1 /*

     2  * Copyright (c) 2013, 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.NodeCycles.CYCLES_64;

    28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_64;

    29 

    30 import org.graalvm.compiler.graph.NodeClass;

    31 import org.graalvm.compiler.nodeinfo.NodeInfo;

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

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

    34 

    35 /**

    36  * The {@code G1ReferentFieldReadBarrier} is added when a read access is performed to the referent

    37  * field of a {@link java.lang.ref.Reference} object (through a {@code LoadFieldNode} or an

    38  * {@code UnsafeLoadNode}). The return value of the read is passed to the snippet implementing the

    39  * read barrier and consequently is added to the SATB queue if the concurrent marker is enabled.

    40  */

    41 @NodeInfo(cycles = CYCLES_64, size = SIZE_64)

    42 public final class G1ReferentFieldReadBarrier extends ObjectWriteBarrier {

    43     public static final NodeClass<G1ReferentFieldReadBarrier> TYPE = NodeClass.create(G1ReferentFieldReadBarrier.class);

    44 

    45     protected final boolean doLoad;

    46 

    47     public G1ReferentFieldReadBarrier(AddressNode address, ValueNode expectedObject, boolean doLoad) {

    48         super(TYPE, address, expectedObject, true);

    49         this.doLoad = doLoad;

    50     }

    51 

    52     public ValueNode getExpectedObject() {

    53         return getValue();

    54     }

    55 

    56     public boolean doLoad() {

    57         return doLoad;

    58     }

    59 }