如何在Java中的ExecutorService中暂停/恢复所有线程？

Question

我向Java的executorservice提交了一堆作业，但我想以某种方式暂时暂停所有这些作业。最好的方法是什么？我该如何恢复？还是我这样做完全错误？我是否应该遵循其他想要实现的模式（即暂停/恢复执行服务的能力）？

Answer 1

为了回答我自己的问题，我PausableThreadPoolExecutor在ThreadPoolExecutor
本身的javadocs中找到了一个示例。这是我使用番石榴显示器的版本：

import com.google.common.util.concurrent.Monitor;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.ThreadFactory;

public class PausableExecutor extends ScheduledThreadPoolExecutor {

    private boolean isPaused;

    private final Monitor monitor = new Monitor();
    private final Monitor.Guard paused = new Monitor.Guard(monitor) {
        @Override
        public boolean isSatisfied() {
            return isPaused;
        }
    };

    private final Monitor.Guard notPaused = new Monitor.Guard(monitor) {
        @Override
        public boolean isSatisfied() {
            return !isPaused;
        }
    };

    public PausableExecutor(int corePoolSize, ThreadFactory threadFactory) {
        super(corePoolSize, threadFactory);
    }

    protected void beforeExecute(Thread t, Runnable r) {
        super.beforeExecute(t, r);
        monitor.enterWhenUninterruptibly(notPaused);
        try {
            monitor.waitForUninterruptibly(notPaused);
        } finally {
            monitor.leave();
        }
    }

    public void pause() {
        monitor.enterIf(notPaused);
        try {
            isPaused = true;
        } finally {
            monitor.leave();
        }
    }

    public void resume() {
        monitor.enterIf(paused);
        try {
            isPaused = false;
        } finally {
            monitor.leave();
        }
    }
}