Passing state into a Task called from a continuation

Question

I have implemented a solution from Crafting a Task.TimeoutAfter Method and I curious about the best practice regarding passing data upwards from a Task to its continuation.
I would like to know if the parent task released the semaphore, I could simply release it only in the continuation, is that safe enough?
Task task = Task.Factory.StartNew(
() =>
try
this.MyMethod(foo, bar);
catch
// Signal termination.
taskCancellationTokenSource.Cancel();
// Propagate up.
throw;
finally
// Release handle.
semaphore.Release();
TaskCreationOptions.AttachedToParent)
.TimeoutAfter(5000)
.ContinueWith(
antecedent =>
// How can I pass state/indicator into this task to know if I need to do ths?
semaphore.Release();
if (antecedent.IsCanceled || antecedent.IsFaulted)
throw new System.TimeoutException("A task has hung.");
Thanks!

Answer 1

Hi Ritmo2k,
The Semaphore.Release method will release one semaphore to the pool. If the pool is already full, it'll throw SemaphoreFullException, that means you cannot call Release method until a thread has called WaitOne method. And this method will return an integer
which indicates the count on the semaphore before Release method is called.
If I understand you correctly,you want to know the count on the semaphorebefore you call the second Release method. I think you could create a global integer variable to store the return value from the first call of the Release method.
We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
Click
HERE to participate the survey.