Ensure middleware executes once per request timeout (#2615)

sanic/http/http1.py

@@ -16,6 +16,7 @@ from sanic.exceptions import (
     PayloadTooLarge,
     RequestCancelled,
     ServerError,
+    ServiceUnavailable,
 )
 from sanic.headers import format_http1_response
 from sanic.helpers import has_message_body
@@ -428,8 +429,11 @@ class Http(Stream, metaclass=TouchUpMeta):
             if self.request is None:
                 self.create_empty_request()
 
+            request_middleware = not isinstance(exception, ServiceUnavailable)
             try:
-                await app.handle_exception(self.request, exception)
+                await app.handle_exception(
+                    self.request, exception, request_middleware
+                )
             except Exception as e:
                 await app.handle_exception(self.request, e, False)
 

sanic/request.py

@@ -104,6 +104,7 @@ class Request:
         "_protocol",
         "_remote_addr",
         "_request_middleware_started",
+        "_response_middleware_started",
         "_scheme",
         "_socket",
         "_stream_id",
@@ -179,6 +180,7 @@ class Request:
             Tuple[bool, bool, str, str], List[Tuple[str, str]]
         ] = defaultdict(list)
         self._request_middleware_started = False
+        self._response_middleware_started = False
         self.responded: bool = False
         self.route: Optional[Route] = None
         self.stream: Optional[Stream] = None
@@ -337,7 +339,8 @@ class Request:
             middleware = (
                 self.route and self.route.extra.response_middleware
             ) or self.app.response_middleware
-            if middleware:
+            if middleware and not self._response_middleware_started:
+                self._response_middleware_started = True
                 response = await self.app._run_response_middleware(
                     self, response, middleware
                 )