Author: markt
Date: Thu Jun 18 08:32:29 2009
New Revision: 785952
URL: http://svn.apache.org/viewvc?rev=785952&view=rev
Log:
Add some micro-benchmarks that enable the differences between the Sync and
ThreadLocal approach to be compared
Added:
tomcat/trunk/test/org/apache/catalina/valves/
tomcat/trunk/test/org/apache/catalina/valves/Benchmarks.java
Added: tomcat/trunk/test/org/apache/catalina/valves/Benchmarks.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/test/org/apache/catalina/valves/Benchmarks.java?rev=785952&view=auto
==============================================================================
--- tomcat/trunk/test/org/apache/catalina/valves/Benchmarks.java (added)
+++ tomcat/trunk/test/org/apache/catalina/valves/Benchmarks.java Thu Jun 18
08:32:29 2009
@@ -0,0 +1,260 @@
+/*
+ * 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.catalina.valves;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+import junit.framework.TestCase;
+
+/**
+ * Some simple micro-benchmarks to help determine best approach for thread
+ * safety in valves, particularly the {...@link AccessLogValve}. Implemented as
+ * JUnit tests to make the simple to execute but does not used Test* as the
+ * class name to avoid being included in the automated unit tests.
+ */
+public class Benchmarks extends TestCase {
+ public void testAccessLogGetDate() throws Exception {
+ // Is it better to use a sync or a thread local here?
+ BenchmarkTest getDate = new GetDateBenchmarkTest();
+ getDate.doTest(5);
+ }
+
+ private static class GetDateBenchmarkTest extends BenchmarkTest {
+ private long currentMillis = 0;
+ private Date currentDate = null;
+
+ private ThreadLocal<Long> currentMillisLocal = new ThreadLocal<Long>()
{
+ protected Long initialValue() {
+ return Long.valueOf(0);
+ }
+ };
+
+ private ThreadLocal<Date> currentDateLocal = new ThreadLocal<Date>();
+
+ public Object doSync() {
+ long systime = System.currentTimeMillis();
+ if ((systime - currentMillis) > 1000) {
+ synchronized (this) {
+ if ((systime - currentMillis) > 1000) {
+ currentDate = new Date(systime);
+ currentMillis = systime;
+ }
+ }
+ }
+ return currentDate;
+ }
+
+ public Object doLocal() {
+ long systime = System.currentTimeMillis();
+ if ((systime - currentMillisLocal.get().longValue()) > 1000) {
+ currentDateLocal.set(new Date(systime));
+ currentMillisLocal.set(Long.valueOf(systime));
+ }
+ return currentDateLocal.get();
+ }
+ }
+
+
+ public void testAccessLogTimeDateElement() throws Exception {
+ // Is it better to use a sync or a thread local here?
+ BenchmarkTest timeDateElement = new TimeDateElementBenchmarkTest();
+ timeDateElement.doTest(5);
+ }
+
+ private static class TimeDateElementBenchmarkTest extends BenchmarkTest {
+ private long currentMillis = 0;
+ private Date currentDate = null;
+ private String currentDateString = null;
+ private SimpleDateFormat dayFormatter = new SimpleDateFormat("dd");
+ private SimpleDateFormat monthFormatter = new SimpleDateFormat("MM");
+ private SimpleDateFormat yearFormatter = new SimpleDateFormat("yyyy");
+ private SimpleDateFormat timeFormatter = new
SimpleDateFormat("hh:mm:ss");
+
+ private ThreadLocal<Long> currentMillisLocal = new ThreadLocal<Long>()
{
+ protected Long initialValue() {
+ return Long.valueOf(0);
+ }
+ };
+ private ThreadLocal<Date> currentDateLocal = new ThreadLocal<Date>();
+ private ThreadLocal<SimpleDateFormat> dayFormatterLocal =
+ new ThreadLocal<SimpleDateFormat>() {
+ protected SimpleDateFormat initialValue() {
+ return new SimpleDateFormat("dd");
+ }
+ };
+ private ThreadLocal<SimpleDateFormat> monthFormatterLocal =
+ new ThreadLocal<SimpleDateFormat>() {
+ protected SimpleDateFormat initialValue() {
+ return new SimpleDateFormat("MM");
+ }
+ };
+ private ThreadLocal<SimpleDateFormat> yearFormatterLocal =
+ new ThreadLocal<SimpleDateFormat>() {
+ protected SimpleDateFormat initialValue() {
+ return new SimpleDateFormat("yyyy");
+ }
+ };
+ private ThreadLocal<SimpleDateFormat> timeFormatterLocal =
+ new ThreadLocal<SimpleDateFormat>() {
+ protected SimpleDateFormat initialValue() {
+ return new SimpleDateFormat("hh:mm:ss");
+ }
+ };
+
+ public Object doSync() {
+ StringBuffer buf = new StringBuffer();
+ Date date = getDateSync();
+ if (currentDate != date) {
+ synchronized (this) {
+ if (currentDate != date) {
+ StringBuffer current = new StringBuffer(32);
+ current.append('[');
+ current.append(dayFormatter.format(date)); // Day
+ current.append('/');
+ current.append(lookup(monthFormatter.format(date)));
// Month
+ current.append('/');
+ current.append(yearFormatter.format(date)); // Year
+ current.append(':');
+ current.append(timeFormatter.format(date)); // Time
+ current.append(']');
+ currentDateString = current.toString();
+ currentDate = date;
+ }
+ }
+ }
+ buf.append(currentDateString);
+ return buf;
+ }
+
+ protected static final String months[] =
+ { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
+
+ private String lookup(String month) {
+ int index;
+ try {
+ index = Integer.parseInt(month) - 1;
+ } catch (Throwable t) {
+ index = 0; // Can not happen, in theory
+ }
+ return (months[index]);
+ }
+
+ private Date getDateSync() {
+ long systime = System.currentTimeMillis();
+ if ((systime - currentMillis) > 1000) {
+ synchronized (this) {
+ if ((systime - currentMillis) > 1000) {
+ currentDate = new Date(systime);
+ currentMillis = systime;
+ }
+ }
+ }
+ return currentDate;
+ }
+
+ public Object doLocal() {
+ StringBuffer buf = new StringBuffer();
+ Date date = getDateLocal();
+ if (currentDate != date) {
+ StringBuffer current = new StringBuffer(32);
+ current.append('[');
+ current.append(dayFormatterLocal.get().format(date)); // Day
+ current.append('/');
+
current.append(lookup(monthFormatterLocal.get().format(date))); // Month
+ current.append('/');
+ current.append(yearFormatterLocal.get().format(date)); // Year
+ current.append(':');
+ current.append(timeFormatterLocal.get().format(date)); // Time
+ current.append(']');
+ currentDateString = current.toString();
+ currentDate = date;
+ }
+ buf.append(currentDateString);
+ return buf;
+ }
+
+ private Date getDateLocal() {
+ long systime = System.currentTimeMillis();
+ if ((systime - currentMillisLocal.get().longValue()) > 1000) {
+ currentDateLocal.set(new Date(systime));
+ currentMillisLocal.set(Long.valueOf(systime));
+ }
+ return currentDateLocal.get();
+ }
+ }
+
+
+ private static abstract class BenchmarkTest {
+ public abstract Object doSync();
+ public abstract Object doLocal();
+
+ public void doTest(int threadCount) throws Exception {
+ for (int iterations = 1000000; iterations < 10000001;
iterations+=1000000) {
+ doTestInternal(threadCount, iterations, true);
+ doTestInternal(threadCount, iterations, false);
+ }
+ }
+
+ private void doTestInternal(int threadCount, int iterations,
+ boolean useSyncs) throws Exception {
+ long start = System.currentTimeMillis();
+ Thread[] threads = new Thread[threadCount];
+ for (int i = 0; i < threadCount; i++) {
+ threads[i] = new Thread(new TestThread(iterations, useSyncs,
this));
+ }
+ for (int i = 0; i < threadCount; i++) {
+ threads[i].start();
+ }
+ for (int i = 0; i < threadCount; i++) {
+ threads[i].join();
+ }
+ long end = System.currentTimeMillis();
+
+ System.out.println("testAccessLogGetDate: " + threadCount +
+ " threads and " + iterations + " iterations " +
+ (useSyncs?"using Syncs":"using ThreadLocals") +
+ " took " + (end-start) + "ms");
+ }
+
+ }
+
+ private static class TestThread implements Runnable {
+ private int count;
+ private boolean useSync;
+ private BenchmarkTest benchmarkTest;
+
+ public TestThread(int count, boolean useSync, BenchmarkTest
benchmarkTest) {
+ this.count = count;
+ this.useSync = useSync;
+ this.benchmarkTest = benchmarkTest;
+ }
+
+ public void run() {
+ for (int i = 0; i < count; i++) {
+ if (useSync) {
+ benchmarkTest.doSync();
+ } else {
+ benchmarkTest.doLocal();
+ }
+ }
+ }
+
+ }
+}
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