> Uh, you are confusing the problem. 

*sigh* thats always the way.

Thank you FUKUMOTO for clearing that up :)

> Critical sections are nature in
> multi-thread programming.  In Ruby, Queue class is as much a primitive
> tool as Mutex class for inter-thread communication.  Rewriting the
> Queue class using Mutex gains nothing, and probably it will become
> slower.  (My experiment showed it's about ten times slower when
> written using Mutex.  Though some optimization may be possible.)

Rob