1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18 package org.apache.hadoop.hbase.util;
19
20 import java.util.concurrent.atomic.AtomicLong;
21
22 import org.apache.hadoop.hbase.classification.InterfaceAudience;
23
24 /**
25 * Utilities related to atomic operations.
26 */
27 @InterfaceAudience.Private
28 public final class AtomicUtils {
29 private AtomicUtils() {
30 }
31
32 /**
33 * Updates a AtomicLong which is supposed to maintain the minimum values. This method is not
34 * synchronized but is thread-safe.
35 */
36 public static void updateMin(AtomicLong min, long value) {
37 while (true) {
38 long cur = min.get();
39 if (value >= cur) {
40 break;
41 }
42
43 if (min.compareAndSet(cur, value)) {
44 break;
45 }
46 }
47 }
48
49 /**
50 * Updates a AtomicLong which is supposed to maintain the maximum values. This method is not
51 * synchronized but is thread-safe.
52 */
53 public static void updateMax(AtomicLong max, long value) {
54 while (true) {
55 long cur = max.get();
56 if (value <= cur) {
57 break;
58 }
59
60 if (max.compareAndSet(cur, value)) {
61 break;
62 }
63 }
64 }
65 }