Re: Compiler warnings with the new base code

[Richard Frith-Macdonald]

On 18 Feb 2010, at 10:42, Richard Frith-Macdonald wrote:

> 
> On 18 Feb 2010, at 10:33, David Chisnall wrote:
> 
>> On 18 Feb 2010, at 09:09, Fred Kiefer wrote:
>> 
>>> base/NSNumber/basic.m:
>>> FAIL: Object 0 of class 'NSNumber' is retained by copy with other zone
>> 
>> 
>> This one is mine, but I'm not certain that the behaviour it is expecting is 
>> correct.  Shouldn't copyWithZone: in a different zone always result in a 
>> real copy?  Not doing this makes zones somewhat useless.
> 
> I think zones *are* somewhat useless...
> 
> There are a *lot* of cases where OSX Foundation does not honor them.
> 
> They are unused when garbage collecting is enabled anyway.
> 
> Also, I strongly suspect that modern computer cache designs mean that the 
> supposed benefit of zones (being able to allocate a group of objects close 
> together in physical memory) has mostly been a fiction for many years now.

PS. the above test is checking conformance with OSX behavior

This will be a cached NSNumber (one of the small integer values), and 
presumably OSX will just return the cached value rather than a copy of it, 
because they think that using cached values is more important than using the 
correct zone.