[Python-checkins] cpython: Issue #20311: selector.PollSelector.select() now rounds the timeout away from

Tue Jan 21 01:49:20 CET 2014

http://hg.python.org/cpython/rev/e042ea77a152
changeset: 88594:e042ea77a152
user: Victor Stinner <victor.stinner at gmail.com>
date: Tue Jan 21 01:48:28 2014 +0100
summary:
 Issue #20311: selector.PollSelector.select() now rounds the timeout away from
zero, instead of rounding towards zero. For example, a timeout of one
microsecond is now rounded to one millisecond, instead of being rounded to
zero.
Move also a test in test_epoll which was moved by my previous merge.
files:
 Lib/selectors.py | 8 +++++++-
 Lib/test/test_epoll.py | 23 +++++++++++------------
 Lib/test/test_selectors.py | 18 +++++++++++++++++-
 Misc/NEWS | 5 +++++
 4 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/Lib/selectors.py b/Lib/selectors.py
--- a/Lib/selectors.py
+++ b/Lib/selectors.py
@@ -8,6 +8,7 @@
 from abc import ABCMeta, abstractmethod
 from collections import namedtuple, Mapping
 import functools
+import math
 import select
 import sys
 
@@ -351,7 +352,12 @@
 return key
 
 def select(self, timeout=None):
- timeout = None if timeout is None else max(int(1000 * timeout), 0)
+ if timeout is None:
+ timeout = None
+ elif timeout < 0:
+ timeout = 0
+ else:
+ timeout = int(math.ceil(timeout * 1000.0))
 ready = []
 try:
 fd_event_list = self._poll.poll(timeout)
diff --git a/Lib/test/test_epoll.py b/Lib/test/test_epoll.py
--- a/Lib/test/test_epoll.py
+++ b/Lib/test/test_epoll.py
@@ -47,18 +47,6 @@
 self.serverSocket.listen(1)
 self.connections = [self.serverSocket]
 
- def test_timeout_rounding(self):
- # epoll_wait() has a resolution of 1 millisecond, check if the timeout
- # is correctly rounded to the upper bound
- epoll = select.epoll()
- self.addCleanup(epoll.close)
- for timeout in (1e-2, 1e-3, 1e-4):
- t0 = time.perf_counter()
- epoll.poll(timeout)
- dt = time.perf_counter() - t0
- self.assertGreaterEqual(dt, timeout)
-
-
 def tearDown(self):
 for skt in self.connections:
 skt.close()
@@ -266,6 +254,17 @@
 self.addCleanup(epoll.close)
 self.assertEqual(os.get_inheritable(epoll.fileno()), False)
 
+ def test_timeout_rounding(self):
+ # epoll_wait() has a resolution of 1 millisecond, check if the timeout
+ # is correctly rounded to the upper bound
+ epoll = select.epoll()
+ self.addCleanup(epoll.close)
+ for timeout in (1e-2, 1e-3, 1e-4):
+ t0 = time.perf_counter()
+ epoll.poll(timeout)
+ dt = time.perf_counter() - t0
+ self.assertGreaterEqual(dt, timeout)
+
 
 def test_main():
 support.run_unittest(TestEPoll)
diff --git a/Lib/test/test_selectors.py b/Lib/test/test_selectors.py
--- a/Lib/test/test_selectors.py
+++ b/Lib/test/test_selectors.py
@@ -5,7 +5,7 @@
 import signal
 import socket
 from test import support
-from time import sleep
+from time import sleep, perf_counter
 import unittest
 import unittest.mock
 try:
@@ -363,6 +363,22 @@
 self.assertFalse(s.select(2))
 self.assertLess(time() - t, 2.5)
 
+ def test_timeout_rounding(self):
+ # Issue #20311: Timeout must be rounded away from zero to wait *at
+ # least* timeout seconds. For example, epoll_wait() has a resolution of
+ # 1 ms (10^-3), epoll.select(0.0001) must wait 1 ms, not 0 ms.
+ s = self.SELECTOR()
+ self.addCleanup(s.close)
+
+ rd, wr = self.make_socketpair()
+ s.register(rd, selectors.EVENT_READ)
+
+ for timeout in (1e-2, 1e-3, 1e-4):
+ t0 = perf_counter()
+ s.select(timeout)
+ dt = perf_counter() - t0
+ self.assertGreaterEqual(dt, timeout)
+
 
 class ScalableSelectorMixIn:
 
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -25,6 +25,11 @@
 Library
 -------
 
+- Issue #20311: selector.PollSelector.select() now rounds the timeout away from
+ zero, instead of rounding towards zero. For example, a timeout of one
+ microsecond is now rounded to one millisecond, instead of being rounded to
+ zero.
+
 - Issue #20311: select.epoll.poll() now rounds the timeout away from zero,
 instead of rounding towards zero. For example, a timeout of one microsecond
 is now rounded to one millisecond, instead of being rounded to zero.
-- 
Repository URL: http://hg.python.org/cpython
