multithreading

问题 There is example of using condition_variable taken from cppreference.com: #include <condition_variable> #include <mutex> #include <thread> #include <iostream> #include <queue> #include <chrono> int main() { std::queue<int> produced_nums; std::mutex m; std::condition_variable cond_var; bool done = false; bool notified = false; std::thread producer([&]() { for (int i = 0; i < 5; ++i) { std::this_thread::sleep_for(std::chrono::seconds(1)); std::lock_guard<std::mutex> lock(m); std::cout <<

问题 I was wondering whether it's easy to make a race condition using MRI ruby(2.0.0) and some global variables, but as it turns out it's not that easy. It looks like it should fail at some point, but it doesn't and I've been running it for 10 minutes. This is the code I've been trying to achieve it: def inc(*) a = $x a += 1 a *= 3000 a /= 3000 $x = a end THREADS = 10 COUNT = 5000 loop do $x = 1 THREADS.times.map do Thread.new { COUNT.times(&method(:inc)) } end.each(&:join) break puts "woo hoo!"

问题 I want to call WaitHandle.WaitOne(TimeSpan) in .NET, but I'm on the STA thread and it pumps messages while waiting. For reasons that are beyond the scope of this question, I need to wait without pumping. How can I wait for a WaitHandle to be signaled without pumping messages? It seems in some scenarios that WaitHandle.WaitOne does not pump messages. But it does sometimes for some messages. See these links for more information on that: Managed and Unmanaged Threading in Microsoft Windows

问题 I've read many of the questions related to this and learned a lot but I still haven't been able to solve my problem. I'm building a wxPython app that runs a c++ executable and displays the stdout from that executable in real time. I've run into several strange results trying to make this work. Here's my current setup/problem: //test.cc (compiled as test.out with gcc 4.5.2) #include <stdio.h> int main() { FILE* fh = fopen("output.txt", "w"); for (int i = 0; i < 10000; i++) { printf("Outputting

问题 Is there any way to get the UI thread's Dispatcher when you have no reference to any UI elements? 回答1: You can grab the UI Dispatcher from the static application instance: Application.Current.Dispatcher You may want to check Application.Current for null first, as it can be cleared during a shutdown sequence. 回答2: The following works much better for me when being used in a WinForms application that happens to be also using WPF (in my case Esri's Arcmap.exe) private System.Windows.Threading

问题 I have recently inherited a large Java Application that has almost no Thread safety in it. What I'm currently working on is getting all of the Threads to correctly handle being interrupted instead of using the very bad Thread.stop() . Part of the problem has been that I do not know every method call out there that clears the interrupt flag. Currently I know that the following will clear the interrupt flag: Thread.interrupted() Thread.sleep(long) Thread.join() Thread.join(long) Object.wait()

问题 I want to run a processing loop on a separate thread: _processingThread = new Thread(new ThreadStart(DoWork))); But DoWork needs to be async: private async Task QueueProcessorDoWork() { while (true) { await something(); } } How can I connect the two together? When I add async Task , it doesn't match the parameter of ThreadStart. It is possible to make the method that sets up the thread async Task , I think, but I am not sure if that would help. What's the best solution here? I need my thread

问题 I am trying to override the virtual TThread::Terminate method, but am finding my override gets called only after the Terminated flag is set. What is the correct way to implement this? TTestThrd = class(TThread) private { Private declarations } protected { Protected declarations } procedure Execute(); override; procedure DoTerminate(); override; public { Public declarations } end; procedure TTestThrd.Execute(); var bTerminated: Boolean; begin // This is the main thread loop try while (not

问题 I'm trying to make a program that when the user holds down the left or right arrow key along with the space bar it shoots some red picture boxes that move upwards until the get removed, when I just create one it works fine but when I create two or more the first picture box stops moving and the second one starts moving and if there were three picture boxes then the first and second would stop and the third would start, once the third has finished then the second starts again and then the

问题 When two audio's are played at the same time...the sound is canceling out. How do I fix this weird phenomenon? I have some code where there is audio on button click and audio in ten second intervals (in a background service). I have the following code to stop the button audio when the ten second interval plays, and it works fine: public static void myPop(Context context){ AudioManager manager = (AudioManager)context.getSystemService(Context.AUDIO_SERVICE); if(!manager.isMusicActive()) { /