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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
 * 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).
 *
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 * 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
 * @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");
    }
  }
}