1 /* 2 * Copyright (c) 2014, 2014, 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 package jdk.vm.ci.hotspot; 24 25 import java.util.HashMap; 26 import java.util.HashSet; 27 import java.util.Set; 28 import java.util.Map; 29 30 import jdk.vm.ci.meta.JavaConstant; 31 import jdk.vm.ci.meta.SpeculationLog; 32 33 public class HotSpotSpeculationLog implements SpeculationLog { 34 public static final class HotSpotSpeculation extends Speculation { 35 private JavaConstant encoding; 36 37 HotSpotSpeculation(SpeculationReason reason, JavaConstant encoding) { 38 super(reason); 39 this.encoding = encoding; 40 } 41 42 public JavaConstant getEncoding() { 43 return encoding; 44 } 45 } 46 47 /** Written by the C++ code that performs deoptimization. */ 48 private volatile long lastFailed; 49 50 /** All speculations that have caused a deoptimization. */ 51 private Set<SpeculationReason> failedSpeculations; 52 53 /** Strong references to all reasons embedded in the current nmethod. */ 54 private Map<Long, SpeculationReason> speculations; 55 56 private long currentSpeculationID; 57 58 @Override 59 public synchronized void collectFailedSpeculations() { 60 if (lastFailed != 0) { 61 if (failedSpeculations == null) { 62 failedSpeculations = new HashSet<>(2); 63 } 64 if (speculations != null) { 65 SpeculationReason lastFailedSpeculation = speculations.get(lastFailed); 66 if (lastFailedSpeculation != null) { 67 failedSpeculations.add(lastFailedSpeculation); 68 } 69 lastFailed = 0; 70 speculations = null; 71 } 72 } 73 } 74 75 @Override 76 public synchronized boolean maySpeculate(SpeculationReason reason) { 77 if (failedSpeculations != null && failedSpeculations.contains(reason)) { 78 return false; 79 } 80 return true; 81 } 82 83 @Override 84 public synchronized Speculation speculate(SpeculationReason reason) { 85 if (speculations == null) { 86 speculations = new HashMap<>(); 87 } 88 speculations.put(++currentSpeculationID, reason); 89 return new HotSpotSpeculation(reason, JavaConstant.forLong(currentSpeculationID)); 90 } 91 92 @Override 93 public synchronized boolean hasSpeculations() { 94 return speculations != null && !speculations.isEmpty(); 95 } 96 97 @Override 98 public synchronized Speculation lookupSpeculation(JavaConstant constant) { 99 if (constant.isDefaultForKind()) { 100 return NO_SPECULATION; 101 } 102 SpeculationReason reason = speculations.get(constant.asLong()); 103 assert reason != null : "Speculation should have been registered"; 104 return new HotSpotSpeculation(reason, constant); 105 } 106 }