Java example source code file (ReleaseCommittedMemory.java)

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Java - Java tags/keywords

exception, releasecommittedmemory, whitebox

The ReleaseCommittedMemory.java Java example source code

/*
 * 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
 * @bug 8013120
 * @summary Release committed memory and make sure NMT handles it correctly
 * @key nmt regression
 * @library /testlibrary /testlibrary/whitebox
 * @build ReleaseCommittedMemory
 * @run main ClassFileInstaller sun.hotspot.WhiteBox
 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:NativeMemoryTracking=detail ReleaseCommittedMemory
 */

import sun.hotspot.WhiteBox;

public class ReleaseCommittedMemory {

  public static void main(String args[]) throws Exception {
    WhiteBox wb = WhiteBox.getWhiteBox();
    long reserveSize = 256 * 1024;
    long addr;

    addr = wb.NMTReserveMemory(reserveSize);
    wb.NMTCommitMemory(addr, 128*1024);
    wb.NMTReleaseMemory(addr, reserveSize);
    wb.NMTWaitForDataMerge();
  }
}