What advantage(s) does dispatch_sync have over @synchronized?

Question

Lets say I want to make this code thread-safe:

- (void) addThing:(id)thing { // Can be called from different threads
    [_myArray addObject:thing];
}
         


        

Answer 1

I have found that dispatch_sync() is a poor way to do locking, it does not support nested calls.

So you can't call dispatch_sync on a serial Q and then call it again in a subroutine with the same Q. Which means it does not behave in the same way as @synchronized does at all.