001/*
002 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.hotspot.nodes;
024
025import java.util.*;
026
027import jdk.internal.jvmci.code.*;
028import jdk.internal.jvmci.meta.*;
029
030import com.oracle.graal.compiler.common.type.*;
031import com.oracle.graal.graph.*;
032import com.oracle.graal.nodeinfo.*;
033import com.oracle.graal.nodes.calc.*;
034import com.oracle.graal.nodes.spi.*;
035import com.oracle.graal.word.*;
036
037/**
038 * Node that is used to maintain a stack based counter of how many locks are currently held.
039 */
040@NodeInfo
041public final class MonitorCounterNode extends FloatingNode implements LIRLowerable {
042    public static final NodeClass<MonitorCounterNode> TYPE = NodeClass.create(MonitorCounterNode.class);
043
044    public MonitorCounterNode(@InjectedNodeParameter WordTypes wordTypes) {
045        super(TYPE, StampFactory.forKind(wordTypes.getWordKind()));
046    }
047
048    @Override
049    public void generate(NodeLIRBuilderTool gen) {
050        assert graph().getNodes().filter(MonitorCounterNode.class).count() == 1 : "monitor counters not canonicalized to single instance";
051        VirtualStackSlot counter = gen.getLIRGeneratorTool().getResult().getFrameMapBuilder().allocateStackSlots(1, new BitSet(0), null);
052        Value result = gen.getLIRGeneratorTool().emitAddress(counter);
053        gen.setResult(this, result);
054    }
055
056    @NodeIntrinsic
057    public static native Word counter();
058}