Re: GCJ 3.4.3 and 3.3 classloading problem

On Tue, Sep 8, 2009 at 10:50 PM, Tom Tromey <[email protected]> wrote:
>>>>>> "Craig" == Craig Vanderborgh <[email protected]> writes:
>
>
> Craig> The faults usually occur somewhere in string processing,
> Craig> typically in java::lang::String::getChars.
>
> I don't recall seeing any problems like this.  Of course, since these
> releases were so long ago, I wouldn't really expect to remember...
>
> Did you search bugzilla for closed bugs along these lines?
> That might yield something.
>
> The String thing is interesting.  We've had various bugs involving
> String.intern and also java.lang.ref that might cause inappropriate
> collection.
>

Until you suggested that GC might be involved I did not really think
about that possibility.  Well, further testing reveals that it is.
The crash happens not when GC is invoked generally, but the first time
that GC is invoked AND the heap is expanded during GC.  And this is
absolutely consistent.  Is this what "inappropriate collection" could
look like?  Is it possible that the classloaded objects are different
in some (incorrect) way, such that objects or parts of objects might
be getting garbage collected when they are still needed?  Is this what
you're suggesting?

If so, any suggestions on how I could constructively proceed from here?

Thanks again, guys!

Craig Vanderborgh

> I don't have a theory that covers why changing the executable helps.
>
> Craig> We are in a position where I have to fix this at any cost.  If I have
> Craig> to climb Mount Everest, I will do that.  Any ideas on where to start
> Craig> or what we could look at would be greatly appreciated.
>
> This is a tough sort of problem.  I hesitate to suggest any approaches
> without knowing what you've tried.  (Also my libgcj debugging expertise
> is not completely fresh...)
>
> Tom
>