Avoid copying NSMutableArray for reading with multithreaded writes

Question

I have a class that uses a mutable array that is modified once after a lot of reads (new items arrive).

The problem is that when times comes to mutate the array, rea

Answer 1

The simplest approach is to use @synchronized, like this:

-(void) accessTheArray {
    MyClass *obj;
    @synchronized(theArray) {
        obj = [theArray objectAtIndex:...];
    }
    [obj someMessage];
}

EDIT: If not using ARC, you might want to retain/autorelease the object, otherwise it might be removed from the array (and released) before someMessage is called (thanks for omz for this excellent comment).