BFTask retain cycle

[sgl0v]

There is a way to introduce retain cycle and get a BFTask object leaked. Just create a task that is never finished with result/error or cancelled. Here is the example:

[[self asyncTask] continueWithSuccessBlock:^id _Nullable(BFTask * _Nonnull t) {
    ...
}];

- (BFTask *)syncTask {
    BFTaskCompletionSource *taskSource = [BFTaskCompletionSource taskCompletionSource];
    return taskSource.task;
}

The BFTask object is captured in the executionBlock block of the continueWithExecutor:block:cancellationToken: method.

I'd propose to get rid of self reference capturing and cancel the task on deallocation (if needed).

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[hhanesand]

I'm pretty sure we can't implement this suggestion, as the retain cycle is needed to keep one off tasks alive before they finish/cancel/error. If this was implemented, tasks that do not have external references to them would be deallocated immediately.

IMO: It's a user error not to finish or cancel your task, not the frameworks error.

[passwords3]

Remove block