[issue20452] test_timeout_rounding() of test_asyncio fails on "x86 Ubuntu Shared 3.x" buildbot

[Charles-François Natali]

Charles-François Natali added the comment:

> It looks like select() and poll() in Linux < 2.6.28 has a resolution
> of 1/HZ, where HZ can be retrieved from os.sysconf('SC_CLK_TCK'). Since
> Linux 2.6.28, hrtimers are now used for timeouts.

> Attached patch improves the resolution field of selectors.BaseSelector.
> By the way, resolution should be a method (selector.resolution())
> rather than a property, because we may query the kernel to compute the
> resolution, as shown in the patch.

That's exactly why I said that an explicit resolution is a bad idea:
- it's an implementation detail
- it's fragile (just look at your latest patch)
- it's useless

Just round the timeout away from 0 and be happy: this will fix the busy-wait problem, and that's all we want.
Once again, I know I keep repeating myself, but having select/epoll/whatever wake up 10usec before the timeout isn't an issue: *all* async-IO frameworks out there work just fine with this.

So please, revert all this granuarity complexity, and re-apply the timeout rounding.

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nosy: +neologix

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<http://bugs.python.org/issue20452>
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