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  */
  23 package org.graalvm.compiler.hotspot.nodes;
  24 
  25 import static org.graalvm.compiler.nodeinfo.InputType.Memory;
  26 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
  27 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
  28 
  29 import org.graalvm.compiler.core.common.LocationIdentity;
  30 import org.graalvm.compiler.core.common.type.StampFactory;
  31 import org.graalvm.compiler.graph.NodeClass;
  32 import org.graalvm.compiler.hotspot.HotSpotLIRGenerator;
  33 import org.graalvm.compiler.lir.VirtualStackSlot;
  34 import org.graalvm.compiler.nodeinfo.NodeInfo;
  35 import org.graalvm.compiler.nodes.extended.MonitorEnter;
  36 import org.graalvm.compiler.nodes.memory.AbstractMemoryCheckpoint;
  37 import org.graalvm.compiler.nodes.memory.MemoryCheckpoint;
  38 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  39 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  40 import org.graalvm.compiler.word.Word;
  41 import org.graalvm.compiler.word.WordTypes;
  42 
  43 import 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)
  52 public 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 }