挂起调度队列是否会暂停其目标队列？

Question

我想创建两个串行队列A和B.其中队列B是队列A的目标.我想在B上排队一些块,并暂停它直到我准备执行它们,但是我想继续执行块在队列A.

如果我暂停B,它还会暂停它的目标队列(队列A)吗？

我的想法是,我想安排这些特定的块(在队列B上)在稍后(未指定的)日期执行但是我不希望它们同时运行(这涉及核心数据^ _ ^)而我不这样做想要处理信号量.但是我希望队列A继续处理它的块,而B则被暂停

如果不清楚这里是一些示例代码

dispatch_queue_t queueA = dispatch_queue_create("app.queue.A");
dispatch_queue_t queueB = dispatch_queue_create("app.queue.B");

dispatch_set_target_queue( queueB, queueA );

dispatch_suspend( queueB );
/*
*   Add a bunch of blocks to queue B or A 
*   Where the ones added to A should execute immediately
*/


//Wait till blocks on queue A have finished and start up B
dispatch_resume( queueB );

dispatch_release(queueA);
dispatch_release(queueB);

Answer 1

dispatch_set_target_queue(queueB, queueA);
dispatch_suspend(queueB);

queueB被挂起,但queueA未被挂起.

dispatch_set_target_queue(queueB, queueA);
dispatch_suspend(queueA);

queueA和queueB被挂起.