STINNER Victor added the comment: I understood that:
* code fills the write buffer of the transport until writing is paused because of the high water mark * a function calls drain() which waits until the server reads until packets to reduce the size of the write buffer * a second function calls drain(), but the first function is already waiting on drain(): bug occurs since the code doesn't support having two coroutines waiting on drain() in parallel Notes: * the minimum is to document that drain() must not be called twice in parallel. Right now, nothing is said about that: https://docs.python.org/dev/library/asyncio-stream.html#asyncio.StreamWriter.drain * we can probably design something to allow to have multiple coroutines waiting on the same event -- Metathink told me that he got the bug on a much more complex code using websockets. Thank you Metathink for isolating the bug to a few lines of Python code with simpler asyncio functions! ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue29930> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
