Crashes randomly when working with a background queue

[DevAlansc]

Hi guys,

I've been using this library for some months and I really like it. Unfortunately, I start having some crashes in the latest versions (Currently, I'm using the version 1.0.3).

I don't receive an exception, only a signal: EXC_BAD_ACCESS. Please, see the attached images.

The first image shows how the tasks are added to the queue in background mode.
The other ones show where the lib fails.

Could you give me any suggestion? I don't have any idea about what can be failing Many thanks.

[calvadoser]

Having the same issue, @DevAlansc @icanzilb did you find any solution for that ?
Thanks.

[icanzilb]

If there is an error trace or other more informative error, this potentially could be addressed

[mzbik]

I think it will be hard to come up with a trace; I believe there are a number of multithreaded race conditions in the code due to >all< accesses to arrays not being protected. Looking at the code more:

1. hasCompletions is never reset. Seems like a needless optimization...
2. you are calling completions while synchronized. Could you run into deadlocks?
3. calls to .insert(at:), .remove(at:) and .removeAll are not synchronized
4. the += operator on tasks and completions is not synchronized

I believe there are other races as well since the public methods themselves are not synchronized

[alexandremorgado]

Having the same issue here, too. I've been using this awesome class on my download manager, to queue a large number of image downloads on background (usually more them 1.000 images). But I had to limit maximumNumberOfActiveTasks to 3. If a set to 10 active tasks, sometimes the app crash.

[DouweBos]

I just replaced TaskQueue with the following: https://github.com/couchdeveloper/TaskQueue

So far it's no longer randomly crashing