Search Results

Search found 9879 results on 396 pages for 'thread dump'.

Page 50/396 | < Previous Page | 46 47 48 49 50 51 52 53 54 55 56 57  | Next Page >

  • Thread travailleur avec Qt en utilisant les signaux et les slots, un article de Christophe Dumez traduit par Thibaut Cuvelier

    Qt fournit des classes de threads indépendantes de la plateforme, une manière thread-safe de poster des événements et des connexions entre signaux et slots entre les threads. La programmation multithreadée s'avantage des machines à plusieurs processeurs et est aussi utile pour effectuer les opérations chronophages sans geler l'interface utilisateur d'une application. Sans multithreading, tout est fait dans le thread principal.

    Read the article

  • How do I make this rendering thread run together with the main one?

    - by funk
    I'm developing an Android game and need to show an animation of an exploding bomb. It's a spritesheet with 1 row and 13 different images. Each image should be displayed in sequence, 200 ms apart. There is one Thread running for the entire game: package com.android.testgame; import android.graphics.Canvas; public class GameLoopThread extends Thread { static final long FPS = 10; // 10 Frames per Second private final GameView view; private boolean running = false; public GameLoopThread(GameView view) { this.view = view; } public void setRunning(boolean run) { running = run; } @Override public void run() { long ticksPS = 1000 / FPS; long startTime; long sleepTime; while (running) { Canvas c = null; startTime = System.currentTimeMillis(); try { c = view.getHolder().lockCanvas(); synchronized (view.getHolder()) { view.onDraw(c); } } finally { if (c != null) { view.getHolder().unlockCanvasAndPost(c); } } sleepTime = ticksPS - (System.currentTimeMillis() - startTime); try { if (sleepTime > 0) { sleep(sleepTime); } else { sleep(10); } } catch (Exception e) {} } } } As far as I know I would have to create a second Thread for the bomb. package com.android.testgame; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Rect; public class Bomb { private final Bitmap bmp; private final int width; private final int height; private int currentFrame = 0; private static final int BMPROWS = 1; private static final int BMPCOLUMNS = 13; private int x = 0; private int y = 0; public Bomb(GameView gameView, Bitmap bmp) { this.width = bmp.getWidth() / BMPCOLUMNS; this.height = bmp.getHeight() / BMPROWS; this.bmp = bmp; x = 250; y = 250; } private void update() { currentFrame++; new BombThread().start(); } public void onDraw(Canvas canvas) { update(); int srcX = currentFrame * width; int srcY = height; Rect src = new Rect(srcX, srcY, srcX + width, srcY + height); Rect dst = new Rect(x, y, x + width, y + height); canvas.drawBitmap(bmp, src, dst, null); } class BombThread extends Thread { @Override public void run() { try { sleep(200); } catch(InterruptedException e){ } } } } The Threads would then have to run simultaneously. How do I do this?

    Read the article

  • When creating a library for a simple program, what must I do to protect others from its lack of thread safety?

    - by DeveloperDon
    When creating a library for a simple program, is it more cost effective to make it thread safe or is there a way to detect the program's use in a multithreaded program and ASSERT() or otherwise determine (preferably at compile or link time) that it may create problems. Related help for this question would be automated tool support for finding potential problems with thread safety, programming language features that enforce it,

    Read the article

  • In C#, what thread will Events be handled in?

    - by Ben
    Hi, I have attempted to implement a producer/consumer pattern in c#. I have a consumer thread that monitors a shared queue, and a producer thread that places items onto the shared queue. The producer thread is subscribed to receive data...that is, it has an event handler, and just sits around and waits for an OnData event to fire (the data is being sent from a 3rd party api). When it gets the data, it sticks it on the queue so the consumer can handle it. When the OnData event does fire in the producer, I had expected it to be handled by my producer thread. But that doesn't seem to be what is happening. The OnData event seems as if it's being handled on a new thread instead! Is this how .net always works...events are handled on their own thread? Can I control what thread will handle events when they're raised? What if hundreds of events are raised near-simultaneously...would each have its own thread? Thank in advance! Ben

    Read the article

  • What does flushing thread local memory to global memory mean?

    - by Jack Griffith
    Hi, I am aware that the purpose of volatile variables in Java is that writes to such variables are immediately visible to other threads. I am also aware that one of the effects of a synchronized block is to flush thread-local memory to global memory. I have never fully understood the references to 'thread-local' memory in this context. I understand that data which only exists on the stack is thread-local, but when talking about objects on the heap my understanding becomes hazy. I was hoping that to get comments on the following points: When executing on a machine with multiple processors, does flushing thread-local memory simply refer to the flushing of the CPU cache into RAM? When executing on a uniprocessor machine, does this mean anything at all? If it is possible for the heap to have the same variable at two different memory locations (each accessed by a different thread), under what circumstances would this arise? What implications does this have to garbage collection? How aggressively do VMs do this kind of thing? Overall, I think am trying to understand whether thread-local means memory that is physically accessible by only one CPU or if there is logical thread-local heap partitioning done by the VM? Any links to presentations or documentation would be immensely helpful. I have spent time researching this, and although I have found lots of nice literature, I haven't been able to satisfy my curiosity regarding the different situations & definitions of thread-local memory. Thanks very much.

    Read the article

  • Difference in BackgroundWorker thread access in VS2010 / .NET 4.0?

    - by Jonners
    Here's an interesting one - in VS2005 / VS2008 running against .NET 2.0 / .NET 3.0 / .NET 3.5, a BackgroundWorker thread may not directly update controls on a WinForms form that initiated that thread - you'll get a System.InvalidOperationException out of the BackgroundWorker stating "Cross-thread operation not valid: Control 'thecontrol' accessed from a thread other than the thread it was created on". I remember hitting this back in 2004 or so when I first started writing .NET WinForms apps with background threads. There are several ways around the problem - this is not a question asking for that answer. I've been told recently that this kind of operation is now allowed when written in VS2010 / .NET 4.0. This seems unlikely to me, since this kind of object access restriction has always been a fairly fundamental part of thread-safe programming. Allowing a BackgroundWorker thread direct access to objects owned not by itself but by its parent UI form seems contrary to that principle. A trawl through the .NET 4.0 docs hasn't revealed any obvious changes that could account for this behaviour. I don't have VS2010 / .NET 4.0 to test this out - does anyone who has access to that toolset know for sure whether the model has changed to allow that kind of thread interaction? I'd like to either take advantage of it in future, or deploy the cluestick. ;)

    Read the article

  • How to pass data to a C++0x lambda function that will run in a different thread?

    - by Dimitri C.
    In our company we've written a library function to call a function asynchronously in a separate thread. It works using a combination of inheritance and template magic. The client code looks as follows: DemoThread thread; std::string stringToPassByValue = "The string to pass by value"; AsyncCall(thread, &DemoThread::SomeFunction, stringToPassByValue); Since the introduction of lambda functions I'd like to use it in combination with lambda functions. I'd like to write the following client code: DemoThread thread; std::string stringToPassByValue = "The string to pass by value"; AsyncCall(thread, [=]() { const std::string someCopy = stringToPassByValue; }); Now, with the Visual C++ 2010 this code doesn't work. What happens is that the stringToPassByValue is not copied. Instead the "capture by value" feature passes the data by reference. The result is that if the function is executed after stringToPassByValue has gone out of scope, the application crashes as its destructor is called already. So I wonder: is it possible to pass data to a lambda function as a copy? Note: One possible solution would be to modify our framework to pass the data in the lambda parameter declaration list, as follows: DemoThread thread; std::string stringToPassByValue = "The string to pass by value"; AsyncCall(thread, [=](const std::string stringPassedByValue) { const std::string someCopy = stringPassedByValue; } , stringToPassByValue); However, this solution is so verbose that our original function pointer solution is both shorter and easier to read. Update: The full implementation of AsyncCall is too big to post here. In short, what happens is that the AsyncCall template function instantiates a template class holding the lambda function. This class is derived from a base class that contains a virtual Execute() function, and upon an AsyncCall() call, the function call class is put on a call queue. A different thread then executes the queued calls by calling the virtual Execute() function, which is polymorphically dispatched to the template class which then executes the lambda function.

    Read the article

  • How: Start an Activity inside a Thread and use finish() to get back.

    - by Kirk Becker
    Hello, I am programming a game on android. I'm using a Thread while calling a Surface View class to update and draw my game. Inside the update I wanted to start an activity based on if the game has just started and this would launch my MENUS. My Thread for the most part.. while (myThreadRun) { Canvas c = null; try { gameTime = System.currentTimeMillis(); c = myThreadSurfaceHolder.lockCanvas(null); synchronized (myThreadSurfaceHolder) { // Update Game. myThreadSurfaceView.onUpdate(); // Draw Game. myThreadSurfaceView.onDraw(c); You can see there where I am updating the game... here is onUpdate(); protected void onUpdate() { // Test if menu needs to be displayed. while (thread.getMenu()) { // Test if menu activity has been started. if (thread.getMenuRunning() == false) { Intent menuIntent = new Intent(this.getContext(), MyMenu.class); ((Activity) cxt).startActivityForResult(menuIntent, 1); thread.setMenuRunning(true); } } I am using a while loop because if I didn't use it the thread just keeps going. Basically I just don't know how to implement my menus using a thread as a game loop. Everywhere I look it seems like that's best practice. In my menu activity I just display the menu layout and a few buttons and when the person wants to start the game it uses finish() to go back to my thread where they play the game. I am very new to this so any insight will be helpful, Thanks

    Read the article

  • Synchronized Enumerator in C#

    - by Dan Bryant
    I'm putting together a custom SynchronizedCollection<T> class so that I can have a synchronized Observable collection for my WPF application. The synchronization is provided via a ReaderWriterLockSlim, which, for the most part, has been easy to apply. The case I'm having trouble with is how to provide thread-safe enumeration of the collection. I've created a custom IEnumerator<T> nested class that looks like this: private class SynchronizedEnumerator : IEnumerator<T> { private SynchronizedCollection<T> _collection; private int _currentIndex; internal SynchronizedEnumerator(SynchronizedCollection<T> collection) { _collection = collection; _collection._lock.EnterReadLock(); _currentIndex = -1; } #region IEnumerator<T> Members public T Current { get; private set;} #endregion #region IDisposable Members public void Dispose() { var collection = _collection; if (collection != null) collection._lock.ExitReadLock(); _collection = null; } #endregion #region IEnumerator Members object System.Collections.IEnumerator.Current { get { return Current; } } public bool MoveNext() { var collection = _collection; if (collection == null) throw new ObjectDisposedException("SynchronizedEnumerator"); _currentIndex++; if (_currentIndex >= collection.Count) { Current = default(T); return false; } Current = collection[_currentIndex]; return true; } public void Reset() { if (_collection == null) throw new ObjectDisposedException("SynchronizedEnumerator"); _currentIndex = -1; Current = default(T); } #endregion } My concern, however, is that if the Enumerator is not Disposed, the lock will never be released. In most use cases, this is not a problem, as foreach should properly call Dispose. It could be a problem, however, if a consumer retrieves an explicit Enumerator instance. Is my only option to document the class with a caveat implementer reminding the consumer to call Dispose if using the Enumerator explicitly or is there a way to safely release the lock during finalization? I'm thinking not, since the finalizer doesn't even run on the same thread, but I was curious if there other ways to improve this.

    Read the article

  • Synchronized IEnumerator<T>

    - by Dan Bryant
    I'm putting together a custom SynchronizedCollection<T> class so that I can have a synchronized Observable collection for my WPF application. The synchronization is provided via a ReaderWriterLockSlim, which, for the most part, has been easy to apply. The case I'm having trouble with is how to provide thread-safe enumeration of the collection. I've created a custom IEnumerator<T> nested class that looks like this: private class SynchronizedEnumerator : IEnumerator<T> { private SynchronizedCollection<T> _collection; private int _currentIndex; internal SynchronizedEnumerator(SynchronizedCollection<T> collection) { _collection = collection; _collection._lock.EnterReadLock(); _currentIndex = -1; } #region IEnumerator<T> Members public T Current { get; private set;} #endregion #region IDisposable Members public void Dispose() { var collection = _collection; if (collection != null) collection._lock.ExitReadLock(); _collection = null; } #endregion #region IEnumerator Members object System.Collections.IEnumerator.Current { get { return Current; } } public bool MoveNext() { var collection = _collection; if (collection == null) throw new ObjectDisposedException("SynchronizedEnumerator"); _currentIndex++; if (_currentIndex >= collection.Count) { Current = default(T); return false; } Current = collection[_currentIndex]; return true; } public void Reset() { if (_collection == null) throw new ObjectDisposedException("SynchronizedEnumerator"); _currentIndex = -1; Current = default(T); } #endregion } My concern, however, is that if the Enumerator is not Disposed, the lock will never be released. In most use cases, this is not a problem, as foreach should properly call Dispose. It could be a problem, however, if a consumer retrieves an explicit Enumerator instance. Is my only option to document the class with a caveat implementer reminding the consumer to call Dispose if using the Enumerator explicitly or is there a way to safely release the lock during finalization? I'm thinking not, since the finalizer doesn't even run on the same thread, but I was curious if there other ways to improve this. EDIT After thinking about this a bit and reading the responses (particular thanks to Hans), I've decided this is definitely a bad idea. The biggest issue actually isn't forgetting to Dispose, but rather a leisurely consumer creating deadlock while enumerating. I now only read-lock long enough to get a copy and return the enumerator for the copy.

    Read the article

  • Variable lenght arguments in log4cxx LOG4CXX_ macros

    - by Horacio
    I am using log4cxx in a big C++ project but I really don't like how log4cxx handles multiple variables when logging: LOG4CXX_DEBUG(logger, "test " << var1 << " and " << var3 " and .....) I prefer using printf like variable length arguments: LOG4CXX_DEBUG(logger, "test %d and %d", var1, var3) So I implemented this small wrapper on top of log4cxx #include <string.h> #include <stdio.h> #include <stdarg.h> #include <log4cxx/logger.h> #include "log4cxx/basicconfigurator.h" const char * log_format(const char *fmt, ...); #define MYLOG_TRACE(logger, fmt, ...) LOG4CXX_TRACE(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_DEBUG(logger, fmt, ...) LOG4CXX_DEBUG(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_INFO(logger, fmt, ...) LOG4CXX_INFO(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_WARN(logger, fmt, ...) LOG4CXX_WARN(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_ERROR(logger, fmt, ...) LOG4CXX_ERROR(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_FATAL(logger, fmt, ...) LOG4CXX_FATAL(logger, log_format(fmt, ## __VA_ARGS__)) static log4cxx::LoggerPtr logger(log4cxx::Logger::getRootLogger()); int main(int argc, char **argv) { log4cxx::BasicConfigurator::configure(); MYLOG_INFO(logger, "Start "); MYLOG_WARN(logger, log_format("In running this in %d threads safe?", 1000)); MYLOG_INFO(logger, "End "); return 0; } const char *log_format(const char *fmt, ...) { va_list va; static char formatted[1024]; va_start(va, fmt); vsprintf(formatted, 1024, fmt, va); va_end(va); return formatted; } And this works perfectly but I know using that static variable (formatted) can become problematic if I start using threads and each thread logging to the same place. I am no expert in log4cxx so I was wondering if the LOG4CXX macros are handling concurrent thread access automatically? or do I have to implement some sort of locking around the log_format method? something that I wan't to avoid due to performance implications. Also I would like to ask why if I replace the vsprintf inside the log_format method with vsnprintf (that is more secure) then I get nothing printed? To compile and test this program (in Ubuntu) use : g++ -o loggertest loggertest.cpp -llog4cxx

    Read the article

  • Unmanaged Code calling leads to heavy memory leak!!

    - by konnychen
    Maybe I need change the title as "Unmanaged Code calling leads to heavy memory leak!" The leak is around 30M/hour I think maybe I need complete my code here because the memory leak maybe not from a static string whereas my real code derive this string from external device (see new code attached). so I handle also unmanaged code. Could it be possible the leak comes from unmanaged code? But I freed the resouce by Marshal.FreeCoTaskMem(pos); oThread2 = new Thread(new ThreadStart(Cyclic_Call)); oThread2.Start(); delegate void SetText_lab_Statubar(string text); private void m_SetText_lab_Statubar(string text) { if (this.lab_Statubar.InvokeRequired) { SetText_lab_Statubar d = new SetText_lab_Statubar(m_SetText_lab_Statubar); this.Invoke(d, new object[] { text }); } else { this.lab_Statubar.Text = text; } } private void Cyclic_Call() { do { //... ... ReadMatrixCode(Station6, 0, str_Code); this.m_SetText_lab_Statubar(str_Code[4]); Thread.Sleep(100); } while (!b_AbortThraed); } private void ReadMatrixCode(Station st, int ItemNr, string[] str_Code) { IntPtr pItemStates = IntPtr.Zero; IntPtr pErrors = IntPtr.Zero; int NumItems = itemServerHandles.Length; m_SyncIO.Read(DataSrc, NumItems, itemServerHandles, out pItemStates, out pErrors); // This calls external dll which has some of "out IntPtr" errors = new int[NumItems]; Marshal.Copy(pErrors, errors, 0, NumItems); IntPtr pos = pItemStates; // Now get the read values and check errors for (int dwCount = 0; dwCount < NumItems; dwCount++) { result[dwCount] = (ITEMSTATE)Marshal.PtrToStructure(pos, typeof(ITEMSTATE)); pos = (IntPtr)(pos.ToInt32() + Marshal.SizeOf(typeof(ITEMSTATE))); } // Free allocated COM-ressouces Marshal.FreeCoTaskMem(pItemStates); Marshal.FreeCoTaskMem(pErrors); pItemStates = IntPtr.Zero; pErrors = IntPtr.Zero; } m_syncIO is a class and finally it will call COM component which is defined below [Guid("39C12B52-011E-11D0-9675-1020AFD8ADB3")] [InterfaceType(1)] [ComConversionLoss] public interface ISyncIO { void Read(DATASOURCE dwSource, int dwCount, int[] phServer, out IntPtr ppItemValues, out IntPtr ppErrors); void Write(int dwCount, int[] phServer, object[] pItemValues, out IntPtr ppErrors); }

    Read the article

  • Run a external program with specified max running time

    - by jack
    I want to execute an external program in each thread of a multi-threaded python program. Let's say max running time is set to 1 second. If started process completes within 1 second, main program capture its output for further processing. If it doesn't finishes in 1 second, main program just terminate it and start another new process. How to implement this?

    Read the article

  • Are +=, |=, &= etc atomic?

    - by SF.
    Are the "modify" operators like +=, |=, &= etc atomic? I know ++ is atomic (if you perform x++; in two different threads "simultaneously", you will always end up with x increased by 2, as opposed to x=x+1 with optimization switched off.) What I wonder is whether variable |= constant, and the likes are thread-safe or do I have to protect them with a mutex? (...or is it CPU-dependent? In this case, how is it on ARM?)

    Read the article

  • Abort call to unmanaged DLL

    - by phq
    I have an unmanaged DLL with a function that can run for a long time if the input parameter is a large value, sometimes that is desirable but not always. How can I in c# call this function so that I can abort it when needed? So far I have tried to put the call in a separate thread, but neither interrupt nor abort seem to stop the process, which runs at 100% CPU until the dll is done. Is it possible to terminate the running dll code?

    Read the article

  • Sockets and multithreading

    - by V0idExp
    Hi to all! I have an interesting (to me) problem... There are two threads, one for capturing data from std input and sending it through socket to server, and another one which receives data from blocking socket. So, when there's no reply from server, recv() call waits indefenitely, right? But instead of blocking only its calling thread, it blocks the overall process! Why this thing occurs?

    Read the article

  • ldd output showing shared object file whose function is not called

    - by iamrohitbanga
    I ran ldd command on an executable created by Open MPI. It shows a reference to libpthread.so Using LD_PRELOAD variable I created my own implementation of pthread_create, but from the it output it seems that MPI implementation is not calling pthread_create as I had expected. Why does ldd show pthread so file in output if it is not being used? does Open MPI not use a separate MPI thread for every node to implement the functionality?

    Read the article

  • Do the changes to cpumask using sched_setaffinity() take place immediately

    - by Sukanto
    I am writing a linux kernel module that needs to pin two threads on two different cpus. I am planning to use sched_setaffinity() after exporting it in the kernel. Is there any other exported function for the same ? Also, if I set only 1 CPU in the cpumask, will the thread be moved to that cpu with immediate effect ? If not, how do I enforce the same ? Will it help to call schedule() just after sched_setaffinity() ?

    Read the article

< Previous Page | 46 47 48 49 50 51 52 53 54 55 56 57  | Next Page >