Merge pull request #1361 from yunstanford/cancel-request-when-connect…

…ion-lost

Cancel request when connection lost

sanic/server.py

@@ -120,6 +120,10 @@ def connection_made(self, transport):
 
     def connection_lost(self, exc):
         self.connections.discard(self)
+        if self._request_handler_task:
+            self._request_handler_task.cancel()
+        if self._request_stream_task:
+            self._request_stream_task.cancel()
         if self._request_timeout_handler:
             self._request_timeout_handler.cancel()
         if self._response_timeout_handler:

tests/test_request_cancel.py

@@ -0,0 +1,73 @@
+import pytest
+import asyncio
+import contextlib
+
+from sanic.response import text, stream
+
+
+async def test_request_cancel_when_connection_lost(loop, app, test_client):
+    app.still_serving_cancelled_request = False
+
+    @app.get('/')
+    async def handler(request):
+        await asyncio.sleep(1.0)
+        # at this point client is already disconnected
+        app.still_serving_cancelled_request = True
+        return text('OK')
+
+    test_cli = await test_client(app)
+
+    # schedule client call
+    task = loop.create_task(test_cli.get('/'))
+    loop.call_later(0.01, task)
+    await asyncio.sleep(0.5)
+
+    # cancelling request and closing connection after 0.5 sec
+    task.cancel()
+
+    with contextlib.suppress(asyncio.CancelledError):
+        await task
+
+    # Wait for server and check if it's still serving the cancelled request
+    await asyncio.sleep(1.0)
+
+    assert app.still_serving_cancelled_request is False
+
+
+async def test_stream_request_cancel_when_connection_lost(loop, app, test_client):
+    app.still_serving_cancelled_request = False
+
+    @app.post('/post/<id>', stream=True)
+    async def post(request, id):
+        assert isinstance(request.stream, asyncio.Queue)
+
+        async def streaming(response):
+            while True:
+                body = await request.stream.get()
+                if body is None:
+                    break
+                await response.write(body.decode('utf-8'))
+
+        await asyncio.sleep(1.0)
+        # at this point client is already disconnected
+        app.still_serving_cancelled_request = True
+
+        return stream(streaming)
+
+    test_cli = await test_client(app)
+
+    # schedule client call
+    task = loop.create_task(test_cli.post('/post/1'))
+    loop.call_later(0.01, task)
+    await asyncio.sleep(0.5)
+
+    # cancelling request and closing connection after 0.5 sec
+    task.cancel()
+
+    with contextlib.suppress(asyncio.CancelledError):
+        await task
+
+    # Wait for server and check if it's still serving the cancelled request
+    await asyncio.sleep(1.0)
+
+    assert app.still_serving_cancelled_request is False