Change comment

Author: ishymko

src/a2a/server/request_handlers/request_handler.py

@@ -241,11 +241,11 @@ async def async_gen_wrapper(
         ) -> Any:
             if params is not None:
                 validate_proto_required_fields(params)
-            # Explicitly close the inner async generator in a finally block
-            # so that its cleanup (except/finally) runs deterministically
-            # during aclose(). On Python < 3.13, async-for does NOT call
-            # aclose() on the iterator when an exception (e.g. GeneratorExit)
-            # propagates through the loop body, leaving cleanup to the GC.
+            # Ensure the inner async generator is closed explicitly;
+            # bare async-for does not call aclose() on GeneratorExit,
+            # which on Python 3.12+ prevents the except/finally blocks
+            # in on_message_send_stream from running on client disconnect
+            # (background_consume and cleanup_producer tasks are never created).
             inner = method(self, params, context, *args, **kwargs)
             try:
                 async for item in inner: