/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.cassandra.utils.concurrent; import sun.misc.Unsafe; import java.lang.reflect.Field; public class Locks { static final Unsafe unsafe; static { try { Field field = sun.misc.Unsafe.class.getDeclaredField("theUnsafe"); field.setAccessible(true); unsafe = (sun.misc.Unsafe) field.get(null); } catch (Exception e) { throw new AssertionError(e); } } // enters the object's monitor IF UNSAFE IS PRESENT. If it isn't, this is a no-op. public static void monitorEnterUnsafe(Object object) { if (unsafe != null) unsafe.monitorEnter(object); } public static void monitorExitUnsafe(Object object) { if (unsafe != null) unsafe.monitorExit(object); } }