From a706b98bd8842b190c6a3e16e28186adb6d131a1 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Wed, 8 Feb 2023 20:12:47 +0000
Subject: [PATCH 1/3] asyncio: Remove obsolete code

AsyncioLoop.start() used to save, set, and restore the thread-local
event loop. This avoided some edge cases in early versions of asyncio;
this appears to no longer be necessary since Python 3.7 introduced
the get_running_loop() method.

Removing this logic improves compatibility with Python 3.12, where
it is difficult if not impossible to do the same thing without
generating DeprecationWarnings.
---
 tornado/platform/asyncio.py | 23 +----------------------
 1 file changed, 1 insertion(+), 22 deletions(-)

diff --git a/tornado/platform/asyncio.py b/tornado/platform/asyncio.py
index d839e87d6a..a3fbdc37e3 100644
--- a/tornado/platform/asyncio.py
+++ b/tornado/platform/asyncio.py
@@ -74,19 +74,6 @@ def _atexit_callback() -> None:
 
 atexit.register(_atexit_callback)
 
-if sys.version_info >= (3, 10):
-
-    def _get_event_loop() -> asyncio.AbstractEventLoop:
-        try:
-            return asyncio.get_running_loop()
-        except RuntimeError:
-            pass
-
-        return asyncio.get_event_loop_policy().get_event_loop()
-
-else:
-    from asyncio import get_event_loop as _get_event_loop
-
 
 class BaseAsyncIOLoop(IOLoop):
     def initialize(  # type: ignore
@@ -205,15 +192,7 @@ def _handle_events(self, fd: int, events: int) -> None:
         handler_func(fileobj, events)
 
     def start(self) -> None:
-        try:
-            old_loop = _get_event_loop()
-        except (RuntimeError, AssertionError):
-            old_loop = None  # type: ignore
-        try:
-            asyncio.set_event_loop(self.asyncio_loop)
-            self.asyncio_loop.run_forever()
-        finally:
-            asyncio.set_event_loop(old_loop)
+        self.asyncio_loop.run_forever()
 
     def stop(self) -> None:
         self.asyncio_loop.stop()

From 6a2c60c62a95248458c5d6206538b63c6e259cc7 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Wed, 8 Feb 2023 17:47:27 +0000
Subject: [PATCH 2/3] ci: Re-enable Python 3.12 alphas

As of 3.12a5 the deprecation warnings should be in their final
state.

Also update setup-python action to silence a warning.
---
 .github/workflows/build.yml |  4 ++--
 .github/workflows/test.yml  | 10 ++++------
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 3f56564249..8734328f4f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
         name: Install Python
         with:
           python-version: ${{ env.python-version }}
@@ -47,7 +47,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
         name: Install Python
         with:
           python-version: ${{ env.python-version }}
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 21fd213d1b..997ed1183a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
         name: Install Python
         with:
           # Lint python version must be synced with tox.ini
@@ -44,10 +44,8 @@ jobs:
             tox_env: py310-full
           - python: '3.11'
             tox_env: py311-full
-          # Need more work for python 3.12. See
-          # https://github.com/python/cpython/issues/93453
-          #- python: '3.12.0-alpha - 3.12'
-          #  tox_env: py312-full
+          - python: '3.12.0-alpha - 3.12'
+            tox_env: py312-full
           - python: 'pypy-3.8'
             # Pypy is a lot slower due to jit warmup costs, so don't run the
             # "full" test config there.
@@ -58,7 +56,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
         name: Install Python
         with:
           python-version: ${{ matrix.python}}

From 129e622215faffae534c60b7859e2ce8e66e7f01 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Wed, 8 Feb 2023 21:28:02 +0000
Subject: [PATCH 3/3] ci: Add Python 3.10.8 and 3.11.0 to the build matrix

Early releases in these two branches had different deprecation warnings
so we want to test them too.
---
 .github/workflows/test.yml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 997ed1183a..d9a6082dd0 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -42,8 +42,15 @@ jobs:
             tox_env: py39-full
           - python: '3.10'
             tox_env: py310-full
+          - python: '3.10.8'
+            # Early versions of 3.10 and 3.11 had different deprecation
+            # warnings in asyncio. Test with them too to make sure everything
+            # works the same way.
+            tox_env: py310-full
           - python: '3.11'
             tox_env: py311-full
+          - python: '3.11.0'
+            tox_env: py311-full
           - python: '3.12.0-alpha - 3.12'
             tox_env: py312-full
           - python: 'pypy-3.8'