Question

I’m running into a common pattern in the code that I’m writing, where I need to wait for all threads in a group to complete, with a timeout. The timeout is supposed to be the time required for all threads to complete, so simply doing Thread.Join(timeout) for each thread won’t work, since the possible timeout is then timeout * numThreads.

Right now I do something like the following:

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); 

However, it seems like there should be a simpler idiom for this sort of thing.

Answer 1

I still think using Join is simpler. Record the expected completion time (as Now+timeout), then, in a loop, do

if(!thread.Join(End-now))     throw new NotFinishedInTime();