/*

 * Copyright (c) 1998, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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 */

/* @test

   @bug 4098742

   @summary Test biginteger modpow method

   @author Michael McCloskey

   @run main/othervm ModPowPowersof2

*/

import java.math.BigInteger;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.io.File;

import java.io.IOException;

/**

 * This class tests to see if using modPow on a power

 * of two crashes the vm

 *

 */

public class ModPowPowersof2 {

      public static void main(String args[]) throws Exception {

          // Construct a command that runs the test in other vm

          String[] command = new String[4];

          int n = 0;

          command[n++] = System.getProperty("java.home") + File.separator +

              "bin" + File.separator + "java";

          if (System.getProperty("java.class.path") != null) {

              command[n++] = "-classpath";

              command[n++] = System.getProperty("java.class.path");

          }

          command[n++] = "ModPowPowersof2$ModTester";

          // Exec another vm to run test in

          Process p = null;

          p = Runtime.getRuntime().exec(command);

          // Read the result to determine if test failed

          BufferedReader in = new BufferedReader(new InputStreamReader(

                                             p.getInputStream()));

          String s;

          s = in.readLine();

          if (s == null)

              throw new RuntimeException("ModPow causes vm crash");

     }

    public static class ModTester {

        public static void main(String [] args) {

            BigInteger two = BigInteger.valueOf(2);

            BigInteger four = BigInteger.valueOf(4);

            two.modPow(two, BigInteger.valueOf(4));

            two.modPow(two, BigInteger.valueOf(8));

            two.modPow(four, BigInteger.valueOf(8));

            System.out.println("success");

        }

    }

}