001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.util;
019
020import java.util.concurrent.atomic.AtomicLong;
021import org.apache.yetus.audience.InterfaceAudience;
022
023/**
024 * Utilities related to atomic operations.
025 */
026@InterfaceAudience.Private
027public final class AtomicUtils {
028  private AtomicUtils() {
029  }
030
031  /**
032   * Updates a AtomicLong which is supposed to maintain the minimum values. This method is not
033   * synchronized but is thread-safe.
034   */
035  public static void updateMin(AtomicLong min, long value) {
036    while (true) {
037      long cur = min.get();
038      if (value >= cur) {
039        break;
040      }
041
042      if (min.compareAndSet(cur, value)) {
043        break;
044      }
045    }
046  }
047
048  /**
049   * Updates a AtomicLong which is supposed to maintain the maximum values. This method is not
050   * synchronized but is thread-safe.
051   */
052  public static void updateMax(AtomicLong max, long value) {
053    while (true) {
054      long cur = max.get();
055      if (value <= cur) {
056        break;
057      }
058
059      if (max.compareAndSet(cur, value)) {
060        break;
061      }
062    }
063  }
064}