bpo-42392: Improve removal of *loop* parameter in asyncio primitives (GH-23499)
* Update code after merge review from 1st1
* Use a sentinel approach for loop parameter
Remove unnecessary _get_running_loop patching
* Use more clear function name (_verify_parameter_is_marker -> _verify_no_loop)
* Add init method to _LoopBoundMixin to check that loop param wasn't used
diff --git a/Lib/asyncio/locks.py b/Lib/asyncio/locks.py
index 6f322c2..a7453fb 100644
--- a/Lib/asyncio/locks.py
+++ b/Lib/asyncio/locks.py
@@ -19,7 +19,7 @@ async def __aexit__(self, exc_type, exc, tb):
self.release()
-class Lock(_ContextManagerMixin, mixins._LoopBoundedMixin):
+class Lock(_ContextManagerMixin, mixins._LoopBoundMixin):
"""Primitive lock objects.
A primitive lock is a synchronization primitive that is not owned
@@ -73,7 +73,8 @@ class Lock(_ContextManagerMixin, mixins._LoopBoundedMixin):
"""
- def __init__(self):
+ def __init__(self, *, loop=mixins._marker):
+ super().__init__(loop=loop)
self._waiters = None
self._locked = False
@@ -153,7 +154,7 @@ def _wake_up_first(self):
fut.set_result(True)
-class Event(mixins._LoopBoundedMixin):
+class Event(mixins._LoopBoundMixin):
"""Asynchronous equivalent to threading.Event.
Class implementing event objects. An event manages a flag that can be set
@@ -162,7 +163,8 @@ class Event(mixins._LoopBoundedMixin):
false.
"""
- def __init__(self):
+ def __init__(self, *, loop=mixins._marker):
+ super().__init__(loop=loop)
self._waiters = collections.deque()
self._value = False
@@ -214,7 +216,7 @@ async def wait(self):
self._waiters.remove(fut)
-class Condition(_ContextManagerMixin, mixins._LoopBoundedMixin):
+class Condition(_ContextManagerMixin, mixins._LoopBoundMixin):
"""Asynchronous equivalent to threading.Condition.
This class implements condition variable objects. A condition variable
@@ -224,7 +226,8 @@ class Condition(_ContextManagerMixin, mixins._LoopBoundedMixin):
A new Lock object is created and used as the underlying lock.
"""
- def __init__(self, lock=None):
+ def __init__(self, lock=None, *, loop=mixins._marker):
+ super().__init__(loop=loop)
if lock is None:
lock = Lock()
elif lock._loop is not self._get_loop():
@@ -328,7 +331,7 @@ def notify_all(self):
self.notify(len(self._waiters))
-class Semaphore(_ContextManagerMixin, mixins._LoopBoundedMixin):
+class Semaphore(_ContextManagerMixin, mixins._LoopBoundMixin):
"""A Semaphore implementation.
A semaphore manages an internal counter which is decremented by each
@@ -343,7 +346,8 @@ class Semaphore(_ContextManagerMixin, mixins._LoopBoundedMixin):
ValueError is raised.
"""
- def __init__(self, value=1):
+ def __init__(self, value=1, *, loop=mixins._marker):
+ super().__init__(loop=loop)
if value < 0:
raise ValueError("Semaphore initial value must be >= 0")
self._value = value
@@ -406,9 +410,9 @@ class BoundedSemaphore(Semaphore):
above the initial value.
"""
- def __init__(self, value=1):
+ def __init__(self, value=1, *, loop=mixins._marker):
self._bound_value = value
- super().__init__(value)
+ super().__init__(value, loop=loop)
def release(self):
if self._value >= self._bound_value:
diff --git a/Lib/asyncio/mixins.py b/Lib/asyncio/mixins.py
index dbc4b5f..650df05 100644
--- a/Lib/asyncio/mixins.py
+++ b/Lib/asyncio/mixins.py
@@ -5,10 +5,20 @@
_global_lock = threading.Lock()
+# Used as a sentinel for loop parameter
+_marker = object()
-class _LoopBoundedMixin:
+
+class _LoopBoundMixin:
_loop = None
+ def __init__(self, *, loop=_marker):
+ if loop is not _marker:
+ raise TypeError(
+ f'As of 3.10, the *loop* parameter was removed from '
+ f'{type(self).__name__}() since it is no longer necessary'
+ )
+
def _get_loop(self):
loop = events._get_running_loop()
@@ -17,5 +27,5 @@ def _get_loop(self):
if self._loop is None:
self._loop = loop
if loop is not self._loop:
- raise RuntimeError(f'{type(self).__name__} have already bounded to another loop')
+ raise RuntimeError(f'{self!r} is bound to a different event loop')
return loop
diff --git a/Lib/asyncio/queues.py b/Lib/asyncio/queues.py
index 78ae9e9..a87ec8b 100644
--- a/Lib/asyncio/queues.py
+++ b/Lib/asyncio/queues.py
@@ -17,7 +17,7 @@ class QueueFull(Exception):
pass
-class Queue(mixins._LoopBoundedMixin):
+class Queue(mixins._LoopBoundMixin):
"""A queue, useful for coordinating producer and consumer coroutines.
If maxsize is less than or equal to zero, the queue size is infinite. If it
@@ -29,7 +29,8 @@ class Queue(mixins._LoopBoundedMixin):
interrupted between calling qsize() and doing an operation on the Queue.
"""
- def __init__(self, maxsize=0):
+ def __init__(self, maxsize=0, *, loop=mixins._marker):
+ super().__init__(loop=loop)
self._maxsize = maxsize
# Futures.