从线程池联接线程

int running = myTasks.Count;
AutoResetEvent done = new AutoResetEvent(false);
foreach (var task in myTasks) {
    ThreadPool.QueueUserWorkItem(state => { 
    task(state); 
    if (0 == Interlocked.Decrement(ref running))
      done.Set ();
    });
}
done.WaitOne();

使用C#4.0,您可以使用新的 CountdownEvent

Joe Duffy 写了一篇关于这类事情的好文章:

CLR Inside Out: 9 Reusable Parallel Data Structures and Algorithms

我把倒计时锁定得特别适合你的要求。

根据这篇文章: Overview of Synchronization Primitives

CountdownEvent Class

或者类似的: Barrier (.NET Framework)

对于较新版本,请使用TPL(任务并行库),对于此场景,此代码是相关的:

// Create an ActionBlock<int> object that prints its input
// and throws ArgumentOutOfRangeException if the input
// is less than zero.
var throwIfNegative = new ActionBlock<int>(n =>
{
   Console.WriteLine("n = {0}", n);
   if (n < 0)
   {
      throw new ArgumentOutOfRangeException();
   }
});

// Post values to the block.
throwIfNegative.Post(0);
throwIfNegative.Post(-1);
throwIfNegative.Post(1);
throwIfNegative.Post(-2);
throwIfNegative.Complete();

// Wait for completion in a try/catch block.
try
{
   throwIfNegative.Completion.Wait();
}
catch (AggregateException ae)
{
   // If an unhandled exception occurs during dataflow processing, all
   // exceptions are propagated through an AggregateException object.
   ae.Handle(e =>
   {
      Console.WriteLine("Encountered {0}: {1}", 
         e.GetType().Name, e.Message);
      return true;
   });
}

/* Output:
n = 0
n = -1
Encountered ArgumentOutOfRangeException: Specified argument was out of the range
 of valid values.
*/

从 https://msdn.microsoft.com/en-us/library/hh228603.aspx