How to Implement Semaphores in iOS Application?

Question

Is it possible to implement Counting Semaphore in ios application?

Answer 1

Like this:

dispatch_semaphore_t sem = dispatch_semaphore_create(0);

[self methodWithABlock:^(id result){
    //put code here
    dispatch_semaphore_signal(sem);

    [self methodWithABlock:^(id result){
        //put code here
        dispatch_semaphore_signal(sem);
    }];
}];

dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);

Credit http://www.g8production.com/post/76942348764/wait-for-blocks-execution-using-a-dispatch