| /* |
| * Copyright (c) 2014, 2014, 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 jdk.vm.ci.hotspot; |
| |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentLinkedQueue; |
| |
| import jdk.vm.ci.meta.JavaConstant; |
| import jdk.vm.ci.meta.SpeculationLog; |
| |
| public class HotSpotSpeculationLog implements SpeculationLog { |
| |
| /** Written by the C++ code that performs deoptimization. */ |
| private volatile Object lastFailed; |
| |
| /** All speculations that have caused a deoptimization. */ |
| private Set<SpeculationReason> failedSpeculations; |
| |
| /** Strong references to all reasons embedded in the current nmethod. */ |
| private volatile Collection<SpeculationReason> speculations; |
| |
| @Override |
| public synchronized void collectFailedSpeculations() { |
| if (lastFailed != null) { |
| if (failedSpeculations == null) { |
| failedSpeculations = new HashSet<>(2); |
| } |
| failedSpeculations.add((SpeculationReason) lastFailed); |
| lastFailed = null; |
| speculations = null; |
| } |
| } |
| |
| @Override |
| public synchronized boolean maySpeculate(SpeculationReason reason) { |
| if (failedSpeculations != null && failedSpeculations.contains(reason)) { |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public JavaConstant speculate(SpeculationReason reason) { |
| assert maySpeculate(reason); |
| |
| /* |
| * Objects referenced from nmethods are weak references. We need a strong reference to the |
| * reason objects that are embedded in nmethods, so we add them to the speculations |
| * collection. |
| */ |
| if (speculations == null) { |
| synchronized (this) { |
| if (speculations == null) { |
| speculations = new ConcurrentLinkedQueue<>(); |
| } |
| } |
| } |
| speculations.add(reason); |
| |
| return HotSpotObjectConstantImpl.forObject(reason); |
| } |
| |
| @Override |
| public synchronized boolean hasSpeculations() { |
| return speculations != null && !speculations.isEmpty(); |
| } |
| } |