Joel VanderWerf wrote:
> The main reason I'm interested in this is some heavily threaded code 
> that spends 20% of process time in Thread.exclusive (according to the 
> profiler). I can probably improve this by using Thread.critical and 
> Thread.critical= instead, but why not improve Thread.exclusive itself?

Yep, I just verified that replacing Thread.exclusive (the fast version) 
with Thread.critical and Thread.critical= improves speed by about 20%. 
But this is ignoring the possibility of exceptions in some places, so I 
would have to add some rescue clauses, and that would narrow the difference.

None of this is terribly important, but if I can get a performance 
improvement for free, I'll take it.