如何在特定时间后停止执行方法？ [英] How to stop the execution of a method after a specific time?

问题描述

如果在有限的时间内未完成方法，我需要停止执行该方法。

I need to stop the execution of a method if it has not completed within a limited period of time.

要执行此工作，我可以使用 Thread.Abort 方法：

To do this work I can use the Thread.Abort method in this way:

void RunWithTimeout(ThreadStart entryPoint, int timeout)
{
    var thread = new Thread(() =>
    {
        try
        {
            entryPoint();
        }
        catch (ThreadAbortException)
        {   }

    }) { IsBackground = true };

    thread.Start();

    if (!thread.Join(timeout))
        thread.Abort();
}

鉴于我正在使用.NET 3.5，是否有更好的方法？

Given that I'm using .NET 3.5, is there a better way?

编辑：在此处按照我的 entryPoint 的注释进行操作，但我正在为任何 entryPoint 。

following the comments here my entryPoint, but I'm looking for a good way for any entryPoint.

void entryPoint()
{
   // I can't use ReceiveTimeout property
   // there is not a ReceiveTimeout for the Compact Framework
   socket.Receive(...);
}

推荐答案

答案取决于工作'。如果可以安全地停止工作（即不执行某些I / O阻止操作），请使用 Backgroundworker.CancelAsync（...）

Answer depends on 'the work'. If work is something that can be safely stopped (i.e. not some I/O blocking operation) - use Backgroundworker.CancelAsync(...)

如果您必须努力工作-我会考虑使用程序，在这种情况下，正在中止进程更干净-并且 process.WaitForExit（timeout）是您的朋友。

If you do have to cut hard - I'd consider using a Process, in which case the Aborting process is cleaner - and process.WaitForExit(timeout) is your friend.

建议的TPL是很棒，但不幸的是，在.Net 3.5中不存在。

Suggested TPL is great but unfortunately does not exist in .Net 3.5.

编辑：您可以使用反应式扩展以遵循Jan de Vaan的建议。

You can use Reactive Extensions to follow Jan de Vaan's suggestion.

这是我的动作超时片段-主要是在这里供其他人评论：

Here is my 'action timeout' snip - it's mainly here for others to comment on:

    public static bool WaitforExit(this Action act, int timeout)
    {
        var cts = new CancellationTokenSource();
        var task = Task.Factory.StartNew(act, cts.Token);
        if (Task.WaitAny(new[] { task }, TimeSpan.FromMilliseconds(timeout)) < 0)
        { // timeout
            cts.Cancel();
            return false;
        }
        else if (task.Exception != null)
        { // exception
            cts.Cancel();
            throw task.Exception;
        }
        return true;
    }

编辑：显然，这不完全是OP想要。这是我设计可取消套接字接收器的尝试：

EDIT: Apparently this isn't exactly what OP wanted. Here's my attempt to devise a 'cancelable' socket receiver:

public static class Ext
{
    public static object RunWithTimeout<T>(Func<T,object> act, int timeout, T obj) where T : IDisposable
    {
        object result = null;
        Thread thread = new Thread(() => { 
            try { result = act(obj); }
            catch {}    // this is where we end after timeout...
        });

        thread.Start();
        if (!thread.Join(timeout))
        {
            obj.Dispose();
            thread.Join();
        }
        return result;
    }       
}

class Test
{
    public void SocketTimeout(int timeout)
    {
        using (var sock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp))
        {
            Object res = Ext.RunWithTimeout(EntryPoint, timeout, sock);
        }
    }

    private object EntryPoint(Socket sock)
    {
        var buf = new byte[256];
        sock.Receive(buf);
        return buf;
    }
}

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