[Misc] Refactor platform to get device specific stream and event (#14411)

Signed-off-by: shen-shanshan <467638484@qq.com>

vllm/platforms/interface.py

@@ -404,6 +404,15 @@ class Platform:
     ) -> None:
         """Raises if this request is unsupported on this platform"""
 
+    def __getattr__(self, key: str):
+        device = getattr(torch, self.device_name, None)
+        if device is not None and hasattr(device, key):
+            return getattr(device, key)
+        else:
+            logger.warning("Current platform %s doesn't has '%s' attribute.",
+                           self.device_name, key)
+            return None
+
 
 class UnspecifiedPlatform(Platform):
     _enum = PlatformEnum.UNSPECIFIED

vllm/spec_decode/metrics.py

@@ -8,6 +8,7 @@ import torch
 
 from vllm.model_executor.layers.spec_decode_base_sampler import (
     SpecDecodeBaseSampler)
+from vllm.platforms import current_platform
 from vllm.utils import is_pin_memory_available
 
 
@@ -89,14 +90,14 @@ class AsyncMetricsCollector:
         self._rank = rank
         if isinstance(device_type, torch.device):
             device_type = device_type.type
-        if device_type == 'cuda':
-            self._copy_stream = torch.cuda.Stream()
+        stream = current_platform.Stream
+        if stream is not None:
+            self._copy_stream = stream()
 
     def maybe_collect_rejsample_metrics(
             self, k: int) -> Optional[SpecDecodeWorkerMetrics]:
-        # currently using cuda.Event, skip for any non_cuda_alike platform
-        from vllm.platforms import current_platform
-        if not current_platform.is_cuda_alike():
+        # Skip for any platform that doesn't have device Event
+        if current_platform.Event is None:
             return None
 
         # If a copy was initiated in the previous call, collect and return.