public int Release()
{
TaskNode head = null;
int count;
do
{
lock (_lockObj)
{
count = _currentCount;
if (_head == null)
{
++_currentCount;
head = null;
}
else
{
head = _head;
if (_head == _tail)
{
_head = _tail = null;
}
else
{
_head = _head.Next;
}
}
}
} while (head != null && head.Task.IsCompleted);
if (head != null)
{
if (head.Cancellation != default(CancellationTokenRegistration))
{
head.Cancellation.Dispose();
}
Task.Run(() => head.TrySetResult(false));
}
return(count);
}