Re: How can an object know when another object has gone away?

FROM : Jens Alfke
DATE : Mon Jun 16 20:23:50 2008

On 15 Jun '08, at 5:39 PM, James W. Walker wrote:

> No, the controller does not keep a reference to the task.  Why would 
> it need to do that in order to "keep it alive"?


Because objects only exist if they have references (i.e. a refcount > 
0), and it generally makes your code cleaner if those references 
"belong to" other objects, i.e. the typical retained-instance-variable 
pattern. While it's possible in a ref-counted environment to have an 
object that calls retain and release on itself to manage its own 
lifespan, it can be confusing to keep track of. It also has the 
distinct problem of not working with real garbage collection — if the 
garbage collector sees that nothing else in the app points to your 
object, it will dealloc it.

—Jens