1 /*
2 * Copyright (c) 2014, 2015, 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 * @modules java.base/sun.misc
29 * java.management
30 * @run driver RandomGeneratorTest SAME_SEED
31 * @run driver RandomGeneratorTest NO_SEED
32 * @run driver RandomGeneratorTest DIFFERENT_SEED
33 */
34
35 import jdk.test.lib.ProcessTools;
36 import jdk.test.lib.Utils;
37 import java.util.ArrayList;
38 import java.util.List;
39 import java.util.Random;
40
41 /**
42 * The test verifies correctness of work {@link jdk.test.lib.Utils#getRandomInstance()}.
43 * Test works in three modes: same seed provided, no seed provided and
44 * different seed provided. In the first case the test expects that all random numbers
45 * will be repeated in all next iterations. For other two modes test expects that
46 * randomly generated numbers differ from original.
47 */
48 public class RandomGeneratorTest {
49 private static final String SEED_VM_OPTION = "-D" + Utils.SEED_PROPERTY_NAME + "=";
50
51 public static void main( String[] args) throws Throwable {
52 if (args.length == 0) {
53 throw new Error("TESTBUG: No test mode provided.");
54 }
55 SeedOption seedOpt = SeedOption.valueOf(args[0]);
56 List<String> jvmArgs = new ArrayList<String>();
57 String optStr = seedOpt.getSeedOption();
58 if (optStr != null) {
59 jvmArgs.add(optStr);
60 }
61 jvmArgs.add(RandomRunner.class.getName());
62 String[] cmdLineArgs = jvmArgs.toArray(new String[jvmArgs.size()]);
63 String etalon = ProcessTools.executeTestJvm(cmdLineArgs).getStdout().trim();
64 seedOpt.verify(etalon, cmdLineArgs);
65 }
66
67 /**
68 * The utility enum helps to generate an appropriate string that should be passed
69 * to the command line depends on the testing mode. It is also responsible for the result
70 * validation.
71 */
72 private enum SeedOption {
73 SAME_SEED {
74 @Override
75 public String getSeedOption() {
76 return SEED_VM_OPTION + Utils.SEED;
77 }
78
79 @Override
80 protected boolean isOutputExpected(String orig, String output) {
81 return output.equals(orig);
82 }
83 },
84 DIFFERENT_SEED {
85 @Override
86 public String getSeedOption() {
87 return SEED_VM_OPTION + Utils.getRandomInstance().nextLong();
88 }
89
90 @Override
91 public void verify(String orig, String[] cmdLine) {
92 cmdLine[0] = getSeedOption();
93 super.verify(orig, cmdLine);
94 }
95 },
96 NO_SEED {
97 @Override
98 public String getSeedOption() {
99 return null;
100 }
101 };
102
103 /**
104 * Generates a string to be added as a command line argument.
105 * It contains "-D" prefix, system property name, '=' sign
106 * and seed value.
107 * @return command line argument
108 */
109 public abstract String getSeedOption();
110
111 protected boolean isOutputExpected(String orig, String output) {
112 return !output.equals(orig);
113 }
114
115 /**
116 * Verifies that the original output meets expectations
117 * depending on the test mode. It compares the output of second execution
118 * to original one.
119 * @param orig original output
120 * @param cmdLine command line arguments
121 * @throws Throwable - Throws an exception in case test failure.
122 */
123 public void verify(String orig, String[] cmdLine) {
124 String lastLineOrig = getLastLine(orig);
125 String lastLine;
126 try {
127 lastLine = getLastLine(ProcessTools.executeTestJvm(cmdLine).getStdout().trim());
128 } catch (Throwable t) {
129 throw new Error("TESTBUG: Unexpedted exception during jvm execution.", t);
130 }
131 if (!isOutputExpected(lastLineOrig, lastLine)) {
132 throw new AssertionError("Unexpected random number sequence for mode: " + this.name());
133 }
134 }
135
136 private static String getLastLine(String output) {
137 return output.substring(output.lastIndexOf(Utils.NEW_LINE)).trim();
138 }
139 }
140
141 /**
142 * The helper class generates several random numbers
143 * and prints them out.
144 */
145 public static class RandomRunner {
146 private static final int COUNT = 10;
147 public static void main(String[] args) {
148 StringBuilder sb = new StringBuilder();
149 Random rng = Utils.getRandomInstance();
150 for (int i = 0; i < COUNT; i++) {
151 sb.append(rng.nextLong()).append(' ');
152 }
153 System.out.println(sb.toString());
154 }
155 }
156 }