gh-126353: remove implicit creation of loop from `asyncio.get_event_loop` (#126354)

Remove implicit creation of loop from `asyncio.get_event_loop`. This is a step forward of deprecating the policy system of asyncio.

2 files changed, 11 insertions, 29 deletions

diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py
index 4dcf9f0..2ab638d 100644
--- a/Lib/test/test_asyncio/test_events.py
+++ b/Lib/test/test_asyncio/test_events.py
@@ -2704,33 +2704,22 @@ class PolicyTests(unittest.TestCase):
     def test_get_event_loop(self):
         policy = asyncio.DefaultEventLoopPolicy()
         self.assertIsNone(policy._local._loop)
-        with self.assertWarns(DeprecationWarning) as cm:
-            loop = policy.get_event_loop()
-        self.assertEqual(cm.filename, __file__)
-        self.assertIsInstance(loop, asyncio.AbstractEventLoop)
 
-        self.assertIs(policy._local._loop, loop)
-        self.assertIs(loop, policy.get_event_loop())
-        loop.close()
+        with self.assertRaises(RuntimeError):
+            loop = policy.get_event_loop()
+        self.assertIsNone(policy._local._loop)
 
-    def test_get_event_loop_calls_set_event_loop(self):
+    def test_get_event_loop_does_not_call_set_event_loop(self):
         policy = asyncio.DefaultEventLoopPolicy()
 
         with mock.patch.object(
                 policy, "set_event_loop",
                 wraps=policy.set_event_loop) as m_set_event_loop:
 
-            with self.assertWarns(DeprecationWarning) as cm:
+            with self.assertRaises(RuntimeError):
                 loop = policy.get_event_loop()
-            self.addCleanup(loop.close)
-            self.assertEqual(cm.filename, __file__)
 
-            # policy._local._loop must be set through .set_event_loop()
-            # (the unix DefaultEventLoopPolicy needs this call to attach
-            # the child watcher correctly)
-            m_set_event_loop.assert_called_with(loop)
-
-        loop.close()
+            m_set_event_loop.assert_not_called()
 
     def test_get_event_loop_after_set_none(self):
         policy = asyncio.DefaultEventLoopPolicy()
@@ -2912,17 +2901,12 @@ class GetEventLoopTestsMixin:
             loop = asyncio.new_event_loop()
             self.addCleanup(loop.close)
 
-            with self.assertWarns(DeprecationWarning) as cm:
-                loop2 = asyncio.get_event_loop()
-            self.addCleanup(loop2.close)
-            self.assertEqual(cm.filename, __file__)
-            asyncio.set_event_loop(None)
             with self.assertRaisesRegex(RuntimeError, 'no current'):
                 asyncio.get_event_loop()
 
-            with self.assertRaisesRegex(RuntimeError, 'no running'):
-                asyncio.get_running_loop()
-            self.assertIs(asyncio._get_running_loop(), None)
+            asyncio.set_event_loop(None)
+            with self.assertRaisesRegex(RuntimeError, 'no current'):
+                asyncio.get_event_loop()
 
             async def func():
                 self.assertIs(asyncio.get_event_loop(), loop)
diff --git a/Lib/test/test_asyncio/test_unix_events.py b/Lib/test/test_asyncio/test_unix_events.py
index 9ae54b6..021f454 100644
--- a/Lib/test/test_asyncio/test_unix_events.py
+++ b/Lib/test/test_asyncio/test_unix_events.py
@@ -1195,8 +1195,7 @@ class TestFork(unittest.IsolatedAsyncioTestCase):
         if pid == 0:
             # child
             try:
-                with self.assertWarns(DeprecationWarning):
-                    loop = asyncio.get_event_loop_policy().get_event_loop()
+                loop = asyncio.get_event_loop()
                 os.write(w, b'LOOP:' + str(id(loop)).encode())
             except RuntimeError:
                 os.write(w, b'NO LOOP')
@@ -1207,8 +1206,7 @@ class TestFork(unittest.IsolatedAsyncioTestCase):
         else:
             # parent
             result = os.read(r, 100)
-            self.assertEqual(result[:5], b'LOOP:', result)
-            self.assertNotEqual(int(result[5:]), id(loop))
+            self.assertEqual(result, b'NO LOOP')
             wait_process(pid, exitcode=0)
 
     @hashlib_helper.requires_hashdigest('md5')