java - Objective-C 中是否允许嵌套同步块(synchronized block)？

Question

我阅读了 this article在 Java 中，允许嵌套同步块(synchronized block)。我知道 Objective-C 的同步块(synchronized block)看起来很像 Java 的。所以我想知道:Objective-C 中是否允许嵌套 block ？

我还有一个附带问题:递归 block 有实际限制吗？

感谢您的快速答复!

Answer 1

是的，他们是。来自 the docs (现已退休):

The Objective-C synchronization feature supports recursive and reentrant code. A thread can use a single semaphore several times in a recursive manner; other threads are blocked from using it until the thread releases all the locks obtained with it; that is, every @synchronized() block is exited normally or through an exception.

有关此方法和其他同步/锁定方法的性能讨论，请参阅 here .