[util] fixed communication API depth with PyTorch 1.9 (#721)

colossalai/communication/collective.py

@@ -211,7 +211,7 @@ def reduce(tensor: Tensor,
 def scatter_object_list(scatter_object_output_list, scatter_object_input_list, src=0, group=None):
     r"""Modified from `torch.distributed.scatter_object_list <https://pytorch.org/docs/stable/_modules/torch/distributed/distributed_c10d.html#scatter_object_list>` to fix issues
     """
-    if dist._rank_not_in_group(group):
+    if dist.distributed_c10d._rank_not_in_group(group):
         return
 
     if (not isinstance(scatter_object_output_list, list) or len(scatter_object_output_list) < 1):
@@ -220,7 +220,7 @@ def scatter_object_list(scatter_object_output_list, scatter_object_input_list, s
     # set tensor device to cuda if backend is nccl
     device = torch.cuda.current_device() if dist.get_backend(group) == 'nccl' else torch.device("cpu")
 
-    my_rank = dist.get_rank()  # use global rank
+    my_rank = dist.get_rank()    # use global rank
     if my_rank == src:
         tensor_list, tensor_sizes = zip(
             *[dist.distributed_c10d._object_to_tensor(obj) for obj in scatter_object_input_list])