1/*
2 * Copyright (c) 1998, 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/* @test
25   @bug 4098742
26   @summary Test biginteger modpow method
27   @author Michael McCloskey
28   @run main/othervm ModPowPowersof2
29*/
30
31import java.math.BigInteger;
32import java.io.BufferedReader;
33import java.io.InputStreamReader;
34import java.io.File;
35import java.io.IOException;
36
37/**
38 * This class tests to see if using modPow on a power
39 * of two crashes the vm
40 *
41 */
42public class ModPowPowersof2 {
43
44      public static void main(String args[]) throws Exception {
45          // Construct a command that runs the test in other vm
46          String[] command = new String[4];
47          int n = 0;
48
49          command[n++] = System.getProperty("java.home") + File.separator +
50              "bin" + File.separator + "java";
51          if (System.getProperty("java.class.path") != null) {
52              command[n++] = "-classpath";
53              command[n++] = System.getProperty("java.class.path");
54          }
55
56          command[n++] = "ModPowPowersof2$ModTester";
57
58          // Exec another vm to run test in
59          Process p = null;
60          p = Runtime.getRuntime().exec(command);
61
62          // Read the result to determine if test failed
63          BufferedReader in = new BufferedReader(new InputStreamReader(
64                                             p.getInputStream()));
65          String s;
66          s = in.readLine();
67          if (s == null)
68              throw new RuntimeException("ModPow causes vm crash");
69
70     }
71
72    public static class ModTester {
73        public static void main(String [] args) {
74            BigInteger two = BigInteger.valueOf(2);
75            BigInteger four = BigInteger.valueOf(4);
76
77            two.modPow(two, BigInteger.valueOf(4));
78            two.modPow(two, BigInteger.valueOf(8));
79            two.modPow(four, BigInteger.valueOf(8));
80
81            System.out.println("success");
82        }
83    }
84
85}
86