[QPID-6402] python: freeze on session.close() if an exception was raised in session.receiver()

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.30
• Component/s: Python Client

Environment

Ubuntu 10.04 (python 2.6.5) and 12.04 (python 2.7.3). QPID is compiled from source on both platforms, with proton 0.8.

• Assignee: Unassigned
• Reporter: Jan David Mol
• Created: 20/Feb/15 16:28
• Updated: 20/Feb/15 16:30

Description

If a receiver is created but causes an error (no such queue, malformed address, etc), the session.close() can freeze in certain circumstances. Example code:

import qpid.messaging as m

class Foo:
  def __init__(self):
    self.conn = m.Connection("127.0.0.1")
    self.conn.open()
    self.session = self.c.session()
    try:
      self.r = self.s.receiver("sdklfdsdls")
    except:
      print "no such queue"

  def __del__(self):
    self.session.close()

f = Foo()

The above sequence does not stall if the code is simply put in a function (or _del_ is merged into _init_).

Note that providing session.close() with a timeout prevents the freeze, but of course can cause data loss if the stall was legit.