Why dispatch_sync( ) call on main queue is blocking the main queue?

Question

I know this is not a strong question but I have to clear my mind on this concept.

I have defined myBlock as follows.

void(^myBlock)(v         


        

Answer 1

When using dispatch_sync on a serial queue (like the main queue) the current thread has to wait until the dispatched code is executed.

A dead lock occurs when a block is dispatched synchronously on from a serial queue to the same queue.