Fix instrumentation for workflows

llama-index-core/llama_index/core/instrumentation/dispatcher.py

@@ -1,3 +1,5 @@
+import asyncio
+from functools import partial
 from contextlib import contextmanager
 from contextvars import ContextVar, Token
 from typing import Any, Callable, Generator, List, Optional, Dict, Protocol
@@ -261,20 +263,53 @@ def wrapper(func: Callable, instance: Any, args: list, kwargs: dict) -> Any:
                 parent_id=parent_id,
                 tags=tags,
             )
+
+            def handle_future_result(future, span_id, bound_args, instance):
+                try:
+                    result = future.result()
+                    self.span_exit(
+                        id_=span_id,
+                        bound_args=bound_args,
+                        instance=instance,
+                        result=result,
+                    )
+                    return result
+                except BaseException as e:
+                    self.event(SpanDropEvent(span_id=span_id, err_str=str(e)))
+                    self.span_drop(
+                        id_=span_id, bound_args=bound_args, instance=instance, err=e
+                    )
+                    raise
+                finally:
+                    active_span_id.reset(token)
+
             try:
                 result = func(*args, **kwargs)
+                if isinstance(result, asyncio.Future):
+                    # If the result is a Future, wrap it
+                    new_future = asyncio.ensure_future(result)
+                    new_future.add_done_callback(
+                        partial(
+                            handle_future_result,
+                            span_id=id_,
+                            bound_args=bound_args,
+                            instance=instance,
+                        )
+                    )
+                    return new_future
+                else:
+                    # For non-Future results, proceed as before
+                    self.span_exit(
+                        id_=id_, bound_args=bound_args, instance=instance, result=result
+                    )
+                    return result
             except BaseException as e:
                 self.event(SpanDropEvent(span_id=id_, err_str=str(e)))
                 self.span_drop(id_=id_, bound_args=bound_args, instance=instance, err=e)
                 raise
-            else:
-                self.span_exit(
-                    id_=id_, bound_args=bound_args, instance=instance, result=result
-                )
-                return result
             finally:
-                # clean up
-                active_span_id.reset(token)
+                if not isinstance(result, asyncio.Future):
+                    active_span_id.reset(token)
 
         @wrapt.decorator
         async def async_wrapper(