From 4e746cb9553b33fbcd6f61b51a9cd2f7e96d6248 Mon Sep 17 00:00:00 2001
From: Adam Hopkins <admhpkns@gmail.com>
Date: Mon, 27 Sep 2021 10:22:30 +0300
Subject: [PATCH] Close HTTP loop when connection task cancelled (#2245)

* Terminate loop when no transport exists

* Add log when closing HTTP loop because of shutdown

* Add unit test
---
 sanic/http.py                           |  6 ++++
 sanic/server/protocols/http_protocol.py |  2 +-
 tests/test_graceful_shutdown.py         | 46 +++++++++++++++++++++++++
 tests/test_signal_handlers.py           |  7 +---
 4 files changed, 54 insertions(+), 7 deletions(-)
 create mode 100644 tests/test_graceful_shutdown.py

diff --git a/sanic/http.py b/sanic/http.py
index 7bdca6a296..3fafd83a9f 100644
--- a/sanic/http.py
+++ b/sanic/http.py
@@ -148,6 +148,12 @@ async def http1(self):
                     await self.response.send(end_stream=True)
             except CancelledError:
                 # Write an appropriate response before exiting
+                if not self.protocol.transport:
+                    logger.info(
+                        f"Request: {self.request.method} {self.request.url} "
+                        "stopped. Transport is closed."
+                    )
+                    return
                 e = self.exception or ServiceUnavailable("Cancelled")
                 self.exception = None
                 self.keep_alive = False
diff --git a/sanic/server/protocols/http_protocol.py b/sanic/server/protocols/http_protocol.py
index b898d3b1bc..c609694eea 100644
--- a/sanic/server/protocols/http_protocol.py
+++ b/sanic/server/protocols/http_protocol.py
@@ -109,7 +109,7 @@ async def connection_task(self):  # no cov
         except Exception:
             error_logger.exception("protocol.connection_task uncaught")
         finally:
-            if self.app.debug and self._http:
+            if self.app.debug and self._http and self.transport:
                 ip = self.transport.get_extra_info("peername")
                 error_logger.error(
                     "Connection lost before response written"
diff --git a/tests/test_graceful_shutdown.py b/tests/test_graceful_shutdown.py
new file mode 100644
index 0000000000..8380ed50d2
--- /dev/null
+++ b/tests/test_graceful_shutdown.py
@@ -0,0 +1,46 @@
+import asyncio
+import logging
+import time
+
+from collections import Counter
+from multiprocessing import Process
+
+import httpx
+
+
+PORT = 42101
+
+
+def test_no_exceptions_when_cancel_pending_request(app, caplog):
+    app.config.GRACEFUL_SHUTDOWN_TIMEOUT = 1
+
+    @app.get("/")
+    async def handler(request):
+        await asyncio.sleep(5)
+
+    @app.after_server_start
+    def shutdown(app, _):
+        time.sleep(0.2)
+        app.stop()
+
+    def ping():
+        time.sleep(0.1)
+        response = httpx.get("http://127.0.0.1:8000")
+        print(response.status_code)
+
+    p = Process(target=ping)
+    p.start()
+
+    with caplog.at_level(logging.INFO):
+        app.run()
+
+    p.kill()
+
+    counter = Counter([r[1] for r in caplog.record_tuples])
+
+    assert counter[logging.INFO] == 5
+    assert logging.ERROR not in counter
+    assert (
+        caplog.record_tuples[3][2]
+        == "Request: GET http://127.0.0.1:8000/ stopped. Transport is closed."
+    )
diff --git a/tests/test_signal_handlers.py b/tests/test_signal_handlers.py
index c51cdd219f..f7657ad64b 100644
--- a/tests/test_signal_handlers.py
+++ b/tests/test_signal_handlers.py
@@ -7,7 +7,6 @@
 
 import pytest
 
-from sanic_testing.reusable import ReusableClient
 from sanic_testing.testing import HOST, PORT
 
 from sanic.compat import ctrlc_workaround_for_windows
@@ -29,13 +28,9 @@ def set_loop(app, loop):
         signal.signal = mock
     else:
         loop.add_signal_handler = mock
-    print(">>>>>>>>>>>>>>>1", id(loop))
-    print(">>>>>>>>>>>>>>>1", loop.add_signal_handler)
 
 
 def after(app, loop):
-    print(">>>>>>>>>>>>>>>2", id(loop))
-    print(">>>>>>>>>>>>>>>2", loop.add_signal_handler)
     calledq.put(mock.called)
 
 
@@ -100,7 +95,7 @@ async def atest(stop_first):
         os.kill(os.getpid(), signal.SIGINT)
         await asyncio.sleep(0.2)
         assert app.is_stopping
-        assert app.stay_active_task.result() == None
+        assert app.stay_active_task.result() is None
         # Second Ctrl+C should raise
         with pytest.raises(KeyboardInterrupt):
             os.kill(os.getpid(), signal.SIGINT)