Re: stl_threads.h cleanups

[Benjamin Kosnik <bkoz at redhat dot com>]

>> Large parts of this file appear to be unused, or under-used. For example, 
>
>>   struct _STL_auto_lock
>
>> is completely unused.
>
>>   struct _Refcount_Base
>
>> is used only in ext/rope, and then only if #__GC is not defined. 

_STL_mutex_lock only used in pool_alloc...

>My best guess is junk of configurations past.  I'd support seeing all
>macro-guarded regions resolved (either way) and now unused code axed.

Me too. I'm not going to do this though.

>There is also flatting, refactoring possible (e.g. there are still at
>least two/three different idioms used to key threading support,
>sometimes layered) now that we "know" an external code base will never
>be merged again.  I think that was a real issue raised in the past.  I
>have no comment on whether that could ever happen again.

Yes. I'd rather see the thread layer coalesce into atomic bits and a
single mutex class.

I leave this for somebody else....

-benjamin