OSError: [Errno 9] Bad file descriptor

[buendiya]

I came across this exception when I try to close socketio Client.

Exception in thread Thread-17:
Traceback (most recent call last):
  File "/usr/lib/python3.6/threading.py", line 916, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.6/threading.py", line 864, in run
    self._target(*self._args, **self._kwargs)
  File "/home/jingsz/.virtualenvs/webrtc_peer/lib/python3.6/site-packages/engineio/client.py", line 687, in _write_loop
    self.ws.send(encoded_packet)
  File "/home/jingsz/.virtualenvs/webrtc_peer/lib/python3.6/site-packages/websocket/_core.py", line 253, in send
    return self.send_frame(frame)
  File "/home/jingsz/.virtualenvs/webrtc_peer/lib/python3.6/site-packages/websocket/_core.py", line 279, in send_frame
    l = self._send(data)
  File "/home/jingsz/.virtualenvs/webrtc_peer/lib/python3.6/site-packages/websocket/_core.py", line 449, in _send
    return send(self.sock, data)
  File "/home/jingsz/.virtualenvs/webrtc_peer/lib/python3.6/site-packages/websocket/_socket.py", line 157, in send
    return _send()
  File "/home/jingsz/.virtualenvs/webrtc_peer/lib/python3.6/site-packages/websocket/_socket.py", line 139, in _send
    return sock.send(data)
OSError: [Errno 9] Bad file descriptor

The reason maybe is that it is sending STOP packet after the connection have been closed.

[miguelgrinberg]

You must be using an old version of the python-engineio package, because this was fixed a few months ago. See miguelgrinberg/python-engineio#177.

[devupmaster]

I'm having the same problem.
When I disconnect a client sio.disconnect(), this error occurs on the server.

python-engineio 4.5.1
python-socketio 5.8.0

2023-07-24 16:19:39 -0300] [30597] [ERROR] Socket error processing request.
Traceback (most recent call last):
  File "/home/yuri/.local/lib/python3.11/site-packages/gunicorn/workers/gthread.py", line 282, in handle
    keepalive = self.handle_request(req, conn)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/yuri/.local/lib/python3.11/site-packages/gunicorn/workers/gthread.py", line 354, in handle_request
    util.reraise(*sys.exc_info())
  File "/home/yuri/.local/lib/python3.11/site-packages/gunicorn/util.py", line 641, in reraise
    raise value
  File "/home/yuri/.local/lib/python3.11/site-packages/gunicorn/workers/gthread.py", line 340, in handle_request
    resp.write(item)
  File "/home/yuri/.local/lib/python3.11/site-packages/gunicorn/http/wsgi.py", line 326, in write
    self.send_headers()
  File "/home/yuri/.local/lib/python3.11/site-packages/gunicorn/http/wsgi.py", line 322, in send_headers
    util.write(self.sock, util.to_bytestring(header_str, "latin-1"))
  File "/home/yuri/.local/lib/python3.11/site-packages/gunicorn/util.py", line 299, in write
    sock.sendall(data)
OSError: [Errno 9] Bad file descriptor

[miguelgrinberg]

Your error has nothing to do with what's reported above. Please write a new discussion and provide a reproduction environment with versions for all the dependencies, especially gunicorn.

[devupmaster]

resolved by setting gunicorn worker_class to "eventlet"

[junk-skunk-3]

Strange, for me 'eventlet' always caused Bad file descriptor :
server=127.0.0.1:5000//socket.io/ client=127.0.0.1:34222 socket shutdown error: [Errno 9] Bad file descriptorHII

(on manjaro linux, all packages latest, python 3.11)

That happened even in the most basic test application, when I reload the page and reconnect.

Switching to gevent solved the problem for me

[pay748]

I encountered the exact same problem as you. Inspired by you, I made some discoveries in https://github.com/eventlet/eventlet. Switching to gevent may be the lowest cost option at present. The following is a warning on eventlet github. Summary of information:

New usages of eventlet are now heavily discouraged! Please read the following.

Eventlet was created almost 18 years ago, at a time where async features were absent from the CPython stdlib. With time eventlet evolved and CPython too, but since several years the maintenance activity of eventlet dicreased leading to a growing gap between eventlet and the CPython implementation.

This gap is now too high and can lead you to unexpected side effects and bugs in your applications.

Eventlet now follows a new maintenance policy. Only maintenance for stability and bug fixing will be provided. No new features will be accepted, except those related to the asyncio migration. Usages in new projects are discouraged. Our goal is to plan the retirement of eventlet and to give you ways to move away from eventlet.