为什么我们在@synchronized块中传递self? [英] Why do we pass self in @synchronized block?

问题描述

我猜@synchronized块不是对象相关的，而是线程相关的...对吗?在那种情况下，我们为什么要传递自我?

I guess @synchronized blocks are not object dependent but thread dependent...right? In that case why do we pass self?

推荐答案

@synchronized是该语言提供的用于创建同步作用域的构造.由于使用简单的全局共享互斥锁并因此序列化应用程序中的每个@synchronized作用域效率非常低，因此该语言允许我们指定同步点.

@synchronized is a construct provided by the language to create synchronized scopes. As it would be highly inefficient to use a simple global shared mutex, and thus serializing every single @synchronized scope in the application, the language allows us to specify a synchronization point.

然后由开发者决定哪些同步点适合该任务.

Then it's up to the developer(s) to decide which synchronization points are appropriate for the task.

在实例方法上，通常使用self:实例是同步点.可以在任意数量的实例上调用@synchronized(self)范围，但对于给定的实例只能调用一次.每个@synchronized(self)范围都将针对给定实例进行序列化.

On an instance method, using self is common: the instance is the synchronization point. The @synchronized(self) scope can be called on any number of instances, but only once for a given instance. Every @synchronized(self) scope will be serialized for a given instance.

当然，如果需要，您可以自由使用另一个同步点.您可以使用类(@synchronized(self.class))或其他任何适合您需要的东西.

Of course, you are free to use another synchronization point if you want to do so. You can use the class (@synchronized(self.class)) or anything else that suits your needs.

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