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/jdk.internal.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 java.io.FileWriter;
36 import java.io.IOException;
37 import java.io.PrintWriter;
38 import java.util.ArrayList;
39 import java.util.List;
40 import java.util.Random;
41 import jdk.test.lib.OutputAnalyzer;
42 import jdk.test.lib.ProcessTools;
43 import jdk.test.lib.Utils;
44
45 /**
46 * The test verifies correctness of work {@link jdk.test.lib.Utils#getRandomInstance()}.
47 * Test works in three modes: same seed provided, no seed provided and
48 * different seed provided. In the first case the test expects that all random numbers
49 * will be repeated in all next iterations. For other two modes test expects that
50 * randomly generated numbers differ from original.
51 */
52 public class RandomGeneratorTest {
53 private static final String SEED_VM_OPTION = "-D" + Utils.SEED_PROPERTY_NAME + "=";
54
55 public static void main( String[] args) throws Throwable {
56 if (args.length == 0) {
57 throw new Error("TESTBUG: No test mode provided.");
58 }
59 SeedOption seedOpt = SeedOption.valueOf(args[0]);
60 List<String> jvmArgs = new ArrayList<String>();
61 String optStr = seedOpt.getSeedOption();
62 if (optStr != null) {
63 jvmArgs.add(optStr);
64 }
65 jvmArgs.add(RandomRunner.class.getName());
66 String origFileName = seedOpt.name() + "_orig";
67 jvmArgs.add(origFileName);
68 int fileNameIndex = jvmArgs.size() - 1;
69 String[] cmdLineArgs = jvmArgs.toArray(new String[jvmArgs.size()]);
70 ProcessTools.executeTestJvm(cmdLineArgs).shouldHaveExitValue(0);
71 String etalon = Utils.fileAsString(origFileName).trim();
72 cmdLineArgs[fileNameIndex] = seedOpt.name();
73 seedOpt.verify(etalon, cmdLineArgs);
74 }
75
76 /**
77 * The utility enum helps to generate an appropriate string that should be passed
78 * to the command line depends on the testing mode. It is also responsible for the result
79 * validation.
80 */
81 private enum SeedOption {
82 SAME_SEED {
83 @Override
84 public String getSeedOption() {
85 return SEED_VM_OPTION + Utils.SEED;
86 }
87
88 @Override
89 protected boolean isOutputExpected(String orig, String output) {
90 return output.equals(orig);
91 }
92 },
93 DIFFERENT_SEED {
94 @Override
95 public String getSeedOption() {
96 return SEED_VM_OPTION + Utils.getRandomInstance().nextLong();
97 }
98
99 @Override
100 public void verify(String orig, String[] cmdLine) {
101 cmdLine[0] = getSeedOption();
102 super.verify(orig, cmdLine);
103 }
104 },
105 NO_SEED {
106 @Override
107 public String getSeedOption() {
108 return null;
109 }
110 };
111
112 /**
113 * Generates a string to be added as a command line argument.
114 * It contains "-D" prefix, system property name, '=' sign
115 * and seed value.
116 * @return command line argument
117 */
118 public abstract String getSeedOption();
119
120 protected boolean isOutputExpected(String orig, String output) {
121 return !output.equals(orig);
122 }
123
124 /**
125 * Verifies that the original output meets expectations
126 * depending on the test mode. It compares the output of second execution
127 * to original one.
128 * @param orig original output
129 * @param cmdLine command line arguments
130 * @throws Throwable - Throws an exception in case test failure.
131 */
132 public void verify(String orig, String[] cmdLine) {
133 String output;
134 OutputAnalyzer oa;
135 try {
136 oa = ProcessTools.executeTestJvm(cmdLine);
137 } catch (Throwable t) {
138 throw new Error("TESTBUG: Unexpedted exception during jvm execution.", t);
139 }
140 oa.shouldHaveExitValue(0);
141 try {
142 output = Utils.fileAsString(name()).trim();
143 } catch (IOException ioe) {
144 throw new Error("TESTBUG: Problem during IO operation with file: " + name(), ioe);
145 }
146 if (!isOutputExpected(orig, output)) {
147 System.err.println("Initial output: " + orig);
148 System.err.println("Second run output: " + output);
149 throw new AssertionError("Unexpected random number sequence for mode: " + this.name());
150 }
151 }
152 }
153
154 /**
155 * The helper class generates several random numbers
156 * and put results to a file. The file name came as first
157 * command line argument.
158 */
159 public static class RandomRunner {
160 private static final int COUNT = 10;
161 public static void main(String[] args) {
162 StringBuilder sb = new StringBuilder();
163 Random rng = Utils.getRandomInstance();
164 for (int i = 0; i < COUNT; i++) {
165 sb.append(rng.nextLong()).append(' ');
166 }
167 try (PrintWriter pw = new PrintWriter(new FileWriter(args[0]))) {
168 pw.write(sb.toString());
169 } catch (IOException ioe) {
170 throw new Error("TESTBUG: Problem during IO operation with file: " + args[0], ioe);
171 }
172 }
173 }
174 }