/*

 * Copyright (c) 2004, 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.runtime;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.oops.*;

import sun.jvm.hotspot.types.*;

public class PerfMemory {

    private static AddressField  startField;

    private static AddressField  endField;

    private static AddressField  topField;

    private static CIntegerField capacityField;

    private static AddressField  prologueField;

    private static JIntField     initializedField;

    static {

        VM.registerVMInitializedObserver(new Observer() {

                public void update(Observable o, Object data) {

                    initialize(VM.getVM().getTypeDataBase());

                }

            });

    }

    private static synchronized void initialize(TypeDataBase db) {

        Type type = db.lookupType("PerfMemory");

        startField = type.getAddressField("_start");

        endField = type.getAddressField("_end");

        topField = type.getAddressField("_top");

        capacityField = type.getCIntegerField("_capacity");

        prologueField = type.getAddressField("_prologue");

        initializedField = type.getJIntField("_initialized");

    }

    // Accessors

    public static Address start() {

        return startField.getValue();

    }

    public static Address end() {

        return endField.getValue();

    }

    public static Address top() {

        return topField.getValue();

    }

    public static long capacity() {

        return capacityField.getValue();

    }

    public static boolean initialized() {

        return ((int) initializedField.getValue()) != 0;

    }

    public static PerfDataPrologue prologue() {

        return (PerfDataPrologue) VMObjectFactory.newObject(

                   PerfDataPrologue.class, prologueField.getValue());

    }

    public static boolean contains(Address addr) {

        return start() != null &&

            addr.minus(start()) >= 0 &&

            end().minus(addr) > 0;

    }

    // an interface supplied to iterate PerfDataEntries

    public static interface PerfDataEntryVisitor {

        // returns false to stop the iteration

        public boolean visit(PerfDataEntry pde);

    }

    public static void iterate(PerfDataEntryVisitor visitor) {

        PerfDataPrologue header = prologue();

        int off = header.entryOffset();

        int num = header.numEntries();

        Address addr = header.getAddress();

        for (int i = 0; i < num; i++) {

            PerfDataEntry pde = (PerfDataEntry) VMObjectFactory.newObject(

                               PerfDataEntry.class, addr.addOffsetTo(off));

            off += pde.entryLength();

            if (visitor.visit(pde) == false) return;

        }

    }

}