Charles-François Natali added the comment: > > But what problem does it cause if, once in a while, the call takes less > > than the passed timeout? > > If that's the case, you'll simply perform another loop, an wake up 1ms > > later, that's all. > > "perform another loop" is my problem. If possible, I would like > useless calls to the loop. With my latest patch to asyncio, there is > no more useless calls to the loop (at least, not because of a time > rounding issue).
Still, you fail to provide an example: you will only perform another call if you pass a tilmeout really close to an exact multiple of the granularity, *and* the syscall returns early. Just perform a test on your machine, you'll see that early wakeups are *really* rare. And even if that's the case, I argue that performing an extra loop isn't a problem: for example, noone ever complained about the way timpeouts are rounded in the select module. If you think otherwise, please back your claim by an example. > Oh, I forgot to mention that I'm also concerned by the backward > compatibility. Changing how poll and epoll round the timeout changes > the behaviour. It may break applications or maybe change performances > of applications (efficiency or reactivity). Changing the rounding > method in Python 3.3 was not a good idea. Don't apply it to 3.3 then. > @Charles-François: I'm not sure that we are talking about the same > thing. If you still want to change poll and epoll, go ahead. Since the > performance issue has been fixed directly in asyncio, I don't feel the > need of changing the poll or epoll anymore in Python 3.4. Or maybe you > disagree with my change in the asyncio module? I disagree with the introduction of a granularity to selectors. If you really want to keep the change in asyncio, just introduce a fixed "slack" value, e.g. 1e-3 seconds. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue20311> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
