Revert "Fix async cancellation behaviour (#580)" (#627)

This reverts commit ce8f872.

Author: lovelydinosaur

httpcore/_async/connection_pool.py

@@ -214,9 +214,9 @@ async def handle_async_request(self, request: Request) -> Response:
             )
 
         status = RequestStatus(request)
-        self._requests.append(status)
 
         async with self._pool_lock:
+            self._requests.append(status)
             await self._close_expired_connections()
             await self._attempt_to_acquire_connection(status)
 
@@ -229,8 +229,9 @@ async def handle_async_request(self, request: Request) -> Response:
                 # If we timeout here, or if the task is cancelled, then make
                 # sure to remove the request from the queue before bubbling
                 # up the exception.
-                self._requests.remove(status)
-                raise exc
+                async with self._pool_lock:
+                    self._requests.remove(status)
+                    raise exc
 
             try:
                 response = await connection.handle_async_request(request)
@@ -273,11 +274,10 @@ async def response_closed(self, status: RequestStatus) -> None:
         assert status.connection is not None
         connection = status.connection
 
-        if status in self._requests:
-            self._requests.remove(status)
-
         async with self._pool_lock:
             # Update the state of the connection pool.
+            if status in self._requests:
+                self._requests.remove(status)
 
             if connection.is_closed() and connection in self._pool:
                 self._pool.remove(connection)

httpcore/_sync/connection_pool.py

@@ -214,9 +214,9 @@ def handle_request(self, request: Request) -> Response:
             )
 
         status = RequestStatus(request)
-        self._requests.append(status)
 
         with self._pool_lock:
+            self._requests.append(status)
             self._close_expired_connections()
             self._attempt_to_acquire_connection(status)
 
@@ -229,8 +229,9 @@ def handle_request(self, request: Request) -> Response:
                 # If we timeout here, or if the task is cancelled, then make
                 # sure to remove the request from the queue before bubbling
                 # up the exception.
-                self._requests.remove(status)
-                raise exc
+                with self._pool_lock:
+                    self._requests.remove(status)
+                    raise exc
 
             try:
                 response = connection.handle_request(request)
@@ -273,11 +274,10 @@ def response_closed(self, status: RequestStatus) -> None:
         assert status.connection is not None
         connection = status.connection
 
-        if status in self._requests:
-            self._requests.remove(status)
-
         with self._pool_lock:
             # Update the state of the connection pool.
+            if status in self._requests:
+                self._requests.remove(status)
 
             if connection.is_closed() and connection in self._pool:
                 self._pool.remove(connection)