| /* |
| * 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.TimeUnit; |
| import java.util.concurrent.locks.LockSupport; |
| |
| import org.apache.logging.log4j.core.util.CachedClock; |
| import org.apache.logging.log4j.core.util.Clock; |
| import org.apache.logging.log4j.core.util.CoarseCachedClock; |
| import org.apache.logging.log4j.core.util.SystemClock; |
| import org.openjdk.jmh.annotations.Benchmark; |
| import org.openjdk.jmh.annotations.BenchmarkMode; |
| import org.openjdk.jmh.annotations.Level; |
| import org.openjdk.jmh.annotations.Mode; |
| import org.openjdk.jmh.annotations.OutputTimeUnit; |
| import org.openjdk.jmh.annotations.Scope; |
| import org.openjdk.jmh.annotations.Setup; |
| import org.openjdk.jmh.annotations.State; |
| |
| /** |
| * Tests performance of various clock implementation. |
| */ |
| // ============================== HOW TO RUN THIS TEST: ==================================== |
| // |
| // single thread: |
| // java -jar log4j-perf/target/benchmarks.jar ".*Clocks.*" -f 1 -wi 5 -i 5 |
| // |
| // multiple threads (for example, 4 threads): |
| // java -jar log4j-perf/target/benchmarks.jar ".*Clocks.*" -f 1 -wi 5 -i 5 -t 4 -si true |
| // |
| // Usage help: |
| // java -jar log4j-perf/target/benchmarks.jar -help |
| // |
| @State(Scope.Thread) |
| public class ClocksBenchmark { |
| |
| Clock systemClock = new SystemClock(); |
| Clock cachedClock; |
| Clock oldCachedClock; |
| Clock coarseCachedClock; |
| Clock fixedClock; |
| Clock fixedFinalClock; |
| |
| @Setup(Level.Trial) |
| public void up() { |
| cachedClock = CachedClock.instance(); |
| oldCachedClock = OldCachedClock.instance(); |
| coarseCachedClock = CoarseCachedClock.instance(); |
| fixedClock = new FixedTimeClock(System.nanoTime()); |
| fixedFinalClock = new FixedFinalTimeClock(System.nanoTime()); |
| } |
| |
| @Benchmark |
| @BenchmarkMode(Mode.SampleTime) |
| @OutputTimeUnit(TimeUnit.NANOSECONDS) |
| public void baseline() { |
| } |
| |
| @Benchmark |
| @BenchmarkMode(Mode.SampleTime) |
| @OutputTimeUnit(TimeUnit.NANOSECONDS) |
| public long systemCurrentTimeMillis() { |
| return System.currentTimeMillis(); |
| } |
| |
| @Benchmark |
| @BenchmarkMode(Mode.SampleTime) |
| @OutputTimeUnit(TimeUnit.NANOSECONDS) |
| public long systemClock() { |
| return systemClock.currentTimeMillis(); |
| } |
| |
| @Benchmark |
| @BenchmarkMode(Mode.SampleTime) |
| @OutputTimeUnit(TimeUnit.NANOSECONDS) |
| public long cachedClock() { |
| return cachedClock.currentTimeMillis(); |
| } |
| |
| @Benchmark |
| @BenchmarkMode(Mode.SampleTime) |
| @OutputTimeUnit(TimeUnit.NANOSECONDS) |
| public long oldCachedClock() { |
| return oldCachedClock.currentTimeMillis(); |
| } |
| |
| @Benchmark |
| @BenchmarkMode(Mode.SampleTime) |
| @OutputTimeUnit(TimeUnit.NANOSECONDS) |
| public long coarseCachedClock() { |
| return coarseCachedClock.currentTimeMillis(); |
| } |
| |
| @Benchmark |
| @BenchmarkMode(Mode.SampleTime) |
| @OutputTimeUnit(TimeUnit.NANOSECONDS) |
| public long fixedClock() { |
| return fixedClock.currentTimeMillis(); |
| } |
| |
| @Benchmark |
| @BenchmarkMode(Mode.SampleTime) |
| @OutputTimeUnit(TimeUnit.NANOSECONDS) |
| public long fixedFinalClock() { |
| return fixedFinalClock.currentTimeMillis(); |
| } |
| |
| private static final class FixedTimeClock implements Clock { |
| private final long fixedTime; |
| |
| public FixedTimeClock(final long fixedTime) { |
| this.fixedTime = fixedTime; |
| } |
| |
| @Override |
| public long currentTimeMillis() { |
| return fixedTime; |
| } |
| } |
| |
| private static final class FixedFinalTimeClock implements Clock { |
| private final long fixedFinalTime; |
| |
| public FixedFinalTimeClock(final long fixedTime) { |
| this.fixedFinalTime = fixedTime; |
| } |
| |
| @Override |
| public long currentTimeMillis() { |
| return fixedFinalTime; |
| } |
| } |
| |
| private static final class OldCachedClock implements Clock { |
| private static final int UPDATE_THRESHOLD = 0x3FF; |
| private static volatile OldCachedClock instance; |
| private static final Object INSTANCE_LOCK = new Object(); |
| private volatile long millis = System.currentTimeMillis(); |
| private volatile short count = 0; |
| |
| private OldCachedClock() { |
| final Thread updater = new Thread(new Runnable() { |
| @Override |
| public void run() { |
| while (true) { |
| final long time = System.currentTimeMillis(); |
| millis = time; |
| |
| // avoid explicit dependency on sun.misc.Util |
| LockSupport.parkNanos(1000 * 1000); |
| } |
| } |
| }, "Clock Updater Thread"); |
| updater.setDaemon(true); |
| updater.start(); |
| } |
| |
| public static OldCachedClock instance() { |
| // LOG4J2-819: use lazy initialization of threads |
| if (instance == null) { |
| synchronized (INSTANCE_LOCK) { |
| if (instance == null) { |
| instance = new OldCachedClock(); |
| } |
| } |
| } |
| return instance; |
| } |
| |
| @Override |
| public long currentTimeMillis() { |
| |
| // improve granularity: also update time field every 1024 calls. |
| // (the bit fiddling means we don't need to worry about overflows) |
| if ((++count & UPDATE_THRESHOLD) == UPDATE_THRESHOLD) { |
| millis = System.currentTimeMillis(); |
| } |
| return millis; |
| } |
| } |
| } |