超时后中断任务的ExecutorService

问题描述

我正在寻找一个 可以提供超时的 ExecutorService 实现.提交给 ExecutorService 的任务如果运行时间超过超时时间，则会被中断.实现这样的野兽并不是一项艰巨的任务，但我想知道是否有人知道现有的实现.

I'm looking for an ExecutorService implementation that can be provided with a timeout. Tasks that are submitted to the ExecutorService are interrupted if they take longer than the timeout to run. Implementing such a beast isn't such a difficult task, but I'm wondering if anybody knows of an existing implementation.

这是我根据下面的一些讨论得出的结论.有什么意见吗?

Here's what I came up with based on some of the discussion below. Any comments?

import java.util.List;
import java.util.concurrent.*;

public class TimeoutThreadPoolExecutor extends ThreadPoolExecutor {
    private final long timeout;
    private final TimeUnit timeoutUnit;

    private final ScheduledExecutorService timeoutExecutor = Executors.newSingleThreadScheduledExecutor();
    private final ConcurrentMap<Runnable, ScheduledFuture> runningTasks = new ConcurrentHashMap<Runnable, ScheduledFuture>();

    public TimeoutThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, long timeout, TimeUnit timeoutUnit) {
        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue);
        this.timeout = timeout;
        this.timeoutUnit = timeoutUnit;
    }

    public TimeoutThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory, long timeout, TimeUnit timeoutUnit) {
        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory);
        this.timeout = timeout;
        this.timeoutUnit = timeoutUnit;
    }

    public TimeoutThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, RejectedExecutionHandler handler, long timeout, TimeUnit timeoutUnit) {
        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, handler);
        this.timeout = timeout;
        this.timeoutUnit = timeoutUnit;
    }

    public TimeoutThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory, RejectedExecutionHandler handler, long timeout, TimeUnit timeoutUnit) {
        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory, handler);
        this.timeout = timeout;
        this.timeoutUnit = timeoutUnit;
    }

    @Override
    public void shutdown() {
        timeoutExecutor.shutdown();
        super.shutdown();
    }

    @Override
    public List<Runnable> shutdownNow() {
        timeoutExecutor.shutdownNow();
        return super.shutdownNow();
    }

    @Override
    protected void beforeExecute(Thread t, Runnable r) {
        if(timeout > 0) {
            final ScheduledFuture<?> scheduled = timeoutExecutor.schedule(new TimeoutTask(t), timeout, timeoutUnit);
            runningTasks.put(r, scheduled);
        }
    }

    @Override
    protected void afterExecute(Runnable r, Throwable t) {
        ScheduledFuture timeoutTask = runningTasks.remove(r);
        if(timeoutTask != null) {
            timeoutTask.cancel(false);
        }
    }

    class TimeoutTask implements Runnable {
        private final Thread thread;

        public TimeoutTask(Thread thread) {
            this.thread = thread;
        }

        @Override
        public void run() {
            thread.interrupt();
        }
    }
}

推荐答案

您可以使用 ScheduledExecutorService 为此.首先，您只需提交一次即可立即开始并保留创建的未来.之后，您可以提交一个新任务，该任务会在一段时间后取消保留的未来.

You can use a ScheduledExecutorService for this. First you would submit it only once to begin immediately and retain the future that is created. After that you can submit a new task that would cancel the retained future after some period of time.

 ScheduledExecutorService executor = Executors.newScheduledThreadPool(2);
 final Future handler = executor.submit(new Callable(){ ... });
 executor.schedule(new Runnable(){
     public void run(){
         handler.cancel();
     }
 }, 10000, TimeUnit.MILLISECONDS);

这将执行您的处理程序(要中断的主要功能)10 秒，然后将取消(即中断)该特定任务.

This will execute your handler (main functionality to be interrupted) for 10 seconds, then will cancel (i.e. interrupt) that specific task.

这篇关于超时后中断任务的ExecutorService的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！