async void OnElapsed(object context)
{
if (!this.stopGuard.TryLock())
{
return;
}
try
{
await Elapsed.InvokeAsync(this, new TimerElapsedEventArgs(context, CancellationToken.None));
}
finally
{
Interlocked.Increment(ref this.elapsed);
this.stopGuard.Release();
// Try to change one-shot state to 3 (stopping by inside) only if it is 1 (one-shot not fired). If the
// current value is 1 that mean this method have responsibility to clean up resources.
if (Interlocked.CompareExchange(ref this.oneShotState, 3, 1) == 1)
{
Stop();
}
}
}