My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

Showing the changes to java/pkg/sun/management/NotificationEmitterSupport.java (1 of 18352 files). Show all

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java/pkg/sun/management/NotificationEmitterSupport.java+198−0

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	1	+/*
	2	+ * Copyright (c) 2003, 2008, 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.management;
	27	+
	28	+import javax.management.ListenerNotFoundException;
	29	+import javax.management.MBeanNotificationInfo;
	30	+import javax.management.Notification;
	31	+import javax.management.NotificationEmitter;
	32	+import javax.management.NotificationFilter;
	33	+import javax.management.NotificationListener;
	34	+
	35	+import java.util.List;
	36	+import java.util.ArrayList;
	37	+import java.util.ListIterator;
	38	+import java.util.Collections;
	39	+
	40	+/**
	41	+ * Abstract helper class for notification emitter support.
	42	+ */
	43	+abstract class NotificationEmitterSupport implements NotificationEmitter {
	44	+
	45	+ protected NotificationEmitterSupport() {
	46	+ }
	47	+
	48	+ private Object listenerLock = new Object();
	49	+
	50	+ // Implementation of NotificationEmitter interface
	51	+ // Cloned from JMX NotificationBroadcasterSupport class.
	52	+ public void addNotificationListener(NotificationListener listener,
	53	+ NotificationFilter filter,
	54	+ Object handback) {
	55	+
	56	+ if (listener == null) {
	57	+ throw new IllegalArgumentException ("Listener can't be null") ;
	58	+ }
	59	+
	60	+ /* Adding a new listener takes O(n) time where n is the number
	61	+ of existing listeners. If you have a very large number of
	62	+ listeners performance could degrade. That's a fairly
	63	+ surprising configuration, and it is hard to avoid this
	64	+ behaviour while still retaining the property that the
	65	+ listenerList is not synchronized while notifications are
	66	+ being sent through it. If this becomes a problem, a
	67	+ possible solution would be a multiple-readers single-writer
	68	+ setup, so any number of sendNotification() calls could run
	69	+ concurrently but they would exclude an
	70	+ add/removeNotificationListener. A simpler but less
	71	+ efficient solution would be to clone the listener list
	72	+ every time a notification is sent. */
	73	+ synchronized (listenerLock) {
	74	+ List<ListenerInfo> newList = new ArrayList<ListenerInfo>(listenerList.size() + 1);
	75	+ newList.addAll(listenerList);
	76	+ newList.add(new ListenerInfo(listener, filter, handback));
	77	+ listenerList = newList;
	78	+ }
	79	+ }
	80	+
	81	+ public void removeNotificationListener(NotificationListener listener)
	82	+ throws ListenerNotFoundException {
	83	+
	84	+ synchronized (listenerLock) {
	85	+ List<ListenerInfo> newList = new ArrayList<ListenerInfo>(listenerList);
	86	+ /* We scan the list of listeners in reverse order because
	87	+ in forward order we would have to repeat the loop with
	88	+ the same index after a remove. */
	89	+ for (int i=newList.size()-1; i>=0; i--) {
	90	+ ListenerInfo li = (ListenerInfo)newList.get(i);
	91	+
	92	+ if (li.listener == listener)
	93	+ newList.remove(i);
	94	+ }
	95	+ if (newList.size() == listenerList.size())
	96	+ throw new ListenerNotFoundException("Listener not registered");
	97	+ listenerList = newList;
	98	+ }
	99	+ }
	100	+
	101	+ public void removeNotificationListener(NotificationListener listener,
	102	+ NotificationFilter filter,
	103	+ Object handback)
	104	+ throws ListenerNotFoundException {
	105	+
	106	+ boolean found = false;
	107	+
	108	+ synchronized (listenerLock) {
	109	+ List<ListenerInfo> newList = new ArrayList<ListenerInfo>(listenerList);
	110	+ final int size = newList.size();
	111	+ for (int i = 0; i < size; i++) {
	112	+ ListenerInfo li = (ListenerInfo) newList.get(i);
	113	+
	114	+ if (li.listener == listener) {
	115	+ found = true;
	116	+ if (li.filter == filter
	117	+ && li.handback == handback) {
	118	+ newList.remove(i);
	119	+ listenerList = newList;
	120	+ return;
	121	+ }
	122	+ }
	123	+ }
	124	+ }
	125	+
	126	+ if (found) {
	127	+ /* We found this listener, but not with the given filter
	128	+ * and handback. A more informative exception message may
	129	+ * make debugging easier. */
	130	+ throw new ListenerNotFoundException("Listener not registered " +
	131	+ "with this filter and " +
	132	+ "handback");
	133	+ } else {
	134	+ throw new ListenerNotFoundException("Listener not registered");
	135	+ }
	136	+ }
	137	+
	138	+ void sendNotification(Notification notification) {
	139	+
	140	+ if (notification == null) {
	141	+ return;
	142	+ }
	143	+
	144	+ List<ListenerInfo> currentList;
	145	+ synchronized (listenerLock) {
	146	+ currentList = listenerList;
	147	+ }
	148	+
	149	+ final int size = currentList.size();
	150	+ for (int i = 0; i < size; i++) {
	151	+ ListenerInfo li = (ListenerInfo) currentList.get(i);
	152	+
	153	+ if (li.filter == null
	154	+ \|\| li.filter.isNotificationEnabled(notification)) {
	155	+ try {
	156	+ li.listener.handleNotification(notification, li.handback);
	157	+ } catch (Exception e) {
	158	+ e.printStackTrace();
	159	+ throw new AssertionError("Error in invoking listener");
	160	+ }
	161	+ }
	162	+ }
	163	+ }
	164	+
	165	+ boolean hasListeners() {
	166	+ synchronized (listenerLock) {
	167	+ return !listenerList.isEmpty();
	168	+ }
	169	+ }
	170	+
	171	+ private class ListenerInfo {
	172	+ public NotificationListener listener;
	173	+ NotificationFilter filter;
	174	+ Object handback;
	175	+
	176	+ public ListenerInfo(NotificationListener listener,
	177	+ NotificationFilter filter,
	178	+ Object handback) {
	179	+ this.listener = listener;
	180	+ this.filter = filter;
	181	+ this.handback = handback;
	182	+ }
	183	+ }
	184	+
	185	+ /**
	186	+ * Current list of listeners, a List of ListenerInfo. The object
	187	+ * referenced by this field is never modified. Instead, the field
	188	+ * is set to a new object when a listener is added or removed,
	189	+ * within a synchronized(this). In this way, there is no need to
	190	+ * synchronize when traversing the list to send a notification to
	191	+ * the listeners in it. That avoids potential deadlocks if the
	192	+ * listeners end up depending on other threads that are themselves
	193	+ * accessing this NotificationBroadcasterSupport.
	194	+ */
	195	+ private List<ListenerInfo> listenerList = Collections.emptyList();
	196	+
	197	+ abstract public MBeanNotificationInfo[] getNotificationInfo();
	198	+}