changeset:   88614:7ce7295393c2
user:        Victor Stinner <victor.stinner@gmail.com>
date:        Tue Jan 21 21:00:47 2014 +0100
files:       Lib/selectors.py
description:
Issue #20311: EpollSelector now also rounds the timeout towards zero, as
PollSelector.

This change is not really required in Python 3.4, since select.epoll.poll() now
rounds also correctly the timeout. But Guido van Rossum prefers to have exactly
the same selectors.py file in CPython and Tulip projects: "it's not harmful".


diff -r 29b4eb47f65e -r 7ce7295393c2 Lib/selectors.py
--- a/Lib/selectors.py	Tue Jan 21 20:52:17 2014 +0100
+++ b/Lib/selectors.py	Tue Jan 21 21:00:47 2014 +0100
@@ -411,7 +411,14 @@
             return key
 
         def select(self, timeout=None):
-            timeout = -1 if timeout is None else max(timeout, 0)
+            if timeout is None:
+                timeout = -1
+            elif timeout <= 0:
+                timeout = 0
+            else:
+                # epoll_wait() has a resolution of 1 millisecond, round away
+                # from zero to wait *at least* timeout seconds.
+                timeout = math.ceil(timeout * 1e3) * 1e-3
             max_ev = len(self._fd_to_key)
             ready = []
             try: