public static Task TimeoutAfter(this Task task, int millisecondsTimeout)
{
if (task is null)
{
throw new ArgumentNullException(nameof(task));
}
// Short-circuit #1: infinite timeout or task already completed
if (task.IsCompleted || (millisecondsTimeout == Timeout.Infinite))
{
// Either the task has already completed or timeout will never occur.
// No proxy necessary.
return(task);
}
// tcs.Task will be returned as a proxy to the caller
var tcs = new TaskCompletionSource <VoidTypeStruct>();
// Short-circuit #2: zero timeout
if (millisecondsTimeout == 0)
{
// We've already timed out.
tcs.SetException(new TimeoutException());
return(tcs.Task);
}
// Set up a timer to complete after the specified timeout period
var timer = new Timer(
callback: state => ((TaskCompletionSource <VoidTypeStruct>)state !).TrySetException(new TimeoutException()),
state: tcs,
dueTime: millisecondsTimeout,
period: Timeout.Infinite);
// Wire up the logic for what happens when source task completes
_ = task.ContinueWith(
(antecedent, state) =>
{
// Recover our state data
#pragma warning disable CS8600 // Converting null literal or possible null value to non-nullable type.
var tuple = (Tuple <Timer, TaskCompletionSource <VoidTypeStruct> >)state;
#pragma warning restore CS8600 // Converting null literal or possible null value to non-nullable type.
// Cancel the Timer
tuple !.Item1.Dispose();
// Marshal results to proxy
MarshalTaskResults(antecedent, tuple.Item2);
},
Tuple.Create(timer, tcs),
CancellationToken.None,
TaskContinuationOptions.ExecuteSynchronously,
TaskScheduler.Default);
return(tcs.Task);
}
/// <inheritdoc />
public void Dispose()
{
Item1.Dispose();
Item2.Dispose();
}