Merge branch 'main' into clear-ts

Doc/library/asyncio-policy.rst

@@ -40,6 +40,10 @@ for the current process:
 
    Return the current process-wide policy.
 
+   .. deprecated:: next
+      The :func:`get_event_loop_policy` function is deprecated and
+      will be removed in Python 3.16.
+
 .. function:: set_event_loop_policy(policy)
 
    Set the current process-wide policy to *policy*.

Doc/whatsnew/3.14.rst

@@ -780,6 +780,96 @@ asyncio
   It now raises a :exc:`RuntimeError` if there is no current event loop.
   (Contributed by Kumar Aditya in :gh:`126353`.)
 
+  There's a few patterns that use :func:`asyncio.get_event_loop`, most
+  of them can be replaced with :func:`asyncio.run`.
+
+  If you're running an async function, simply use :func:`asyncio.run`.
+
+  Before::
+
+    async def main():
+        ...
+
+
+    loop = asyncio.get_event_loop()
+    try:
+        loop.run_until_complete(main())
+    finally:
+        loop.close()
+
+  After::
+
+    async def main():
+        ...
+
+    asyncio.run(main())
+
+  If you need to start something, e.g. a server listening on a socket
+  and then run forever, use :func:`asyncio.run` and an
+  :class:`asyncio.Event`.
+
+  Before::
+
+    def start_server(loop):
+        ...
+
+    loop = asyncio.get_event_loop()
+    try:
+        start_server(loop)
+        loop.run_forever()
+    finally:
+        loop.close()
+
+  After::
+
+    def start_server(loop):
+        ...
+
+    async def main():
+        start_server(asyncio.get_running_loop())
+        await asyncio.Event().wait()
+
+    asyncio.run(main())
+
+  If you need to run something in an event loop, then run some blocking
+  code around it, use :class:`asyncio.Runner`.
+
+  Before::
+
+    async def operation_one():
+        ...
+
+    def blocking_code():
+        ...
+
+    async def operation_two():
+        ...
+
+    loop = asyncio.get_event_loop()
+    try:
+        loop.run_until_complete(operation_one())
+        blocking_code()
+        loop.run_until_complete(operation_two())
+    finally:
+        loop.close()
+
+  After::
+
+    async def operation_one():
+        ...
+
+    def blocking_code():
+        ...
+
+    async def operation_two():
+        ...
+
+    with asyncio.Runner() as runner:
+        runner.run(operation_one())
+        blocking_code()
+        runner.run(operation_two())
+
+
 
 collections.abc
 ---------------

Lib/asyncio/events.py

@@ -8,6 +8,7 @@
     'AbstractEventLoopPolicy',
     'AbstractEventLoop', 'AbstractServer',
     'Handle', 'TimerHandle',
+    '_get_event_loop_policy',
     'get_event_loop_policy',
     '_set_event_loop_policy',
     'set_event_loop_policy',
@@ -761,12 +762,15 @@ def _init_event_loop_policy():
             _event_loop_policy = DefaultEventLoopPolicy()
 
 
-def get_event_loop_policy():
+def _get_event_loop_policy():
     """Get the current event loop policy."""
     if _event_loop_policy is None:
         _init_event_loop_policy()
     return _event_loop_policy
 
+def get_event_loop_policy():
+    warnings._deprecated('asyncio.get_event_loop_policy', remove=(3, 16))
+    return _get_event_loop_policy()
 
 def _set_event_loop_policy(policy):
     """Set the current event loop policy.
@@ -778,7 +782,7 @@ def _set_event_loop_policy(policy):
     _event_loop_policy = policy
 
 def set_event_loop_policy(policy):
-    warnings._deprecated('set_event_loop_policy', remove=(3,16))
+    warnings._deprecated('asyncio.set_event_loop_policy', remove=(3,16))
     _set_event_loop_policy(policy)
 
 def get_event_loop():
@@ -794,17 +798,17 @@ def get_event_loop():
     current_loop = _get_running_loop()
     if current_loop is not None:
         return current_loop
-    return get_event_loop_policy().get_event_loop()
+    return _get_event_loop_policy().get_event_loop()
 
 
 def set_event_loop(loop):
     """Equivalent to calling get_event_loop_policy().set_event_loop(loop)."""
-    get_event_loop_policy().set_event_loop(loop)
+    _get_event_loop_policy().set_event_loop(loop)
 
 
 def new_event_loop():
     """Equivalent to calling get_event_loop_policy().new_event_loop()."""
-    return get_event_loop_policy().new_event_loop()
+    return _get_event_loop_policy().new_event_loop()
 
 
 # Alias pure-Python implementations for testing purposes.

Lib/tempfile.py

@@ -437,11 +437,19 @@ class _TemporaryFileCloser:
     cleanup_called = False
     close_called = False
 
-    def __init__(self, file, name, delete=True, delete_on_close=True):
+    def __init__(
+        self,
+        file,
+        name,
+        delete=True,
+        delete_on_close=True,
+        warn_message="Implicitly cleaning up unknown file",
+    ):
         self.file = file
         self.name = name
         self.delete = delete
         self.delete_on_close = delete_on_close
+        self.warn_message = warn_message
 
     def cleanup(self, windows=(_os.name == 'nt'), unlink=_os.unlink):
         if not self.cleanup_called:
@@ -469,7 +477,10 @@ def close(self):
                     self.cleanup()
 
     def __del__(self):
+        close_called = self.close_called
         self.cleanup()
+        if not close_called:
+            _warnings.warn(self.warn_message, ResourceWarning)
 
 
 class _TemporaryFileWrapper:
@@ -483,8 +494,17 @@ class _TemporaryFileWrapper:
     def __init__(self, file, name, delete=True, delete_on_close=True):
         self.file = file
         self.name = name
-        self._closer = _TemporaryFileCloser(file, name, delete,
-                                            delete_on_close)
+        self._closer = _TemporaryFileCloser(
+            file,
+            name,
+            delete,
+            delete_on_close,
+            warn_message=f"Implicitly cleaning up {self!r}",
+        )
+
+    def __repr__(self):
+        file = self.__dict__['file']
+        return f"<{type(self).__name__} {file=}>"
 
     def __getattr__(self, name):
         # Attribute lookups are delegated to the underlying file

Lib/test/test_asyncio/test_events.py

@@ -2397,7 +2397,7 @@ def test_handle_repr_debug(self):
         self.assertRegex(repr(h), regex)
 
     def test_handle_source_traceback(self):
-        loop = asyncio.get_event_loop_policy().new_event_loop()
+        loop = asyncio.new_event_loop()
         loop.set_debug(True)
         self.set_event_loop(loop)
 
@@ -2759,24 +2759,31 @@ def test_set_event_loop(self):
         old_loop.close()
 
     def test_get_event_loop_policy(self):
-        policy = asyncio.get_event_loop_policy()
-        self.assertIsInstance(policy, asyncio.AbstractEventLoopPolicy)
-        self.assertIs(policy, asyncio.get_event_loop_policy())
+        with self.assertWarnsRegex(
+                DeprecationWarning, "'asyncio.get_event_loop_policy' is deprecated"):
+            policy = asyncio.get_event_loop_policy()
+            self.assertIsInstance(policy, asyncio.AbstractEventLoopPolicy)
+            self.assertIs(policy, asyncio.get_event_loop_policy())
 
     def test_set_event_loop_policy(self):
         with self.assertWarnsRegex(
-                DeprecationWarning, "'set_event_loop_policy' is deprecated"):
+                DeprecationWarning, "'asyncio.set_event_loop_policy' is deprecated"):
             self.assertRaises(
                 TypeError, asyncio.set_event_loop_policy, object())
 
-        old_policy = asyncio.get_event_loop_policy()
+        with self.assertWarnsRegex(
+                DeprecationWarning, "'asyncio.get_event_loop_policy' is deprecated"):
+            old_policy = asyncio.get_event_loop_policy()
 
         policy = asyncio.DefaultEventLoopPolicy()
         with self.assertWarnsRegex(
-                DeprecationWarning, "'set_event_loop_policy' is deprecated"):
+                DeprecationWarning, "'asyncio.set_event_loop_policy' is deprecated"):
             asyncio.set_event_loop_policy(policy)
-        self.assertIs(policy, asyncio.get_event_loop_policy())
-        self.assertIsNot(policy, old_policy)
+
+        with self.assertWarnsRegex(
+                DeprecationWarning, "'asyncio.get_event_loop_policy' is deprecated"):
+            self.assertIs(policy, asyncio.get_event_loop_policy())
+            self.assertIsNot(policy, old_policy)
 
 
 class GetEventLoopTestsMixin:
@@ -2859,7 +2866,7 @@ class Policy(asyncio.DefaultEventLoopPolicy):
             def get_event_loop(self):
                 raise TestError
 
-        old_policy = asyncio.get_event_loop_policy()
+        old_policy = asyncio._get_event_loop_policy()
         try:
             asyncio._set_event_loop_policy(Policy())
             loop = asyncio.new_event_loop()
@@ -2899,7 +2906,7 @@ async def func():
         self.assertIs(asyncio._get_running_loop(), None)
 
     def test_get_event_loop_returns_running_loop2(self):
-        old_policy = asyncio.get_event_loop_policy()
+        old_policy = asyncio._get_event_loop_policy()
         try:
             asyncio._set_event_loop_policy(asyncio.DefaultEventLoopPolicy())
             loop = asyncio.new_event_loop()

Lib/test/test_asyncio/test_runners.py

@@ -64,7 +64,7 @@ def setUp(self):
         asyncio._set_event_loop_policy(policy)
 
     def tearDown(self):
-        policy = asyncio.get_event_loop_policy()
+        policy = asyncio._get_event_loop_policy()
         if policy.loop is not None:
             self.assertTrue(policy.loop.is_closed())
             self.assertTrue(policy.loop.shutdown_ag_run)
@@ -208,7 +208,7 @@ async def main():
             await asyncio.sleep(0)
             return 42
 
-        policy = asyncio.get_event_loop_policy()
+        policy = asyncio._get_event_loop_policy()
         policy.set_event_loop = mock.Mock()
         asyncio.run(main())
         self.assertTrue(policy.set_event_loop.called)
@@ -495,7 +495,7 @@ def test_set_event_loop_called_once(self):
         async def coro():
             pass
 
-        policy = asyncio.get_event_loop_policy()
+        policy = asyncio._get_event_loop_policy()
         policy.set_event_loop = mock.Mock()
         runner = asyncio.Runner()
         runner.run(coro())

Lib/test/test_asyncio/test_subprocess.py

@@ -886,8 +886,7 @@ class SubprocessWatcherMixin(SubprocessMixin):
 
         def setUp(self):
             super().setUp()
-            policy = asyncio.get_event_loop_policy()
-            self.loop = policy.new_event_loop()
+            self.loop = asyncio.new_event_loop()
             self.set_event_loop(self.loop)
 
         def test_watcher_implementation(self):

Lib/test/test_asyncio/test_windows_events.py

@@ -332,7 +332,7 @@ async def main():
                 asyncio.get_running_loop(),
                 asyncio.SelectorEventLoop)
 
-        old_policy = asyncio.get_event_loop_policy()
+        old_policy = asyncio._get_event_loop_policy()
         try:
             asyncio._set_event_loop_policy(
                 asyncio.WindowsSelectorEventLoopPolicy())
@@ -346,7 +346,7 @@ async def main():
                 asyncio.get_running_loop(),
                 asyncio.ProactorEventLoop)
 
-        old_policy = asyncio.get_event_loop_policy()
+        old_policy = asyncio._get_event_loop_policy()
         try:
             asyncio._set_event_loop_policy(
                 asyncio.WindowsProactorEventLoopPolicy())

Lib/test/test_contextlib_async.py

@@ -496,7 +496,7 @@ class TestAsyncExitStack(TestBaseExitStack, unittest.IsolatedAsyncioTestCase):
     class SyncAsyncExitStack(AsyncExitStack):
         @staticmethod
         def run_coroutine(coro):
-            loop = asyncio.get_event_loop_policy().get_event_loop()
+            loop = asyncio.new_event_loop()
             t = loop.create_task(coro)
             t.add_done_callback(lambda f: loop.stop())
             loop.run_forever()

Lib/test/test_ctypes/test_dlerror.py

@@ -133,24 +133,20 @@ def configure_locales(func):
     @classmethod
     def setUpClass(cls):
         cls.libc_filename = find_library("c")
+        if cls.libc_filename is None:
+            raise unittest.SkipTest('cannot find libc')
 
     @configure_locales
     def test_localized_error_from_dll(self):
         dll = CDLL(self.libc_filename)
-        with self.assertRaises(AttributeError) as cm:
+        with self.assertRaises(AttributeError):
             dll.this_name_does_not_exist
-        if sys.platform.startswith('linux'):
-            # On macOS, the filename is not reported by dlerror().
-            self.assertIn(self.libc_filename, str(cm.exception))
 
     @configure_locales
     def test_localized_error_in_dll(self):
         dll = CDLL(self.libc_filename)
-        with self.assertRaises(ValueError) as cm:
+        with self.assertRaises(ValueError):
             c_int.in_dll(dll, 'this_name_does_not_exist')
-        if sys.platform.startswith('linux'):
-            # On macOS, the filename is not reported by dlerror().
-            self.assertIn(self.libc_filename, str(cm.exception))
 
     @unittest.skipUnless(hasattr(_ctypes, 'dlopen'),
                          'test requires _ctypes.dlopen()')
@@ -172,11 +168,8 @@ def test_localized_error_dlopen(self):
     @configure_locales
     def test_localized_error_dlsym(self):
         dll = _ctypes.dlopen(self.libc_filename)
-        with self.assertRaises(OSError) as cm:
+        with self.assertRaises(OSError):
             _ctypes.dlsym(dll, 'this_name_does_not_exist')
-        if sys.platform.startswith('linux'):
-            # On macOS, the filename is not reported by dlerror().
-            self.assertIn(self.libc_filename, str(cm.exception))
 
 
 if __name__ == "__main__":