dispatch_suspend和dispatch_resume

dispatch_suspend用于挂起队列，dispatch_resume用于恢复队列，但是从这两个方法的传参来看，计时器或者其他dispatch_object_t都是可以的。
队列挂起后，已经在执行的任务无法停止，但是没开始的任务是会等待resume后才开始执行。但是经过测试发现，系统提供的dispatch_get_global_queue获取的并行队列并不受到挂起和恢复的影响

- (void)func08
{
    dispatch_queue_t queue = dispatch_queue_create("MYQUEUE", DISPATCH_QUEUE_SERIAL);
//    dispatch_queue_t queue = dispatch_queue_create("MYQUEUE", DISPATCH_QUEUE_CONCURRENT);
//    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_async(queue, ^{
        for (NSInteger i = 0; i < 10; i++) {
            NSLog(@"0: == %@", [NSThread currentThread]);
            [NSThread sleepForTimeInterval:1];
        }
    });
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(4 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        NSLog(@"挂起队列");
        dispatch_suspend(queue);
    });
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        NSLog(@"插入任务");
        dispatch_async(queue, ^{
            for (NSInteger i = 0; i < 10; i++) {
                NSLog(@"1: == %@", [NSThread currentThread]);
                [NSThread sleepForTimeInterval:1];
            }
        });
        NSLog(@"插入完成");
    });
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(12 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        NSLog(@"恢复队列");
        dispatch_resume(queue);
    });
}