Re: Looking for ideas to fix X server crash running GCJ-compiled program

[Tom Tromey <tromey at redhat dot com>]

>>>>> "Scott" == Scott Gilbertson <scottg at mantatest dot com> writes:

Scott> Recent tests of my application cause the X server to crash.  I
Scott> don't know if it's a problem with the server, the peers, awt,
Scott> the garbage collector or the optimizer (or something else).

With a typical X server, any crash is a priori an X server bug.
(Of course there could be other bugs in our code as well.)

Scott> Now the X server crashes (taking my application with it, of
Scott> course) after a few minutes of high load.  According to a gdb
Scott> backtrace, the problem is a SEGV in CopyGC.  I'm using Xfbdev
Scott> (tiny-X with frame-buffer driver).

Is this "tiny" because they removed error checking?  That would
account for a crash.

One thing to try would be running your application against an ordinary
full-featured desktop X server.  Maybe that one won't crash but will
instead report an error message.  That would help you track back to a
bug in the peers.

I say a bug in the peers since in an ordinary environment, the X
client and the X server are very well separated.  I doubt anything in
libgcj, like the GC for instance, could affect the X server.

Things may be different if you're running in an embedded environment
with no memory protection.  Then, unfortunately, anything goes.  But
the fact that we haven't seen random libgcj crashes (which one might
expect if there were some memory trashing bug) seems to indicate a bug
elsewhere.

Tom