1 /* 2 * Copyright (c) 2013, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.webkit; 27 28 import java.util.concurrent.ScheduledFuture; 29 import java.util.concurrent.ScheduledThreadPoolExecutor; 30 import java.util.concurrent.ThreadFactory; 31 import java.util.concurrent.TimeUnit; 32 import java.util.concurrent.atomic.AtomicInteger; 33 import static java.util.logging.Level.WARNING; 34 import java.util.logging.Logger; 35 36 final class WatchdogTimer { 37 38 private static final Logger logger = 39 Logger.getLogger(WatchdogTimer.class.getName()); 40 private static final ThreadFactory threadFactory = 41 new CustomThreadFactory(); 42 43 44 // The executor is intentionally made a non-static/instance 45 // field (as opposed to a static/class field) in order for 46 // fwkDestroy() to be able to orderly shutdown the executor 47 // and wait for the outstanding runnable, if any, to complete. 48 // Currently, there is just a single instance of this class 49 // per process, so having a non-static executor should not 50 // be a problem. 51 private final ScheduledThreadPoolExecutor executor; 52 private final Runnable runnable; 53 private ScheduledFuture<?> future; 54 55 56 private WatchdogTimer(final long nativePointer) { 57 executor = new ScheduledThreadPoolExecutor(1, threadFactory); 58 executor.setRemoveOnCancelPolicy(true); 59 60 runnable = () -> { 61 try { 62 twkFire(nativePointer); 63 } catch (Throwable th) { 64 logger.log(WARNING, "Error firing watchdog timer", th); 65 } 66 }; 67 } 68 69 70 private static WatchdogTimer fwkCreate(long nativePointer) { 71 return new WatchdogTimer(nativePointer); 72 } 73 74 private void fwkStart(double limit) { 75 if (future != null) { 76 throw new IllegalStateException(); 77 } 78 future = executor.schedule(runnable, (long) (limit * 1000) + 50, 79 TimeUnit.MILLISECONDS); 80 } 81 82 private void fwkStop() { 83 if (future == null) { 84 throw new IllegalStateException(); 85 } 86 future.cancel(false); 87 future = null; 88 } 89 90 private void fwkDestroy() { 91 executor.shutdownNow(); 92 while (true) { 93 try { 94 if (executor.awaitTermination(1, TimeUnit.SECONDS)) { 95 break; 96 } 97 } catch (InterruptedException ex) { 98 // continue waiting 99 } 100 } 101 } 102 103 private native void twkFire(long nativePointer); 104 105 private static final class CustomThreadFactory implements ThreadFactory { 106 private final ThreadGroup group; 107 private final AtomicInteger index = new AtomicInteger(1); 108 109 private CustomThreadFactory() { 110 SecurityManager s = System.getSecurityManager(); 111 group = (s != null) ? s.getThreadGroup() 112 : Thread.currentThread().getThreadGroup(); 113 } 114 115 @Override 116 public Thread newThread(Runnable r) { 117 Thread t = new Thread(group, r, 118 "Watchdog-Timer-" + index.getAndIncrement()); 119 t.setDaemon(true); 120 return t; 121 } 122 } 123 }