On Fri, Jul 11, 2008 at 4:38 PM, Charles Oliver Nutter
<charles.nutter@[...].com>  wrote:
>  Michael Guterl wrote:
> >
> > I am not sure that what I am doing in the code is even reasonable,
> > however, I thought it might be worth pointing out.
> 
>  Ok, there's good news and bad news. First the good news.
> 
>  I've found several egregious threading bugs in JRuby's Enumerable
>  implementation that probably caused the bulk of errors you saw. Basically,
>  the runtime information for the main Ruby thread in JRuby was getting reused
>  by the blocks passed into threadify, causing all sorts of wacky errors
>  (multiple threads all sharing runtime thread data...fun!). Fixing that seems
>  to have resolved most of the errors.
> 
>  Now the bad news...
> 
>  What you're doing is a bit suspect. In this case, it works out reasonable
>  well, since you're just doing a map and gathering results. There's some
>  remaining bugs in JRuby wrt the temporary data structure used to gather map
>  results (it needs to be made thread-safe) but it can work. However in
>  general I don't think this use of threadify is going to apply well to
>  Enumera(ble|tor) since so many of the operations depend on the result of the
>  previous iteration.
> 
>  I'll have the remaining issues wrapped up shortly, but I'd love to see
>  someone come up with a safe set of Enumerable-like operations that can run
>  in parallel. For example, a detect that uses a cross-thread trigger to stop
>  all iterations (rather than the naive threadification of detect which would
>  not propagate a successful detection out of the thread). Things like that
>  could be very useful.
> 
>  I'd also love to see someone come up with a nice installable gem of truly
>  thread-safe wrappers around the core collections, since in general I don't
>  believe the core array and friends should suffer the perf penalty that comes
>  from always synchronizing.
> 

Thanks Charlie, I just verified that my script no longer crashes with
my latest pull of JRuby.

jruby 1.1.3-dev (ruby 1.8.6 patchlevel 114) (2008-07-12 rev 7146) [i386-java]

Regards,
Michael Guterl