OSC server timeout

After starting an OSC server and idling, the listener times out due to recv on Python 2.7.

    #Initialise OSC server
    osc = OSCThreadServer()
    sock = osc.listen(address='0.0.0.0', port=8000, default=True)

After a minute or so:

Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/home/rc/venv-python2-ros/local/lib/python2.7/site-packages/oscpy/server.py", line 257, in _listen
    data, sender = sender_socket.recvfrom(65535)
timeout: timed out

A temporary workaround is to get the OSC server to poll itself, something along the lines of:

    while not shutdownevent.isSet():
        osc.send_message(b'/keepalive', [], '127.0.0.1', 8000)
        time.sleep(2)

Perhaps using Select() (Python 2, Python 3) would be better.

Interestingly, select is used if the server is listening on more than one port/address, it just felt suboptimal for performances to do that in the more common case of just one.

oscpy/oscpy/server.py

Lines 264 to 267 in 507af64

    
           elif len(self.sockets) < 2: 
        
               read = self.sockets 
        
           else: 
        
               read, write, error = select(self.sockets, [], [], self.timeout)

maybe we should just do that all the time.

fixed by 885318b

I wonder if it's worth creating a regression test for this bug, and if so, how to allow the test to run quickly (rather than actually wait for 15mn). Maybe i'll open an actual issue about it.

	elif len(self.sockets) < 2:
	read = self.sockets
	else:
	read, write, error = select(self.sockets, [], [], self.timeout)