我正在编写我正在编写的代码中的常见模式,我需要等待组中的所有线程完成,并超时。超时应该是所有线程完成所需的时间,因此简单地为每个线程执行thread.Join(timeout)将不起作用,因为可能的超时是超时* numThreads。 / p>
现在我做的事情如下:
var threadFinishEvents = new List<EventWaitHandle>();
foreach (DataObject data in dataList)
{
// Create local variables for the thread delegate
var threadFinish = new EventWaitHandle(false, EventResetMode.ManualReset);
threadFinishEvents.Add(threadFinish);
var localData = (DataObject) data.Clone();
var thread = new Thread(
delegate()
{
DoThreadStuff(localData);
threadFinish.Set();
}
);
thread.Start();
}
Mutex.WaitAll(threadFinishEvents.ToArray(), timeout);
然而,对于这类事情,似乎应该有一个更简单的习语。
答案 0 :(得分:26)
我仍然认为使用Join更简单。记录预期的完成时间(如现在+超时),然后在循环中执行
if(!thread.Join(End-now))
throw new NotFinishedInTime();
答案 1 :(得分:22)
使用.NET 4.0,我发现System.Threading.Tasks更容易使用。这是旋转等待循环,对我来说可靠。它会阻塞主线程,直到完成所有任务。还有Task.WaitAll,但这对我来说并不总是有用。
for (int i = 0; i < N; i++)
{
tasks[i] = Task.Factory.StartNew(() =>
{
DoThreadStuff(localData);
});
}
while (tasks.Any(t => !t.IsCompleted)) { } //spin wait
答案 2 :(得分:9)
由于问题受到了影响,我将继续发布我的解决方案。
using (var finished = new CountdownEvent(1))
{
for (DataObject data in dataList)
{
finished.AddCount();
var localData = (DataObject)data.Clone();
var thread = new Thread(
delegate()
{
try
{
DoThreadStuff(localData);
threadFinish.Set();
}
finally
{
finished.Signal();
}
}
);
thread.Start();
}
finished.Signal();
finished.Wait(YOUR_TIMEOUT);
}
答案 3 :(得分:8)
关闭我的头脑,你为什么不只是Thread.Join(超时)并从总超时中删除加入所花费的时间?
// pseudo-c#:
TimeSpan timeout = timeoutPerThread * threads.Count();
foreach (Thread thread in threads)
{
DateTime start = DateTime.Now;
if (!thread.Join(timeout))
throw new TimeoutException();
timeout -= (DateTime.Now - start);
}
编辑代码现在更少伪。不清楚为什么你会修改答案-2当你修改的答案+4完全相同,只是不那么详细。
答案 4 :(得分:7)
这不回答问题(没有超时),但我做了一个非常简单的扩展方法来等待集合的所有线程:
using System.Collections.Generic;
using System.Threading;
namespace Extensions
{
public static class ThreadExtension
{
public static void WaitAll(this IEnumerable<Thread> threads)
{
if(threads!=null)
{
foreach(Thread thread in threads)
{ thread.Join(); }
}
}
}
}
然后你只需致电:
List<Thread> threads=new List<Thread>();
//Add your threads to this collection
threads.WaitAll();
答案 5 :(得分:6)
这可能不是您的选择,但是如果您可以使用.NET的并行扩展,则可以使用Task
而不是原始线程,然后使用Task.WaitAll()
等待它们完整。
答案 6 :(得分:1)
我想弄清楚如何做到这一点,但我无法从谷歌得到任何答案。 我知道这是一个老线程,但这是我的解决方案:
使用以下课程:
class ThreadWaiter
{
private int _numThreads = 0;
private int _spinTime;
public ThreadWaiter(int SpinTime)
{
this._spinTime = SpinTime;
}
public void AddThreads(int numThreads)
{
_numThreads += numThreads;
}
public void RemoveThread()
{
if (_numThreads > 0)
{
_numThreads--;
}
}
public void Wait()
{
while (_numThreads != 0)
{
System.Threading.Thread.Sleep(_spinTime);
}
}
}
答案 7 :(得分:1)
我读过C#4.0书:Herbert Schildt的完整参考书。作者使用join来提供解决方案:
class MyThread
{
public int Count;
public Thread Thrd;
public MyThread(string name)
{
Count = 0;
Thrd = new Thread(this.Run);
Thrd.Name = name;
Thrd.Start();
}
// Entry point of thread.
void Run()
{
Console.WriteLine(Thrd.Name + " starting.");
do
{
Thread.Sleep(500);
Console.WriteLine("In " + Thrd.Name +
", Count is " + Count);
Count++;
} while (Count < 10);
Console.WriteLine(Thrd.Name + " terminating.");
}
}
// Use Join() to wait for threads to end.
class JoinThreads
{
static void Main()
{
Console.WriteLine("Main thread starting.");
// Construct three threads.
MyThread mt1 = new MyThread("Child #1");
MyThread mt2 = new MyThread("Child #2");
MyThread mt3 = new MyThread("Child #3");
mt1.Thrd.Join();
Console.WriteLine("Child #1 joined.");
mt2.Thrd.Join();
Console.WriteLine("Child #2 joined.");
mt3.Thrd.Join();
Console.WriteLine("Child #3 joined.");
Console.WriteLine("Main thread ending.");
Console.ReadKey();
}
}
答案 8 :(得分:0)
可能的解决方案:
var tasks = dataList
.Select(data => Task.Factory.StartNew(arg => DoThreadStuff(data), TaskContinuationOptions.LongRunning | TaskContinuationOptions.PreferFairness))
.ToArray();
var timeout = TimeSpan.FromMinutes(1);
Task.WaitAll(tasks, timeout);
假设dataList是项目列表,并且每个项目都需要在单独的线程中处理。