1 /*
   2  * Copyright (c) 2014, 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  * @test
  26  * @summary Verify correctnes of the random generator from Utility.java
  27  * @library /testlibrary
  28  * @run driver RandomGeneratorTest SAME_SEED
  29  * @run driver RandomGeneratorTest NO_SEED
  30  * @run driver RandomGeneratorTest DIFFERENT_SEED
  31  */
  32 
  33 import com.oracle.java.testlibrary.ProcessTools;
  34 import com.oracle.java.testlibrary.Utils;
  35 import java.util.ArrayList;
  36 import java.util.List;
  37 import java.util.Random;
  38 
  39 /**
  40  * The test verifies correctness of work {@link com.oracle.java.testlibrary.Utils#getRandomInstance()}.
  41  * Test works in three modes: same seed provided, no seed provided and
  42  * different seed provided. In the first case the test expects that all random numbers
  43  * will be repeated in all next iterations. For other two modes test expects that
  44  * randomly generated numbers differ from original.
  45  */
  46 public class RandomGeneratorTest {
  47     private static final String SEED_VM_OPTION = "-D" + Utils.SEED_PROPERTY_NAME + "=";
  48 
  49     public static void main( String[] args) throws Throwable {
  50         if (args.length == 0) {
  51             throw new Error("TESTBUG: No test mode provided.");
  52         }
  53         SeedOption seedOpt = SeedOption.valueOf(args[0]);
  54         List<String> jvmArgs = new ArrayList<String>();
  55         String optStr = seedOpt.getSeedOption();
  56         if (optStr != null) {
  57             jvmArgs.add(optStr);
  58         }
  59         jvmArgs.add(RandomRunner.class.getName());
  60         String[] cmdLineArgs = jvmArgs.toArray(new String[jvmArgs.size()]);
  61         String etalon = ProcessTools.executeTestJvm(cmdLineArgs).getOutput().trim();
  62         seedOpt.verify(etalon, cmdLineArgs);
  63     }
  64 
  65     /**
  66      * The utility enum helps to generate an appropriate string that should be passed
  67      * to the command line depends on the testing mode. It is also responsible for the result
  68      * validation.
  69      */
  70     private enum SeedOption {
  71         SAME_SEED {
  72             @Override
  73             public String getSeedOption() {
  74                 return SEED_VM_OPTION + Utils.SEED;
  75             }
  76 
  77             @Override
  78             protected boolean isOutputExpected(String orig, String output) {
  79                 return output.equals(orig);
  80             }
  81         },
  82         DIFFERENT_SEED {
  83             @Override
  84             public String getSeedOption() {
  85                 return SEED_VM_OPTION + Utils.getRandomInstance().nextLong();
  86             }
  87 
  88             @Override
  89             public void verify(String orig, String[] cmdLine) {
  90                 cmdLine[0] = getSeedOption();
  91                 super.verify(orig, cmdLine);
  92             }
  93         },
  94         NO_SEED {
  95             @Override
  96             public String getSeedOption() {
  97                 return null;
  98             }
  99         };
 100 
 101         /**
 102          * Generates a string to be added as a command line argument.
 103          * It contains "-D" prefix, system property name, '=' sign
 104          * and seed value.
 105          * @return command line argument
 106          */
 107         public abstract String getSeedOption();
 108 
 109         protected boolean isOutputExpected(String orig, String output) {
 110             return !output.equals(orig);
 111         }
 112 
 113         /**
 114          * Verifies that the original output meets expectations
 115          * depending on the test mode. It compares the output of second execution
 116          * to original one.
 117          * @param orig original output
 118          * @param cmdLine command line arguments
 119          * @throws Throwable - Throws an exception in case test failure.
 120          */
 121         public void verify(String orig, String[] cmdLine) {
 122             String lastLineOrig = getLastLine(orig);
 123             String lastLine;
 124             try {
 125                 lastLine = getLastLine(ProcessTools.executeTestJvm(cmdLine).getOutput().trim());
 126             } catch (Throwable t) {
 127                 throw new Error("TESTBUG: Unexpedted exception during jvm execution.", t);
 128             }
 129             if (!isOutputExpected(lastLineOrig, lastLine)) {
 130                     throw new AssertionError("Unexpected random number sequence for mode: " + this.name());
 131             }
 132         }
 133 
 134         private static String getLastLine(String output) {
 135             return output.substring(output.lastIndexOf(Utils.NEW_LINE)).trim();
 136         }
 137     }
 138 
 139     /**
 140      * The helper class generates several random numbers
 141      * and prints them out.
 142      */
 143     public static class RandomRunner {
 144         private static final int COUNT = 10;
 145         public static void main(String[] args) {
 146             StringBuilder sb = new StringBuilder();
 147             Random rng = Utils.getRandomInstance();
 148             for (int i = 0; i < COUNT; i++) {
 149                 sb.append(rng.nextLong()).append(' ');
 150             }
 151             System.out.println(sb.toString());
 152         }
 153     }
 154 }