[omniORB] Missing Object Reference

[dmitry.dolinsky@tumbleweed.com]

We are running to a problem with omniORB 2.6.1. The ORB throws an
invalid object reference exception on a multiprocessor machine (
Solaris2.7 ) running for several hours under heavy load. The exception
was due to the fact that we try to _duplicate() or release() an object
reference where the reference count was at zero. After spending a fair
amount of time looking for missing _duplicate and race conditions in our
code, we did not
find the cause of the problem.
Has anyone experienced anything similar? Could this be a bug in omniORB
2.6.1 perhaps fixed in a later version? (For a number of reasons we
can't jump to a later version at this time, BTW). Any advice for
tracking this down?
Also, on a very rare occasion we are seeing an error that make us
suspect that an operation is dispatched to wrong object. This does not
happen as often as losing the object ref problem, but when this does
happen, it
happens at about the same time. We suspect that the two problems may be
related.
Here is some more information about what we do. We backported some
patches for the scavenger from 2.8. Also, our objects persist in the
database. A limited number of them is in memory at any given time. Those
that are in
memory are in the cache maintained by us. When a request for an object
arrives that is not in memory, we load the object from database,
register it with ORB, and add it to the cache possibly removing some
other object
from the cache and deleting it (by calling _dispose()). This happens in
omniORB::loader hook. Typically the problem manifests itself when we are
calling _dispose(). The object that we have in our cache has the
reference
count of zero.

Thanks in advance.

Dmitry Dolinsky
Tumbleweed Communication Corp.