1 - (void)gcdTest1 {
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3
4
5 //1.GCD应用 单例模式
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7
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9 static dispatch_once_t onceToken;
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11 dispatch_once(&onceToken, ^{
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13
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15 NSLog(@"执行一次%@",[NSThread currentThread]);
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17 });
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19 }
1 - (void)gcdTest2 {
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3
4
5 //延迟操作
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7 //1、
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9 NSLog(@"开始执行");
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11
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13 // [self performSelector:@selector(handleAction) withObject:nil afterDelay:0];
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15
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17 //2、
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19
20
21 //DISPATCH_TIME_NOW 从现在开始
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23 //delayInSeconds 延迟几秒
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25
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27 dispatch_time_t time = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC));
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29
30
31 // when dispatch_time_t
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33
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35 dispatch_after(time, dispatch_get_main_queue(), ^{
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37
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39 NSLog(@"%@",[NSThread currentThread]);
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41
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43 });
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45
46
47 }
- (void)gcdTest2 {
//延迟操作
//1、
NSLog(@"开始执行");
// [self performSelector:@selector(handleAction) withObject:nil afterDelay:0];
//2、
//DISPATCH_TIME_NOW 从现在开始
//delayInSeconds 延迟几秒
dispatch_time_t time = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC));
// when dispatch_time_t
dispatch_after(time, dispatch_get_main_queue(), ^{
NSLog(@"%@",[NSThread currentThread]);
});
}
1 - (void)gcdTest3 {
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3
4
5 //创建调度组
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7 dispatch_group_t group = dispatch_group_create();
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9 //获取全局队列
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11 dispatch_queue_t queue = dispatch_get_global_queue(0, 0);
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13 //调度组的异步请求
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15 dispatch_group_async(group, queue, ^{
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17
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19 [NSThread sleepForTimeInterval:2];
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21 NSLog(@"下载第一张图");
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23 });
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25 dispatch_group_async(group, queue, ^{
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27 [NSThread sleepForTimeInterval:3];
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29
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31 NSLog(@"下载第二张图");
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33 });
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35 dispatch_group_async(group, queue, ^{
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37 [NSThread sleepForTimeInterval:1];
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39
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41 NSLog(@"下载第三张图");
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43 });
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45 dispatch_group_async(group, queue, ^{
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47 [NSThread sleepForTimeInterval:5];
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49
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51 NSLog(@"下载第四张图");
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53 });
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55 //notify通知，当所有异步请求完成时调用dispatch_group_notify
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57 dispatch_group_notify(group, queue, ^{
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59 NSLog(@"更新UI");
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61 });
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63
64
65 }
1 //队列调度的第二种方法
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3 - (void)gcdTest4 {
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5
6
7 //创建调度组
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9 dispatch_group_t group = dispatch_group_create();
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11 //获取全局队列
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13 dispatch_queue_t queue = dispatch_get_global_queue(0, 0);
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15
16
17 //进入队列
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19 dispatch_group_enter(group);
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21 dispatch_async(queue, ^{
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23
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25 [NSThread sleepForTimeInterval:2];
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27 NSLog(@"下载第一张图");
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29
30
31 //离开队列
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33 dispatch_group_leave(group);
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35 });
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37
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39 dispatch_group_enter(group);
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41 dispatch_async(queue, ^{
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43
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45 [NSThread sleepForTimeInterval:1];
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47 NSLog(@"下载第er张图");
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49
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51 dispatch_group_leave(group);
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53 });
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55
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57 dispatch_group_enter(group);
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59 dispatch_async(queue, ^{
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61
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63 [NSThread sleepForTimeInterval:3];
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65 NSLog(@"下载第san张图");
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67
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69 dispatch_group_leave(group);
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71 });
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73
74
75 //等待调度队列wait相当于一个阻塞状态
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77 dispatch_group_wait(group, DISPATCH_TIME_FOREVER);
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79
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81 NSLog(@"更新UI");
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83
84
85 }
1 //中断操作
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3
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5 - (void)gcdTest5 {
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7
8
9 //dispatch_barrier_async一定是自定义队列
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11 //这里指定的并发队列应该是自己通过dispatch_queue_create函数创建的。如果你传的是一个串行队列或者全局并发队列，这个函数等同于dispatch_async函数。
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13
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15 dispatch_queue_t queue = dispatch_queue_create("com.bjsxt", DISPATCH_QUEUE_CONCURRENT); //dispatch_get_global_queue(0, 0);
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17
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19 dispatch_async(queue, ^{
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21 [NSThread sleepForTimeInterval:1];
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23 NSLog(@"1");
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25 });
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27
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29 dispatch_async(queue, ^{
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31 [NSThread sleepForTimeInterval:3];
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33
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35 NSLog(@"2");
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37 });
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39 dispatch_async(queue, ^{
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41
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43 [NSThread sleepForTimeInterval:2];
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45
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47 NSLog(@"3");
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49 });
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51
52
53 //中断操作dispatch_barrier_async
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55 dispatch_barrier_async(queue, ^{
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57 NSLog(@"--------");
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59 [NSThread sleepForTimeInterval:1];
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61
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63 });
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65
66
67 dispatch_async(queue, ^{
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69
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71 [NSThread sleepForTimeInterval:1];
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73 NSLog(@"4");
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75 });
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77 dispatch_async(queue, ^{
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79 NSLog(@"5");
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81 });
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83 }
1 - (void)gcdTest6 {
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3
4
5 //遍历操作
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7 dispatch_queue_t queue = dispatch_get_global_queue(0, 0);
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9 //iterations 遍历的次数
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11 dispatch_apply(5, queue, ^(size_t i) {
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13 NSLog(@"%@",@(i));
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15 });
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17 }