From: Bill Kelly <billk@...>
Date: 2004-08-25T03:58:26+09:00
Subject: [BUG?] timeout{wait}  (was: Re: How safe is 'timeout' ?)

Hi again,

> I'm experiencing strange behavior in a Ruby app doing
> multithreaded I/O, and I seem to have narrowed it down
> to my using a timeout { } block around a condition 
> variable wait.  E.g.
> 
>   timeout(1.0) { @condition_variable.wait(@mutex) }


I have gotten the code down to a couple hundred lines,
and am able to reproduce the problem easily on:

  ruby 1.8.0 (2003-08-04) [i386-mswin32]
  ruby 1.8.2 (2004-07-29) [i386-mswin32]
  ruby 1.8.0 (2003-10-24) [i686-linux]

My apologies in advance if I turn out to be doing something
stupid in my own code.
http://bwk.homeip.net/ftp/buffered-io-test3.rb

If I comment out line 216
  100.times { global_signal.timed_wait(0.003) }

and uncomment line 213 instead
  100.times { sleep(0.003) }

...I don't experience the problem.  But as-is, with line 216
in place, the problem I experience is that the background_write
thread will sporradically not awaken, even after being
signalled repeatedly.

If anyone is able to help confirm that this really is a
bug, or, point out that I'm doing something stupid....
I'd really appreciate it.

Thanks for your help!

Regards,

Bill