OC 线程操作 - GCD队列组-白红宇

OC 线程操作 - GCD队列组

阅读量：6710 次

发布时间：2019-06-25

本文共 3352 字，大约阅读时间需要 11 分钟。

1.队列组两种使用方法

2.队列组等待 wait

/** 新方法 队列组一般用在在异步操作，在主线程写队列组毫无任何作用 */- (void)GCD_Group_new_group___notify{    dispatch_queue_t queue = dispatch_queue_create("11", DISPATCH_QUEUE_CONCURRENT);    dispatch_queue_t globalqueue = dispatch_get_global_queue(0, 0);    dispatch_group_t group = dispatch_group_create();    /*     1.封装任务     2.把任务加到队列     3.会监听任务的执行情况     */    dispatch_group_async(group, globalqueue, ^{ NSLog(@"1111---%@---", [NSThread currentThread]); }); dispatch_group_async(group, globalqueue, ^{ NSLog(@"22222---%@---", [NSThread currentThread]); }); dispatch_group_async(group, globalqueue, ^{ NSLog(@"333---%@---", [NSThread currentThread]); }); // 一定要加上这行，不然不起任何作用 dispatch_group_notify(group, globalqueue, ^{ NSLog(@"完成----4444---%@---", [NSThread currentThread]); }); /* 打印结果： 2018-06-28 10:18:44.191407+0800 5线程操作-GCD-快速迭代[7808:56262] 333---
      
       {number = 4, name = (null)}--- 2018-06-28 10:18:44.191409+0800 5线程操作-GCD-快速迭代[7808:56266] 1111---
       
        {number = 3, name = (null)}--- 2018-06-28 10:18:44.191434+0800 5线程操作-GCD-快速迭代[7808:56264] 22222---
        
         {number = 5, name = (null)}--- 2018-06-28 10:18:44.191758+0800 5线程操作-GCD-快速迭代[7808:56264] 完成----4444---
         
          {number = 5, name = (null)}--- */

//DISPATCH_TIME_FOREVER ：等待队列所有任务执行完后 执行下面代码后面的内容    dispatch_group_wait(group, DISPATCH_TIME_FOREVER);    NSLog(@"执行完了");    /*     打印结果:     2018-06-28 10:58:34.631990+0800 5线程操作-GCD-快速迭代[8500:86081] 1111---
       
        {number = 3, name = (null)}---     2018-06-28 10:58:34.632041+0800 5线程操作-GCD-快速迭代[8500:86084] 22222---
        
         {number = 4, name = (null)}---     2018-06-28 10:58:34.632065+0800 5线程操作-GCD-快速迭代[8500:86080] 333---
         
          {number = 5, name = (null)}---     2018-06-28 10:58:34.633261+0800 5线程操作-GCD-快速迭代[8500:86052] 执行完了     2018-06-28 10:58:34.633284+0800 5线程操作-GCD-快速迭代[8500:86080] 完成----4444---
          
           {number = 5, name = (null)}---     */

//老式写法

- (void)GCD_GroupDemo_old___enter_leave{    dispatch_queue_t queue = dispatch_queue_create("11", DISPATCH_QUEUE_CONCURRENT);    dispatch_queue_t globalqueue = dispatch_get_global_queue(0, 0);    dispatch_group_t group = dispatch_group_create();    dispatch_group_enter(group);            // 旧 写法    dispatch_group_async(group, globalqueue, ^{        NSLog(@"离开---%@---", [NSThread currentThread]);        dispatch_group_leave(group);    });    dispatch_group_async(group, globalqueue, ^{        NSLog(@"222---%@---", [NSThread currentThread]);    });    dispatch_group_async(group, globalqueue, ^{        NSLog(@"333---%@---", [NSThread currentThread]);    });        dispatch_group_async(group, globalqueue, ^{        NSLog(@"111---%@---", [NSThread currentThread]);    });    /*     2018-06-28 10:25:06.997243+0800 5线程操作-GCD-快速迭代[7942:62493] 离开---
     
      {number = 3, name = (null)}---     2018-06-28 10:25:06.997286+0800 5线程操作-GCD-快速迭代[7942:62491] 333---
      
       {number = 5, name = (null)}---     2018-06-28 10:25:06.997306+0800 5线程操作-GCD-快速迭代[7942:62489] 111---
       
        {number = 6, name = (null)}---     2018-06-28 10:25:06.997287+0800 5线程操作-GCD-快速迭代[7942:62492] 222---
        
         {number = 4, name = (null)}---     */}