support DDP in webui

Former-commit-id: d059262ff8dc857f597d2657546ec625726a664a

src/llamafactory/extras/misc.py

@@ -165,13 +165,15 @@ def get_current_device() -> torch.device:
 
 def get_device_count() -> int:
     r"""
-    Gets the number of available GPU devices.
+    Gets the number of available GPU or NPU devices.
     """
-    if not torch.cuda.is_available():
+    if is_torch_npu_available():
+        return torch.npu.device_count()
+    elif is_torch_cuda_available():
+        return torch.cuda.device_count()
+    else:
         return 0
 
-    return torch.cuda.device_count()
-
 
 def get_logits_processor() -> "LogitsProcessorList":
     r"""
@@ -194,6 +196,13 @@ def infer_optim_dtype(model_dtype: torch.dtype) -> torch.dtype:
         return torch.float32
 
 
+def is_gpu_or_npu_available() -> bool:
+    r"""
+    Checks if the GPU or NPU is available.
+    """
+    return is_torch_npu_available() or is_torch_cuda_available()
+
+
 def has_tokenized_data(path: os.PathLike) -> bool:
     r"""
     Checks if the path has a tokenized dataset.