Memory management count

Question

Hello all,
I have a general inquiry on keeping the memory count in regards to memory management. Suppose my set routine is this (which I believe is the general set routine, save for checking that the new input does not equal the current value):
-(void)setVariable:(id)newValue{
[[variable release]];
[[newValue retain]];
Variable = newValue;
1. Assuming 'newValue' has not been retained or allocated elsewhere, it's count here is 1. Is that right?
2. Is the count of 'variable' also 1? We didn't actually retain 'variable'. But what it's pointing to is retained. I am unsure how the count is kept. Who get's the extra 1? 'variable' or 'newValue'?
Message was edited by: rpstro02
Message was edited by: rpstro02

Answer 1

Keep in mind that the variables you're dealing with here are pointers to objects. And that it's the actual objects that have a retainCount, not the pointers.
So when you do:
[newValue retain];
... it's whatever object newValue is pointing to that gets an incremented retainCount... not the newValue pointer itself.
Then when you do:
variable = newValue;
... now you've just made your "variable" pointer point to the _same object_ that newValue is pointing to. There's only one retainCount involved. So there is not an "extra 1" if I'm understanding that part of your question correctly.
Steve