Hi
We are using DCOracle2 from CVS head branch, but I'm testing
chrisw_fixconnectionleak_branch branch created by chrisw and
I've fallen into some errors with this.
First of all, is chrisw_fixconnectionleak_branch branch the
recommended one? I've seen Carsten Gerner question about the
version of DCOracle but the answer says only about cvs version...
I have a page that renders a table with 70 rows and when I'm
refreshing this page fast for a few times I'm receiving
the errors like:
*Error Type: ConnectionReleasedError*
*Error Value: 3
I've added some debugging commands to connections.py file
and the output is a bit strange for me. Below modified (with print
commands) connections.py file and it's output.
As far as I've analyzed this I see that 'close' function is called
somehow, but I don't know why and by what.
I've checked db.py and query method which calls 'close' for some
kinds of exceptions but it is not this piece of code that is executed.
**Any ideas what is happening? Are these leaking connections?
With older version of DCOracle2 (from CVS trunk) compiled with
Oracle8 there are no errors.**
My Zope is 2.7.2, Python 2.3.5. Zope is running with 10 threads
(I tried 4 but no difference) in ZEO. DCOracle2 is compiled for
Oracle9.
**#---------------------------------------------------------------
# Output
*2005-07-13T08:16:51 INFO(0) Zope Ready to handle requests
close; thread: <_DummyThread(Dummy-3, started daemon)>
_register; thread: <_DummyThread(Dummy-3, started daemon)>
assignConnection; creatingConnection: 0; time:1121235431.48; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 0; time: 1121235431.48; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 0; time: 1121235431.48; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 0; time: 1121235431.51; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 0; time: 1121235431.62; thread:
<_DummyThread(Dummy-3, started daemon)>
returnConnection; deleting assigned id: 0; time: 1121235431.62;
thread:<_DummyThread(Dummy-3, started daemon)>
_register; thread: <_DummyThread(Dummy-3, started daemon)>
assignConnection; getting availaible: 0; time: 1121235431.73; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 0; time: 1121235431.73; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 0; time: 1121235431.91; thread:
<_DummyThread(Dummy-3, started daemon)>
returnConnection; deleting assigned id: 0; time: 1121235431.91;
thread:<_DummyThread(Dummy-3, started daemon)>
close; thread: <_DummyThread(Dummy-3, started daemon)>
_register; thread: <_DummyThread(Dummy-3, started daemon)>
assignConnection; creatingConnection: 1; time:1121235437.68; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235437.68; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235437.69; thread:
<_DummyThread(Dummy-3, started daemon)>
returnConnection; deleting assigned id: 1; time: 1121235437.69;
thread:<_DummyThread(Dummy-3, started daemon)>
_register; thread: <_DummyThread(Dummy-3, started daemon)>
assignConnection; getting availaible: 1; time: 1121235438.23; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235438.23; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235438.44; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235438.71; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235438.96; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235439.07; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235439.07; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235439.17; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235439.84; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235440.25; thread:
<_DummyThread(Dummy-3, started daemon)>
returnConnection; deleting assigned id: 1; time: 1121235440.25;
thread:<_DummyThread(Dummy-3, started daemon)>
_register; thread: <_DummyThread(Dummy-3, started daemon)>
assignConnection; getting availaible: 1; time: 1121235448.29; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235448.29; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235448.3; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235448.34; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235448.43; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235448.43; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235448.48; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235448.52; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235449.4; thread:
<_DummyThread(Dummy-3, started daemon)>
returnConnection; deleting assigned id: 1; time: 1121235449.4;
thread:<_DummyThread(Dummy-3, started daemon)>
_register; thread: <_DummyThread(Dummy-3, started daemon)>
assignConnection; getting availaible: 1; time: 1121235456.17; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235456.17; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235456.17; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235456.22; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235456.32; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235456.33; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235456.39; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Returned connection: 1; time: 1121235456.42; thread:
<_DummyThread(Dummy-3, started daemon)>
close; thread: <_DummyThread(Dummy-1, started daemon)>
_register; thread: <_DummyThread(Dummy-1, started daemon)>
assignConnection; creatingConnection: 2; time:1121235458.33; thread:
<_DummyThread(Dummy-1, started daemon)>
getConnection; Returned connection: 2; time: 1121235458.33; thread:
<_DummyThread(Dummy-1, started daemon)>
getConnection; Exception: 1; time: 1121235458.88; thread:
<_DummyThread(Dummy-3, started daemon)>
getConnection; Exception: 1; time: 1121235458.89; thread:
<_DummyThread(Dummy-3, started daemon)>
_register; thread: <_DummyThread(Dummy-2, started daemon)>
assignConnection; creatingConnection: 3; time:1121235459.07; thread:
<_DummyThread(Dummy-2, started daemon)>
getConnection; Returned connection: 3; time: 1121235459.07; thread:
<_DummyThread(Dummy-2, started daemon)>
getConnection; Returned connection: 2; time: 1121235459.41; thread:
<_DummyThread(Dummy-1, started daemon)>
close; thread: <_DummyThread(Dummy-4, started daemon)>
_register; thread: <_DummyThread(Dummy-4, started daemon)>
assignConnection; creatingConnection: 4; time:1121235459.54; thread:
<_DummyThread(Dummy-4, started daemon)>
getConnection; Returned connection: 4; time: 1121235459.54; thread:
<_DummyThread(Dummy-4, started daemon)>
getConnection; Exception: 3; time: 1121235459.89; thread:
<_DummyThread(Dummy-2, started daemon)>
getConnection; Returned connection: 4; time: 1121235460.23; thread:
<_DummyThread(Dummy-4, started daemon)>
getConnection; Exception: 2; time: 1121235460.87; thread:
<_DummyThread(Dummy-1, started daemon)>
getConnection; Returned connection: 4; time: 1121235461.12; thread:
<_DummyThread(Dummy-4, started daemon)>
getConnection; Returned connection: 4; time: 1121235461.23; thread:
<_DummyThread(Dummy-4, started daemon)>
getConnection; Returned connection: 4; time: 1121235461.23; thread:
<_DummyThread(Dummy-4, started daemon)>
getConnection; Returned connection: 4; time: 1121235461.46; thread:
<_DummyThread(Dummy-4, started daemon)>
getConnection; Returned connection: 4; time: 1121235461.69; thread:
<_DummyThread(Dummy-4, started daemon)>
getConnection; Returned connection: 4; time: 1121235462.67; thread:
<_DummyThread(Dummy-4, started daemon)>
returnConnection; deleting assigned id: 4; time: 1121235462.67;
thread:<_DummyThread(Dummy-4, started daemon)>
getConnection; Exception: 2; time: 1121235462.76; thread:
<_DummyThread(Dummy-1, started daemon)>
getConnection; Exception: 3; time: 1121235462.76; thread:
<_DummyThread(Dummy-2, started daemon)>
*#
--------------------------------------------------------------------------------
*
*#
--------------------------------------------------------------------------------
# connections.py
import DCOracle2
import threading
from Shared.DC.ZRDB.TM import Surrogate
from exceptions import ConnectionReleasedError, NoConnectionError
import time
# a pool of connections
# connection string -> list of available connections
pool = {}
# connections currently in use
# connection id -> connection object
assigned = {}
# connection count of created connections
# connecting string -> number of connections around
connection_count = {}
# the next id to be assigned
next_id = 0
# the big fat lock for when modifying the above
lock = threading.Lock()
def assignConnection(connectionString):
global lock
global pool
global assigned
global next_id
global connection_count
id = 0
try:
lock.acquire()
available = pool.get(connectionString,None)
if available is None:
available = pool[connectionString] = []
if available:
id, conn = available.pop()
print 'assignConnection; getting availaible: %s; time: %s;
thread: %s' % (id, time.time(), threading.currentThread())
else:
conn = DCOracle2.connect(connectionString)
id = next_id
next_id += 1
connection_count[
connectionString
] = connection_count.get(
connectionString,
0) + 1
print 'assignConnection; creatingConnection: %s; time:%s;
thread: %s' % (id, time.time(),threading.currentThread() )
assigned[id]=(conn,connectionString)
finally:
lock.release()
return id
def getConnection(id):
try:
connpair = assigned[id]
print 'getConnection; Returned connection: %s; time: %s; thread:
%s' % (id, time.time(), threading.currentThread())
except KeyError,e:
print 'getConnection; Exception: %s; time: %s; thread: %s' %
(e.args[0], time.time(), threading.currentThread())
if e.args:
raise ConnectionReleasedError,e.args[0]
else:
raise NoConnectionError,id
return connpair[0]
def returnConnection(id):
global lock
global pool
global assigned
try:
lock.acquire()
try:
conn,connectionString = assigned[id]
except KeyError,e:
print 'returnConnection; Exception: %s; thread:' %
(e.args[0], threading.currentThread())
if e.args:
raise ConnectionReleasedError,e.args[0]
else:
raise NoConnectionError,id
print 'returnConnection; deleting assigned id: %s; time: %s;
thread:%s' % (id, time.time(), threading.currentThread())
del assigned[id]
pool[connectionString].append((id,conn))
finally:
lock.release()
def close(connectionString=None, theId=None):
global lock
global pool
global assigned
global next_id
global connection_count
print 'close; thread: %s' % (threading.currentThread())
try:
lock.acquire()
for connstring,connections in pool.items():
if connectionString is None or connstring==connectionString:
for id,conn in connections:
if theId is None or id==theId:
pool[connstring].remove((id,conn))
conn.cursor().close()
conn.close()
if not pool[connstring]:
del pool[connstring]
for id,connpair in assigned.items():
if theId is None or id==theId:
conn,connstring = connpair
if connectionString is None or connstring==connectionString:
conn.cursor().close()
conn.close()
del assigned[id]
if connectionString is None and theId is None:
next_id = 0
for key in connection_count.keys():
del connection_count[key]
elif theId is None:
if connection_count.has_key(connectionString):
del connection_count[connectionString]
else:
connection_count[connectionString] -= 1
finally:
lock.release()
def countConnections(connectionString):
return connection_count.get(connectionString,0)
class CTM:
"""A class providing transaction manager support
for connection pooling.
Also stores _registered and _finalised as
_v_ variables"""
_v_connection_id = _v_registered = None
def _register(self):
print '_register; thread: %s' % (threading.currentThread())
if not self._v_registered:
get_transaction().register(Surrogate(self))
self._begin()
self._v_registered = 1
self._v_finalize = 0
def tpc_begin(self, *ignored): pass
commit=tpc_begin
def tpc_vote(self, *ignored):
self._v_finalize = 1
def tpc_finish(self, *ignored):
if self._v_finalize:
try: self._finish()
finally: self._v_registered=0
def abort(self, *ignored):
try: self._abort()
finally: self._v_registered=0
tpc_abort = abort
def sortKey(self, *ignored):
""" The sortKey method is used for recent ZODB compatibility which
needs to have a known commit order for lock acquisition. Most
DA's talking to RDBMS systems do not care about commit order, so
return the constant 1
"""
return 1
def getDB(self):
if self._v_connection_id is None:
self._register()
return getConnection(
self._v_connection_id
)
def __del__(self):
if self._v_connection_id is not None:
returnConnection(
self._v_connection_id
)
self._v_connection_id = None
def _begin(self):
# assertion checks we've not already got a
# connection which would get leaked at this
# point
assert self._v_connection_id is None
# either use the connection string
# or, if it's not there (we're a stored procedure)
# then get the connection string from our DA
self._v_connection_id = assignConnection(
getattr(self,'connection_string',None) or \
getattr(self,self.connection).connection_string
)
def _finish(self, *ignored):
if self._v_connection_id is not None:
db = getConnection(
self._v_connection_id
)
db.commit()
returnConnection(
self._v_connection_id
)
self._v_connection_id = None
def _abort(self, *ignored):
if self._v_connection_id is not None:
db = getConnection(
self._v_connection_id
)
db.rollback()
returnConnection(
self._v_connection_id
)
self._v_connection_id = None
#---------------------------------------------------------------
--
Maciej Wisniowski
*
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