Description

When I press <Ctrl-C> to close MoinMoin Desktop Edition, it generates a traceback, complaining of select.error: (4, 'Interrupted system call').

Steps to reproduce

1. Start with a Mac running OS X 10.4.11.

2. Install Python 2.6.1 from www.python.org.

3. Install MoinMoin 1.8.2.

4. Launch MoinMoin from Terminal.app command line

5. Press <Ctrl-c> to close MoinMoin.

Example

Component selection

• general

Details

Transcripts from Terminal.app follow.

The first one shows the build of Python used.

• Mac:~/Desktop/moin-1.8.2 username$ echo $PATH
  /usr/local/bin:/bin:/sbin:/usr/bin:/usr/sbin
  Mac:~/Desktop/moin-1.8.2 username$ which python
  /usr/local/bin/python
  Mac:~/Desktop/moin-1.8.2 username$ python
  Python 2.6.1 (r261:67515, Dec  6 2008, 16:42:21)
  [GCC 4.0.1 (Apple Computer, Inc. build 5370)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.

The second one shows exactly what happens when launching MoinMoin from Terminal.app using the above-mentioned build of Python.

• Mac:~/Desktop/moin-1.8.2 username$ python wikiserver.py
  2009-03-25 20:19:23,111 INFO MoinMoin.log:126 using logging configuration read from "/Users/username/Desktop/moin-1.8.2/wikiserverlogging.conf"
  2009-03-25 20:19:23,315 INFO MoinMoin.server.server_standalone:72 ThreadPoolServer serving on 127.0.0.1:8080
  ^C2009-03-25 20:19:25,422 INFO MoinMoin.server.server_standalone:491 Thanks for using MoinMoin!
  Traceback (most recent call last):
    File "wikiserver.py", line 38, in <module>
      MoinScript().run()
    File "/Users/davidbiovision/Desktop/moin-1.8.2/MoinMoin/script/__init__.py", line 138, in run
      self.mainloop()
    File "/Users/davidbiovision/Desktop/moin-1.8.2/MoinMoin/script/__init__.py", line 255, in mainloop
      plugin_class(args[2:], self.options).run() # all starts again there
    File "/Users/davidbiovision/Desktop/moin-1.8.2/MoinMoin/script/__init__.py", line 138, in run
      self.mainloop()
    File "/Users/davidbiovision/Desktop/moin-1.8.2/MoinMoin/script/server/standalone.py", line 131, in mainloop
      run(Config)
    File "/Users/davidbiovision/Desktop/moin-1.8.2/MoinMoin/server/server_standalone.py", line 638, in run
      httpd.serve_forever()
    File "/Users/davidbiovision/Desktop/moin-1.8.2/MoinMoin/server/server_standalone.py", line 189, in serve_forever
      SimpleServer.serve_forever(self)
    File "/Users/davidbiovision/Desktop/moin-1.8.2/MoinMoin/server/server_standalone.py", line 77, in serve_forever
      self.handle_request()
    File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/SocketServer.py", line 262, in handle_request
      fd_sets = select.select([self], [], [], timeout)
  select.error: (4, 'Interrupted system call')
  Mac:~/Desktop/moin-1.8.2 username$

Workaround

Discussion

Python issue 7978 ("SocketServer doesn't handle syscall interruption") may be the cause of this. A thread on Python-dev discusses it.

From Python issue 7978:

• SocketServer's handle_request function uses "select" call to handle io, but sending POSIX signal will result in 'Interrupted system call' exception raised. After that Paste (http://pythonpaste.org/) http server will crash.

  I suppose EINTR must be handled properly (i.e. syscall must be restarted silently) on SocketServer's side. That must be pretty easy task. . . .

• Wrapping select in (taken from twisted sources) can help:

def untilConcludes(f, *a, **kw):
    while True:
        try:
            return f(*a, **kw)
        except (IOError, OSError), e:
            if e.args[0] == errno.EINTR:
                continue
            raise

The bug may also happen in 1.8.7 I am not sure about this. But please for many reasons (SecurityFixes) please do this update to 1.8.7. -- ReimarBauer 2010-04-08 20:02:15

Plan

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• Assigned to:
• Status:

CategoryMoinMoinBug