/*
 * Copyright (c) 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.jvm.hotspot.gc.z;

import sun.jvm.hotspot.runtime.VM;
import sun.jvm.hotspot.types.Field;
import sun.jvm.hotspot.types.Type;
import sun.jvm.hotspot.types.TypeDataBase;

public class ZGlobals {
    private static Field instanceField;

    // Global phase state
    public static int ZPhaseRelocate;

    public static byte ZPageTypeSmall;
    public static byte ZPageTypeMedium;
    public static byte ZPageTypeLarge;

    // Page size shifts
    public static long ZPageSizeSmallShift;
    public static long ZPageSizeMediumShift;
    public static long ZPageSizeMinShift;

    // Object alignment shifts
    public static int  ZObjectAlignmentMediumShift;
    public static int  ZObjectAlignmentLargeShift;

    // Pointer part of address
    public static long ZAddressOffsetShift;

    // Pointer part of address
    public static long ZAddressOffsetBits;
    public static long ZAddressOffsetMask;
    public static long ZAddressOffsetMax;

    // Address space start/end/size
    public static long ZAddressSpaceStart;

    static {
        VM.registerVMInitializedObserver((o, d) -> initialize(VM.getVM().getTypeDataBase()));
    }

    static private synchronized void initialize(TypeDataBase db) {
        Type type = db.lookupType("ZGlobalsForVMStructs");

        instanceField = type.getField("_instance_p");

        ZPhaseRelocate = db.lookupIntConstant("ZPhaseRelocate").intValue();

        ZPageTypeSmall = db.lookupIntConstant("ZPageTypeSmall").byteValue();
        ZPageTypeMedium = db.lookupIntConstant("ZPageTypeMedium").byteValue();
        ZPageTypeLarge = db.lookupIntConstant("ZPageTypeLarge").byteValue();

        ZPageSizeSmallShift = db.lookupLongConstant("ZPageSizeSmallShift").longValue();
        ZPageSizeMediumShift = db.lookupLongConstant("ZPageSizeMediumShift").longValue();
        ZPageSizeMinShift = db.lookupLongConstant("ZPageSizeMinShift").longValue();

        ZObjectAlignmentMediumShift = db.lookupIntConstant("ZObjectAlignmentMediumShift").intValue();
        ZObjectAlignmentLargeShift = db.lookupIntConstant("ZObjectAlignmentLargeShift").intValue();;

        ZAddressOffsetShift = db.lookupLongConstant("ZAddressOffsetShift").longValue();

        ZAddressOffsetBits = db.lookupLongConstant("ZAddressOffsetBits").longValue();
        ZAddressOffsetMask = db.lookupLongConstant("ZAddressOffsetMask").longValue();
        ZAddressOffsetMax  = db.lookupLongConstant("ZAddressOffsetMax").longValue();

        ZAddressSpaceStart = db.lookupLongConstant("ZAddressSpaceStart").longValue();
    }

    private static ZGlobalsForVMStructs instance() {
        return new ZGlobalsForVMStructs(instanceField.getAddress());
    }

    public static int ZGlobalPhase() {
        return instance().ZGlobalPhase();
    }

    public static int ZGlobalSeqNum() {
        return instance().ZGlobalSeqNum();
    }

    public static long ZAddressGoodMask() {
        return instance().ZAddressGoodMask();
    }

    public static long ZAddressBadMask() {
        return instance().ZAddressBadMask();
    }

    public static long ZAddressWeakBadMask() {
        return instance().ZAddressWeakBadMask();
    }

    public static int ZObjectAlignmentSmallShift() {
        return instance().ZObjectAlignmentSmallShift();
    }

    public static int ZObjectAlignmentSmall() {
        return instance().ZObjectAlignmentSmall();
    }
}