iOS Objective-c同步

Question

In Java if I have the keyword synchronized in a method, it will prevent being executed by more than one thread at same time, no matter what thread is:

public synchronized void doSomething() {
  //synchronous code here
}

In objective-c if do this, will I have the same result?

-(void)doSomething{
    @synchronized (self) {
       //synchonous code here
    }
}

Answer 1

Yes, with a caveat.

The @synchronized directive creates a mutex lock—preventing the code within the curly brackets from being executed by different threads at the same time. The caveat is that it uses the object that was passed to it as a unique identifier to distinguish the protected block. So if you're using @synchronized(self) in two different methods, those two methods are prevented from being executed by different threads at the same time (because they share the same identifier (in this case self )).