Question

Suppose I have an @property declared like this:

@property (readwrite,retain) NSObject *someObject; 

And I synthesize it like this:

@synthesize someObject = _someObject; 

This generates getters/setters for me. Also, according to the docs, the setter will have built in thread safety code.

Now, suppose I want to add some code to the setSomeObject: method. Is there any way that I can extend the existing on from @synthesize? I want to be able to reuse the the thread safety code that it autogenerates.

Answer 1

What @synthesize does is equivalent to:

-(void)setSomeObject:(NSObject *)anObject {     [anObject retain];     [someObject release];     someObject = anObject; } 

or

-(void)setSomeObject:(NSObject *)anObject {     if(someObject != anObject) {         [someObject release];         someObject = [anObject retain];     } } 

so you can use this code and extend the method.

However, as you said, this code might not be thread-safe.

For thread safety, you might want to take a look at NSLock or @synchronized (thanks to unwesen for pointing this out).