[Python-bugs-list] [Bug #113812] Serious garbage collection problems with 2.0b1

[Nobody]

From: noreply@sourceforge.net

Bug #113812, was updated on 2000-Sep-07 10:10
Here is a current snapshot of the bug.

Project: Python
Category: Modules
Status: Open
Resolution: None
Bug Group: None
Priority: 5
Summary: Serious garbage collection problems with 2.0b1


Details: Since I've installed version 2.0b1, I ran into a few (serious) problems
with a non-trivial application (+80,000 lines of Python). It seems that
the are all related to the new garbage collection:

 - Suddenly, assertions fail because lists have become empty 
   while they shouldn't have. I looks like their elements have been
   garbage collected while they were still reachable.

 - Under other circumstances, I get coredumps which always 
   seem to happen in function "move_root_reachable" of gcmodule.c:
   the "traverse" function pointer seems to contain a bogus address.

 - When I run a Purified version of the interpreter, I can't reproduce
   either problem, but instead, the garbage collector seems to get
   stuck in an endless loop each time. This always happens in the
   same function "move_root_reachable". Purify doesn't produce any 
   relevant warning.

The code runs just fine with version 1.6 of the interpreter, or when I
disable the garbage collector.

Probably relevant is the fact that the objects (10,000's) in my application
are very heavily cross-linked (nearly all links are bi-directional), which 
probably puts a lot of stress on the garbage collector.

My platform: HP-UX 10.20 / c89 compiler


Follow-Ups:

Date: 2000-Sep-07 10:14
By: edg

Comment:
Just one more thing: when I turn on the gc debugging,
the interpreter also seems to get stuck in an endless loop.
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For detailed info, follow this link:
http://sourceforge.net/bugs/?func=detailbug&bug_id=113812&group_id=5470