概览

• 创建一个调度源指定源类型、回调、绑定mask、设置队列

dispatch_source_t
dispatch_source_create(dispatch_source_type_t type,
    uintptr_t handle,
    uintptr_t mask,
    dispatch_queue_t _Nullable queue);

• 为调度源source设置回调block

void
dispatch_source_set_event_handler(dispatch_source_t source,
    dispatch_block_t _Nullable handler);

• 为调度源source设置回调c函数指针

void
dispatch_source_set_event_handler_f(dispatch_source_t source,
    dispatch_function_t _Nullable handler);

• 为调度源source设置取消时调用的回调block

dispatch_source_set_cancel_handler(dispatch_source_t source,
    dispatch_block_t _Nullable handler);

• 为调度源source设置取消时调用的回调c函数指针

void
dispatch_source_set_cancel_handler_f(dispatch_source_t source,
    dispatch_function_t _Nullable handler);

• 异步取消调度源

void
dispatch_source_cancel(dispatch_source_t source);

• 检测调度源是否被取消

intptr_t
dispatch_source_testcancel(dispatch_source_t source);

• 获取调度源绑定的回调

uintptr_t
dispatch_source_get_handle(dispatch_source_t source);

获取调度源绑定的mask

uintptr_t
dispatch_source_get_mask(dispatch_source_t source);

获取调度源的待处理数据

uintptr_t
dispatch_source_get_data(dispatch_source_t source);

• 将数据合并到调度源中，并将回调提交到目标队列

void
dispatch_source_merge_data(dispatch_source_t source, uintptr_t value);

• 设置计时器源的开始时间、时间间隔、回程值

void
dispatch_source_set_timer(dispatch_source_t source,
    dispatch_time_t start,
    uint64_t interval,
    uint64_t leeway);

• 为调度源设置激活后就调用的回调block

void
dispatch_source_set_registration_handler(dispatch_source_t source,
    dispatch_block_t _Nullable handler);

• 为调度源设置激活后就调用的回调c函数指针

void
dispatch_source_set_registration_handler_f(dispatch_source_t source,
    dispatch_function_t _Nullable handler);

使用场景

累加

dispatch_source_t source = dispatch_source_create(DISPATCH_SOURCE_TYPE_DATA_ADD, 0, 0, dispatch_get_main_queue());
dispatch_source_set_event_handler(source,^{
    uintptr_t data = dispatch_source_get_data(source);
    NSLog(@"data = %lu, 线程：%@", data, [NSThread currentThread]);
});
dispatch_resume(source);
NSInteger count = 6;
while (count--) {
    dispatch_source_merge_data(source, count);
    NSLog(@"data + %ld", (long)count);
}

输出：

2021-08-22 16:02:16.857397+0800 GCDDemo[4081:758127] data + 5
2021-08-22 16:02:16.857470+0800 GCDDemo[4081:758127] data + 4
2021-08-22 16:02:16.857499+0800 GCDDemo[4081:758127] data + 3
2021-08-22 16:02:16.857526+0800 GCDDemo[4081:758127] data + 2
2021-08-22 16:02:16.857550+0800 GCDDemo[4081:758127] data + 1
2021-08-22 16:02:16.857574+0800 GCDDemo[4081:758127] data + 0
2021-08-22 16:02:16.865296+0800 GCDDemo[4081:758127] data = 15, 线程：<NSThread: 0x2815a8980>{number = 1, name = main}

使用场景：

所有合并操作执行完毕会执行dispatch_source_set_event_handler，就是一组data合并之后执行一个回调

定时器

+ (dispatch_source_t)gcdTimerRepeatInterval:(Float64)interval
                              afterSeconds:(Float64)seconds
                         identifier:(const char *)identifier
                           callback:(dispatch_block_t)block
                        cancelBlock:(dispatch_block_t)cancelBlock {
    dispatch_queue_t queue = dispatch_queue_create(identifier, DISPATCH_QUEUE_CONCURRENT);
    dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
    dispatch_source_set_timer(timer, dispatch_time(DISPATCH_TIME_NOW, seconds * NSEC_PER_SEC), interval * NSEC_PER_SEC, 0);
    
    dispatch_source_set_event_handler(timer, ^{
        if (block) {
            block();
        }
    });
    dispatch_source_set_cancel_handler(timer, ^{
        dispatch_async(dispatch_get_main_queue(), ^{
            if (cancelBlock) {
                cancelBlock();
            }
        });
    });
    return timer;
}

+ (void)gcdTimerStart:(dispatch_source_t)timer {
    if (timer) {
        dispatch_resume(timer);
    }
}

+ (void)gcdTimerStop:(dispatch_source_t)timer {
    if (timer) {
        dispatch_source_cancel(timer);
    }
}