asyncio version of `os.chmod` in Python

Question

I have some Python3 code running inside an asyncio event loop.

I want to use the functionality of os.chmod(...), but would ideally like a non-blocking version of this, so that I can use await os.chmod(...), and avoid making a blocking system call.

I don't believe there any libraries available that supply this functionality yet, at least from what I can see.

How would I go about implementing a non-blocking os.chmod(...) from scratch? Better still, is there a pre-existing solution?

For context, I'm implementing a Gunicorn worker process, that uses asyncio. Gunicorn uses a spinning `fchmod` status for signalling worker process aliveness. https://github.com/benoitc/gunicorn/blob/master/gunicorn/workers/workertmp.py — Tom Christie, Jun 05 '17 at 15:56

score 7 · Accepted Answer · edited Jun 06 '17 at 12:17

7

UNIX systems have not implemented an asynchronous API for the chmod syscall. Thus the best you can do is run it in a thread pool:

await loop.run_in_executor(None, os.chmod, fname, mode)

edited Jun 06 '17 at 12:17

davidism

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answered Jun 05 '17 at 18:59

Andrew Svetlov

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Did you mean: `await loop.run_in_executer(None, os.chmod, fname, mode)`? – Yuval Pruss Jun 06 '17 at 06:12
@YuvalPruss Did you mean `await loop.run_in_executor(None, os.chmod, fname, mode)`? ;) – Tom Christie Jun 06 '17 at 10:55

asyncio version of `os.chmod` in Python

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