[Python-checkins] cpython: Fix issue #20367: concurrent.futures.as_completed() for duplicate arguments.
guido.van.rossum
python-checkins at python.org
Sun Jan 26 18:59:20 CET 2014
http://hg.python.org/cpython/rev/58b0f3e1ddf8
changeset: 88731:58b0f3e1ddf8
user: Guido van Rossum <guido at python.org>
date: Sun Jan 26 09:57:51 2014 -0800
summary:
Fix issue #20367: concurrent.futures.as_completed() for duplicate arguments.
Patch by Glenn Langford.
files:
Doc/library/concurrent.futures.rst | 3 ++-
Lib/concurrent/futures/_base.py | 6 ++++--
Lib/test/test_concurrent_futures.py | 7 +++++++
Misc/NEWS | 3 +++
4 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/Doc/library/concurrent.futures.rst b/Doc/library/concurrent.futures.rst
--- a/Doc/library/concurrent.futures.rst
+++ b/Doc/library/concurrent.futures.rst
@@ -371,7 +371,8 @@
Returns an iterator over the :class:`Future` instances (possibly created by
different :class:`Executor` instances) given by *fs* that yields futures as
- they complete (finished or were cancelled). Any futures that completed
+ they complete (finished or were cancelled). Any futures given by *fs* that
+ are duplicated will be returned once. Any futures that completed
before :func:`as_completed` is called will be yielded first. The returned
iterator raises a :exc:`TimeoutError` if :meth:`~iterator.__next__` is
called and the result isn't available after *timeout* seconds from the
diff --git a/Lib/concurrent/futures/_base.py b/Lib/concurrent/futures/_base.py
--- a/Lib/concurrent/futures/_base.py
+++ b/Lib/concurrent/futures/_base.py
@@ -181,7 +181,8 @@
Returns:
An iterator that yields the given Futures as they complete (finished or
- cancelled).
+ cancelled). If any given Futures are duplicated, they will be returned
+ once.
Raises:
TimeoutError: If the entire result iterator could not be generated
@@ -190,11 +191,12 @@
if timeout is not None:
end_time = timeout + time.time()
+ fs = set(fs)
with _AcquireFutures(fs):
finished = set(
f for f in fs
if f._state in [CANCELLED_AND_NOTIFIED, FINISHED])
- pending = set(fs) - finished
+ pending = fs - finished
waiter = _create_and_install_waiters(fs, _AS_COMPLETED)
try:
diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py
--- a/Lib/test/test_concurrent_futures.py
+++ b/Lib/test/test_concurrent_futures.py
@@ -350,6 +350,13 @@
SUCCESSFUL_FUTURE]),
completed_futures)
+ def test_duplicate_futures(self):
+ # Issue 20367. Duplicate futures should not raise exceptions or give
+ # duplicate responses.
+ future1 = self.executor.submit(time.sleep, 2)
+ completed = [f for f in futures.as_completed([future1,future1])]
+ self.assertEqual(len(completed), 1)
+
class ThreadPoolAsCompletedTests(ThreadPoolMixin, AsCompletedTests, unittest.TestCase):
pass
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -36,6 +36,9 @@
Library
-------
+- Issue #20367: Fix behavior of concurrent.futures.as_completed() for
+ duplicate arguments. Patch by Glenn Langford.
+
- Issue #8260: The read(), readline() and readlines() methods of
codecs.StreamReader returned incomplete data when were called after
readline() or read(size). Based on patch by Amaury Forgeot d'Arc.
--
Repository URL: http://hg.python.org/cpython
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