How many times do I release an allocated or retained object?

Question

Hi,

I am making an iPhone game. I want to release all the object that have been allocated or retained. In the dealloc function I am releasing all such objects but then realized sometimes i end up releasing objects when they have not been allocated yet. So I figured I need to check if its retainCount is greater than zero or not before i release it.

My question is: Do I just check if the retainCount is greater than zero and the release is

if([bg retainCount]!=0)
{
  [bg release];
}

or

Should I release it as many number of times as its retainCount

while([bg retainCount]!=0)
{
  [bg release];
}

Thanks for your help

Abhinav Chandran

Answer 1

Do not use -retainCount.

The absolute retain count of an object is meaningless.

You should call release exactly same number of times that you caused the object to be retained. No less (unless you like leaks) and, certainly, no more (unless you like crashes).

See the Memory Management Guidelines for full details.

Answer 2

Autorelease makes retainCount meaningless. Keep track of retains & whether you own an object. Study & remember these rules: http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/MemoryMgmt/Articles/mmRules.html#//apple_ref/doc/uid/20000994-BAJHFBGH