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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package org.graalvm.compiler.nodes.java;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_64;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_64;

import org.graalvm.compiler.graph.IterableNodeType;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.extended.MonitorExit;
import org.graalvm.compiler.nodes.memory.MemoryCheckpoint;
import org.graalvm.compiler.nodes.spi.Lowerable;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.nodes.spi.Virtualizable;
import org.graalvm.compiler.nodes.spi.VirtualizerTool;
import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
import jdk.internal.vm.compiler.word.LocationIdentity;

The MonitorExitNode represents a monitor release. If it is the release of the monitor of a synchronized method, then the return value of the method will be referenced via the edge escapedReturnValue, so that it will be materialized before releasing the monitor.
/** * The {@code MonitorExitNode} represents a monitor release. If it is the release of the monitor of * a synchronized method, then the return value of the method will be referenced via the edge * {@link #escapedReturnValue}, so that it will be materialized before releasing the monitor. */
@NodeInfo(cycles = CYCLES_64, size = SIZE_64) public final class MonitorExitNode extends AccessMonitorNode implements Virtualizable, Lowerable, IterableNodeType, MonitorExit, MemoryCheckpoint.Single { public static final NodeClass<MonitorExitNode> TYPE = NodeClass.create(MonitorExitNode.class);
Non-null for the monitor exit introduced due to a synchronized root method and null in all other cases.
/** * Non-null for the monitor exit introduced due to a synchronized root method and null in all * other cases. */
@OptionalInput ValueNode escapedReturnValue; public MonitorExitNode(ValueNode object, MonitorIdNode monitorId, ValueNode escapedValue) { super(TYPE, object, monitorId); this.escapedReturnValue = escapedValue; }
Return value is cleared when a synchronized method graph is inlined.
/** * Return value is cleared when a synchronized method graph is inlined. */
public void clearEscapedValue() { updateUsages(escapedReturnValue, null); this.escapedReturnValue = null; } @Override public LocationIdentity getLocationIdentity() { return LocationIdentity.any(); } @Override public void lower(LoweringTool tool) { tool.getLowerer().lower(this, tool); } @Override public void virtualize(VirtualizerTool tool) { ValueNode alias = tool.getAlias(object()); if (alias instanceof VirtualObjectNode) { VirtualObjectNode virtual = (VirtualObjectNode) alias; if (virtual.hasIdentity()) { MonitorIdNode removedLock = tool.removeLock(virtual); assert removedLock == getMonitorId() : "mismatch at " + this + ": " + removedLock + " vs. " + getMonitorId(); tool.delete(); } } } }