[Python-checkins] cpython: selectors: add a comment to explain why and how poll timeout is rounded

[victor.stinner]

http://hg.python.org/cpython/rev/b81293d895d6
changeset:   88607:b81293d895d6
user:        Victor Stinner <victor.stinner at gmail.com>
date:        Tue Jan 21 17:49:41 2014 +0100
summary:
  selectors: add a comment to explain why and how poll timeout is rounded

files:
  Lib/selectors.py |  6 ++++--
  1 files changed, 4 insertions(+), 2 deletions(-)


diff --git a/Lib/selectors.py b/Lib/selectors.py
--- a/Lib/selectors.py
+++ b/Lib/selectors.py
@@ -354,10 +354,12 @@
         def select(self, timeout=None):
             if timeout is None:
                 timeout = None
-            elif timeout < 0:
+            elif timeout <= 0:
                 timeout = 0
             else:
-                timeout = int(math.ceil(timeout * 1000.0))
+                # poll() has a resolution of 1 millisecond, round away from
+                # zero to wait *at least* timeout seconds.
+                timeout = int(math.ceil(timeout * 1e3))
             ready = []
             try:
                 fd_event_list = self._poll.poll(timeout)

-- 
Repository URL: http://hg.python.org/cpython