/*
 * Copyright (c) 2011, 2012, 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
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 * questions.
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package sun.jvm.hotspot.gc_implementation.g1;

import java.util.Iterator;
import java.util.Observable;
import java.util.Observer;

import sun.jvm.hotspot.debugger.Address;
import sun.jvm.hotspot.gc_interface.CollectedHeap;
import sun.jvm.hotspot.gc_interface.CollectedHeapName;
import sun.jvm.hotspot.memory.MemRegion;
import sun.jvm.hotspot.memory.SpaceClosure;
import sun.jvm.hotspot.runtime.VM;
import sun.jvm.hotspot.runtime.VMObjectFactory;
import sun.jvm.hotspot.types.AddressField;
import sun.jvm.hotspot.types.Type;
import sun.jvm.hotspot.types.TypeDataBase;

// Mirror class for G1CollectedHeap.

public class G1CollectedHeap extends CollectedHeap {
    // HeapRegionManager _hrm;
    static private long hrmFieldOffset;
    // MemRegion _g1_reserved;
    static private long g1ReservedFieldOffset;
    // G1Allocator* _allocator
    static private AddressField g1Allocator;
    // G1MonitoringSupport* _g1mm;
    static private AddressField g1mmField;
    // HeapRegionSet _old_set;
    static private long oldSetFieldOffset;
    // HeapRegionSet _humongous_set;
    static private long humongousSetFieldOffset;

    static {
        VM.registerVMInitializedObserver(new Observer() {
                public void update(Observable o, Object data) {
                    initialize(VM.getVM().getTypeDataBase());
                }
            });
    }

    static private synchronized void initialize(TypeDataBase db) {
        Type type = db.lookupType("G1CollectedHeap");

        hrmFieldOffset = type.getField("_hrm").getOffset();
        g1Allocator = type.getAddressField("_allocator");
        g1mmField = type.getAddressField("_g1mm");
        oldSetFieldOffset = type.getField("_old_set").getOffset();
        humongousSetFieldOffset = type.getField("_humongous_set").getOffset();
    }

    public long capacity() {
        return hrm().capacity();
    }

    public long used() {
        return allocator().getSummaryBytes();
    }

    public long n_regions() {
        return hrm().length();
    }

    private HeapRegionManager hrm() {
        Address hrmAddr = addr.addOffsetTo(hrmFieldOffset);
        return (HeapRegionManager) VMObjectFactory.newObject(HeapRegionManager.class,
                                                         hrmAddr);
    }

    public G1MonitoringSupport g1mm() {
        Address g1mmAddr = g1mmField.getValue(addr);
        return (G1MonitoringSupport) VMObjectFactory.newObject(G1MonitoringSupport.class, g1mmAddr);
    }

    public G1Allocator allocator() {
        Address g1AllocatorAddr = g1Allocator.getValue(addr);
        return (G1Allocator) VMObjectFactory.newObject(G1Allocator.class, g1AllocatorAddr);
    }

    public HeapRegionSetBase oldSet() {
        Address oldSetAddr = addr.addOffsetTo(oldSetFieldOffset);
        return (HeapRegionSetBase) VMObjectFactory.newObject(HeapRegionSetBase.class,
                                                             oldSetAddr);
    }

    public HeapRegionSetBase humongousSet() {
        Address humongousSetAddr = addr.addOffsetTo(humongousSetFieldOffset);
        return (HeapRegionSetBase) VMObjectFactory.newObject(HeapRegionSetBase.class,
                                                             humongousSetAddr);
    }

    private Iterator<HeapRegion> heapRegionIterator() {
        return hrm().heapRegionIterator();
    }

    public void heapRegionIterate(SpaceClosure scl) {
        Iterator<HeapRegion> iter = heapRegionIterator();
        while (iter.hasNext()) {
            HeapRegion hr = iter.next();
            scl.doSpace(hr);
        }
    }

    public CollectedHeapName kind() {
        return CollectedHeapName.G1_COLLECTED_HEAP;
    }

    public G1CollectedHeap(Address addr) {
        super(addr);
    }
}