classpath pre-0.10, Jikes RVM, and AWT

[Steven Augart]

There seems to be an unfortunate interaction between Classpath
pre-0.10, Jikes RVM, and AWT.  When I run a simple test program, using
a Jikes RVM "prototype" build linked with Classpath's current CVS
head, I get the errors:

   1[7] VM_Lock: unlock error: thin lock word =  0x00000000
   1[7] VM_Lock: unlock error: thin lock word =  0xa0288da8
   JikesRVM: ../../../../classpath/native/jni/gtk-peer/gthread-jni.c:500: 
rethrow: 
   Assertion `cause' failed.
   Aborted (core dumped)

The same program runs fine if I link Jikes RVM against classpath
0.08.

The same problem occurs with a prototype-opt build (not much of a
surprise), eh?

This message seems to be indicating that there is some sort of memory
corruption going on.  (The Jikes RVM thin-locking code, which is
rather finicky, hasn't been touched in months.)  

Mark Wielaard discovered the problem, and I thank him for this.  Two
major possiblities come to mind:

  1) There some problem that has been recently introduced, with
     Classpath's C code (AWT), that is corrupting memory.  Jikes RVM
     detects the problem; it should affect other VMs subtly too.

  2) There's a previously undetected memory corrupting bug in Jikes RVM.

I am still attempting to further locate the source of the corruption
(have been doing so for about an hour and a half so far).  I do not
know how long this will take to figure out.

--Steve Augart