New submission from STINNER Victor: Rounding issue causes performance bug in asyncio, see issue #20311 for the rationale. This issue address bugs for select and kqueue because their implementation is different.
OS multiplexer: - select: microsecond resolution (10^-6), timeout converted by _PyTime_ObjectToTimeval() which converts 1e-7 to zero => BUG! - kqueue: nanosecond resolution (10^-9), timeout converted by _PyTime_ObjectToTimespec() which converts 1e-10 to zero => BUG! _PyTime_ObjectToTimeval() is used in various places: - datetime.datetime.fromtimestamp(), datetime.datetime.utcfromtimestamp() - select.select(), _PyTime_ObjectToTimespec() is used in various places: - posix.utime() - signal.sigtimedwait() - select.kqueue.control() - time.clock_settime() Attached patch adds a new round parameter to _PyTime_ObjectToTimeval() and _PyTime_ObjectToTimespec() to choose the rounding method: * _PyTime_ROUND_DOWN: Round towards zero. (current implementation) * _PyTime_ROUND_UP: Round away from zero. (new rounding method) The patch changes the rounding method for select, kqueue but also for sigtimedwait(). ---------- files: time_rouding.patch keywords: patch messages: 208594 nosy: belopolsky, haypo, neologix, pitrou, serhiy.storchaka, skrah priority: normal severity: normal status: open title: select.select(timeout) and select.kqueue.control(timeout) must round the timeout to the upper bound versions: Python 3.3, Python 3.4 Added file: http://bugs.python.org/file33581/time_rouding.patch _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue20320> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
