From: James Britt <james_b@...>
Date: 2005-05-09T22:47:43+09:00
Subject: Re: No Thing Here vs Uninitialized and RCR 303

Pit Capitain wrote:
> James Britt schrieb:
> 
>> Far more interesting and useful would be to solve the threading issue 
>> with using nil.blackhole = true inside of blocks or methods where that 
>> behavior is an overall win.
> 
> 
> Could you describe the threading issue, maybe in form of some unit tests?

If you change the behavior of NilClass (e.g., NilClass.blackhole = true) 
it is changed for all nil occurrences (nil is a singleton object, so 
there is only one instance).

If there are multiple threads running, and one of them decides NilClass 
should swallow all unknown methods (even if only during the execution of 
a specific block) then all processes will see the same behavior until 
some code sets NilClass.blackhole = false.



James