/*

 * Copyright (c) 2013, 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * @test

 * @key regression

 * @bug 8012015

 * @summary Make sure reserved (but uncommitted) memory is not accessible

 * @library /testlibrary /testlibrary/whitebox

 * @build ReserveMemory

 * @run main ClassFileInstaller sun.hotspot.WhiteBox

 * @run main ReserveMemory

 */

import com.oracle.java.testlibrary.*;

import java.lang.reflect.Field;

import sun.hotspot.WhiteBox;

import sun.misc.Unsafe;

public class ReserveMemory {

  private static Unsafe getUnsafe() throws Exception {

    Field f = Unsafe.class.getDeclaredField("theUnsafe");

    f.setAccessible(true);

    return (Unsafe)f.get(null);

  }

  private static boolean isWindows() {

    return System.getProperty("os.name").toLowerCase().startsWith("win");

  }

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

    if (args.length > 0) {

      long address = WhiteBox.getWhiteBox().reserveMemory(4096);

      System.out.println("Reserved memory at address: 0x" + Long.toHexString(address));

      System.out.println("Will now read from the address, expecting a crash!");

      int x = getUnsafe().getInt(address);

      throw new Exception("Read of reserved/uncommitted memory unexpectedly succeeded, expected crash!");

    }

    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(

          "-Xbootclasspath/a:.",

          "-XX:+UnlockDiagnosticVMOptions",

          "-XX:+WhiteBoxAPI",

          "ReserveMemory",

          "test");

    OutputAnalyzer output = new OutputAnalyzer(pb.start());

    if (isWindows()) {

      output.shouldContain("EXCEPTION_ACCESS_VIOLATION");

    } else {

      output.shouldContain("SIGSEGV");

    }

  }

}