Managing Memory with Blocks

From: blockMemory.m

5 __block int counter;
6 int(^block)(void) =
7   ^(void) { return counter++; };
8 block = [block retain];
9 _Block_release(block);

Memory management in Cocoa traditionally uses reference counting. Blocks work in the same way. There are two functions controlling the reference count of a block. The _Block_copy() function increases its reference count, while the _Block_release() function decreases it.