Bugs item #788526, was opened at 2003-08-13 22:13
Message generated for change (Comment added) made by nnorwitz
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=788526&group_id=5470
Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Python Library
>Group: Python 2.4
>Status: Closed
>Resolution: Works For Me
Priority: 5
Submitted By: Jane Austine (janeaustine50)
Assigned to: Gregory P. Smith (greg)
Summary: Closing dbenv first bsddb doesn't release locks & segfau
Initial Comment:
There is a test code named test_env_close in
bsddb/test, but it
doesn't test the case thoroughly. There seems to be a
bug in closing
the db environment first -- the lock is not released, and
sometimes it
seg-faults.
Following is the code that shows this bug.
<code>
import os
from bsddb import db
dir,dbname='test_dbenv','test_db'
def getDbEnv(dir):
try:
os.mkdir(dir)
except:
pass
dbenv = db.DBEnv()
dbenv.open(dir, db.DB_INIT_CDB| db.DB_CREATE
|db.DB_INIT_MPOOL)
return dbenv
def getDbHandler(db_env,db_name):
d = db.DB(dbenv)
d.open(db_name, db.DB_BTREE, db.DB_CREATE)
return d
dbenv=getDbEnv(dir)
assert dbenv.lock_stat()['nlocks']==0
d=getDbHandler(dbenv,dbname)
assert dbenv.lock_stat()['nlocks']==1
try:
dbenv.close()
except db.DBError:
pass
else:
assert 0
del d
import gc
gc.collect()
dbenv=getDbEnv(dir)
assert dbenv.lock_stat()['nlocks']==0,'number of current
locks should
be 0' #this fails
</code>
If you close dbenv before db handler, the lock is not
released.
Moreover, try this with dbshelve and it segfaults.
<code>
>>> from bsddb import dbshelve
>>> dbenv2=getDbEnv('test_dbenv2')
>>> d2=dbshelve.open(dbname,dbenv=dbenv2)
>>> try:
... dbenv2.close()
... except db.DBError:
... pass
... else:
... assert 0
...
>>>
>>>
Exception bsddb._db.DBError: (0, 'DBEnv object has
been closed') in
Segmentation fault
</code>
Tested on:
1. linux with Python 2.3 final, Berkeley DB 4.1.25
2. windows xp with Python 2.3 final (with _bsddb that
comes along)
----------------------------------------------------------------------
>Comment By: Neal Norwitz (nnorwitz)
Date: 2006-01-24 22:05
Message:
Logged In: YES
user_id=33168
Assuming this was fixed by the patch.
----------------------------------------------------------------------
Comment By: Neal Norwitz (nnorwitz)
Date: 2006-01-24 00:04
Message:
Logged In: YES
user_id=33168
Jane could try the patch in bug 1413192 to see if it fixes
your problem?
----------------------------------------------------------------------
Comment By: Gregory P. Smith (greg)
Date: 2004-06-16 15:18
Message:
Logged In: YES
user_id=413
Yes this bug is still there. A "workaround" is just a
"don't do that" when it comes to closing sleepycat DBEnv
objects while there are things using them still open. I
believe we can prevent this...
One proposal: internally in _bsddb.c DBEnv could be made to
keep a weak reference to all objects created using it (DB
and DBLock objects) and refuse to call the sleepycat close()
method if any still exist (overridable using a force=1 flag).
----------------------------------------------------------------------
Comment By: Neal Norwitz (nnorwitz)
Date: 2004-06-15 20:14
Message:
Logged In: YES
user_id=33168
Greg do you know anything about this? Is it still a problem?
----------------------------------------------------------------------
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=788526&group_id=5470
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
