GCD学习(六) dispatch_async 和dispatch_sync
dispatch_sync(),同步添加操作。他是等待添加进队列里面的操作完成之后再继续执行。
dispatch_queue_t concurrentQueue = dispatch_queue_create("my.concurrent.queue", DISPATCH_QUEUE_CONCURRENT);
NSLog(@"1");
dispatch_sync(concurrentQueue,^(){
NSLog(@"2");
[NSThread sleepForTimeInterval:10];
NSLog(@"3");
});
NSLog(@"4");
输出 ：
11:36:25.313 GCDSeTest[544:303] 1
11:36:25.313 GCDSeTest[544:303] 2
11:36:30.313 GCDSeTest[544:303] 3//模拟长时间操作
11:36:30.314 GCDSeTest[544:303] 4
dispatch_async ,异步添加进任务队列，它不会做任何等待
dispatch_queue_t concurrentQueue = dispatch_queue_create("my.concurrent.queue", DISPATCH_QUEUE_CONCURRENT);
NSLog(@"1");
dispatch_async(concurrentQueue,^(){
NSLog(@"2");
[NSThread sleepForTimeInterval:5];
NSLog(@"3");
});
NSLog(@"4");
输出：
11:42:43.820 GCDSeTest[568:303] 1
11:42:43.820 GCDSeTest[568:303] 4
11:42:43.820 GCDSeTest[568:1003] 2
11:42:48.821 GCDSeTest[568:1003] 3//模拟长时间操作时间
网友评论