1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     3  *

     4  * This code is free software; you can redistribute it and/or modify it

     5  * under the terms of the GNU General Public License version 2 only, as

     6  * published by the Free Software Foundation.

     7  *

     8  * This code is distributed in the hope that it will be useful, but WITHOUT

     9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    11  * version 2 for more details (a copy is included in the LICENSE file that

    12  * accompanied this code).

    13  *

    14  * You should have received a copy of the GNU General Public License version

    15  * 2 along with this work; if not, write to the Free Software Foundation,

    16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    17  *

    18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    19  * or visit www.oracle.com if you need additional information or have any

    20  * questions.

    21  */

    22 

    23 /*

    24  * This file is available under and governed by the GNU General Public

    25  * License version 2 only, as published by the Free Software Foundation.

    26  * However, the following notice accompanied the original version of this

    27  * file:

    28  *

    29  * Written by Doug Lea with assistance from members of JCP JSR-166

    30  * Expert Group and released to the public domain, as explained at

    31  * http://creativecommons.org/publicdomain/zero/1.0/

    32  */

    33 /*

    34  * @test

    35  * @bug 6785442

    36  * @summary Benchmark that tries to GC-tenure head, followed by

    37  * many add/remove operations.

    38  * @run main GCRetention 12345

    39  */

    40 

    41 import static java.util.concurrent.TimeUnit.SECONDS;

    42 

    43 import java.lang.ref.WeakReference;

    44 import java.util.concurrent.ArrayBlockingQueue;

    45 import java.util.concurrent.ConcurrentHashMap;

    46 import java.util.concurrent.ConcurrentLinkedDeque;

    47 import java.util.concurrent.ConcurrentLinkedQueue;

    48 import java.util.concurrent.CountDownLatch;

    49 import java.util.concurrent.LinkedBlockingDeque;

    50 import java.util.concurrent.LinkedBlockingQueue;

    51 import java.util.concurrent.LinkedTransferQueue;

    52 import java.util.concurrent.PriorityBlockingQueue;

    53 import java.util.LinkedList;

    54 import java.util.PriorityQueue;

    55 import java.util.ArrayList;

    56 import java.util.Collection;

    57 import java.util.Collections;

    58 import java.util.List;

    59 import java.util.Queue;

    60 import java.util.Map;

    61 

    62 public class GCRetention {

    63     // Suitable for benchmarking.  Overridden by args[0] for testing.

    64     int count = 1024 * 1024;

    65 

    66     /** No guarantees, but effective in practice. */

    67     static void forceFullGc() {

    68         CountDownLatch finalizeDone = new CountDownLatch(1);

    69         WeakReference<?> ref = new WeakReference<Object>(new Object() {

    70             protected void finalize() { finalizeDone.countDown(); }});

    71         try {

    72             for (int i = 0; i < 10; i++) {

    73                 System.gc();

    74                 if (finalizeDone.await(1L, SECONDS) && ref.get() == null) {

    75                     System.runFinalization(); // try to pick up stragglers

    76                     return;

    77                 }

    78             }

    79         } catch (InterruptedException unexpected) {

    80             throw new AssertionError("unexpected InterruptedException");

    81         }

    82         throw new AssertionError("failed to do a \"full\" gc");

    83     }

    84 

    85     final Map<String,String> results = new ConcurrentHashMap<>();

    86 

    87     Collection<Queue<Boolean>> queues() {

    88         List<Queue<Boolean>> queues = new ArrayList<>();

    89         queues.add(new ConcurrentLinkedDeque<Boolean>());

    90         queues.add(new ConcurrentLinkedQueue<Boolean>());

    91         queues.add(new ArrayBlockingQueue<Boolean>(count, false));

    92         queues.add(new ArrayBlockingQueue<Boolean>(count, true));

    93         queues.add(new LinkedBlockingQueue<Boolean>());

    94         queues.add(new LinkedBlockingDeque<Boolean>());

    95         queues.add(new PriorityBlockingQueue<Boolean>());

    96         queues.add(new PriorityQueue<Boolean>());

    97         queues.add(new LinkedList<Boolean>());

    98         queues.add(new LinkedTransferQueue<Boolean>());

    99 

   100         // Following additional implementations are available from:

   101         // http://gee.cs.oswego.edu/dl/concurrency-interest/index.html

   102         // queues.add(new SynchronizedLinkedListQueue<Boolean>());

   103 

   104         // Avoid "first fast, second slow" benchmark effect.

   105         Collections.shuffle(queues);

   106         return queues;

   107     }

   108 

   109     void prettyPrintResults() {

   110         List<String> classNames = new ArrayList<>(results.keySet());

   111         Collections.sort(classNames);

   112         int maxClassNameLength = 0;

   113         int maxNanosLength = 0;

   114         for (String name : classNames) {

   115             if (maxClassNameLength < name.length())

   116                 maxClassNameLength = name.length();

   117             if (maxNanosLength < results.get(name).length())

   118                 maxNanosLength = results.get(name).length();

   119         }

   120         String format = String.format("%%%ds %%%ds nanos/item%%n",

   121                                       maxClassNameLength, maxNanosLength);

   122         for (String name : classNames)

   123             System.out.printf(format, name, results.get(name));

   124     }

   125 

   126     void test(String[] args) {

   127         if (args.length > 0)

   128             count = Integer.valueOf(args[0]);

   129         // Warmup

   130         for (Queue<Boolean> queue : queues())

   131             test(queue);

   132         results.clear();

   133         for (Queue<Boolean> queue : queues())

   134             test(queue);

   135 

   136         prettyPrintResults();

   137     }

   138 

   139     void test(Queue<Boolean> q) {

   140         long t0 = System.nanoTime();

   141         for (int i = 0; i < count; i++)

   142             check(q.add(Boolean.TRUE));

   143         forceFullGc();

   144         // forceFullGc();

   145         Boolean x;

   146         while ((x = q.poll()) != null)

   147             equal(x, Boolean.TRUE);

   148         check(q.isEmpty());

   149 

   150         for (int i = 0; i < 10 * count; i++) {

   151             for (int k = 0; k < 3; k++)

   152                 check(q.add(Boolean.TRUE));

   153             for (int k = 0; k < 3; k++)

   154                 if (q.poll() != Boolean.TRUE)

   155                     fail();

   156         }

   157         check(q.isEmpty());

   158 

   159         String className = q.getClass().getSimpleName();

   160         long elapsed = System.nanoTime() - t0;

   161         int nanos = (int) ((double) elapsed / (10 * 3 * count));

   162         results.put(className, String.valueOf(nanos));

   163     }

   164 

   165     //--------------------- Infrastructure ---------------------------

   166     volatile int passed = 0, failed = 0;

   167     void pass() {passed++;}

   168     void fail() {failed++; Thread.dumpStack();}

   169     void fail(String msg) {System.err.println(msg); fail();}

   170     void unexpected(Throwable t) {failed++; t.printStackTrace();}

   171     void check(boolean cond) {if (cond) pass(); else fail();}

   172     void equal(Object x, Object y) {

   173         if (x == null ? y == null : x.equals(y)) pass();

   174         else fail(x + " not equal to " + y);}

   175     public static void main(String[] args) throws Throwable {

   176         new GCRetention().instanceMain(args);}

   177     public void instanceMain(String[] args) throws Throwable {

   178         try {test(args);} catch (Throwable t) {unexpected(t);}

   179         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);

   180         if (failed > 0) throw new AssertionError("Some tests failed");}

   181 }