Showing the changes to java/pkg/sun/rmi/runtime/RuntimeUtil.java (1 of 18352 files). Show all
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| 1 | +/* | |
| 2 | + * Copyright (c) 2005, 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 sun.rmi.runtime; | |
| 27 | + | |
| 28 | +import java.security.AccessController; | |
| 29 | +import java.security.Permission; | |
| 30 | +import java.security.PrivilegedAction; | |
| 31 | +import java.util.concurrent.ScheduledThreadPoolExecutor; | |
| 32 | +import java.util.concurrent.ThreadFactory; | |
| 33 | +import java.util.concurrent.TimeUnit; | |
| 34 | +import java.util.concurrent.atomic.AtomicInteger; | |
| 35 | +import java.util.logging.Level; | |
| 36 | +import sun.security.action.GetIntegerAction; | |
| 37 | + | |
| 38 | +/** | |
| 39 | + * RMI runtime implementation utilities. | |
| 40 | + * | |
| 41 | + * There is a single instance of this class, which can be obtained | |
| 42 | + * with a GetInstanceAction. Getting the instance requires | |
| 43 | + * RuntimePermission("sun.rmi.runtime.RuntimeUtil.getInstance") | |
| 44 | + * because the public methods of this class expose security-sensitive | |
| 45 | + * capabilities. | |
| 46 | + * | |
| 47 | + * @author Peter Jones | |
| 48 | + **/ | |
| 49 | +public final class RuntimeUtil { | |
| 50 | + | |
| 51 | + /** runtime package log */ | |
| 52 | + private static final Log runtimeLog = | |
| 53 | + Log.getLog("sun.rmi.runtime", null, false); | |
| 54 | + | |
| 55 | + /** number of scheduler threads */ | |
| 56 | + private static final int schedulerThreads = // default 1 | |
| 57 | + AccessController.doPrivileged( | |
| 58 | + new GetIntegerAction("sun.rmi.runtime.schedulerThreads", 1)); | |
| 59 | + | |
| 60 | + /** permission required to get instance */ | |
| 61 | + private static final Permission GET_INSTANCE_PERMISSION = | |
| 62 | + new RuntimePermission("sun.rmi.runtime.RuntimeUtil.getInstance"); | |
| 63 | + | |
| 64 | + /** the singleton instance of this class */ | |
| 65 | + private static final RuntimeUtil instance = new RuntimeUtil(); | |
| 66 | + | |
| 67 | + /** thread pool for scheduling delayed tasks */ | |
| 68 | + private final ScheduledThreadPoolExecutor scheduler; | |
| 69 | + | |
| 70 | + private RuntimeUtil() { | |
| 71 | + scheduler = new ScheduledThreadPoolExecutor( | |
| 72 | + schedulerThreads, | |
| 73 | + new ThreadFactory() { | |
| 74 | + private final AtomicInteger count = new AtomicInteger(0); | |
| 75 | + public Thread newThread(Runnable runnable) { | |
| 76 | + try { | |
| 77 | + return AccessController.doPrivileged( | |
| 78 | + new NewThreadAction(runnable, | |
| 79 | + "Scheduler(" + count.getAndIncrement() + ")", | |
| 80 | + true)); | |
| 81 | + } catch (Throwable t) { | |
| 82 | + runtimeLog.log(Level.WARNING, | |
| 83 | + "scheduler thread factory throws", t); | |
| 84 | + return null; | |
| 85 | + } | |
| 86 | + } | |
| 87 | + }); | |
| 88 | + /* | |
| 89 | + * We would like to allow the scheduler's threads to terminate | |
| 90 | + * if possible, but a bug in DelayQueue.poll can cause code | |
| 91 | + * like this to result in a busy loop: | |
| 92 | + */ | |
| 93 | + // stpe.setKeepAliveTime(10, TimeUnit.MINUTES); | |
| 94 | + // stpe.allowCoreThreadTimeOut(true); | |
| 95 | + } | |
| 96 | + | |
| 97 | + /** | |
| 98 | + * A PrivilegedAction for getting the RuntimeUtil instance. | |
| 99 | + **/ | |
| 100 | + public static class GetInstanceAction | |
| 101 | + implements PrivilegedAction<RuntimeUtil> | |
| 102 | + { | |
| 103 | + /** | |
| 104 | + * Creates an action that returns the RuntimeUtil instance. | |
| 105 | + **/ | |
| 106 | + public GetInstanceAction() { | |
| 107 | + } | |
| 108 | + | |
| 109 | + public RuntimeUtil run() { | |
| 110 | + return getInstance(); | |
| 111 | + } | |
| 112 | + } | |
| 113 | + | |
| 114 | + private static RuntimeUtil getInstance() { | |
| 115 | + SecurityManager sm = System.getSecurityManager(); | |
| 116 | + if (sm != null) { | |
| 117 | + sm.checkPermission(GET_INSTANCE_PERMISSION); | |
| 118 | + } | |
| 119 | + return instance; | |
| 120 | + } | |
| 121 | + | |
| 122 | + /** | |
| 123 | + * Returns the shared thread pool for scheduling delayed tasks. | |
| 124 | + * | |
| 125 | + * Note that the returned pool has limited concurrency, so | |
| 126 | + * submitted tasks should be short-lived and should not block. | |
| 127 | + **/ | |
| 128 | + public ScheduledThreadPoolExecutor getScheduler() { | |
| 129 | + return scheduler; | |
| 130 | + } | |
| 131 | +} | |