New submission from Manoj C <manojc...@gmail.com>:
I have been using asyncio to run subprocess calls in a separate thread. For this purpose I start an event loop in my main thread as per the recommendation - https://docs.python.org/3/library/asyncio-subprocess.html#subprocess-and-threads . Now when I use a normal subprocess call in the main thread, I start getting following file descriptor error after few iterations: ``` Exception ignored when trying to write to the signal wakeup fd: BlockingIOError: [Errno 11] Resource temporarily unavailable ``` I have reproduced the problem in a small script and am seeing that the error goes away if I do not start the even loop in the main thread. ``` import asyncio import subprocess import time def try_error(): for i in range(1,500): print(i) try: subprocess.run(["ls", "-l"], check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) except subprocess.CalledProcessError as e: print(f"Exception raised {e.stderr}\nOutput {e.stdout}") def definite_error(): w = asyncio.get_child_watcher() l = asyncio.get_event_loop() try_error() if __name__ == "__main__": definite_error() ``` This is the smallest subset of the code which can reproduce the error. In the original code, I run a asyncio.create_subprocess_exec in a parallel thread. The normal subprocess call is part of third party code which call from the main thread and hence cannot modify it. ---------- components: asyncio messages: 351795 nosy: Manoj C, asvetlov, yselivanov priority: normal severity: normal status: open title: File descriptor error when subprocess call is used with event loop enabled in main thread type: crash versions: Python 3.6 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue38104> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
