From 0a28c0d12ee7201de039ced4d815f57f1f8fd48c Mon Sep 17 00:00:00 2001 From: jhaydaman <33549221+jhaydaman@users.noreply.github.com> Date: Wed, 30 May 2018 02:15:06 -0500 Subject: bpo-33238: Add InvalidStateError to concurrent.futures. (GH-7056) Future.set_result and Future.set_exception now raise InvalidStateError if the futures are not pending or running. This mirrors the behavior of asyncio.Future, and prevents AssertionErrors in asyncio.wrap_future when set_result is called multiple times. --- Doc/library/concurrent.futures.rst | 16 +++++++++++++ Lib/asyncio/base_futures.py | 8 ++----- Lib/concurrent/futures/__init__.py | 1 + Lib/concurrent/futures/_base.py | 8 +++++++ Lib/test/test_concurrent_futures.py | 28 ++++++++++++++++++++++ .../2018-05-24-09-15-52.bpo-33238.ooDfoo.rst | 4 ++++ 6 files changed, 59 insertions(+), 6 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2018-05-24-09-15-52.bpo-33238.ooDfoo.rst diff --git a/Doc/library/concurrent.futures.rst b/Doc/library/concurrent.futures.rst index 707d24d..6934acc 100644 --- a/Doc/library/concurrent.futures.rst +++ b/Doc/library/concurrent.futures.rst @@ -380,6 +380,11 @@ The :class:`Future` class encapsulates the asynchronous execution of a callable. This method should only be used by :class:`Executor` implementations and unit tests. + .. versionchanged:: 3.8 + This method raises + :exc:`concurrent.futures.InvalidStateError` if the :class:`Future` is + already done. + .. method:: set_exception(exception) Sets the result of the work associated with the :class:`Future` to the @@ -388,6 +393,10 @@ The :class:`Future` class encapsulates the asynchronous execution of a callable. This method should only be used by :class:`Executor` implementations and unit tests. + .. versionchanged:: 3.8 + This method raises + :exc:`concurrent.futures.InvalidStateError` if the :class:`Future` is + already done. Module Functions ---------------- @@ -466,6 +475,13 @@ Exception classes .. versionadded:: 3.7 +.. exception:: InvalidStateError + + Raised when an operation is performed on a future that is not allowed + in the current state. + + .. versionadded:: 3.8 + .. currentmodule:: concurrent.futures.thread .. exception:: BrokenThreadPool diff --git a/Lib/asyncio/base_futures.py b/Lib/asyncio/base_futures.py index 5182884..bd65bee 100644 --- a/Lib/asyncio/base_futures.py +++ b/Lib/asyncio/base_futures.py @@ -1,17 +1,13 @@ __all__ = () -import concurrent.futures._base +import concurrent.futures import reprlib from . import format_helpers -Error = concurrent.futures._base.Error CancelledError = concurrent.futures.CancelledError TimeoutError = concurrent.futures.TimeoutError - - -class InvalidStateError(Error): - """The operation is not allowed in this state.""" +InvalidStateError = concurrent.futures.InvalidStateError # States for Future. diff --git a/Lib/concurrent/futures/__init__.py b/Lib/concurrent/futures/__init__.py index 8434fcf..d746aea 100644 --- a/Lib/concurrent/futures/__init__.py +++ b/Lib/concurrent/futures/__init__.py @@ -10,6 +10,7 @@ from concurrent.futures._base import (FIRST_COMPLETED, ALL_COMPLETED, CancelledError, TimeoutError, + InvalidStateError, BrokenExecutor, Future, Executor, diff --git a/Lib/concurrent/futures/_base.py b/Lib/concurrent/futures/_base.py index 4f22f7e..d4416c6 100644 --- a/Lib/concurrent/futures/_base.py +++ b/Lib/concurrent/futures/_base.py @@ -53,6 +53,10 @@ class TimeoutError(Error): """The operation exceeded the given deadline.""" pass +class InvalidStateError(Error): + """The operation is not allowed in this state.""" + pass + class _Waiter(object): """Provides the event that wait() and as_completed() block on.""" def __init__(self): @@ -513,6 +517,8 @@ class Future(object): Should only be used by Executor implementations and unit tests. """ with self._condition: + if self._state in {CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED}: + raise InvalidStateError('{}: {!r}'.format(self._state, self)) self._result = result self._state = FINISHED for waiter in self._waiters: @@ -526,6 +532,8 @@ class Future(object): Should only be used by Executor implementations and unit tests. """ with self._condition: + if self._state in {CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED}: + raise InvalidStateError('{}: {!r}'.format(self._state, self)) self._exception = exception self._state = FINISHED for waiter in self._waiters: diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py index b258a0e..f2c28ac 100644 --- a/Lib/test/test_concurrent_futures.py +++ b/Lib/test/test_concurrent_futures.py @@ -1206,6 +1206,34 @@ class FutureTests(BaseTestCase): self.assertTrue(isinstance(f1.exception(timeout=5), OSError)) t.join() + def test_multiple_set_result(self): + f = create_future(state=PENDING) + f.set_result(1) + + with self.assertRaisesRegex( + futures.InvalidStateError, + 'FINISHED: ' + ): + f.set_result(2) + + self.assertTrue(f.done()) + self.assertEqual(f.result(), 1) + + def test_multiple_set_exception(self): + f = create_future(state=PENDING) + e = ValueError() + f.set_exception(e) + + with self.assertRaisesRegex( + futures.InvalidStateError, + 'FINISHED: ' + ): + f.set_exception(Exception()) + + self.assertEqual(f.exception(), e) + @test.support.reap_threads def test_main(): diff --git a/Misc/NEWS.d/next/Library/2018-05-24-09-15-52.bpo-33238.ooDfoo.rst b/Misc/NEWS.d/next/Library/2018-05-24-09-15-52.bpo-33238.ooDfoo.rst new file mode 100644 index 0000000..b03ab10 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2018-05-24-09-15-52.bpo-33238.ooDfoo.rst @@ -0,0 +1,4 @@ +Add ``InvalidStateError`` to :mod:`concurrent.futures`. +``Future.set_result`` and ``Future.set_exception`` now raise +``InvalidStateError`` if the futures are not pending or running. Patch by +Jason Haydaman. -- cgit v0.12