Java多线程之notifyAll的作用域

浏览数：29 / 时间：2015年06月08日

notifyAll()因某个特定锁而被调用时，只有等待这个锁的任务才会被唤醒。

package Thread.Wait;

import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

class Blocker {
    synchronized void waitingCall() {
        try {
            while (!Thread.interrupted()) {
                wait();
                System.out.println(Thread.currentThread() + " ");
            }
        } catch (Exception e) {
            // OK to exit this way
        }
    }

    synchronized void prod() {
        notify();
    }

    synchronized void proAll() {
        notifyAll();
    }
}

class Task implements Runnable {
    static Blocker blocker = new Blocker();

    public void run() {
        blocker.waitingCall();
    }
}

class Task2 implements Runnable {
    static Blocker blocker = new Blocker();

    public void run() {
        blocker.waitingCall();
    }
}

public class NotifyVsNotifyAll {
    public static void main(String[] args) throws Exception {
        ExecutorService exec = Executors.newCachedThreadPool();
        for (int i = 0; i < 5; i++) {
            exec.execute(new Task());
        }
        exec.execute(new Task2());
        Timer timer = new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {
            boolean prod = true;

            @Override
            public void run() {
                if (prod) {
                    System.out.println("\nnotify() ");
                    Task.blocker.prod();
                    prod = false;
                } else {
                    System.out.println("\nnotifyAll()");
                    Task.blocker.proAll();
                    prod = true;
                }
            }
        }, 400, 400);
    }
}