Question

我目前正在尝试在C＃中实现实时多线程软件。我需要3个线程。每个线程执行必须在截止期限（500µs / 100µs / 50µs）之前完成。在整个运行期间，线程必须并行运行（直到用户关闭程序）。

是否存在可以确保线程执行不会超过期限的机制？

这是我的代码：

static void Main(string[] args)
{
    Thread thread1 = new Thread(FirstThread);
    Thread thread2 = new Thread(SecondThread);
    Thread thread3 = new Thread(ThirdThread);

    thread1.start();
    thread2.start();
    thread3.start();
}

static void FirstThread()
{
    while(true)
    {
        SleepMicroSec(500);
    }
}

static void SecondThread()
{
    while(true)
    {
        SleepMicroSec(100);
    }
}

static void ThirdThread()
{
    while(true)
    {
        SleepMicroSec(50);
    }
}

private static void SleepMicroSec(long microSec)
{
    var sw = Stopwatch.StartNew();

    while (sw.ElapsedTicks / (Stopwatch.Frequency / (1000L * 1000L)) < microSec)
    {

    }
}

如果达到任务期限，我希望调度程序能够执行上下文切换。

预先感谢您的回答！

Answer 1

这里是一种在后台线程中重复调用动作的方法，每次超过期限时，都会中止并重新启动线程。它还接受CancellationToken以允许过早取消该过程（在程序结束之前）。

private static void RepeatInBackgroundThread(Action action, int timeout,
    CancellationToken cancellationToken)
{
    var timer = new System.Timers.Timer(timeout);
    timer.AutoReset = false; // to raise the Elapsed event only once
    var thread = new Thread(() =>
    {
        while (true)
        {
            if (cancellationToken.IsCancellationRequested) return;
            timer.Start();
            action();
            timer.Stop();
        }
    });
    timer.Elapsed += (sender, e) =>
    {
        thread.Abort();
        thread.Join(); // Wait for the thread to die
        if (cancellationToken.IsCancellationRequested) return;
        RepeatInBackgroundThread(action, timeout, cancellationToken);
    };
    thread.IsBackground = true;
    thread.Start();
}

用法示例：

var random = new ThreadLocal<Random>(() => new Random());
var cts = new CancellationTokenSource();
RepeatInBackgroundThread(() => Thread.Sleep(random.Value.Next(0, 1000)), 500, cts.Token);
RepeatInBackgroundThread(() => Thread.Sleep(random.Value.Next(0, 200)), 100, cts.Token);
RepeatInBackgroundThread(() => Thread.Sleep(random.Value.Next(0, 100)), 50, cts.Token);
//cts.CancelAfter(10000);

应该注意，一般aborting threads is not a good practice。

具有截止日期的C＃线程调度

1 个答案: