HI Melchior, On Mon, Feb 9, 2009 at 4:11 PM, Melchior FRANZ <[email protected]> wrote: >> 3rd party debugging tools aren't infaluable. The can and do produce >> false positives. > > Yes, of course. But if I get a segfault in FlightGear which gdb > traces back to some lines of code in OSG, and then helgrind > points out a bug in pretty much exactly the same lines, then > my first assumption is not that helgrind is buggy. And helgrind's > report was IMHO very precise.
How easy is it to build FlightGear these days? I was hoping to get it up and running on my machine so I could you it as another test platform for the OSG. I don't want to spend several days chasing up stuff though... have my own release to make... >> How much we can rely upon valgraind/helgrind is not something >> I can vouch for as this is the first time I'm attempted to use >> tool=helgrind. > > Yeah, same here. I'm a total helgrind newbie. But still: segfault > and threading bug reported by two independent tools in the same > code. > > But before I annoy the last person here, I stop bitching. Just > release OSG as it is. Maybe gdb and helgrind and FlightGear > get fixed and the problem goes away all by itself. ;-) As much as having bugs reported is annoying... if it's a real bug in the OSG then I want to see it fixed. A crash is enough to warrant holding back the release. At my end I do have the helgrind output that suggests a problem, but I don't have a crash, which makes it a bit more difficult for me to fully diagnose the problem and confirm a fix of the problem. The helgrind output is just a hint that somewhere in access of the ReadWriteMutex there is an issue, it doesn't actually pinpoint the actual failure mechanism. I am current reviewing the ReadWriterMutex implementation, and think I have a handle on a possible failure mechanism of the read and write threads changing the locks/unlocks in an unsafe way. I am looking into ways of refactoring this class to fix the potential problems. While it seems likely right now this this could be the cause of the seg faults you are seeing, I can't say this for certain. Also as I can't reproduce the crash the best I can hope is the valigrind will give the refactored code the all clear and FlighGear crash will be solved - but I'll need others to test this for me as I don't have FlightGear to test against. Are you around for the rest of the day? Can I push a testing question of new code in your direction? Robert. _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
