如何在以下或类似情况下避免线程等待（如果真的有必要让线程等待）？

Question

请看下面的代码sn-p。我正在尝试执行一个长时间运行的任务，但我不想等待超过给定的超时时间。我想完全控制任务何时开始，因此产生一个新线程并完成工作，并在父线程中等待它。该模式确实有效，但父线程只是在等待。理想情况下，我不喜欢线程休眠/等待，除非它真的需要。我怎样才能做到这一点？欢迎任何建议/想法/模式。

/// <summary>
/// tries to execute a long running task
/// if the task is not completed in specified time, its deemed un-sccessful.
/// </summary>
/// <param name="timeout"></param>
/// <returns></returns>
bool Task(int timeout)
{
    bool workCompletedSuccessfully = false;
    //I am intentionally spawning thread as i want to have control when the thread start
    //so not using thread pool threads.
    Thread t = new Thread(() =>
    {
        //executes some long running task
        //handles all the error conditions
        //ExecuteTask();
        workCompletedSuccessfully = true;
    });
    t.Start();
    //cannot wait more "timeout"                        
    //My main thread (parent) thread simply waiting for the spawened thread to join
    //HOW CAN I AVOID THIS?ANY PATTERN TO AVOID THIS REALLY HELPS?
    t.Join(timeout);
    if (!workCompletedSuccessfully)
    {
        //deeemed un-successful
        //do the remediation by gracefully disposing the thread
        //itnentionally hidden details about disposing thread etc, to concentrate on 
        //the question - AVOIDING PARENT THREAD TO WAIT
    }
    return workCompletedSuccessfully;
}

问候， 梦想家

Answer 1

使用AutoResetEvent。

bool Task(int timeout)
{
    AutoResetEvent threadFinished = new AutoResetEvent(false);
    //I am intentionally spawning thread as i want to have control when the thread start
    //so not using thread pool threads.
    Thread t = new Thread(() =>
    {
        //executes some long running task
        //handles all the error conditions
        //ExecuteTask();
        threadFinished.Set();
    });
    t.Start();
    //Param - timeout
    bool finished = threadFinished.WaitOne(timeout);
    if (!finished)
    {
        //deeemed un-successful
        //do the remediation by gracefully disposing the thread
    }
    return finished;
}

我在这里看到的唯一问题是您打算如何处理未按时完成的线程。理论上你可以调用Thread.Abort()，但这不是一个好主意，因为它会破坏应用程序的状态。

编辑：您需要了解threadFinished.WaitOne(timeout); 仍处于阻塞状态，但不会超过timeout。