multithreading

问题 Currently, I am implementing a multi-thread project using std::thread in C++11. I use std::condition_variable to synchronize threads. In detail, one consumer function calls wait() member function of std::condition_variable to wait for task from a global task queue, another producer function generates and puts tasks into the queue. But I do not know the difference between notify_all() and notify_one() member functions of std::condition_variable . Which function should I use in the producer

问题 I created following code: using System; using System.Threading.Tasks; namespace ConsoleApplication2 { class Program { static void Main() { Console.WriteLine("M Start"); MyMethodAsync(); Console.WriteLine("M end"); Console.Read(); } static async Task MyMethodAsync() { await Task.Yield(); Task<int> longRunningTask = LongRunningOperationAsync(); Console.WriteLine("M3"); //and now we call await on the task int result = await longRunningTask; //use the result Console.WriteLine(result); } static

问题 I'm new to java. I'm little bit confused between Threadsafe and synchronized. Thread safe means that a method or class instance can be used by multiple threads at the same time without any problems occurring. Where as Synchronized means only one thread can operate at single time. So how they are related to each other? 回答1: The definition of thread safety given in Java Concurrency in Practice is: A class is thread-safe if it behaves correctly when accessed from multiple threads, regardless of

问题 I want to set up a signal handler for SIGSEGV, SIGILL and possibly a few other signals that, rather than terminating the whole process, just terminates the offending thread and perhaps sets a flag somewhere so that a monitoring thread can complain and start another thread. I'm not sure there is a safe way to do this. Pthreads seems to provide functions for exiting the current thread, as well as canceling another thread, but these potentially call a bunch of at-exit handlers. Even if they don

问题 I want to set up a signal handler for SIGSEGV, SIGILL and possibly a few other signals that, rather than terminating the whole process, just terminates the offending thread and perhaps sets a flag somewhere so that a monitoring thread can complain and start another thread. I'm not sure there is a safe way to do this. Pthreads seems to provide functions for exiting the current thread, as well as canceling another thread, but these potentially call a bunch of at-exit handlers. Even if they don

问题 I'm trying to optimize an async version of something similar (in basic funcionality) to the Monitor.Wait and Monitor.Pulse methods. The idea is to use this over an async method. Requirements: 1) I have one Task running, that it is in charge of waiting until someone pulses my monitor. 2) That task may compute a complex (ie: time consuming) operation. In the meanwhile, the pulse method could be called several times without doing anything (as the main task is already doing some processing). 3)

问题 So I followed this tutorial: https://www.youtube.com/watch?v=gyyj57O0FVI and I made exactly the same code in javafx8. public class CountdownController implements Initializable{ @FXML private Label labTime; @Override public void initialize(URL location, ResourceBundle resources) { new Thread(){ public void run(){ while(true){ Calendar calendar = new GregorianCalendar(); int hour = calendar.get(Calendar.HOUR); int minute = calendar.get(Calendar.MINUTE); int second = calendar.get(Calendar.SECOND

问题 So I followed this tutorial: https://www.youtube.com/watch?v=gyyj57O0FVI and I made exactly the same code in javafx8. public class CountdownController implements Initializable{ @FXML private Label labTime; @Override public void initialize(URL location, ResourceBundle resources) { new Thread(){ public void run(){ while(true){ Calendar calendar = new GregorianCalendar(); int hour = calendar.get(Calendar.HOUR); int minute = calendar.get(Calendar.MINUTE); int second = calendar.get(Calendar.SECOND

问题 So I followed this tutorial: https://www.youtube.com/watch?v=gyyj57O0FVI and I made exactly the same code in javafx8. public class CountdownController implements Initializable{ @FXML private Label labTime; @Override public void initialize(URL location, ResourceBundle resources) { new Thread(){ public void run(){ while(true){ Calendar calendar = new GregorianCalendar(); int hour = calendar.get(Calendar.HOUR); int minute = calendar.get(Calendar.MINUTE); int second = calendar.get(Calendar.SECOND

问题 So I followed this tutorial: https://www.youtube.com/watch?v=gyyj57O0FVI and I made exactly the same code in javafx8. public class CountdownController implements Initializable{ @FXML private Label labTime; @Override public void initialize(URL location, ResourceBundle resources) { new Thread(){ public void run(){ while(true){ Calendar calendar = new GregorianCalendar(); int hour = calendar.get(Calendar.HOUR); int minute = calendar.get(Calendar.MINUTE); int second = calendar.get(Calendar.SECOND