1:dispatch_source_t
//dispatch_source_t 默认是挂起的,需要dispatch_resume()//这个和子线程处理数据主线程更新界面的优点在于,当主线程比较空闲一起更新界面.效率更高dispatch_source_t source = dispatch_source_create(DISPATCH_SOURCE_TYPE_DATA_ADD, 0, 0, dispatch_get_main_queue());dispatch_source_set_event_handler(source, ^{NSLog(@"%ld",dispatch_source_get_data(source));});dispatch_resume(source);dispatch_apply(100, dispatch_get_global_queue(0, 0), ^(size_t index) {// do some work on data at indexdispatch_source_merge_data(source, 1);});
2:GCD定时器
// dispatch_suspend(dispatch_object_t object); //暂停线程
// dispatch_resume(dispatch_object_t object); //恢复线程
// dispatch_source_set_timer(dispatch_source_t source, //timer
// dispatch_time_t start, //dispatch_time(开始时间,延迟多少秒)
// uint64_t interval, //间隔时间
// uint64_t leeway); //可以误差时间__block int timeout = 30; //倒计时时间dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, dispatch_get_main_queue());dispatch_source_set_timer(timer, dispatch_time(DISPATCH_TIME_NOW, 0ull*NSEC_PER_SEC), 1ull*NSEC_PER_SEC, 2ull*NSEC_PER_SEC);dispatch_source_set_event_handler(timer, ^{if(timeout == 0) //倒计时结束，关闭{NSLog(@"结束");dispatch_source_cancel(timer); //没有dispatch_source_cancel()方法,timer不会执行
// dispatch_suspend(timer);}else{NSLog(@" == %@, == %@",[NSString stringWithFormat:@"%.2d", timeout--],[NSDate new]);}});dispatch_source_set_cancel_handler(timer, ^{NSLog(@"cancel");});//启动dispatch_resume(timer);3:group,GCD编组的功能
dispatch_group_t group = dispatch_group_create();dispatch_group_wait(group, DISPATCH_TIME_NOW);dispatch_group_async(group, dispatch_get_global_queue(0,0), ^{NSLog(@"============1");});dispatch_group_async(group, dispatch_get_global_queue(0,0), ^{sleep(10);NSLog(@"============2");});//保证dispatch_group_notify是最后输出dispatch_group_notify(group, dispatch_get_global_queue(0,0), ^{NSLog(@"============3");});dispatch_queue_t aDQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0);dispatch_group_t group1 = dispatch_group_create();dispatch_queue_t aDQueue2 = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);dispatch_group_t group2 = dispatch_group_create();// Add a task to the groupdispatch_group_async(group1, aDQueue, ^{printf("task 1 \n");});dispatch_group_async(group1, aDQueue, ^{printf("task 2 \n");});dispatch_group_async(group1, aDQueue, ^{printf("task 3 \n");});dispatch_group_wait(group1, DISPATCH_TIME_FOREVER);printf("task 1 2 3 finished \n");dispatch_group_async(group2, aDQueue2, ^{printf("task2 1 \n");});dispatch_group_async(group2, aDQueue2, ^{printf("task2 2 \n");});dispatch_group_async(group2, aDQueue2, ^{printf("task2 3 \n");});dispatch_group_wait(group2, DISPATCH_TIME_FOREVER);printf("task2 1 2 3 finished \n");
4:用户自定义队列
//队列之间的依赖关系//用户队列最主要的功能就是安排 线程之间的执行顺序.dispatch_queue_t targetQueue = dispatch_queue_create("test.target.queue", DISPATCH_QUEUE_SERIAL);dispatch_queue_t queue1 = dispatch_queue_create("test.1", DISPATCH_QUEUE_SERIAL);dispatch_queue_t queue2 = dispatch_queue_create("test.2", DISPATCH_QUEUE_SERIAL);dispatch_queue_t queue3 = dispatch_queue_create("test.3", DISPATCH_QUEUE_SERIAL);dispatch_set_target_queue(queue1, targetQueue);dispatch_set_target_queue(queue2, targetQueue);dispatch_set_target_queue(queue3, targetQueue);dispatch_async(queue1, ^{NSLog(@"1 in");[NSThread sleepForTimeInterval:3.f];NSLog(@"1 out");});dispatch_async(queue2, ^{NSLog(@"2 in");[NSThread sleepForTimeInterval:2.f];NSLog(@"2 out");});dispatch_async(queue3, ^{NSLog(@"3 in");[NSThread sleepForTimeInterval:1.f];NSLog(@"3 out");});5:信号量
dispatch_semaphore_t semaphore = dispatch_semaphore_create(6); //括号中填几,就可以有几个任务同时并行.for (int i = 0; i < 100; i++){dispatch_async(dispatch_get_global_queue(0, 0), ^{dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);sleep(2);NSLog(@"index = %d",i);//通知信号量,semaphore的value会自动加1.dispatch_semaphore_signal(semaphore);//下面是semaphore的数据.value是信号量当前的值.orig是创建的时候有多少值.//{ xrefcnt = 0x1, refcnt = 0x1, suspend_cnt = 0x0, locked = 0, port = 0x0, value = 2, orig = 3 }});}6:dispatch_barrier_async
// 作用是在并行队列中，等待前面两个操作并行操作完成，再执行后面的输出dispatch_queue_t queue6 =dispatch_queue_create("gcdtest.zfl.demo",DISPATCH_QUEUE_CONCURRENT);dispatch_async(queue6, ^{[NSThread sleepForTimeInterval:2];NSLog(@"dispatch_async1");});dispatch_async(queue6, ^{NSLog(@"dispatch_async2");});dispatch_barrier_async(queue6, ^{NSLog(@"dispatch_barrier_async");});dispatch_async(queue6, ^{NSLog(@"dispatch_async3");});7:dispatch_after
//延迟2.0s执行int64_t delayInSeconds = 2.0;dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW,delayInSeconds * NSEC_PER_SEC);dispatch_after(popTime, dispatch_get_main_queue(), ^(void){//do something...8:dispatch_queue_create
DISPATCH_QUEUE_SERIAL//NULL默认的是 DISPATCH_QUEUE_SERIALNSLog(@"=====Concurrent Diapatch Queue 并发队列,一个队列触发多个线程=====");//创建并发队列 dispatch_queue_t concurrentDiapatchQueue=dispatch_queue_create("com.test.queue", DISPATCH_QUEUE_CONCURRENT); //使用队列 dispatch_async(concurrentDiapatchQueue, ^{ NSLog(@"1"); }); dispatch_async(concurrentDiapatchQueue, ^{ sleep(2); NSLog(@"2"); }); dispatch_async(concurrentDiapatchQueue, ^{ sleep(1); NSLog(@"3"); });
DISPATCH_QUEUE_CONCURRENTNSLog(@"=====Concurrent Diapatch Queue 并发队列,一个队列触发多个线程=====");//创建并发队列 dispatch_queue_t concurrentDiapatchQueue=dispatch_queue_create("com.test.queue", DISPATCH_QUEUE_CONCURRENT); //使用队列 dispatch_async(concurrentDiapatchQueue, ^{ NSLog(@"1"); }); dispatch_async(concurrentDiapatchQueue, ^{ sleep(2); NSLog(@"2"); }); dispatch_async(concurrentDiapatchQueue, ^{ sleep(1); NSLog(@"3"); });