Re-importing embedded thread dumps core

[jaytmiller]

BPO	1220756
Nosy	@mwhudson, @brettcannon, @nascheme

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = 'https://github.com/nascheme'
closed_at = <Date 2010-01-22.21:37:17.669>
created_at = <Date 2005-06-14.21:16:47.000>
labels = ['interpreter-core']
title = 'Re-importing embedded thread dumps core'
updated_at = <Date 2010-01-22.21:37:17.667>
user = 'https://bugs.python.org/jaytmiller'

bugs.python.org fields:

activity = <Date 2010-01-22.21:37:17.667>
actor = 'nascheme'
assignee = 'nascheme'
closed = True
closed_date = <Date 2010-01-22.21:37:17.669>
closer = 'nascheme'
components = ['Interpreter Core']
creation = <Date 2005-06-14.21:16:47.000>
creator = 'jaytmiller'
dependencies = []
files = []
hgrepos = []
issue_num = 1220756
keywords = []
message_count = 4.0
messages = ['25544', '25545', '25546', '25547']
nosy_count = 4.0
nosy_names = ['mwh', 'brett.cannon', 'nascheme', 'jaytmiller']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1220756'
versions = ['Python 2.4']

[jaytmiller]

I noticed the following while working on an "embedding
numarray" problem:

[jmiller@halloween Python-2.4.1]$
Python-2.4.1/Demo/embed/loop 'from thread import *' 10
[6675 refs]
[7009 refs]
[7320 refs]
[7631 refs]
[7942 refs]
[8253 refs]
loop: Objects/typeobject.c:2104: type_dealloc:
Assertion `type->tp_flags & (1L<<9)' failed.
Abort (core dumped)

The tp_flags bit in question is:

#define Py_TPFLAGS_HEAPTYPE (1L<<9)

[mwhudson]

Logged In: YES
user_id=6656

Oh dear. The problem here is that PyModule_AddObject steals a
reference to the object, but this is not taken care of in threadmodule.c (or
gcmodule, it turns out, and I bet many other places).

Shouldn't be too hard to fix.

(Looks like noone's run Demo/embed/loop for a while...)

[mwhudson]

Logged In: YES
user_id=6656

Fixed the issue in the report in revision 2.62 of Modules/threadmodule.c.

I'm leaving this open because "./loop 'import gc'" crashes and because I
think there are too many places that incref before
PyModule_AddObject()...

Neil, any ideas about the gc one?

[nascheme]

Logged In: YES
user_id=35752

I add an incref in gcmodule.c 2.81. "./loop 'import gc'" no
longer crashes but it does leak memory. :-(