multithreading

问题 I am creating 10 threads. Each thread will do some task. There are 7 tasks to be done. Since number of tasks are less than the number of threads, there would always be 3 threads that sleep and do nothing. My main thread must wait for the tasks to get completed and exit only when all the tasks are done (i.e when the thread exits). I am waiting in a for loop and calling pthread_join but with the 3 threads that are sleeping, how can I wake them up and make them exit? Here is what I am doing now.

问题 I was asked this question during an interview, does anybody know? 回答1: If JVM exits as a result of crash the thread will not exist anymore. If crash is some kind of out of memory or similar error, it may or may not exist depending on specific circumstances. 回答2: If a thread is running the JVM has not crashed. However, sometimes people incorrectly describe any exception being throw as a crash. If this is what the interviewer meant, I would say the thread is still running because the exception

问题 I was asked this question during an interview, does anybody know? 回答1: If JVM exits as a result of crash the thread will not exist anymore. If crash is some kind of out of memory or similar error, it may or may not exist depending on specific circumstances. 回答2: If a thread is running the JVM has not crashed. However, sometimes people incorrectly describe any exception being throw as a crash. If this is what the interviewer meant, I would say the thread is still running because the exception

问题 I trying to test the example at here changing it from threading to multiprocessing. Running this (the original example) in jupyter notebook, will display a progress bar that fills up in some time. import threading from IPython.display import display import ipywidgets as widgets import time progress = widgets.FloatProgress(value=0.0, min=0.0, max=1.0) def work(progress): total = 100 for i in range(total): time.sleep(0.2) progress.value = float(i+1)/total thread = threading.Thread(target=work,

问题 I trying to test the example at here changing it from threading to multiprocessing. Running this (the original example) in jupyter notebook, will display a progress bar that fills up in some time. import threading from IPython.display import display import ipywidgets as widgets import time progress = widgets.FloatProgress(value=0.0, min=0.0, max=1.0) def work(progress): total = 100 for i in range(total): time.sleep(0.2) progress.value = float(i+1)/total thread = threading.Thread(target=work,

问题 I am very inexperienced using multi-threading techniques, but here is what I have tried: Thread thread = null; for (int minute = 0; minute < 60; minute++) { Thread.Sleep(60000); if (thread != null) { while (thread.ThreadState == ThreadState.Running) { } } thread = new Thread(delegate() { // Do stuff during the next minute whilst the main thread is sleeping. }); thread.Start(); } What I am trying to achieve here is to have a thread running and doing work whilst the main thread sleeps, but I am

问题 I do not understand how is the control returned to the caller when using async- await, since when i execute this code, the first thread gets practically destroyed when calling task inside the awaited method, and the thread that gives the result executes all remaining code.Below i have also drawn a diagram of how i thought the execution is, but it seems it is wrong. Assumed workflow according to "returning control to the caller": Results Main public static string GetThreadId => Thread

问题 Here is the top of my source file: #include <iostream> #include <thread> #include <fstream> ... thread help(startHelp); Where the thread is inside the function handleRequestsFromServer and startHelp is a void function. When compiling this with g++ on Mac OS X 10.8.4, I get this error: $ g++ diskutilityhelper.cpp -o run.out diskutilityhelper.cpp:5:18: error: thread: No such file or directory diskutilityhelper.cpp: In function ‘void handleRequestsFromServer()’: diskutilityhelper.cpp:140: error:

问题 Below is the source of a sample program: When I run it from ghci both printJob and printJob2 run fine and write ten lines into a text file. But when compiled with -threaded flag, the program writes only one line. I have ghc 7.0.3 on ArchLinux Here's the compile command: ghc -threaded -Wall -O2 -rtsopts -with-rtsopts=-N -o testmvar testmvar.hs What am I am doing wrong ? Why it does not work in threaded mode ? import Control.Concurrent.MVar import Control.Concurrent (forkIO) import Control

问题 I am very inexperienced using multi-threading techniques, but here is what I have tried: Thread thread = null; for (int minute = 0; minute < 60; minute++) { Thread.Sleep(60000); if (thread != null) { while (thread.ThreadState == ThreadState.Running) { } } thread = new Thread(delegate() { // Do stuff during the next minute whilst the main thread is sleeping. }); thread.Start(); } What I am trying to achieve here is to have a thread running and doing work whilst the main thread sleeps, but I am