[Python-checkins] cpython: asyncio: Locks improvements by Arnaud Faure: better repr(), change Conditio\
guido.van.rossum
python-checkins at python.org
Mon Nov 4 22:18:27 CET 2013
http://hg.python.org/cpython/rev/268259370a01
changeset: 86929:268259370a01
user: Guido van Rossum <guido at dropbox.com>
date: Mon Nov 04 13:18:19 2013 -0800
summary:
asyncio: Locks improvements by Arnaud Faure: better repr(), change Conditio\
n structure.
files:
Lib/asyncio/locks.py | 78 +++++++++++-----
Lib/test/test_asyncio/test_locks.py | 71 +++++++++++++++-
2 files changed, 124 insertions(+), 25 deletions(-)
diff --git a/Lib/asyncio/locks.py b/Lib/asyncio/locks.py
--- a/Lib/asyncio/locks.py
+++ b/Lib/asyncio/locks.py
@@ -155,9 +155,11 @@
self._loop = events.get_event_loop()
def __repr__(self):
- # TODO: add waiters:N if > 0.
res = super().__repr__()
- return '<{} [{}]>'.format(res[1:-1], 'set' if self._value else 'unset')
+ extra = 'set' if self._value else 'unset'
+ if self._waiters:
+ extra = '{},waiters:{}'.format(extra, len(self._waiters))
+ return '<{} [{}]>'.format(res[1:-1], extra)
def is_set(self):
"""Return true if and only if the internal flag is true."""
@@ -201,20 +203,38 @@
self._waiters.remove(fut)
-# TODO: Why is this a Lock subclass? threading.Condition *has* a lock.
-class Condition(Lock):
- """A Condition implementation.
+class Condition:
+ """A Condition implementation, our equivalent to threading.Condition.
This class implements condition variable objects. A condition variable
allows one or more coroutines to wait until they are notified by another
coroutine.
+
+ A new Lock object is created and used as the underlying lock.
"""
def __init__(self, *, loop=None):
- super().__init__(loop=loop)
- self._condition_waiters = collections.deque()
+ if loop is not None:
+ self._loop = loop
+ else:
+ self._loop = events.get_event_loop()
- # TODO: Add __repr__() with len(_condition_waiters).
+ # Lock as an attribute as in threading.Condition.
+ lock = Lock(loop=self._loop)
+ self._lock = lock
+ # Export the lock's locked(), acquire() and release() methods.
+ self.locked = lock.locked
+ self.acquire = lock.acquire
+ self.release = lock.release
+
+ self._waiters = collections.deque()
+
+ def __repr__(self):
+ res = super().__repr__()
+ extra = 'locked' if self.locked() else 'unlocked'
+ if self._waiters:
+ extra = '{},waiters:{}'.format(extra, len(self._waiters))
+ return '<{} [{}]>'.format(res[1:-1], extra)
@tasks.coroutine
def wait(self):
@@ -228,19 +248,19 @@
the same condition variable in another coroutine. Once
awakened, it re-acquires the lock and returns True.
"""
- if not self._locked:
+ if not self.locked():
raise RuntimeError('cannot wait on un-acquired lock')
keep_lock = True
self.release()
try:
fut = futures.Future(loop=self._loop)
- self._condition_waiters.append(fut)
+ self._waiters.append(fut)
try:
yield from fut
return True
finally:
- self._condition_waiters.remove(fut)
+ self._waiters.remove(fut)
except GeneratorExit:
keep_lock = False # Prevent yield in finally clause.
@@ -275,11 +295,11 @@
wait() call until it can reacquire the lock. Since notify() does
not release the lock, its caller should.
"""
- if not self._locked:
+ if not self.locked():
raise RuntimeError('cannot notify on un-acquired lock')
idx = 0
- for fut in self._condition_waiters:
+ for fut in self._waiters:
if idx >= n:
break
@@ -293,7 +313,17 @@
calling thread has not acquired the lock when this method is called,
a RuntimeError is raised.
"""
- self.notify(len(self._condition_waiters))
+ self.notify(len(self._waiters))
+
+ def __enter__(self):
+ return self._lock.__enter__()
+
+ def __exit__(self, *args):
+ return self._lock.__exit__(*args)
+
+ def __iter__(self):
+ yield from self.acquire()
+ return self
class Semaphore:
@@ -310,10 +340,10 @@
counter; it defaults to 1. If the value given is less than 0,
ValueError is raised.
- The second optional argument determins can semophore be released more than
- initial internal counter value; it defaults to False. If the value given
- is True and number of release() is more than number of successfull
- acquire() calls ValueError is raised.
+ The second optional argument determines if the semaphore can be released
+ more than initial internal counter value; it defaults to False. If the
+ value given is True and number of release() is more than number of
+ successful acquire() calls ValueError is raised.
"""
def __init__(self, value=1, bound=False, *, loop=None):
@@ -330,12 +360,12 @@
self._loop = events.get_event_loop()
def __repr__(self):
- # TODO: add waiters:N if > 0.
res = super().__repr__()
- return '<{} [{}]>'.format(
- res[1:-1],
- 'locked' if self._locked else 'unlocked,value:{}'.format(
- self._value))
+ extra = 'locked' if self._locked else 'unlocked,value:{}'.format(
+ self._value)
+ if self._waiters:
+ extra = '{},waiters:{}'.format(extra, len(self._waiters))
+ return '<{} [{}]>'.format(res[1:-1], extra)
def locked(self):
"""Returns True if semaphore can not be acquired immediately."""
@@ -373,7 +403,7 @@
When it was zero on entry and another coroutine is waiting for it to
become larger than zero again, wake up that coroutine.
- If Semaphore is create with "bound" paramter equals true, then
+ If Semaphore is created with "bound" parameter equals true, then
release() method checks to make sure its current value doesn't exceed
its initial value. If it does, ValueError is raised.
"""
diff --git a/Lib/test/test_asyncio/test_locks.py b/Lib/test/test_asyncio/test_locks.py
--- a/Lib/test/test_asyncio/test_locks.py
+++ b/Lib/test/test_asyncio/test_locks.py
@@ -2,6 +2,7 @@
import unittest
import unittest.mock
+import re
from asyncio import events
from asyncio import futures
@@ -10,6 +11,15 @@
from asyncio import test_utils
+STR_RGX_REPR = (
+ r'^<(?P<class>.*?) object at (?P<address>.*?)'
+ r'\[(?P<extras>'
+ r'(set|unset|locked|unlocked)(,value:\d)?(,waiters:\d+)?'
+ r')\]>\Z'
+)
+RGX_REPR = re.compile(STR_RGX_REPR)
+
+
class LockTests(unittest.TestCase):
def setUp(self):
@@ -38,6 +48,7 @@
def test_repr(self):
lock = locks.Lock(loop=self.loop)
self.assertTrue(repr(lock).endswith('[unlocked]>'))
+ self.assertTrue(RGX_REPR.match(repr(lock)))
@tasks.coroutine
def acquire_lock():
@@ -45,6 +56,7 @@
self.loop.run_until_complete(acquire_lock())
self.assertTrue(repr(lock).endswith('[locked]>'))
+ self.assertTrue(RGX_REPR.match(repr(lock)))
def test_lock(self):
lock = locks.Lock(loop=self.loop)
@@ -239,9 +251,16 @@
def test_repr(self):
ev = locks.Event(loop=self.loop)
self.assertTrue(repr(ev).endswith('[unset]>'))
+ match = RGX_REPR.match(repr(ev))
+ self.assertEqual(match.group('extras'), 'unset')
ev.set()
self.assertTrue(repr(ev).endswith('[set]>'))
+ self.assertTrue(RGX_REPR.match(repr(ev)))
+
+ ev._waiters.append(unittest.mock.Mock())
+ self.assertTrue('waiters:1' in repr(ev))
+ self.assertTrue(RGX_REPR.match(repr(ev)))
def test_wait(self):
ev = locks.Event(loop=self.loop)
@@ -440,7 +459,7 @@
self.assertRaises(
futures.CancelledError,
self.loop.run_until_complete, wait)
- self.assertFalse(cond._condition_waiters)
+ self.assertFalse(cond._waiters)
self.assertTrue(cond.locked())
def test_wait_unacquired(self):
@@ -600,6 +619,45 @@
cond = locks.Condition(loop=self.loop)
self.assertRaises(RuntimeError, cond.notify_all)
+ def test_repr(self):
+ cond = locks.Condition(loop=self.loop)
+ self.assertTrue('unlocked' in repr(cond))
+ self.assertTrue(RGX_REPR.match(repr(cond)))
+
+ self.loop.run_until_complete(cond.acquire())
+ self.assertTrue('locked' in repr(cond))
+
+ cond._waiters.append(unittest.mock.Mock())
+ self.assertTrue('waiters:1' in repr(cond))
+ self.assertTrue(RGX_REPR.match(repr(cond)))
+
+ cond._waiters.append(unittest.mock.Mock())
+ self.assertTrue('waiters:2' in repr(cond))
+ self.assertTrue(RGX_REPR.match(repr(cond)))
+
+ def test_context_manager(self):
+ cond = locks.Condition(loop=self.loop)
+
+ @tasks.coroutine
+ def acquire_cond():
+ return (yield from cond)
+
+ with self.loop.run_until_complete(acquire_cond()):
+ self.assertTrue(cond.locked())
+
+ self.assertFalse(cond.locked())
+
+ def test_context_manager_no_yield(self):
+ cond = locks.Condition(loop=self.loop)
+
+ try:
+ with cond:
+ self.fail('RuntimeError is not raised in with expression')
+ except RuntimeError as err:
+ self.assertEqual(
+ str(err),
+ '"yield from" should be used as context manager expression')
+
class SemaphoreTests(unittest.TestCase):
@@ -629,9 +687,20 @@
def test_repr(self):
sem = locks.Semaphore(loop=self.loop)
self.assertTrue(repr(sem).endswith('[unlocked,value:1]>'))
+ self.assertTrue(RGX_REPR.match(repr(sem)))
self.loop.run_until_complete(sem.acquire())
self.assertTrue(repr(sem).endswith('[locked]>'))
+ self.assertTrue('waiters' not in repr(sem))
+ self.assertTrue(RGX_REPR.match(repr(sem)))
+
+ sem._waiters.append(unittest.mock.Mock())
+ self.assertTrue('waiters:1' in repr(sem))
+ self.assertTrue(RGX_REPR.match(repr(sem)))
+
+ sem._waiters.append(unittest.mock.Mock())
+ self.assertTrue('waiters:2' in repr(sem))
+ self.assertTrue(RGX_REPR.match(repr(sem)))
def test_semaphore(self):
sem = locks.Semaphore(loop=self.loop)
--
Repository URL: http://hg.python.org/cpython
More information about the Python-checkins
mailing list