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uvloop closes underlying sockets that were established outside upon end of asyncio.run()

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
45/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
backend, networking

Research direction

Start by running the provided Unix-socket reproducer and compare uvloop with the regular asyncio loop. Trace the socket ownership and close lifecycle around asyncio.open_unix_connection() and asyncio.run(); done means the externally created socket remains usable after asyncio.run() and the regression is covered by a test.

Written by the indexing model from the issue text.

Description

This seem to be version/OS unrelated. Sample:

import asyncio
import socket
import uvloop

b = bytes('{"msg": "test"}', 'utf-8')


async def main_async(sock: socket.socket):
    _, writer = await asyncio.open_unix_connection(sock=sock)
    writer.write(b)
    await writer.drain()


if __name__ == '__main__':
    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    sock.connect('data/sockets/echo_server.sock')
    sock.sendall(b)
    uvloop.install()
    asyncio.run(main_async(sock))  # sock gets wrongly closed on asyncio.run() termination
    sock.sendall(b)  # Exception here OSError: [Errno 9] Bad file descriptor

Last line result in exception "OSError: [Errno 9] Bad file descriptor" because sock gets closed right after asyncio.run() terminates. It is wrong behavior, because sock was created outside of asyncio loop and has to be left untouched. The issue doesn't occur using regular asyncio loop.

Dominant language
Cython
Stars
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Forks
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