| /* |
| * 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.logging.log4j.perf.jmh; |
| |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.openjdk.jmh.annotations.Benchmark; |
| import org.openjdk.jmh.annotations.Scope; |
| import org.openjdk.jmh.annotations.State; |
| |
| /** |
| * Compares performance of ThreadLocal, vs ConcurrentHashMap<Thread, Object>. |
| */ |
| // ============================== HOW TO RUN THIS TEST: ==================================== |
| // (Quick build: mvn -DskipTests=true clean package -pl log4j-perf -am ) |
| // |
| // single thread: |
| // java -jar log4j-perf/target/benchmarks.jar ".*ThreadLocalVsConcurrentHashMap.*" -f 1 -wi 10 -i 20 -tu ns -bm sample |
| // |
| // four threads: |
| // java -jar log4j-perf/target/benchmarks.jar ".*ThreadLocalVsConcurrentHashMap.*" -f 1 -wi 10 -i 20 -tu ns -bm sample |
| // -t 4 |
| // |
| // Usage help: |
| // java -jar log4j-perf/target/benchmarks.jar -help |
| // |
| @State(Scope.Benchmark) |
| public class ThreadLocalVsConcurrentHashMapBenchmark { |
| |
| private static final String VALUE = "value"; |
| private static ConcurrentHashMap<Thread, StringBuilder> map = new ConcurrentHashMap<>(); |
| private static ThreadLocal<StringBuilder> threadLocal = new ThreadLocal<>(); |
| |
| @Benchmark |
| public String newInstance() { |
| final StringBuilder sb = getNew(); |
| sb.append(VALUE); |
| return sb.toString(); |
| } |
| |
| @Benchmark |
| public String threadLocal() { |
| final StringBuilder sb = getThreadLocal(); |
| sb.append(VALUE); |
| return sb.toString(); |
| } |
| |
| @Benchmark |
| public String concurrentHashMap() { |
| final StringBuilder sb = getConcurrentMap(); |
| sb.append(VALUE); |
| return sb.toString(); |
| } |
| |
| private StringBuilder getNew() { |
| final StringBuilder buf = new StringBuilder(); |
| return buf; |
| } |
| |
| private StringBuilder getThreadLocal() { |
| StringBuilder buf = threadLocal.get(); |
| if (buf == null) { |
| buf = new StringBuilder(); |
| threadLocal.set(buf); |
| } |
| buf.setLength(0); |
| return buf; |
| } |
| |
| private StringBuilder getConcurrentMap() { |
| StringBuilder buf = map.get(Thread.currentThread()); |
| if (buf == null) { |
| buf = new StringBuilder(); |
| map.put(Thread.currentThread(), buf); |
| } |
| buf.setLength(0); |
| return buf; |
| } |
| } |