Showing the changes to java/pkg/sun/rmi/runtime/RuntimeUtil.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,131 @@ | |||
| 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 | } | ||