--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/util/concurrent/ConcurrentHashMap/MapLoops.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,248 @@
+/*
+ * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.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/publicdomain/zero/1.0/
+ */
+
+/*
+ * @test
+ * @bug 4486658
+ * @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.)
+ * @library /lib/testlibrary/
+ * @run main/timeout=1600 MapLoops
+ */
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+import java.util.List;
+import java.util.Map;
+import java.util.SplittableRandom;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import jdk.testlibrary.Utils;
+
+public class MapLoops {
+ static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
+ static int nkeys = 1000; // 10_000
+ static int pinsert = 60;
+ static int premove = 2;
+ static int maxThreads = 100;
+ static int nops = 10000; // 100_000
+ static int removesPerMaxRandom;
+ static int insertsPerMaxRandom;
+
+ static final ExecutorService pool = Executors.newCachedThreadPool();
+
+ static final List<Throwable> throwables = new CopyOnWriteArrayList<>();
+
+ 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 = java.util.concurrent.ConcurrentHashMap.class;
+
+ if (args.length > 1)
+ maxThreads = Integer.parseInt(args[1]);
+
+ if (args.length > 2)
+ nkeys = Integer.parseInt(args[2]);
+
+ if (args.length > 3)
+ pinsert = Integer.parseInt(args[3]);
+
+ if (args.length > 4)
+ premove = Integer.parseInt(args[4]);
+
+ if (args.length > 5)
+ nops = Integer.parseInt(args[5]);
+
+ // normalize probabilities wrt random number generator
+ removesPerMaxRandom = (int)(((double)premove/100.0 * 0x7FFFFFFFL));
+ insertsPerMaxRandom = (int)(((double)pinsert/100.0 * 0x7FFFFFFFL));
+
+ System.out.print("Class: " + mapClass.getName());
+ System.out.print(" threads: " + maxThreads);
+ System.out.print(" size: " + nkeys);
+ System.out.print(" ins: " + pinsert);
+ System.out.print(" rem: " + premove);
+ System.out.print(" ops: " + nops);
+ System.out.println();
+
+ int k = 1;
+ int warmups = 2;
+ for (int i = 1; i <= maxThreads;) {
+ test(i, nkeys, mapClass);
+ if (warmups > 0)
+ --warmups;
+ else if (i == k) {
+ k = i << 1;
+ i = i + (i >>> 1);
+ }
+ else if (i == 1 && k == 2) {
+ i = k;
+ warmups = 1;
+ }
+ else
+ i = k;
+ }
+ pool.shutdown();
+ if (! pool.awaitTermination(LONG_DELAY_MS, MILLISECONDS))
+ throw new Error();
+
+ if (! throwables.isEmpty())
+ throw new Error
+ (throwables.size() + " thread(s) terminated abruptly.");
+ }
+
+ static Integer[] makeKeys(int n) {
+ SplittableRandom rnd = new SplittableRandom();
+ Integer[] key = new Integer[n];
+ for (int i = 0; i < key.length; ++i)
+ key[i] = new Integer(rnd.nextInt());
+ return key;
+ }
+
+ static void shuffleKeys(Integer[] key) {
+ SplittableRandom rnd = new SplittableRandom();
+ for (int i = key.length; i > 1; --i) {
+ int j = rnd.nextInt(i);
+ Integer tmp = key[j];
+ key[j] = key[i-1];
+ key[i-1] = tmp;
+ }
+ }
+
+ static void test(int i, int nkeys, Class mapClass) throws Exception {
+ System.out.print("Threads: " + i + "\t:");
+ Map<Integer, Integer> map = (Map<Integer,Integer>)mapClass.newInstance();
+ Integer[] key = makeKeys(nkeys);
+ // Uncomment to start with a non-empty table
+ // for (int j = 0; j < nkeys; j += 4) // start 1/4 occupied
+ // map.put(key[j], key[j]);
+ LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
+ CyclicBarrier barrier = new CyclicBarrier(i+1, timer);
+ SplittableRandom rnd = new SplittableRandom();
+ for (int t = 0; t < i; ++t)
+ pool.execute(new Runner(map, key, barrier, rnd.split()));
+ 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();
+ }
+
+ static class Runner implements Runnable {
+ final Map<Integer,Integer> map;
+ final Integer[] key;
+ final CyclicBarrier barrier;
+ final SplittableRandom rnd;
+ int position;
+ int total;
+
+ Runner(Map<Integer,Integer> map,
+ Integer[] key,
+ CyclicBarrier barrier,
+ SplittableRandom rnd) {
+ this.map = map;
+ this.key = key;
+ this.barrier = barrier;
+ this.rnd = rnd;
+ position = key.length / 2;
+ }
+
+ int step() {
+ // random-walk around key positions, bunching accesses
+ int r = rnd.nextInt(Integer.MAX_VALUE);
+ 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) {
+ if (map.remove(k) != null) {
+ position = total % key.length; // move from position
+ return 2;
+ }
+ }
+ }
+ else if (r < insertsPerMaxRandom) {
+ ++position;
+ map.put(k, k);
+ return 2;
+ }
+
+ // Uncomment to add a little computation between accesses
+ // total += LoopHelpers.compute1(k.intValue());
+ total += r;
+ return 1;
+ }
+
+ public void run() {
+ try {
+ barrier.await();
+ int ops = nops;
+ while (ops > 0)
+ ops -= step();
+ barrier.await();
+ }
+ catch (Throwable throwable) {
+ synchronized (System.err) {
+ System.err.println("--------------------------------");
+ throwable.printStackTrace();
+ }
+ throwables.add(throwable);
+ }
+ }
+ }
+}