001/*
002 * Copyright (c) 2012, 2015, 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 jdk.internal.jvmci.code.*;
026import jdk.internal.jvmci.meta.*;
027
028import com.oracle.graal.compiler.common.type.*;
029import com.oracle.graal.graph.*;
030import com.oracle.graal.hotspot.*;
031import com.oracle.graal.nodeinfo.*;
032import com.oracle.graal.nodes.extended.*;
033import com.oracle.graal.nodes.memory.*;
034import com.oracle.graal.nodes.spi.*;
035import com.oracle.graal.word.*;
036
037/**
038 * Intrinsic for opening a scope binding a stack-based lock with an object. A lock scope must be
039 * closed with an {@link EndLockScopeNode}. The frame state after this node denotes that the object
040 * is locked (ensuring the GC sees and updates the object) so it must come after any null pointer
041 * check on the object.
042 */
043@NodeInfo(allowedUsageTypes = {InputType.Memory})
044public final class BeginLockScopeNode extends AbstractMemoryCheckpoint implements LIRLowerable, MonitorEnter, MemoryCheckpoint.Single {
045
046    public static final NodeClass<BeginLockScopeNode> TYPE = NodeClass.create(BeginLockScopeNode.class);
047    protected int lockDepth;
048
049    public BeginLockScopeNode(@InjectedNodeParameter WordTypes wordTypes, int lockDepth) {
050        super(TYPE, StampFactory.forKind(wordTypes.getWordKind()));
051        this.lockDepth = lockDepth;
052    }
053
054    @Override
055    public boolean hasSideEffect() {
056        return false;
057    }
058
059    @Override
060    public LocationIdentity getLocationIdentity() {
061        return LocationIdentity.any();
062    }
063
064    @Override
065    public void generate(NodeLIRBuilderTool gen) {
066        assert lockDepth != -1;
067        HotSpotLIRGenerator hsGen = (HotSpotLIRGenerator) gen.getLIRGeneratorTool();
068        StackSlotValue slot = hsGen.getLockSlot(lockDepth);
069        Value result = gen.getLIRGeneratorTool().emitAddress(slot);
070        gen.setResult(this, result);
071    }
072
073    @NodeIntrinsic
074    public static native Word beginLockScope(@ConstantNodeParameter int lockDepth);
075}