turns out it's a lot of work and time but it's definitely fun to go back and rewatch them. Art isn't always the end result and is more often the process itself. 9. Got any interesting tattoos? Designed any for yourself or other people? Not yet, but not for lack of desire. I've toiled over what and where for years. Last year, I finally decided the back of my shoulders would be the place. Like anything permanent, I want it to have meaning. I thought of somehow incorporating games but I couldn't find something I felt would stand the test of time even with all the classic sprite games. I'm very picky so we'll see if I can get something solid decided. Come see me at Sakura Con April 2 -4!!!

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