PyUserInput and Xlib crashing

Question

I'm using the PyUserInput python library that takes advantage of the python xlib library. When I use the mouse movements, I will randomly get an error. Reproduced here:

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/pymouse/x11.py", line 68, in move
    if (x, y) != self.position():
  File "/usr/local/lib/python2.7/dist-packages/pymouse/x11.py", line 76, in position
    coord = self.display.screen().root.query_pointer()._data
  File "/usr/lib/pymodules/python2.7/Xlib/xobject/drawable.py", line 569, in query_pointer
    window = self.id)
  File "/usr/lib/pymodules/python2.7/Xlib/protocol/rq.py", line 1428, in __init__
    self.reply()
  File "/usr/lib/pymodules/python2.7/Xlib/protocol/rq.py", line 1440, in reply
    self._display.send_and_recv(request = self._serial)
  File "/usr/lib/pymodules/python2.7/Xlib/protocol/display.py", line 547, in send_and_recv
    gotreq = self.parse_response(request)
  File "/usr/lib/pymodules/python2.7/Xlib/protocol/display.py", line 634, in parse_response
    gotreq = self.parse_request_response(request) or gotreq
  File "/usr/lib/pymodules/python2.7/Xlib/protocol/display.py", line 711, in parse_request_response
    req = self.get_waiting_replyrequest()
  File "/usr/lib/pymodules/python2.7/Xlib/protocol/display.py", line 838, in get_waiting_replyrequest
    raise RuntimeError("Request reply to unknown request.  Can't happen!")
RuntimeError: Request reply to unknown request.  Can't happen!

The only way I've been able to reproduce this is through trial and error. It always happens but it occurs at random times.

Answer 1

The reason this was occurring seems to be through some threading issue. Looking into the error I realized that the error was not with the PyUserInput module but with the python-xlib module itself. Redefining my search revealed some possible issues with multi-threaded concurrency (which my program uses). This thread, https://code.google.com/p/pywo/issues/detail?id=12#makechanges, suggested importing Xlib.threaded and like the user in the link, I haven't seen the error since.

import Xlib.threaded