1 /* 2 * Copyright (c) 2013, 2019, 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.gc.g1; 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.hotspot.gc.shared.ObjectWriteBarrier; 32 import org.graalvm.compiler.nodeinfo.NodeInfo; 33 import org.graalvm.compiler.nodes.ValueNode; 34 import org.graalvm.compiler.nodes.memory.address.AddressNode; 35 36 /** 37 * The {@code G1ReferentFieldReadBarrier} is added when a read access is performed to the referent 38 * field of a {@link java.lang.ref.Reference} object (through a {@code LoadFieldNode} or an 39 * {@code UnsafeLoadNode}). The return value of the read is passed to the snippet implementing the 40 * read barrier and consequently is added to the SATB queue if the concurrent marker is enabled. 41 */ 42 @NodeInfo(cycles = CYCLES_64, size = SIZE_64) 43 public final class G1ReferentFieldReadBarrier extends ObjectWriteBarrier { 44 public static final NodeClass<G1ReferentFieldReadBarrier> TYPE = NodeClass.create(G1ReferentFieldReadBarrier.class); 45 46 private final boolean doLoad; 47 48 public G1ReferentFieldReadBarrier(AddressNode address, ValueNode expectedObject, boolean doLoad) { 49 super(TYPE, address, expectedObject, true); 50 this.doLoad = doLoad; 51 } 52 53 public ValueNode getExpectedObject() { 54 return getValue(); 55 } 56 57 public boolean doLoad() { 58 return doLoad; 59 } 60 }