bpo-36373: Deprecate explicit loop parameter in all public asyncio APIs [locks] (GH-13920)

This PR deprecate explicit loop parameters in all public asyncio APIs

This issues is split to be easier to review.

Third step: locks.py





https://bugs.python.org/issue36373

Doc/library/asyncio-sync.rst

@@ -59,6 +59,9 @@ Lock
        finally:
            lock.release()
 
+   .. deprecated-removed:: 3.8 3.10
+      The *loop* parameter.
+
    .. coroutinemethod:: acquire()
 
       Acquire the lock.
@@ -101,6 +104,10 @@ Event
    :meth:`clear` method.  The :meth:`wait` method blocks until the
    flag is set to *true*.  The flag is set to *false* initially.
 
+
+   .. deprecated-removed:: 3.8 3.10
+      The *loop* parameter.
+
    .. _asyncio_example_sync_event:
 
    Example::
@@ -173,6 +180,10 @@ Condition
    ``None``.  In the latter case a new Lock object is created
    automatically.
 
+
+   .. deprecated-removed:: 3.8 3.10
+      The *loop* parameter.
+
    The preferred way to use a Condition is an :keyword:`async with`
    statement::
 
@@ -269,6 +280,10 @@ Semaphore
    internal counter (``1`` by default). If the given value is
    less than ``0`` a :exc:`ValueError` is raised.
 
+
+   .. deprecated-removed:: 3.8 3.10
+      The *loop* parameter.
+
    The preferred way to use a Semaphore is an :keyword:`async with`
    statement::
 
@@ -322,6 +337,9 @@ BoundedSemaphore
    increases the internal counter above the initial *value*.
 
 
+   .. deprecated-removed:: 3.8 3.10
+      The *loop* parameter.
+
 ---------
 
 

Lib/asyncio/locks.py

@@ -160,10 +160,13 @@ class Lock(_ContextManagerMixin):
     def __init__(self, *, loop=None):
         self._waiters = None
         self._locked = False
-        if loop is not None:
-            self._loop = loop
-        else:
+        if loop is None:
             self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
+            warnings.warn("The loop argument is deprecated since Python 3.8, "
+                          "and scheduled for removal in Python 3.10.",
+                          DeprecationWarning, stacklevel=2)
 
     def __repr__(self):
         res = super().__repr__()
@@ -253,10 +256,13 @@ class Event:
     def __init__(self, *, loop=None):
         self._waiters = collections.deque()
         self._value = False
-        if loop is not None:
-            self._loop = loop
-        else:
+        if loop is None:
             self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
+            warnings.warn("The loop argument is deprecated since Python 3.8, "
+                          "and scheduled for removal in Python 3.10.",
+                          DeprecationWarning, stacklevel=2)
 
     def __repr__(self):
         res = super().__repr__()
@@ -317,10 +323,13 @@ class Condition(_ContextManagerMixin):
     """
 
     def __init__(self, lock=None, *, loop=None):
-        if loop is not None:
-            self._loop = loop
-        else:
+        if loop is None:
             self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
+            warnings.warn("The loop argument is deprecated since Python 3.8, "
+                          "and scheduled for removal in Python 3.10.",
+                          DeprecationWarning, stacklevel=2)
 
         if lock is None:
             lock = Lock(loop=self._loop)
@@ -445,10 +454,13 @@ class Semaphore(_ContextManagerMixin):
             raise ValueError("Semaphore initial value must be >= 0")
         self._value = value
         self._waiters = collections.deque()
-        if loop is not None:
-            self._loop = loop
-        else:
+        if loop is None:
             self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
+            warnings.warn("The loop argument is deprecated since Python 3.8, "
+                          "and scheduled for removal in Python 3.10.",
+                          DeprecationWarning, stacklevel=2)
 
     def __repr__(self):
         res = super().__repr__()
@@ -508,6 +520,11 @@ class BoundedSemaphore(Semaphore):
     """
 
     def __init__(self, value=1, *, loop=None):
+        if loop:
+            warnings.warn("The loop argument is deprecated since Python 3.8, "
+                          "and scheduled for removal in Python 3.10.",
+                          DeprecationWarning, stacklevel=2)
+
         self._bound_value = value
         super().__init__(value, loop=loop)
 

Lib/test/test_asyncio/test_pep492.py

@@ -43,12 +43,13 @@ class BaseTest(test_utils.TestCase):
 class LockTests(BaseTest):
 
     def test_context_manager_async_with(self):
-        primitives = [
-            asyncio.Lock(loop=self.loop),
-            asyncio.Condition(loop=self.loop),
-            asyncio.Semaphore(loop=self.loop),
-            asyncio.BoundedSemaphore(loop=self.loop),
-        ]
+        with self.assertWarns(DeprecationWarning):
+            primitives = [
+                asyncio.Lock(loop=self.loop),
+                asyncio.Condition(loop=self.loop),
+                asyncio.Semaphore(loop=self.loop),
+                asyncio.BoundedSemaphore(loop=self.loop),
+            ]
 
         async def test(lock):
             await asyncio.sleep(0.01)
@@ -65,12 +66,13 @@ class LockTests(BaseTest):
             self.assertFalse(primitive.locked())
 
     def test_context_manager_with_await(self):
-        primitives = [
-            asyncio.Lock(loop=self.loop),
-            asyncio.Condition(loop=self.loop),
-            asyncio.Semaphore(loop=self.loop),
-            asyncio.BoundedSemaphore(loop=self.loop),
-        ]
+        with self.assertWarns(DeprecationWarning):
+            primitives = [
+                asyncio.Lock(loop=self.loop),
+                asyncio.Condition(loop=self.loop),
+                asyncio.Semaphore(loop=self.loop),
+                asyncio.BoundedSemaphore(loop=self.loop),
+            ]
 
         async def test(lock):
             await asyncio.sleep(0.01)

Lib/test/test_asyncio/test_tasks.py

@@ -1231,15 +1231,16 @@ class BaseTaskTests:
             for f in asyncio.as_completed([b, c, a], loop=loop):
                 values.append(await f)
             return values
-
-        res = loop.run_until_complete(self.new_task(loop, foo()))
+        with self.assertWarns(DeprecationWarning):
+            res = loop.run_until_complete(self.new_task(loop, foo()))
         self.assertAlmostEqual(0.15, loop.time())
         self.assertTrue('a' in res[:2])
         self.assertTrue('b' in res[:2])
         self.assertEqual(res[2], 'c')
 
         # Doing it again should take no time and exercise a different path.
-        res = loop.run_until_complete(self.new_task(loop, foo()))
+        with self.assertWarns(DeprecationWarning):
+            res = loop.run_until_complete(self.new_task(loop, foo()))
         self.assertAlmostEqual(0.15, loop.time())
 
     def test_as_completed_with_timeout(self):
@@ -1267,7 +1268,8 @@ class BaseTaskTests:
                     values.append((2, exc))
             return values
 
-        res = loop.run_until_complete(self.new_task(loop, foo()))
+        with self.assertWarns(DeprecationWarning):
+            res = loop.run_until_complete(self.new_task(loop, foo()))
         self.assertEqual(len(res), 2, res)
         self.assertEqual(res[0], (1, 'a'))
         self.assertEqual(res[1][0], 2)
@@ -1294,7 +1296,8 @@ class BaseTaskTests:
                 v = await f
                 self.assertEqual(v, 'a')
 
-        loop.run_until_complete(self.new_task(loop, foo()))
+        with self.assertWarns(DeprecationWarning):
+            loop.run_until_complete(self.new_task(loop, foo()))
 
     def test_as_completed_reverse_wait(self):
 
@@ -1308,7 +1311,9 @@ class BaseTaskTests:
         a = asyncio.sleep(0.05, 'a')
         b = asyncio.sleep(0.10, 'b')
         fs = {a, b}
-        futs = list(asyncio.as_completed(fs, loop=loop))
+
+        with self.assertWarns(DeprecationWarning):
+            futs = list(asyncio.as_completed(fs, loop=loop))
         self.assertEqual(len(futs), 2)
 
         x = loop.run_until_complete(futs[1])
@@ -1333,7 +1338,8 @@ class BaseTaskTests:
         a = asyncio.sleep(0.05, 'a')
         b = asyncio.sleep(0.05, 'b')
         fs = {a, b}
-        futs = list(asyncio.as_completed(fs, loop=loop))
+        with self.assertWarns(DeprecationWarning):
+            futs = list(asyncio.as_completed(fs, loop=loop))
         self.assertEqual(len(futs), 2)
         waiter = asyncio.wait(futs)
         done, pending = loop.run_until_complete(waiter)
@@ -1356,8 +1362,9 @@ class BaseTaskTests:
                     result.append((yield from f))
                 return result
 
-        fut = self.new_task(self.loop, runner())
-        self.loop.run_until_complete(fut)
+        with self.assertWarns(DeprecationWarning):
+            fut = self.new_task(self.loop, runner())
+            self.loop.run_until_complete(fut)
         result = fut.result()
         self.assertEqual(set(result), {'ham', 'spam'})
         self.assertEqual(len(result), 2)