I made some apparently unrelated changes to the constraints (mostly to fix the problem I was having with BExprs, as in a previous email) and now the crashes have gone away. If I have time I will try to locate the exact problem, but for the time being I am just happy that it is working.
Malcolm On 22/04/2008, at 1:42 PM, Malcolm Ryan wrote: > Sorry, but that doesn't seem to be it. I've run it in single-processor > mode on both the Mac and in Linux and the crashes are still occurring. > It may be that some of the intermittent ones have stopped, but the > repeatable ones remain. > > Malcolm > > On 21/04/2008, at 7:34 PM, Guido Tack wrote: > >> I'm now certain that it's the concurrent GC that's causing the >> problems (well, because of some bug in Gecode/J, of course). You >> can easily work around it by running java with the -XX:- >> UseParallelGC option. >> >> Cheers, >> Guido >> >> Guido Tack wrote: >> >>> Malcolm Ryan wrote: >>> >>>> I don't mean to hassle you, but I just need to know whether you >>>> think >>>> you can help me with this problem. I am working towards a close >>>> paper >>>> deadline and I need to know whether to stick with Gecode/J in the >>>> hope >>>> that we will be able to sort out these problems, or whether I need >>>> to >>>> look for another solution. >>> >>> I've run some more experiments, and I can finally reproduce your >>> bug. It seems to be a memory management / concurrency issue. I >>> could not reproduce the bug on any 1- or 2-core machine, but only >>> with at least 4 cores. I suspect Java's concurrent garbage >>> collector frees some memory that is still in use because we didn't >>> get the locking right. >>> Did you do all your experiments on multi-core machines (i.e., more >>> than 2 cores)? If that's really the problem, you could run your >>> tests with a limit on the number of CPUs used. On Linux, you can >>> achieve this using the taskset command. On Mac OS 10.5, you can >>> follow this hint to get control of your processors: >>> http://www.macosxhints.com/article.php?story=20071116183942199 >>> >>> I hope this helps. We'll try to figure out the real cause of the >>> problem, but concurrency bugs are typically hard to find - it may >>> take some time. >>> >>> Cheers, >>> Guido >>> >>> _______________________________________________ >>> Gecode users mailing list >>> [EMAIL PROTECTED] >>> https://www.gecode.org/mailman/listinfo/gecode-users >> > > > _______________________________________________ > Gecode users mailing list > [EMAIL PROTECTED] > https://www.gecode.org/mailman/listinfo/gecode-users _______________________________________________ Gecode users mailing list [EMAIL PROTECTED] https://www.gecode.org/mailman/listinfo/gecode-users
