1 /*
   2  * Copyright (c) 2007, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 
  25 /*
  26  * @test
  27  * @key stress gc
  28  *
  29  * @summary converted from VM Testbase gc/gctests/StringIntern.
  30  * VM Testbase keywords: [gc, stress, stressopt, nonconcurrent]
  31  *
  32  * @library /vmTestbase
  33  *          /test/lib
  34  * @run driver jdk.test.lib.FileInstaller . .
  35  * @run main/othervm gc.gctests.StringIntern.StringIntern
  36  */
  37 
  38 package gc.gctests.StringIntern;
  39 
  40 import nsk.share.test.*;
  41 import nsk.share.gc.*;
  42 
  43 /**
  44  * Test that strings returned by String.intern() can be collected.
  45  *
  46  * Create strings consisting of random characters, call String.intern().
  47  * Check that intern() contract.
  48  */
  49 public class StringIntern extends ThreadedGCTest {
  50         private int maxLength = 1000;
  51         private int checkCount = 100;
  52 
  53         private class StringGenerator implements Runnable {
  54                 private StringBuffer sb = new StringBuffer();
  55 
  56                 private void generateRandomBuffer() {
  57                         int length = LocalRandom.nextInt(maxLength);
  58                         for (int i = 0; i < length; ++i)
  59                                 sb.append((char) LocalRandom.nextInt(Integer.MAX_VALUE));
  60                 }
  61 
  62                 private String getString() {
  63                         return sb.toString();
  64                 }
  65 
  66                 public void run() {
  67                         generateRandomBuffer();
  68                         for (int i = 0; i < checkCount; ++i) {
  69                                 String s1 = getString();
  70                                 String s2 = getString();
  71                                 if (s1.intern() != s2.intern()) {
  72                                         log.error("Test failed on: " + s1);
  73                                         setFailed(true);
  74                                 }
  75                         }
  76                 }
  77         }
  78 
  79         protected Runnable createRunnable(int i) {
  80                 return new StringGenerator();
  81         }
  82 
  83         public static void main(String[] args) {
  84                 GC.runTest(new StringIntern(), args);
  85         }
  86 }