1 /*
   2  * Copyright (c) 2012, 2018, 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 
  24 
  25 package org.graalvm.compiler.hotspot.nodes;
  26 
  27 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
  28 
  29 import org.graalvm.compiler.core.common.type.StampFactory;
  30 import org.graalvm.compiler.graph.Node;
  31 import org.graalvm.compiler.graph.NodeClass;
  32 import org.graalvm.compiler.lir.VirtualStackSlot;
  33 import org.graalvm.compiler.nodeinfo.NodeCycles;
  34 import org.graalvm.compiler.nodeinfo.NodeInfo;
  35 import org.graalvm.compiler.nodes.calc.FloatingNode;
  36 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  37 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  38 import org.graalvm.compiler.word.Word;
  39 import org.graalvm.compiler.word.WordTypes;
  40 
  41 import jdk.vm.ci.meta.Value;
  42 
  43 /**
  44  * Node that is used to maintain a stack based counter of how many locks are currently held.
  45  */
  46 @NodeInfo(cycles = NodeCycles.CYCLES_2, size = SIZE_1)
  47 public final class MonitorCounterNode extends FloatingNode implements LIRLowerable, Node.ValueNumberable {
  48     public static final NodeClass<MonitorCounterNode> TYPE = NodeClass.create(MonitorCounterNode.class);
  49 
  50     public MonitorCounterNode(@InjectedNodeParameter WordTypes wordTypes) {
  51         super(TYPE, StampFactory.forKind(wordTypes.getWordKind()));
  52     }
  53 
  54     @Override
  55     public void generate(NodeLIRBuilderTool gen) {
  56         assert graph().getNodes().filter(MonitorCounterNode.class).count() == 1 : "monitor counters not canonicalized to single instance";
  57         VirtualStackSlot counter = gen.getLIRGeneratorTool().getResult().getFrameMapBuilder().allocateStackSlots(1);
  58         Value result = gen.getLIRGeneratorTool().emitAddress(counter);
  59         gen.setResult(this, result);
  60     }
  61 
  62     @NodeIntrinsic
  63     public static native Word counter();
  64 }