1 /*

     2  * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

     3  * Copyright (c) 2019, Red Hat Inc. All rights reserved.

     4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     5  *

     6  * This code is free software; you can redistribute it and/or modify it

     7  * under the terms of the GNU General Public License version 2 only, as

     8  * published by the Free Software Foundation.

     9  *

    10  * This code is distributed in the hope that it will be useful, but WITHOUT

    11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    13  * version 2 for more details (a copy is included in the LICENSE file that

    14  * accompanied this code).

    15  *

    16  * You should have received a copy of the GNU General Public License version

    17  * 2 along with this work; if not, write to the Free Software Foundation,

    18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    19  *

    20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    21  * or visit www.oracle.com if you need additional information or have any

    22  * questions.

    23  */

    24 

    25 

    26 package org.graalvm.compiler.hotspot.gc.g1;

    27 

    28 import org.graalvm.compiler.debug.GraalError;

    29 import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;

    30 import org.graalvm.compiler.hotspot.gc.shared.BarrierSet;

    31 import org.graalvm.compiler.nodes.StructuredGraph;

    32 import org.graalvm.compiler.nodes.ValueNode;

    33 import org.graalvm.compiler.nodes.extended.ArrayRangeWrite;

    34 import org.graalvm.compiler.nodes.java.AbstractCompareAndSwapNode;

    35 import org.graalvm.compiler.nodes.java.LoweredAtomicReadAndWriteNode;

    36 import org.graalvm.compiler.nodes.memory.FixedAccessNode;

    37 import org.graalvm.compiler.nodes.memory.HeapAccess;

    38 import org.graalvm.compiler.nodes.memory.ReadNode;

    39 import org.graalvm.compiler.nodes.memory.WriteNode;

    40 import org.graalvm.compiler.nodes.memory.address.AddressNode;

    41 import org.graalvm.compiler.nodes.type.StampTool;

    42 

    43 public class G1BarrierSet extends BarrierSet {

    44 

    45     public G1BarrierSet(GraalHotSpotVMConfig vmConfig) {

    46         super(vmConfig);

    47     }

    48 

    49     @Override

    50     public void addReadNodeBarriers(ReadNode node, StructuredGraph graph) {

    51         if (node.getBarrierType() == HeapAccess.BarrierType.WEAK_FIELD) {

    52             G1ReferentFieldReadBarrier barrier = graph.add(new G1ReferentFieldReadBarrier(node.getAddress(), node, false));

    53             graph.addAfterFixed(node, barrier);

    54         }

    55     }

    56 

    57     @Override

    58     public void addWriteNodeBarriers(WriteNode node, StructuredGraph graph) {

    59         HeapAccess.BarrierType barrierType = node.getBarrierType();

    60         switch (barrierType) {

    61             case NONE:

    62                 // nothing to do

    63                 break;

    64             case FIELD:

    65             case ARRAY:

    66             case UNKNOWN:

    67                 boolean init = node.getLocationIdentity().isInit();

    68                 if (!init || !getVMConfig().useDeferredInitBarriers) {

    69                     if (!init) {

    70                         // The pre barrier does nothing if the value being read is null, so it can

    71                         // be explicitly skipped when this is an initializing store.

    72                         addG1PreWriteBarrier(node, node.getAddress(), null, true, node.getNullCheck(), graph);

    73                     }

    74                     boolean precise = barrierType != HeapAccess.BarrierType.FIELD;

    75                     addG1PostWriteBarrier(node, node.getAddress(), node.value(), precise, graph);

    76                 }

    77                 break;

    78             default:

    79                 throw new GraalError("unexpected barrier type: " + barrierType);

    80         }

    81     }

    82 

    83     @Override

    84     public void addAtomicReadWriteNodeBarriers(LoweredAtomicReadAndWriteNode node, StructuredGraph graph) {

    85         HeapAccess.BarrierType barrierType = node.getBarrierType();

    86         switch (barrierType) {

    87             case NONE:

    88                 // nothing to do

    89                 break;

    90             case FIELD:

    91             case ARRAY:

    92             case UNKNOWN:

    93                 boolean precise = barrierType != HeapAccess.BarrierType.FIELD;

    94                 addG1PreWriteBarrier(node, node.getAddress(), null, true, node.getNullCheck(), graph);

    95                 addG1PostWriteBarrier(node, node.getAddress(), node.getNewValue(), precise, graph);

    96                 break;

    97             default:

    98                 throw new GraalError("unexpected barrier type: " + barrierType);

    99         }

   100     }

   101 

   102     @Override

   103     public void addCASBarriers(AbstractCompareAndSwapNode node, StructuredGraph graph) {

   104         HeapAccess.BarrierType barrierType = node.getBarrierType();

   105         switch (barrierType) {

   106             case NONE:

   107                 // nothing to do

   108                 break;

   109             case FIELD:

   110             case ARRAY:

   111             case UNKNOWN:

   112                 boolean precise = barrierType != HeapAccess.BarrierType.FIELD;

   113                 addG1PreWriteBarrier(node, node.getAddress(), node.getExpectedValue(), false, false, graph);

   114                 addG1PostWriteBarrier(node, node.getAddress(), node.getNewValue(), precise, graph);

   115                 break;

   116             default:

   117                 throw new GraalError("unexpected barrier type: " + barrierType);

   118         }

   119     }

   120 

   121     @Override

   122     public void addArrayRangeBarriers(ArrayRangeWrite write, StructuredGraph graph) {

   123         if (!write.isInitialization()) {

   124             // The pre barrier does nothing if the value being read is null, so it can

   125             // be explicitly skipped when this is an initializing store.

   126             G1ArrayRangePreWriteBarrier g1ArrayRangePreWriteBarrier = graph.add(new G1ArrayRangePreWriteBarrier(write.getAddress(), write.getLength(), write.getElementStride()));

   127             graph.addBeforeFixed(write.asNode(), g1ArrayRangePreWriteBarrier);

   128         }

   129         G1ArrayRangePostWriteBarrier g1ArrayRangePostWriteBarrier = graph.add(new G1ArrayRangePostWriteBarrier(write.getAddress(), write.getLength(), write.getElementStride()));

   130         graph.addAfterFixed(write.asNode(), g1ArrayRangePostWriteBarrier);

   131     }

   132 

   133     private static void addG1PreWriteBarrier(FixedAccessNode node, AddressNode address, ValueNode value, boolean doLoad, boolean nullCheck, StructuredGraph graph) {

   134         G1PreWriteBarrier preBarrier = graph.add(new G1PreWriteBarrier(address, value, doLoad, nullCheck));

   135         preBarrier.setStateBefore(node.stateBefore());

   136         node.setNullCheck(false);

   137         node.setStateBefore(null);

   138         graph.addBeforeFixed(node, preBarrier);

   139     }

   140 

   141     private static void addG1PostWriteBarrier(FixedAccessNode node, AddressNode address, ValueNode value, boolean precise, StructuredGraph graph) {

   142         final boolean alwaysNull = StampTool.isPointerAlwaysNull(value);

   143         graph.addAfterFixed(node, graph.add(new G1PostWriteBarrier(address, value, precise, alwaysNull)));

   144     }

   145 }