[QPID-5588] Python client fails if socket fd > FD_SETSIZE

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.26, 0.27
• Fix Version/s: 0.28
• Component/s: Python Client
• Assignee: Ken Giusti
• Reporter: Ken Giusti
• Created: 28/Feb/14 14:20
• Updated: 03/Jun/14 15:34
• Resolved: 28/May/14 18:57

Description

The python client uses select() to wait for socket activity. select() is used because it is available on most platforms. However, select() has a hard limit on the value of an file descriptor. If a socket is created that has a file descriptor > the value of FD_SETSIZE, the following exception is thrown:

Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/lib64/python2.4/threading.py", line 442, in __bootstrap
self.run()
File "/usr/lib64/python2.4/threading.py", line 422, in run
self._target(*self.args, **self._kwargs)
File "/usr/lib/python2.4/site-packages/qpid/selector.py", line 119, in run
rd, wr, ex = select(self.reading, self.writing, (), timeout)
ValueError: filedescriptor out of range in select()

Note well: this is caused by the value of the fd, not the number of open fds. A process that has many files open, then attempts to create a qpid connection, could hit this problem.