wait | 易学教程

java多线程及线程池小结

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最近在学习线程池的东西，前面有篇文章《线程池的设计原则》，当然大多都是参考别人的思想。然后发现自己多线程真的写的太少了。现在来补充基础知识咯。。。 wait导致当前的线程等待，直到其他线程调用此对象的 notify() 方法或 notifyAll() 方法。当前的线程必须拥有此对象监视器。该线程发布对此监视器的所有权并等待，直到其他线程通过调用 notify 方法，或 notifyAll 方法通知在此对象的监视器上等待的线程醒来。然后该线程将等到重新获得对监视器的所有权后才能继续执行. 以上是jdk api的说明,对照说明写个测试： Code public class Test extends Thread { @Override public void run() { System.out.println( " before wait! " ); try { synchronized ( this ) { this .wait(); } } catch (InterruptedException e) { e.printStackTrace(); } try { Thread.sleep( 20000 ); } catch (Exception e) { System.out.println( " interrupted! " ); } System.out.println( "

Difference between wait(long timeout) and join(long millis)?

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问题 Both of wait() and join() methods when called by thread-1 on thread-2 makes thread-1 wait for the thread-2, either for sometime or till thread-2 completes. If we are using the overloaded versions of these methods i.e. wait(long timeout) and join(long millis), then In case of wait(long timeout), thread-1 will become runnable either by notify (or notifyall) or even timeout occurs (whichever is first). In case of join(long millis), thread-2 will become runnable either when thread-2 completes or

How to wait until my batch file is finished

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问题 I'm doing a program where I need to start cmd and there start up a batch file. The problem is that I'm using MyProcess.WaithForexit(); and I think it does not wait until the batch file processing is finished. It just waits until the cmd is closed. My code so far: System.Diagnostics.ProcessStartInfo ProcStartInfo = new System.Diagnostics.ProcessStartInfo("cmd"); ProcStartInfo.RedirectStandardOutput = true; ProcStartInfo.UseShellExecute = false; ProcStartInfo.CreateNoWindow = false;

Producer Consumer-Average Wait times not outputting/buffer query

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问题 I am currently making a hypothetical producer consumer problem using java. The object is to have an operating system which is 1000 bytes, but only 500 bytes available to use for threads as 500 bytes have already been consumed by drivers and other operations. The threads are as follows: A thread to start a BubbleWitch2 session of 10 seconds, which requires 100 bytes of RAM per second A thread to start a Spotify stream of 20 seconds, which requires 250 bytes of RAM per second You should also

Batch Script to wait for program to close by user before applying msi update

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问题 I'm using a network management tool to apply updates to software and I have an issue where if a users is already using the program you want to update the update will fail as you would expect. I have been trying to put together a batch script that will detect whether the the program is running and if it is the script will wait until the user closes down the program and the apply the msi update. I've pretty much scoured google but can only really find previous scripts that kill the program

How does one use the wait() function when forking multiple processes?

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问题 Learning to use the fork() command and how to pipe data between a parent and it's children. I am currently trying to write a simple program to test how the fork and pipe functions work. My problem seems to be the correct use/placement of the wait function. I want the parent to wait for both of its children to finish processing. Here is the code I have so far: int main(void) { int n, fd1[2], fd2[2]; pid_t pid; char line[100]; if (pipe(fd1) < 0 || pipe(fd2) < 0) { printf("Pipe error\n"); return

C# : How to pause the thread and continue when some event occur?

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问题 How can I pause a thread and continue when some event occur? I want the thread to continue when a button is clicked. Someone told me that thread.suspend is not the proper way to pause a thread. Is there another solution? 回答1: You could use a System.Threading.EventWaitHandle. An EventWaitHandle blocks until it is signaled. In your case it will be signaled by the button click event. private void MyThread() { // do some stuff myWaitHandle.WaitOne(); // this will block until your button is

Delay or Wait-For Statement

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问题 I have a 500,000 line SQL script: update users set region_id = 9814746 where id = 101 and region_id is null; update users set region_id = 9814731 where id = 102 and region_id is null; update users set region_id = 3470676 where id = 103 and region_id is null; I want to INSERT a delay of 10 seconds every 50 lines. Does pgsql have a waitfor statement like t-sql . Thanks. 回答1: Does pgsql have a waitfor statement like t-sql. Yes, pg_sleep: pg=> SELECT pg_sleep(10); pg_sleep ---------- (1 row) 回答2:

Delay or Wait-For Statement

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delay/sleep in Swift is not working

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问题 I have a problem with the sleep function in Swift code. I'm using import Darwin and usleep(400000) . Some actions before reaching the sleep are blocked and I dont know why. Here a short example from my code: @IBAction func Antwort4Button(_ sender: Any) { if (richtigeAntwort == "4"){ Antwort4.backgroundColor = UIColor.green Ende.text = "Richtig!" NaechsteFrage() } else { Ende.text = "Falsch!" //NaechsteFrage() } } func NaechsteFrage() { usleep(400000) Antwort1.backgroundColor = UIColor.red