Re: 24-bit retain count

[Richard Frith-Macdonald]

> On 21 May 2020, at 15:37, Larry Campbell <address@hidden> wrote:
> 
> Currently gnustep-base raises an exception if the retain count exceeds 24 
> bits. There's a comment there:
> 
>  /* I've seen comments saying that some platforms only support up to          
>                                                      
>   * 24 bits in atomic locking, so raise an exception if we try to             
>                                                      
>   * go beyond 0xfffffe.                                                       
>                                                      
>   */
> 
> Is this really true? On what platforms? 24 bits is really not a very big 
> number. (It is causing me pain right now.)

It's probably not true of modern systems (certainly seems unlikely for 64bit 
systems).
However, the code in NSObject.m was written to support a lot of old systems ...

On the other hand, while 24bits is not huge (16 million) I think it's big 
enough so that hitting that limit is more likely to be a timely warning about a 
memory management error (the same object being retained repeatedly and never 
released) than a limitation,  so making it a configurable limit rather than 
removing it altogether probably make sense (it is of course trivial to hack 
NSObject.m to remove it).