Details
-
Bug
-
Status: Closed
-
Major
-
Resolution: Not A Problem
-
0.32
-
None
-
None
Description
A python process that uses qpid.messaging and then forks causes qpid.messaing use in the child process to randomly hang. To reproduce:
1. in a python process instantiate a qpid.messaing client and call open()
2. Call os.fork()
3. Try to instantiate another qpid.messaging client and call open()
4. observe the child process is waiting on a file descriptor that is shared with the parent which will never wake up.
Here is a potential reproducer with actual python code (from kgiusti):
#!/usr/bin/env python
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
#
import optparse, time
from qpid.messaging import *
from qpid.util import URL
from qpid.log import enable, DEBUG, WARN
import os
import sys
def nameval(st):
idx = st.find("=")
if idx >= 0:
name = st[0:idx]
value = st[idx+1:]
else:
name = st
value = None
return name, value
parser = optparse.OptionParser(usage="usage: %prog [options] ADDRESS [ CONTENT ... ]",
description="Send messages to the supplied address.")
parser.add_option("-b", "--broker", default="localhost",
help="connect to specified BROKER (default %default)")
parser.add_option("-r", "--reconnect", action="store_true",
help="enable auto reconnect")
parser.add_option("-i", "--reconnect-interval", type="float", default=3,
help="interval between reconnect attempts")
parser.add_option("-l", "--reconnect-limit", type="int",
help="maximum number of reconnect attempts")
parser.add_option("-c", "--count", type="int", default=1,
help="stop after count messages have been sent, zero disables (default %default)")
parser.add_option("-d", "--durable", action="store_true",
help="make the message persistent")
parser.add_option("-t", "--timeout", type="float", default=None,
help="exit after the specified time")
parser.add_option("-I", "--id", help="use the supplied id instead of generating one")
parser.add_option("-S", "--subject", help="specify a subject")
parser.add_option("-R", "--reply-to", help="specify reply-to address")
parser.add_option("-P", "--property", dest="properties", action="append", default=[],
metavar="NAME=VALUE", help="specify message property")
parser.add_option("-M", "--map", dest="entries", action="append", default=[],
metavar="KEY=VALUE",
help="specify map entry for message body")
parser.add_option("-v", dest="verbose", action="store_true",
help="enable logging")
opts, args = parser.parse_args()
if opts.verbose:
enable("qpid", DEBUG)
else:
enable("qpid", WARN)
if opts.id is None:
spout_id = str(uuid4())
else:
spout_id = opts.id
if args:
addr = args.pop(0)
else:
parser.error("address is required")
content = None
content_type = None
if args:
text = " ".join(args)
else:
text = None
if opts.entries:
content = {}
if text:
content["text"] = text
for e in opts.entries:
name, val = nameval(e)
content[name] = val
else:
content = text
# no entries were supplied, so assume text/plain for
# compatibility with java (and other) clients
content_type = "text/plain"
import pdb
conn = Connection(opts.broker,
reconnect=opts.reconnect,
reconnect_interval=opts.reconnect_interval,
reconnect_limit=opts.reconnect_limit)
conn.open()
print("Conn open")
pid = os.fork()
if not pid:
#child
try:
#pdb.set_trace()
ssn = conn.session()
snd = ssn.sender(addr)
count = 0
start = time.time()
while (opts.count == 0 or count < opts.count) and \
(opts.timeout is None or time.time() - start < opts.timeout):
msg = Message(subject=opts.subject,
reply_to=opts.reply_to,
content=content)
if opts.durable:
msg.durable = True
if content_type is not None:
msg.content_type = content_type
msg.properties["spout-id"] = "%s:%s" % (spout_id, count)
for p in opts.properties:
name, val = nameval(p)
msg.properties[name] = val
snd.send(msg)
count += 1
print msg
except:
print("booboo")
os._exit(1)
print("buh-bye")
os._exit(0)
else:
status = os.wait()[1]
#pdb.set_trace()
conn.close()
sys.exit(status)