[Python-checkins] cpython: Issue #15064: Implement context manager protocol for multiprocessing types
richard.oudkerk
python-checkins at python.org
Mon Jun 18 18:55:38 CEST 2012
http://hg.python.org/cpython/rev/6d2a773d8e00
changeset: 77509:6d2a773d8e00
user: Richard Oudkerk <shibturn at gmail.com>
date: Mon Jun 18 17:47:52 2012 +0100
summary:
Issue #15064: Implement context manager protocol for multiprocessing types
files:
Doc/library/multiprocessing.rst | 17 ++++++
Lib/multiprocessing/connection.py | 18 ++++++-
Lib/multiprocessing/dummy/connection.py | 12 ++++
Lib/multiprocessing/pool.py | 6 ++
Lib/test/test_multiprocessing.py | 35 +++++++++++++
Misc/NEWS | 2 +
6 files changed, 89 insertions(+), 1 deletions(-)
diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -834,6 +834,10 @@
Connection objects themselves can now be transferred between processes
using :meth:`Connection.send` and :meth:`Connection.recv`.
+ .. versionadded:: 3.3
+ Connection objects now support the context manager protocol -- see
+ :ref:`typecontextmanager`. :meth:`__enter__` returns the
+ connection object, and :meth:`__exit__` calls :meth:`close`.
For example:
@@ -1277,6 +1281,9 @@
The address used by the manager.
+ Manager objects support the context manager protocol -- see
+ :ref:`typecontextmanager`. :meth:`__enter__` returns the
+ manager object, and :meth:`__exit__` calls :meth:`shutdown`.
.. class:: SyncManager
@@ -1747,6 +1754,11 @@
Wait for the worker processes to exit. One must call :meth:`close` or
:meth:`terminate` before using :meth:`join`.
+ .. versionadded:: 3.3
+ Pool objects now support the context manager protocol -- see
+ :ref:`typecontextmanager`. :meth:`__enter__` returns the pool
+ object, and :meth:`__exit__` calls :meth:`terminate`.
+
.. class:: AsyncResult
@@ -1911,6 +1923,11 @@
The address from which the last accepted connection came. If this is
unavailable then it is ``None``.
+ .. versionadded:: 3.3
+ Listener objects now support the context manager protocol -- see
+ :ref:`typecontextmanager`. :meth:`__enter__` returns the
+ listener object, and :meth:`__exit__` calls :meth:`close`.
+
.. function:: wait(object_list, timeout=None)
Wait till an object in *object_list* is ready. Returns the list of
diff --git a/Lib/multiprocessing/connection.py b/Lib/multiprocessing/connection.py
--- a/Lib/multiprocessing/connection.py
+++ b/Lib/multiprocessing/connection.py
@@ -257,6 +257,12 @@
self._check_readable()
return self._poll(timeout)
+ def __enter__(self):
+ return self
+
+ def __exit__(self, exc_type, exc_value, exc_tb):
+ self.close()
+
if _winapi:
@@ -436,6 +442,8 @@
Returns a `Connection` object.
'''
+ if self._listener is None:
+ raise IOError('listener is closed')
c = self._listener.accept()
if self._authkey:
deliver_challenge(c, self._authkey)
@@ -446,11 +454,19 @@
'''
Close the bound socket or named pipe of `self`.
'''
- return self._listener.close()
+ if self._listener is not None:
+ self._listener.close()
+ self._listener = None
address = property(lambda self: self._listener._address)
last_accepted = property(lambda self: self._listener._last_accepted)
+ def __enter__(self):
+ return self
+
+ def __exit__(self, exc_type, exc_value, exc_tb):
+ self.close()
+
def Client(address, family=None, authkey=None):
'''
diff --git a/Lib/multiprocessing/dummy/connection.py b/Lib/multiprocessing/dummy/connection.py
--- a/Lib/multiprocessing/dummy/connection.py
+++ b/Lib/multiprocessing/dummy/connection.py
@@ -53,6 +53,12 @@
address = property(lambda self: self._backlog_queue)
+ def __enter__(self):
+ return self
+
+ def __exit__(self, exc_type, exc_value, exc_tb):
+ self.close()
+
def Client(address):
_in, _out = Queue(), Queue()
@@ -85,3 +91,9 @@
def close(self):
pass
+
+ def __enter__(self):
+ return self
+
+ def __exit__(self, exc_type, exc_value, exc_tb):
+ self.close()
diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py
--- a/Lib/multiprocessing/pool.py
+++ b/Lib/multiprocessing/pool.py
@@ -522,6 +522,12 @@
debug('cleaning up worker %d' % p.pid)
p.join()
+ def __enter__(self):
+ return self
+
+ def __exit__(self, exc_type, exc_val, exc_tb):
+ self.terminate()
+
#
# Class whose instances are returned by `Pool.apply_async()`
#
diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -1719,6 +1719,15 @@
p.close()
p.join()
+ def test_context(self):
+ if self.TYPE == 'processes':
+ L = list(range(10))
+ expected = [sqr(i) for i in L]
+ with multiprocessing.Pool(2) as p:
+ r = p.map_async(sqr, L)
+ self.assertEqual(r.get(), expected)
+ self.assertRaises(AssertionError, p.map_async, sqr, L)
+
def raising():
raise KeyError("key")
@@ -2266,6 +2275,22 @@
self.assertRaises(RuntimeError, reduction.recv_handle, conn)
p.join()
+ def test_context(self):
+ a, b = self.Pipe()
+
+ with a, b:
+ a.send(1729)
+ self.assertEqual(b.recv(), 1729)
+ if self.TYPE == 'processes':
+ self.assertFalse(a.closed)
+ self.assertFalse(b.closed)
+
+ if self.TYPE == 'processes':
+ self.assertTrue(a.closed)
+ self.assertTrue(b.closed)
+ self.assertRaises(IOError, a.recv)
+ self.assertRaises(IOError, b.recv)
+
class _TestListener(BaseTestCase):
ALLOWED_TYPES = ('processes',)
@@ -2277,6 +2302,16 @@
self.assertRaises(OSError, self.connection.Listener,
l.address, family)
+ def test_context(self):
+ with self.connection.Listener() as l:
+ with self.connection.Client(l.address) as c:
+ with l.accept() as d:
+ c.send(1729)
+ self.assertEqual(d.recv(), 1729)
+
+ if self.TYPE == 'processes':
+ self.assertRaises(IOError, l.accept)
+
class _TestListenerClient(BaseTestCase):
ALLOWED_TYPES = ('processes', 'threads')
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -29,6 +29,8 @@
Library
-------
+- Issue #15064: Implement context manager protocol for multiprocessing types
+
- Issue #15101: Make pool finalizer avoid joining current thread.
- Issue #14657: The frozen instance of importlib used for bootstrap is now
--
Repository URL: http://hg.python.org/cpython
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