BeginLockScopeNode.java revision 12651:6ef01bd40ce2 
1/*
2 * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23package org.graalvm.compiler.hotspot.nodes;
24
25import static org.graalvm.compiler.nodeinfo.InputType.Memory;
26import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
27import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
28
29import org.graalvm.compiler.core.common.LocationIdentity;
30import org.graalvm.compiler.core.common.type.StampFactory;
31import org.graalvm.compiler.graph.NodeClass;
32import org.graalvm.compiler.hotspot.HotSpotLIRGenerator;
33import org.graalvm.compiler.lir.VirtualStackSlot;
34import org.graalvm.compiler.nodeinfo.NodeInfo;
35import org.graalvm.compiler.nodes.extended.MonitorEnter;
36import org.graalvm.compiler.nodes.memory.AbstractMemoryCheckpoint;
37import org.graalvm.compiler.nodes.memory.MemoryCheckpoint;
38import org.graalvm.compiler.nodes.spi.LIRLowerable;
39import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
40import org.graalvm.compiler.word.Word;
41import org.graalvm.compiler.word.WordTypes;
42
43import jdk.vm.ci.meta.Value;
44
45/**
46 * Intrinsic for opening a scope binding a stack-based lock with an object. A lock scope must be
47 * closed with an {@link EndLockScopeNode}. The frame state after this node denotes that the object
48 * is locked (ensuring the GC sees and updates the object) so it must come after any null pointer
49 * check on the object.
50 */
51@NodeInfo(allowedUsageTypes = Memory, cycles = CYCLES_2, size = SIZE_1)
52public final class BeginLockScopeNode extends AbstractMemoryCheckpoint implements LIRLowerable, MonitorEnter, MemoryCheckpoint.Single {
53
54    public static final NodeClass<BeginLockScopeNode> TYPE = NodeClass.create(BeginLockScopeNode.class);
55    protected int lockDepth;
56
57    public BeginLockScopeNode(@InjectedNodeParameter WordTypes wordTypes, int lockDepth) {
58        super(TYPE, StampFactory.forKind(wordTypes.getWordKind()));
59        this.lockDepth = lockDepth;
60    }
61
62    @Override
63    public boolean hasSideEffect() {
64        return false;
65    }
66
67    @Override
68    public LocationIdentity getLocationIdentity() {
69        return LocationIdentity.any();
70    }
71
72    @Override
73    public void generate(NodeLIRBuilderTool gen) {
74        assert lockDepth != -1;
75        HotSpotLIRGenerator hsGen = (HotSpotLIRGenerator) gen.getLIRGeneratorTool();
76        VirtualStackSlot slot = hsGen.getLockSlot(lockDepth);
77        Value result = gen.getLIRGeneratorTool().emitAddress(slot);
78        gen.setResult(this, result);
79    }
80
81    @NodeIntrinsic
82    public static native Word beginLockScope(@ConstantNodeParameter int lockDepth);
83}
84