NSBlockOperation添加线程依赖

#pragma mark NSBlockOperation添加线程依赖
- (void)addDependency {
    NSBlockOperation *operation1 = [NSBlockOperation blockOperationWithBlock:^{
        NSLog(@"operation1");
    }];
    NSBlockOperation *operation2 = [NSBlockOperation blockOperationWithBlock:^{
        sleep(3);
        NSLog(@"operation2");
    }];
    NSBlockOperation *operation3 = [NSBlockOperation blockOperationWithBlock:^{
        sleep(5);
        NSLog(@"operation3");
    }];
    [operation1 addDependency:operation2];
    [operation2 addDependency:operation3];;
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    [queue addOperations:@[operation1, operation2, operation3] waitUntilFinished:YES];
    NSLog(@"end");
}

#pragma mark NSBlockOperation添加线程依赖
- (void)addDependency1 {
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    queue.maxConcurrentOperationCount = 2;
    [queue addOperationWithBlock:^{
        sleep(3);
        NSLog(@"operation1");
    }];
    [queue addOperationWithBlock:^{
        sleep(2);
        NSLog(@"operation2");
    }];
    [queue addOperationWithBlock:^{
        NSLog(@"operation3");
    }];
    NSLog(@"end");
}