Fix and enhance dumper (#8725)

python/sglang/srt/debug_utils/dumper.py

@@ -53,7 +53,7 @@ class _Dumper:
         if self._partial_name is None:
             self._partial_name = _get_partial_name()
 
-        rank = dist.get_rank()
+        rank = _get_rank()
         full_kwargs = dict(
             forward_pass_id=self._forward_pass_id,
             rank=rank,
@@ -80,12 +80,20 @@ class _Dumper:
 
 
 def _get_partial_name():
-    rank = dist.get_rank()
+    rank = _get_rank()
     object_list = [str(time.time()) if rank == 0 else None]
-    dist.broadcast_object_list(object_list, device="cuda")
+    if dist.is_initialized():
+        dist.broadcast_object_list(object_list, device="cuda")
     return object_list[0]
 
 
+def _get_rank():
+    if dist.is_initialized():
+        return dist.get_rank()
+    else:
+        return 0
+
+
 def get_truncated_value(value):
     if value is None:
         return None