Showing the changes to java/pkg/java/lang/ApplicationShutdownHooks.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,110 @@ | ||
| 1 | +/* | |
| 2 | + * Copyright (c) 2005, 2010, 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 | +package java.lang; | |
| 26 | + | |
| 27 | +import java.util.*; | |
| 28 | + | |
| 29 | +/* | |
| 30 | + * Class to track and run user level shutdown hooks registered through | |
| 31 | + * <tt>{@link Runtime#addShutdownHook Runtime.addShutdownHook}</tt>. | |
| 32 | + * | |
| 33 | + * @see java.lang.Runtime#addShutdownHook | |
| 34 | + * @see java.lang.Runtime#removeShutdownHook | |
| 35 | + */ | |
| 36 | + | |
| 37 | +class ApplicationShutdownHooks { | |
| 38 | + /* The set of registered hooks */ | |
| 39 | + private static IdentityHashMap<Thread, Thread> hooks; | |
| 40 | + static { | |
| 41 | + try { | |
| 42 | + Shutdown.add(1 /* shutdown hook invocation order */, | |
| 43 | + false /* not registered if shutdown in progress */, | |
| 44 | + new Runnable() { | |
| 45 | + public void run() { | |
| 46 | + runHooks(); | |
| 47 | + } | |
| 48 | + } | |
| 49 | + ); | |
| 50 | + hooks = new IdentityHashMap<>(); | |
| 51 | + } catch (IllegalStateException e) { | |
| 52 | + // application shutdown hooks cannot be added if | |
| 53 | + // shutdown is in progress. | |
| 54 | + hooks = null; | |
| 55 | + } | |
| 56 | + } | |
| 57 | + | |
| 58 | + | |
| 59 | + private ApplicationShutdownHooks() {} | |
| 60 | + | |
| 61 | + /* Add a new shutdown hook. Checks the shutdown state and the hook itself, | |
| 62 | + * but does not do any security checks. | |
| 63 | + */ | |
| 64 | + static synchronized void add(Thread hook) { | |
| 65 | + if(hooks == null) | |
| 66 | + throw new IllegalStateException("Shutdown in progress"); | |
| 67 | + | |
| 68 | + if (hook.isAlive()) | |
| 69 | + throw new IllegalArgumentException("Hook already running"); | |
| 70 | + | |
| 71 | + if (hooks.containsKey(hook)) | |
| 72 | + throw new IllegalArgumentException("Hook previously registered"); | |
| 73 | + | |
| 74 | + hooks.put(hook, hook); | |
| 75 | + } | |
| 76 | + | |
| 77 | + /* Remove a previously-registered hook. Like the add method, this method | |
| 78 | + * does not do any security checks. | |
| 79 | + */ | |
| 80 | + static synchronized boolean remove(Thread hook) { | |
| 81 | + if(hooks == null) | |
| 82 | + throw new IllegalStateException("Shutdown in progress"); | |
| 83 | + | |
| 84 | + if (hook == null) | |
| 85 | + throw new NullPointerException(); | |
| 86 | + | |
| 87 | + return hooks.remove(hook) != null; | |
| 88 | + } | |
| 89 | + | |
| 90 | + /* Iterates over all application hooks creating a new thread for each | |
| 91 | + * to run in. Hooks are run concurrently and this method waits for | |
| 92 | + * them to finish. | |
| 93 | + */ | |
| 94 | + static void runHooks() { | |
| 95 | + Collection<Thread> threads; | |
| 96 | + synchronized(ApplicationShutdownHooks.class) { | |
| 97 | + threads = hooks.keySet(); | |
| 98 | + hooks = null; | |
| 99 | + } | |
| 100 | + | |
| 101 | + for (Thread hook : threads) { | |
| 102 | + hook.start(); | |
| 103 | + } | |
| 104 | + for (Thread hook : threads) { | |
| 105 | + try { | |
| 106 | + hook.join(); | |
| 107 | + } catch (InterruptedException x) { } | |
| 108 | + } | |
| 109 | + } | |
| 110 | +} | |