| /* |
| * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * 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). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| |
| package org.graalvm.compiler.phases.common; |
| |
| import org.graalvm.compiler.nodes.FixedNode; |
| import org.graalvm.compiler.nodes.StructuredGraph; |
| import org.graalvm.compiler.nodes.ValueNode; |
| import org.graalvm.compiler.nodes.extended.OSRMonitorEnterNode; |
| import org.graalvm.compiler.nodes.java.AccessMonitorNode; |
| import org.graalvm.compiler.nodes.java.MonitorEnterNode; |
| import org.graalvm.compiler.nodes.java.MonitorExitNode; |
| import org.graalvm.compiler.nodes.java.MonitorIdNode; |
| import org.graalvm.compiler.nodes.java.RawMonitorEnterNode; |
| import org.graalvm.compiler.nodes.util.GraphUtil; |
| import org.graalvm.compiler.phases.Phase; |
| |
| public class LockEliminationPhase extends Phase { |
| |
| @Override |
| protected void run(StructuredGraph graph) { |
| for (MonitorExitNode monitorExitNode : graph.getNodes(MonitorExitNode.TYPE)) { |
| FixedNode next = monitorExitNode.next(); |
| if ((next instanceof MonitorEnterNode || next instanceof RawMonitorEnterNode)) { |
| // should never happen, osr monitor enters are always direct successors of the graph |
| // start |
| assert !(next instanceof OSRMonitorEnterNode); |
| AccessMonitorNode monitorEnterNode = (AccessMonitorNode) next; |
| if (isCompatibleLock(monitorEnterNode, monitorExitNode)) { |
| /* |
| * We've coarsened the lock so use the same monitor id for the whole region, |
| * otherwise the monitor operations appear to be unrelated. |
| */ |
| MonitorIdNode enterId = monitorEnterNode.getMonitorId(); |
| MonitorIdNode exitId = monitorExitNode.getMonitorId(); |
| if (enterId != exitId) { |
| enterId.replaceAndDelete(exitId); |
| } |
| GraphUtil.removeFixedWithUnusedInputs(monitorEnterNode); |
| GraphUtil.removeFixedWithUnusedInputs(monitorExitNode); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Check that the paired operations operate on the same object at the same lock depth. |
| */ |
| public static boolean isCompatibleLock(AccessMonitorNode lock1, AccessMonitorNode lock2) { |
| /* |
| * It is not always the case that sequential monitor operations on the same object have the |
| * same lock depth: Escape analysis can have removed a lock operation that was in between, |
| * leading to a mismatch in lock depth. |
| */ |
| ValueNode object1 = GraphUtil.unproxify(lock1.object()); |
| ValueNode object2 = GraphUtil.unproxify(lock2.object()); |
| return object1 == object2 && lock1.getMonitorId().getLockDepth() == lock2.getMonitorId().getLockDepth(); |
| } |
| } |