youdao

Another common threading model is to have a single background thread and task queue for tasks of a certain type.

另一个常见的线程模型是为某一类型的任务分配一个后台线程与任务队列。

youdao

There would be a bit of work involved in deciding (and programming) exactly how an arbitrary jump would interact with a linear thread queue, but nothing particularly mysterious about the work.

决定(以及编写)一个任意的跳转究竟会如何与线性线程队列交互将涉及到不少工作，不过这些工作中没有什么特别神秘的地方。

youdao

If theABAddressBookRef object is used throughout the app, then all usage must be dispatched to the same queue to use ABAddressBookRef in a thread-safe manner.

ENGADGET: Apple seeds iOS 6 beta 4 to developers: here's the changelog