[Python-Dev] bsddb3 test hang
21 Jul 2003 18:44:53 -0400
On Mon, 2003-07-21 at 18:15, Martin v. L=F6wis wrote:
> Barry Warsaw <email@example.com> writes:
> > % strace -p 26615
> > futex(0x82fb8c0, FUTEX_WAIT, 0, NULL
> NPTL. 'Nuff said.
Perhaps, but there's more:
Tim, Fred, and I spent some time running tests, turning on verbosity,
etc. I can only reproduce the hang if I run
% make TESTOPTS=3D"-u all" test
and then it hangs almost every time, the second pass through the tests.=20
It can't be interrupted. If I turn on -v or hack the test to be
slightly more verbose, or use a less inclusive -u option, it never
hangs. So clearly <wink> there's some timing issue in the tests.
Tim has had a little more luck on Windows by adding some verbosity and
watching it hang in dbutils.DeadlockWrap() -- or actually infloop in
that function's while 1. This comes from bsddb/test/test_thread.py and
the only place where DeadlockWrap() gets called without passing in
max_retries (i.e. it runs forever) is in readerThread(). So I added
max_retries to both those calls and now I see DBLockDeadlockErrors in
the readerThreads and AssertionErrors in the writerThreads. Fred's seen
these assertions and Tim says that Skip reported these assertions too.
I think I'm going to leave the max_retries in on the readerThread()
calls to DeadlockWrap(). That'll at least prevent the tests from
hanging. We'll investigate a bit more to see if we can find out more
about the underlying cause of the assertion failures. There's some
mystery there too.