private async Task Execute()
{
var cancelToken = _cancellationTokenSource.Token;
while (!cancelToken.IsCancellationRequested)
{
Activity activity = default;
try
{
var activeCount = 0;
lock (_activeTasks)
{
activeCount = _activeTasks.Count;
}
if (activeCount >= MaxConcurrentItems)
{
await Task.Delay(Options.IdleTime);
continue;
}
activity = WorkflowActivity.StartConsume(Queue);
var item = await QueueProvider.DequeueWork(Queue, cancelToken);
if (item == null)
{
activity?.Dispose();
if (!QueueProvider.IsDequeueBlocking)
{
await Task.Delay(Options.IdleTime, cancelToken);
}
continue;
}
activity?.EnrichWithDequeuedItem(item);
var hasTask = false;
lock (_activeTasks)
{
hasTask = _activeTasks.ContainsKey(item);
}
if (hasTask)
{
_secondPasses.Add(item);
if (!EnableSecondPasses)
{
await QueueProvider.QueueWork(item, Queue);
}
activity?.Dispose();
continue;
}
_secondPasses.TryRemove(item);
var waitHandle = new ManualResetEvent(false);
lock (_activeTasks)
{
_activeTasks.Add(item, waitHandle);
}
var task = ExecuteItem(item, waitHandle, activity);
}
catch (OperationCanceledException)
{
}
catch (Exception ex)
{
Logger.LogError(ex, ex.Message);
activity?.RecordException(ex);
}
finally
{
activity?.Dispose();
}
}
List <EventWaitHandle> toComplete;
lock (_activeTasks)
{
toComplete = _activeTasks.Values.ToList();
}
foreach (var handle in toComplete)
{
handle.WaitOne();
}
}