Bad file descriptor in io_worker

[MurphyMc]

Here's a stack trace from Sam:

File "/usr/lib/python2.7/threading.py", line 552, in __bootstrap_inner │
self.run() │
File "/usr/lib/python2.7/threading.py", line 505, in run │
self.__target(*self.__args, **self.__kwargs) │
File "/home/sam/code/debugger/sts/../pox/pox/lib/recoco/recoco.py", line 574, in _threadProc │
xl.keys(), timeout ) │
File "/home/sam/code/debugger/sts/../pox/pox/lib/ioworker/io_worker.py", line 77, in fileno │
return self.socket.fileno() │
File "/usr/lib/python2.7/socket.py", line 224, in meth │
return getattr(self._sock,name)(*args) │
File "/usr/lib/python2.7/socket.py", line 170, in _dummy │
raise error(EBADF, 'Bad file descriptor') │
error: [Errno 9] Bad file descriptor

[MurphyMc]

The problem would seem to be that close() is being called on a worker socket while Select() either still has the socket (because close() is called from other thread or maybe another Task, for example), or close() is called on a socket that is passed back into Select().

It's not immediately clear to me how the latter could be happening, because _workers.remove() or _workers.discard() seems to be called in every place that close() is called on a worker socket.

The former is a possibility, though I don't know the io_worker code well enough to immediately say. 96b8074 fixed a similar problem by changing calls from socket.close() to socket.shutdown(), relying on recoco to close them eventually. This might work here?

[samwhitlock]

I was accidentally closing my socket's file descriptor because I misunderstood how python's finally statement worked. My bad :P