--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/concurrent/locks/ReentrantReadWriteLock/MapLoops.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,190 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/licenses/publicdomain
+ */
+
+/*
+ * @test
+ * @bug 4486658
+ * @compile -source 1.5 MapLoops.java
+ * @run main/timeout=4700 MapLoops
+ * @summary Exercise multithreaded maps, by default ConcurrentHashMap.
+ * Multithreaded hash table test. Each thread does a random walk
+ * though elements of "key" array. On each iteration, it checks if
+ * table includes key. If absent, with probability pinsert it
+ * inserts it, and if present, with probability premove it removes
+ * it. (pinsert and premove are expressed as percentages to simplify
+ * parsing from command line.)
+ */
+
+import java.util.*;
+import java.util.concurrent.*;
+
+public class MapLoops {
+ static final int NKEYS = 100000;
+ static int pinsert = 60;
+ static int premove = 2;
+ static int maxThreads = 5;
+ static int nops = 1000000;
+ static int removesPerMaxRandom;
+ static int insertsPerMaxRandom;
+
+ static final ExecutorService pool = Executors.newCachedThreadPool();
+
+ public static void main(String[] args) throws Exception {
+
+ Class mapClass = null;
+ if (args.length > 0) {
+ try {
+ mapClass = Class.forName(args[0]);
+ } catch(ClassNotFoundException e) {
+ throw new RuntimeException("Class " + args[0] + " not found.");
+ }
+ }
+ else
+ mapClass = RWMap.class;
+
+ if (args.length > 1)
+ maxThreads = Integer.parseInt(args[1]);
+
+ if (args.length > 2)
+ nops = Integer.parseInt(args[2]);
+
+ if (args.length > 3)
+ pinsert = Integer.parseInt(args[3]);
+
+ if (args.length > 4)
+ premove = Integer.parseInt(args[4]);
+
+ // normalize probabilities wrt random number generator
+ removesPerMaxRandom = (int)(((double)premove/100.0 * 0x7FFFFFFFL));
+ insertsPerMaxRandom = (int)(((double)pinsert/100.0 * 0x7FFFFFFFL));
+
+ System.out.println("Using " + mapClass.getName());
+
+ Random rng = new Random(315312);
+ Integer[] key = new Integer[NKEYS];
+ for (int i = 0; i < key.length; ++i)
+ key[i] = new Integer(rng.nextInt());
+
+ // warmup
+ System.out.println("Warmup...");
+ for (int k = 0; k < 2; ++k) {
+ Map<Integer, Integer> map = (Map<Integer,Integer>)mapClass.newInstance();
+ LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
+ CyclicBarrier barrier = new CyclicBarrier(1, timer);
+ new Runner(map, key, barrier).run();
+ map.clear();
+ Thread.sleep(100);
+ }
+
+ for (int i = 1; i <= maxThreads; i += (i+1) >>> 1) {
+ System.out.print("Threads: " + i + "\t:");
+ Map<Integer, Integer> map = (Map<Integer,Integer>)mapClass.newInstance();
+ LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
+ CyclicBarrier barrier = new CyclicBarrier(i+1, timer);
+ for (int k = 0; k < i; ++k)
+ pool.execute(new Runner(map, key, barrier));
+ barrier.await();
+ barrier.await();
+ long time = timer.getTime();
+ long tpo = time / (i * (long)nops);
+ System.out.print(LoopHelpers.rightJustify(tpo) + " ns per op");
+ double secs = (double)(time) / 1000000000.0;
+ System.out.println("\t " + secs + "s run time");
+ map.clear();
+ }
+ pool.shutdown();
+ if (! pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS))
+ throw new Error();
+ }
+
+ static class Runner implements Runnable {
+ final Map<Integer,Integer> map;
+ final Integer[] key;
+ final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom();
+ final CyclicBarrier barrier;
+ int position;
+ int total;
+
+ Runner(Map<Integer,Integer> map, Integer[] key, CyclicBarrier barrier) {
+ this.map = map;
+ this.key = key;
+ this.barrier = barrier;
+ position = key.length / 2;
+ }
+
+ int step() {
+ // random-walk around key positions, bunching accesses
+ int r = rng.next();
+ position += (r & 7) - 3;
+ while (position >= key.length) position -= key.length;
+ while (position < 0) position += key.length;
+
+ Integer k = key[position];
+ Integer x = map.get(k);
+
+ if (x != null) {
+ if (x.intValue() != k.intValue())
+ throw new Error("bad mapping: " + x + " to " + k);
+
+ if (r < removesPerMaxRandom) {
+ // get awy from this position
+ position = r % key.length;
+ map.remove(k);
+ return 2;
+ }
+ else
+ total += LoopHelpers.compute2(LoopHelpers.compute1(x.intValue()));
+ }
+ else {
+ if (r < insertsPerMaxRandom) {
+ map.put(k, k);
+ return 2;
+ }
+ }
+ return 1;
+ }
+
+ public void run() {
+ try {
+ barrier.await();
+ int ops = nops;
+ while (ops > 0)
+ ops -= step();
+ barrier.await();
+ }
+ catch (Exception ex) {
+ ex.printStackTrace();
+ }
+ }
+ }
+}