dispatch_group

group函数操作

- (void)groupSync
{
    dispatch_queue_t disqueue =  dispatch_queue_create("com.shidaiyinuo.NetWorkStudy", DISPATCH_QUEUE_CONCURRENT);
    dispatch_group_t disgroup = dispatch_group_create();
    dispatch_group_async(disgroup, disqueue, ^{
        
        NSLog(@"任务一完成");
    });
    
    dispatch_group_async(disgroup, disqueue, ^{
        sleep(8);
        NSLog(@"任务二完成");
    });
    
    dispatch_group_notify(disgroup, disqueue, ^{
        
        NSLog(@"dispatch_group_notify 执行");
    });
    
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        
        dispatch_group_wait(disgroup, dispatch_time(DISPATCH_TIME_NOW, 5 * NSEC_PER_SEC));
        NSLog(@"dispatch_group_wait 结束");
    });
}