Cancellation observer registration: block not called when the token is already cancelled.

[baoshan]

I'm talking about the registerCancellationObserverWithBlock method of the BFCancellationToken class.

According to the header file: If the token is already cancelled the delegate will be notified immediately. Which (I guess) means the block will be invoked immediately if the token isCancellationRequested.

But I can not reproduce the behavior via the below code:

BFCancellationTokenSource *cts = [BFCancellationTokenSource cancellationTokenSource];
[cts cancel];
[cts.token registerCancellationObserverWithBlock:^{
    NSLog(@"never printed");
}];

Through a quick code review, I found nothing related to the behavior neither. I wonder if it's my own problem, a documentation issue, or a possible bug?

Thanks.