/*
 * Copyright (c) 2012, 2016, 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 org.graalvm.compiler.hotspot.nodes;

import static org.graalvm.compiler.nodeinfo.InputType.Memory;
import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;

import org.graalvm.compiler.core.common.type.StampFactory;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.hotspot.HotSpotLIRGenerator;
import org.graalvm.compiler.lir.VirtualStackSlot;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.extended.MonitorEnter;
import org.graalvm.compiler.nodes.memory.AbstractMemoryCheckpoint;
import org.graalvm.compiler.nodes.memory.MemoryCheckpoint;
import org.graalvm.compiler.nodes.spi.LIRLowerable;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
import org.graalvm.compiler.word.Word;
import org.graalvm.compiler.word.WordTypes;
import jdk.internal.vm.compiler.word.LocationIdentity;

import jdk.vm.ci.meta.JavaKind;
import jdk.vm.ci.meta.Value;

Intrinsic for opening a scope binding a stack-based lock with an object. A lock scope must be closed with an EndLockScopeNode. The frame state after this node denotes that the object is locked (ensuring the GC sees and updates the object) so it must come after any null pointer check on the object. /**
 * Intrinsic for opening a scope binding a stack-based lock with an object. A lock scope must be
 * closed with an {@link EndLockScopeNode}. The frame state after this node denotes that the object
 * is locked (ensuring the GC sees and updates the object) so it must come after any null pointer
 * check on the object.
 */
@NodeInfo(allowedUsageTypes = Memory, cycles = CYCLES_2, size = SIZE_1)
public final class BeginLockScopeNode extends AbstractMemoryCheckpoint implements LIRLowerable, MonitorEnter, MemoryCheckpoint.Single {

    public static final NodeClass<BeginLockScopeNode> TYPE = NodeClass.create(BeginLockScopeNode.class);
    protected int lockDepth;

    public BeginLockScopeNode(@InjectedNodeParameter WordTypes wordTypes, int lockDepth) {
        super(TYPE, StampFactory.forKind(wordTypes.getWordKind()));
        this.lockDepth = lockDepth;
    }

    public BeginLockScopeNode(JavaKind kind, int lockDepth) {
        super(TYPE, StampFactory.forKind(kind));
        this.lockDepth = lockDepth;
    }

    @Override
    public boolean hasSideEffect() {
        return false;
    }

    @Override
    public LocationIdentity getLocationIdentity() {
        return LocationIdentity.any();
    }

    @Override
    public void generate(NodeLIRBuilderTool gen) {
        assert lockDepth != -1;
        HotSpotLIRGenerator hsGen = (HotSpotLIRGenerator) gen.getLIRGeneratorTool();
        VirtualStackSlot slot = hsGen.getLockSlot(lockDepth);
        Value result = gen.getLIRGeneratorTool().emitAddress(slot);
        gen.setResult(this, result);
    }

    @NodeIntrinsic
    public static native Word beginLockScope(@ConstantNodeParameter int lockDepth);
}