From 429d8a196e1ad7317b195b07f0f6a06027d4476f Mon Sep 17 00:00:00 2001 From: Ian Cordasco Date: Fri, 29 Jul 2016 06:49:00 -0500 Subject: [PATCH] Diable multiprocessing behaviour on Windows Due to https://bugs.python.org/issue27649, we cannot continue to expect multiprocessing to work as we expect and document it on Windows. As such, we are going to revert back to our previous behaviour of disabling it across all versions of Python on Windows to provide the default expected behaviour of Flake8 on that Operating System. --- docs/source/release-notes/3.0.3.rst | 6 ++++++ src/flake8/checker.py | 3 ++- src/flake8/utils.py | 12 +++++++++++- tests/unit/test_checker_manager.py | 3 ++- 4 files changed, 21 insertions(+), 3 deletions(-) diff --git a/docs/source/release-notes/3.0.3.rst b/docs/source/release-notes/3.0.3.rst index ded24c7..0361879 100644 --- a/docs/source/release-notes/3.0.3.rst +++ b/docs/source/release-notes/3.0.3.rst @@ -1,6 +1,9 @@ 3.0.3 -- 2016-07-28 (unreleased) -------------------------------- +- Disable ``--jobs`` for any version of Python on Windows. + (See also `this Python bug report`_) + - Fix ``# noqa`` comments followed by a ``:`` and explanation broken by 3.0.0 (See also `GitLab#178`_) @@ -12,3 +15,6 @@ https://gitlab.com/pycqa/flake8/issues/178 .. _GitLab#195: https://gitlab.com/pycqa/flake8/issues/195 + +.. _this Python bug report: + https://bugs.python.org/issue27649 diff --git a/src/flake8/checker.py b/src/flake8/checker.py index d331b0c..57fd896 100644 --- a/src/flake8/checker.py +++ b/src/flake8/checker.py @@ -167,7 +167,8 @@ class Manager(object): if (utils.is_windows() and not utils.can_run_multiprocessing_on_windows()): - LOG.warning('The --jobs option is only available on Windows on ' + LOG.warning('The --jobs option is not available on Windows due to' + ' a bug (https://bugs.python.org/issue27649) in ' 'Python 2.7.11+ and 3.3+. We have detected that you ' 'are running an unsupported version of Python on ' 'Windows. Ignoring --jobs arguments.') diff --git a/src/flake8/utils.py b/src/flake8/utils.py index 1e18316..55c699e 100644 --- a/src/flake8/utils.py +++ b/src/flake8/utils.py @@ -164,10 +164,20 @@ def is_windows(): return os.name == 'nt' +# NOTE(sigmavirus24): If and when https://bugs.python.org/issue27649 is fixed, +# re-enable multiprocessing support on Windows. def can_run_multiprocessing_on_windows(): # type: () -> bool """Determine if we can use multiprocessing on Windows. + This presently will **always** return False due to a `bug`_ in the + :mod:`multiprocessing` module on Windows. Once fixed, we will check + to ensure that the version of Python contains that fix (via version + inspection) and *conditionally* re-enable support on Windows. + + .. _bug: + https://bugs.python.org/issue27649 + :returns: True if the version of Python is modern enough, otherwise False :rtype: @@ -175,7 +185,7 @@ def can_run_multiprocessing_on_windows(): """ is_new_enough_python27 = (2, 7, 11) <= sys.version_info < (3, 0) is_new_enough_python3 = sys.version_info > (3, 2) - return is_new_enough_python27 or is_new_enough_python3 + return False and (is_new_enough_python27 or is_new_enough_python3) def is_using_stdin(paths): diff --git a/tests/unit/test_checker_manager.py b/tests/unit/test_checker_manager.py index 8240723..7e9c5b1 100644 --- a/tests/unit/test_checker_manager.py +++ b/tests/unit/test_checker_manager.py @@ -25,7 +25,8 @@ def test_oserrors_cause_serial_fall_back(): assert manager.using_multiprocessing is False -def test_oserrors_are_reraised(): +@mock.patch('flake8.utils.is_windows', return_value=False) +def test_oserrors_are_reraised(is_windows): """Verify that OSErrors will cause the Manager to fallback to serial.""" err = OSError(errno.EAGAIN, 'Ominous message') style_guide = style_guide_mock()