Sync from v0.13

vllm/utils/counter.py

@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import threading
+
+
+class Counter:
+    def __init__(self, start: int = 0) -> None:
+        super().__init__()
+
+        self.counter = start
+
+    def __next__(self) -> int:
+        i = self.counter
+        self.counter += 1
+        return i
+
+    def reset(self) -> None:
+        self.counter = 0
+
+
+class AtomicCounter:
+    """An atomic, thread-safe counter"""
+
+    def __init__(self, initial: int = 0) -> None:
+        """Initialize a new atomic counter to given initial value"""
+        super().__init__()
+
+        self._value = initial
+        self._lock = threading.Lock()
+
+    @property
+    def value(self) -> int:
+        return self._value
+
+    def inc(self, num: int = 1) -> int:
+        """Atomically increment the counter by num and return the new value"""
+        with self._lock:
+            self._value += num
+            return self._value
+
+    def dec(self, num: int = 1) -> int:
+        """Atomically decrement the counter by num and return the new value"""
+        with self._lock:
+            self._value -= num
+            return self._value