Switch to weakset

Author: anuraaga

instrumentation/opentelemetry-instrumentation-starlette/src/opentelemetry/instrumentation/starlette/__init__.py

@@ -177,6 +177,7 @@ def client_response_hook(span: Span, scope: dict[str, Any], message: dict[str, A
 from __future__ import annotations
 
 from typing import TYPE_CHECKING, Any, Collection, cast
+from weakref import WeakSet
 
 from starlette import applications
 from starlette.routing import Match
@@ -300,7 +301,7 @@ class _InstrumentedStarlette(applications.Starlette):
     _server_request_hook: ServerRequestHook = None
     _client_request_hook: ClientRequestHook = None
     _client_response_hook: ClientResponseHook = None
-    _instrumented_starlette_apps: set[applications.Starlette] = set()
+    _instrumented_starlette_apps: WeakSet[applications.Starlette] = WeakSet()
 
     def __init__(self, *args: Any, **kwargs: Any):
         super().__init__(*args, **kwargs)
@@ -331,9 +332,6 @@ def __init__(self, *args: Any, **kwargs: Any):
         # adding apps to set for uninstrumenting
         _InstrumentedStarlette._instrumented_starlette_apps.add(self)
 
-    def __del__(self):
-        _InstrumentedStarlette._instrumented_starlette_apps.discard(self)
-
 
 def _get_route_details(scope: dict[str, Any]) -> str | None:
     """