Hi, I reverted all my changes in CPython and Tulip in select and selectors modules, the timeout is no more rounded aways zero, but it does not fix the issue. Sometimes, the selector waits less than timeout seconds.
Instead, I added a resolution attribute to selectors.BaseSelector and a granularity attribute to asyncio.BaseEventLoop, and BaseEventLoop._run_once() uses the new granurality to round correctly times. The granularity is the maximum between the resolution of the clock and the resolution of the selector. I also added a unit test counting the number of calls to _run_once(). Victor
