multithreading

问题 Std::thread::join is said to 'synchronize-with' the joined thread, however synchronization doesnt tell anything about visibility of side effects, it merely governs the order of the visiblity, ie. in following example: int g_i = 0; int main() { auto fn = [&] {g_i = 1;}; std::thread t1(fn); t1.join(); return g_i; } Do we have any guarantee in the c++ standard that this program will always return 1? 回答1: [thread.thread.member]: void join(); Effects : Blocks until the thread represented by *this

问题 Using the code below, the timer only fires once. What am I missing? public static List<string> Test = new List<string> { "TEST1", "TEST2" }; public static void Start() { var t = new System.Threading.Timer(o => { foreach (var item in Test) { Console.WriteLine("Say hello!"); } }, null, 0, 1250); } 回答1: The timer is being collected by the GC before it fires again. You need to keep it alive by storing it in a field. 来源： https://stackoverflow.com/questions/8466475/system-threading-timer-only-fires

问题 Using the code below, the timer only fires once. What am I missing? public static List<string> Test = new List<string> { "TEST1", "TEST2" }; public static void Start() { var t = new System.Threading.Timer(o => { foreach (var item in Test) { Console.WriteLine("Say hello!"); } }, null, 0, 1250); } 回答1: The timer is being collected by the GC before it fires again. You need to keep it alive by storing it in a field. 来源： https://stackoverflow.com/questions/8466475/system-threading-timer-only-fires

问题 I have a WebSocket server. my server create a new thread for handle a new connection.the thread is live until websocket break. my problem: for 1_000_000 connections i need 1_000_000 threads. how i can handle many websockets by a thread? without wait? ServerSocket server; private ExecutorService executor = new ThreadPoolExecutor(1_000_000 , 1_000_000 , 7, TimeUnit.SECONDS, queue, threadFactory); try { server = new ServerSocket(port); } catch (IOException e) {} while (true) { Socket client =

问题 I have a WebSocket server. my server create a new thread for handle a new connection.the thread is live until websocket break. my problem: for 1_000_000 connections i need 1_000_000 threads. how i can handle many websockets by a thread? without wait? ServerSocket server; private ExecutorService executor = new ThreadPoolExecutor(1_000_000 , 1_000_000 , 7, TimeUnit.SECONDS, queue, threadFactory); try { server = new ServerSocket(port); } catch (IOException e) {} while (true) { Socket client =

问题 I have a WebSocket server. my server create a new thread for handle a new connection.the thread is live until websocket break. my problem: for 1_000_000 connections i need 1_000_000 threads. how i can handle many websockets by a thread? without wait? ServerSocket server; private ExecutorService executor = new ThreadPoolExecutor(1_000_000 , 1_000_000 , 7, TimeUnit.SECONDS, queue, threadFactory); try { server = new ServerSocket(port); } catch (IOException e) {} while (true) { Socket client =

问题 Closed. This question needs debugging details. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . Improve this question Is there a way to continuously update a JLabel inside a loop from a separate thread. Right now the Jlabel gets only updated once the loop is over. Please do correct me if am wrong, I think this is because the Event Dispatcher Thread is on halt till the other thread finishes

问题 How does OpenMP uses atomic instructions inside reduction constructor? Doesn't it rely on atomic instructions at all? For instance, is the variable sum in the code below accumulated with atomic '+' operator? #include <omp.h> #include <vector> using namespace std; int main() { int m = 1000000; vector<int> v(m); for (int i = 0; i < m; i++) v[i] = i; int sum = 0; #pragma omp parallel for reduction(+:sum) for (int i = 0; i < m; i++) sum += v[i]; } 回答1: How does OpenMP uses atomic instruction

问题 How does OpenMP uses atomic instructions inside reduction constructor? Doesn't it rely on atomic instructions at all? For instance, is the variable sum in the code below accumulated with atomic '+' operator? #include <omp.h> #include <vector> using namespace std; int main() { int m = 1000000; vector<int> v(m); for (int i = 0; i < m; i++) v[i] = i; int sum = 0; #pragma omp parallel for reduction(+:sum) for (int i = 0; i < m; i++) sum += v[i]; } 回答1: How does OpenMP uses atomic instruction

问题 I have an app with two buttons start and end . The start button will start a thread, which runs the audio recording function. This function is written using sounddevice and soundfile libraries. The audio recording can take place for an arbitary duration and the user can stop anytime by pressing ctrl+c . So, now I want to implement a function for the end button to stop the thread which started by pressing start button or the function can send ctrl+c signal to the thread. So, that the current