/*

 * Copyright (c) 2016, 2018, 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.

 */

package sun.hotspot.gc;

import sun.hotspot.WhiteBox;

/**

 * API to obtain information about selected and supported Garbage Collectors

 * retrieved from the VM with the WhiteBox API.

 */

public enum GC {

    /*

     * Enum values must match CollectedHeap::Name

     */

    Serial(1),

    Parallel(2),

    ConcMarkSweep(3),

    G1(4),

    Epsilon(5),

    Z(6),

    Shenandoah(7);

    private static final WhiteBox WB = WhiteBox.getWhiteBox();

    private final int name;

    private GC(int name) {

        this.name = name;

    }

    /**

     * @return true if this GC is supported by the VM, i.e., it is built into the VM.

     */

    public boolean isSupported() {

        return WB.isGCSupported(name);

    }

    /**

     * @return true if this GC is currently selected/used

     */

    public boolean isSelected() {

        return WB.isGCSelected(name);

    }

    /**

     * @return true if GC was selected ergonomically, as opposed

     *         to being explicitly specified on the command line

     */

    public static boolean isSelectedErgonomically() {

        return WB.isGCSelectedErgonomically();

    }

}