Using blocks in NSOperation main method

Question

I'm using blocks inside a NSOperation. The main method of my NSOperation looks like this:

- (void) main {

    [self callMethodOfALiraryUsingCompletionBlock:^() {
       //this method takes time to execute, will call this block when done
    }];
}

I'd like my NSOperationto terminate when what's inside the block is done. Currently, it returns directly, before what's inside the block is executed ... Any idea how I can solve this ?

Answer 1

Little detail in your question, here is one possible outline which may help:

• Create a semaphore (dispatch_semaphore_create)
• Execute your library code asynchronously (dispatch_async)
• Have the completion block for your library code signal the semaphore
• Have your main method wait on the semaphore

HTH