Slightly improve the sampler to skip unnecessary steps (#6956)

python/sglang/srt/utils.py

@@ -1928,16 +1928,18 @@ def next_power_of_2(n: int):
 setattr(triton, "next_power_of_2", next_power_of_2)
 
 
-@contextmanager
-def empty_context(*args, **kwargs):
-    try:
-        # Setup code goes here
-        yield
-    finally:
-        # Cleanup code goes here
+class EmptyContextManager:
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
         pass
 
 
+def empty_context(*args, **kwargs):
+    return EmptyContextManager()
+
+
 def add_prefix(name: str, prefix: str) -> str:
     """Add a weight path prefix to a module name.