What is the correct way to release a GCD dispatch queue property?

Question

I\'m using a dispatch_queue which is accessed through a property of its owner, like this:

@property (nonatomic, assign) dispatch_queue_t queue;

Answer 1

What happens if there is stuff pending/running on the queue while calling release?

It is safe. pending/running queue is retained from system. Calling dispatch_release just affects the retain count of the queue. See man page of dispatch_async or so forth.