fix: crashing while exiting loop agent in web

src/google/adk/agents/base_agent.py

@@ -135,8 +135,10 @@ async def run_async(
     Yields:
       Event: the events generated by the agent.
     """
-
-    with tracer.start_as_current_span(f'agent_run [{self.name}]'):
+    span = tracer.start_span(
+        f'agent_run [{self.name}]'
+    )  # Start the span explicitly
+    try:
       ctx = self._create_invocation_context(parent_context)
 
       if event := await self.__handle_before_agent_callback(ctx):
@@ -152,6 +154,8 @@ async def run_async(
 
       if event := await self.__handle_after_agent_callback(ctx):
         yield event
+    finally:
+      span.end()  # End the span explicitly
 
   @final
   async def run_live(

src/google/adk/agents/loop_agent.py

@@ -16,6 +16,7 @@
 
 from __future__ import annotations
 
+from google.genai import types
 from typing import AsyncGenerator
 from typing import Optional
 
@@ -48,9 +49,29 @@ async def _run_async_impl(
     while not self.max_iterations or times_looped < self.max_iterations:
       for sub_agent in self.sub_agents:
         async for event in sub_agent.run_async(ctx):
-          yield event
+          yield event  # Yield the event immediately
           if event.actions.escalate:
-            return
+            # Ensure the escalation message is processed immediately
+            if event.content and event.content.parts:
+              for part in event.content.parts:
+                if part.function_response.response:
+                  # Yield the escalation message as a new event
+                  yield Event(
+                      invocation_id=ctx.invocation_id,
+                      author=sub_agent.name,
+                      branch=ctx.branch,
+                      content=types.Content(
+                          role='assistant',
+                          parts=[
+                              types.Part(
+                                  text=part.function_response.response.get(
+                                      'message'
+                                  ),
+                              )
+                          ],
+                      ),
+                  )
+            return  # Exit the loop after escalation
       times_looped += 1
     return
 

src/google/adk/flows/llm_flows/base_llm_flow.py

@@ -467,7 +467,8 @@ async def _call_llm_async(
 
     # Calls the LLM.
     llm = self.__get_llm(invocation_context)
-    with tracer.start_as_current_span('call_llm'):
+    span = tracer.start_span(f'call_llm')  # Start the span explicitly
+    try:
       if invocation_context.run_config.support_cfc:
         invocation_context.live_request_queue = LiveRequestQueue()
         async for llm_response in self.run_live(invocation_context):
@@ -507,6 +508,8 @@ async def _call_llm_async(
             llm_response = altered_llm_response
 
           yield llm_response
+    finally:
+      span.end()  # End the span explicitly
 
   async def _handle_before_model_callback(
       self,

src/google/adk/runners.py

@@ -169,7 +169,8 @@ async def run_async(
     Yields:
       The events generated by the agent.
     """
-    with tracer.start_as_current_span('invocation'):
+    span = tracer.start_span('invocation')  # Start the span explicitly
+    try:
       session = self.session_service.get_session(
           app_name=self.app_name, user_id=user_id, session_id=session_id
       )
@@ -196,6 +197,9 @@ async def run_async(
         if not event.partial:
           self.session_service.append_event(session=session, event=event)
         yield event
+    finally:
+      # Ensure the span is finished when the function exits
+      span.end()
 
   async def _append_new_message_to_session(
       self,

src/google/adk/sessions/database_session_service.py

@@ -484,11 +484,11 @@ def append_event(self, session: Session, event: Event) -> Event:
 
       if storage_session.update_time.timestamp() > session.last_update_time:
         raise ValueError(
-          f"Session last_update_time "
-          f"{datetime.fromtimestamp(session.last_update_time):%Y-%m-%d %H:%M:%S} "
-          f"is later than the update_time in storage "
-          f"{storage_session.update_time:%Y-%m-%d %H:%M:%S}"
-      )
+            "Session last_update_time"
+            f" {datetime.fromtimestamp(session.last_update_time):%Y-%m-%d %H:%M:%S} is"
+            " later than the update_time in storage"
+            f" {storage_session.update_time:%Y-%m-%d %H:%M:%S}"
+        )
 
       # Fetch states from storage
       storage_app_state = sessionFactory.get(