group.h相关方法

group.h

方法介绍

/**
 创建组
 */
dispatch_group_t
dispatch_group_create(void);

/**
组内部异步线程

 @param group  组 
 @param queue  队列
 @param block 任务
 */
void
dispatch_group_async(dispatch_group_t group,
    dispatch_queue_t queue,
    dispatch_block_t block);
/*
组内部异步线程

 @param group 组
 @param queue  队列
 @param context 数据指针
 @param work C函数方法名
 */
void
dispatch_group_async_f(dispatch_group_t group,
    dispatch_queue_t queue,
    void *_Nullable context,
    dispatch_function_t work);

/*
等待组任务完成

 @param group 指定被等待的组
 @param timeout  等待的时长
 */
long
dispatch_group_wait(dispatch_group_t group, dispatch_time_t timeout);

/*
组队列中任务完成通知

 @param group 监听的组
 @param queue  监听的队列
 @param block 任务完成回调
 */
void
dispatch_group_notify(dispatch_group_t group,
    dispatch_queue_t queue,
    dispatch_block_t block);

/*
组队列中任务完成通知

 @param group 监听的组
 @param queue  监听的队列
 @param context 任务数据指针
 @param work C函数方法名
 */
void
dispatch_group_notify_f(dispatch_group_t group,
    dispatch_queue_t queue,
    void *_Nullable context,
    dispatch_function_t work);

/*
加入任务组

 @param group 任务组
 */
void
dispatch_group_enter(dispatch_group_t group);

/*
离开任务组

 @param group 任务组
 */
void
dispatch_group_leave(dispatch_group_t group);

举例说明：

dispatch_queue_t quene = dispatch_queue_create("com.Maker", DISPATCH_QUEUE_CONCURRENT);
dispatch_async(quene, ^{
    dispatch_queue_t allTasksQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_group_t allTasksGroup = dispatch_group_create();
    dispatch_group_async(allTasksGroup, allTasksQueue, ^{
        NSLog(@"任务_1-----%d",[NSThread isMainThread]);
    });
    dispatch_group_async(allTasksGroup, allTasksQueue, ^{
        NSLog(@"任务_2-----%d",[NSThread isMainThread]);
    });
    dispatch_group_async(allTasksGroup, allTasksQueue, ^{
        NSLog(@"任务_3-----%d",[NSThread isMainThread]);
    });
    NSLog(@"--------------------");
    dispatch_time_t time = dispatch_time(DISPATCH_TIME_FOREVER, 10 * NSEC_PER_SEC);
    if (dispatch_group_wait(allTasksGroup, time) == 0) {
        NSLog(@"任务已经全部执行完毕-----%d",[NSThread isMainThread]);
    }
    else {
        NSLog(@"任务没有执行完毕-----%d",[NSThread isMainThread]);
    }
    /*
    dispatch_group_notify(allTasksGroup, allTasksQueue, ^{
        NSLog(@"任务已经全部执行完毕-----%d",[NSThread isMainThread]);
    });
    */
});