1 /*
   2  * Copyright (c) 2011, 2015, 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.nodes.java;
  24 
  25 import static org.graalvm.compiler.nodeinfo.InputType.State;
  26 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_UNKNOWN;
  27 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_20;
  28 import static org.graalvm.compiler.nodes.java.ForeignCallDescriptors.REGISTER_FINALIZER;
  29 
  30 import org.graalvm.compiler.core.common.spi.ForeignCallLinkage;
  31 import org.graalvm.compiler.core.common.type.ObjectStamp;
  32 import org.graalvm.compiler.core.common.type.StampFactory;
  33 import org.graalvm.compiler.graph.NodeClass;
  34 import org.graalvm.compiler.graph.spi.Canonicalizable;
  35 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  36 import org.graalvm.compiler.nodeinfo.NodeInfo;
  37 import org.graalvm.compiler.nodes.AbstractStateSplit;
  38 import org.graalvm.compiler.nodes.DeoptimizingNode;
  39 import org.graalvm.compiler.nodes.FrameState;
  40 import org.graalvm.compiler.nodes.ValueNode;
  41 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  42 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  43 import org.graalvm.compiler.nodes.spi.Virtualizable;
  44 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
  45 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
  46 
  47 import jdk.vm.ci.meta.Assumptions;
  48 import jdk.vm.ci.meta.Assumptions.AssumptionResult;
  49 
  50 /**
  51  * This node is used to perform the finalizer registration at the end of the java.lang.Object
  52  * constructor.
  53  */
  54 // @formatter:off
  55 @NodeInfo(cycles = CYCLES_UNKNOWN,
  56           cyclesRationale = "We cannot estimate the time of a runtime call.",
  57           size = SIZE_20,
  58           sizeRationale = "Rough estimation for register handling & calling")
  59 // @formatter:on
  60 public final class RegisterFinalizerNode extends AbstractStateSplit implements Canonicalizable.Unary<ValueNode>, LIRLowerable, Virtualizable, DeoptimizingNode.DeoptAfter {
  61 
  62     public static final NodeClass<RegisterFinalizerNode> TYPE = NodeClass.create(RegisterFinalizerNode.class);
  63     @OptionalInput(State) FrameState deoptState;
  64     @Input ValueNode value;
  65 
  66     public RegisterFinalizerNode(ValueNode value) {
  67         super(TYPE, StampFactory.forVoid());
  68         this.value = value;
  69     }
  70 
  71     @Override
  72     public ValueNode getValue() {
  73         return value;
  74     }
  75 
  76     @Override
  77     public void generate(NodeLIRBuilderTool gen) {
  78         // Note that an unconditional call to the runtime routine is made without
  79         // checking that the object actually has a finalizer. This requires the
  80         // runtime routine to do the check.
  81         ForeignCallLinkage linkage = gen.getLIRGeneratorTool().getForeignCalls().lookupForeignCall(REGISTER_FINALIZER);
  82         gen.getLIRGeneratorTool().emitForeignCall(linkage, gen.state(this), gen.operand(getValue()));
  83     }
  84 
  85     /**
  86      * Determines if the compiler should emit code to test whether a given object has a finalizer
  87      * that must be registered with the runtime upon object initialization.
  88      */
  89     public static boolean mayHaveFinalizer(ValueNode object, Assumptions assumptions) {
  90         ObjectStamp objectStamp = (ObjectStamp) object.stamp();
  91         if (objectStamp.isExactType()) {
  92             return objectStamp.type().hasFinalizer();
  93         } else if (objectStamp.type() != null) {
  94             AssumptionResult<Boolean> result = objectStamp.type().hasFinalizableSubclass();
  95             if (result.canRecordTo(assumptions)) {
  96                 result.recordTo(assumptions);
  97                 return result.getResult();
  98             }
  99         }
 100         return true;
 101     }
 102 
 103     @Override
 104     public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) {
 105         if (!(forValue.stamp() instanceof ObjectStamp)) {
 106             return this;
 107         }
 108         if (!mayHaveFinalizer(forValue, graph().getAssumptions())) {
 109             return null;
 110         }
 111 
 112         return this;
 113     }
 114 
 115     @Override
 116     public void virtualize(VirtualizerTool tool) {
 117         ValueNode alias = tool.getAlias(getValue());
 118         if (alias instanceof VirtualObjectNode && !((VirtualObjectNode) alias).type().hasFinalizer()) {
 119             tool.delete();
 120         }
 121     }
 122 
 123     @Override
 124     public boolean canDeoptimize() {
 125         return true;
 126     }
 127 
 128     @NodeIntrinsic
 129     public static native void register(Object thisObj);
 130 }