[PR #10151/7c12b1a9 backport][3.12] Fix infinite callback loop when time is not moving forward

CHANGES/10149.misc.rst

@@ -0,0 +1,4 @@
+Fixed an infinite loop that can occur when using aiohttp in combination
+with `async-solipsism`_ -- by :user:`bmerry`.
+
+.. _async-solipsism: https://github.com/bmerry/async-solipsism

aiohttp/web_protocol.py

@@ -458,7 +458,7 @@ def _process_keepalive(self) -> None:
         loop = self._loop
         now = loop.time()
         close_time = self._next_keepalive_close_time
-        if now <= close_time:
+        if now < close_time:
             # Keep alive close check fired too early, reschedule
             self._keepalive_handle = loop.call_at(close_time, self._process_keepalive)
             return

tests/test_web_functional.py

@@ -2324,3 +2324,41 @@ async def handler(request: web.Request) -> web.Response:
         # Make 2nd request which will hit the race condition.
         async with client.get("/") as resp:
             assert resp.status == 200
+
+
+async def test_keepalive_expires_on_time(aiohttp_client: AiohttpClient) -> None:
+    """Test that the keepalive handle expires on time."""
+
+    async def handler(request: web.Request) -> web.Response:
+        body = await request.read()
+        assert b"" == body
+        return web.Response(body=b"OK")
+
+    app = web.Application()
+    app.router.add_route("GET", "/", handler)
+
+    connector = aiohttp.TCPConnector(limit=1)
+    client = await aiohttp_client(app, connector=connector)
+
+    loop = asyncio.get_running_loop()
+    now = loop.time()
+
+    # Patch loop time so we can control when the keepalive timeout is processed
+    with mock.patch.object(loop, "time") as loop_time_mock:
+        loop_time_mock.return_value = now
+        resp1 = await client.get("/")
+        await resp1.read()
+        request_handler = client.server.handler.connections[0]
+
+        # Ensure the keep alive handle is set
+        assert request_handler._keepalive_handle is not None
+
+        # Set the loop time to exactly the keepalive timeout
+        loop_time_mock.return_value = request_handler._next_keepalive_close_time
+
+        # sleep twice to ensure the keep alive timeout is processed
+        await asyncio.sleep(0)
+        await asyncio.sleep(0)
+
+        # Ensure the keep alive handle expires
+        assert request_handler._keepalive_handle is None