J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package java.lang.management; |
| 27 | import javax.management.openmbean.CompositeData; |
| 28 | import sun.management.MemoryNotifInfoCompositeData; |
| 29 | |
| 30 | /** |
| 31 | * The information about a memory notification. |
| 32 | * |
| 33 | * <p> |
| 34 | * A memory notification is emitted by {@link MemoryMXBean} |
| 35 | * when the Java virtual machine detects that the memory usage |
| 36 | * of a memory pool is exceeding a threshold value. |
| 37 | * The notification emitted will contain the memory notification |
| 38 | * information about the detected condition: |
| 39 | * <ul> |
| 40 | * <li>The name of the memory pool.</li> |
| 41 | * <li>The memory usage of the memory pool when the notification |
| 42 | * was constructed.</li> |
| 43 | * <li>The number of times that the memory usage has crossed |
| 44 | * a threshold when the notification was constructed. |
| 45 | * For usage threshold notifications, this count will be the |
| 46 | * {@link MemoryPoolMXBean#getUsageThresholdCount usage threshold |
| 47 | * count}. For collection threshold notifications, |
| 48 | * this count will be the |
| 49 | * {@link MemoryPoolMXBean#getCollectionUsageThresholdCount |
| 50 | * collection usage threshold count}. |
| 51 | * </li> |
| 52 | * </ul> |
| 53 | * |
| 54 | * <p> |
| 55 | * A {@link CompositeData CompositeData} representing |
| 56 | * the <tt>MemoryNotificationInfo</tt> object |
| 57 | * is stored in the |
| 58 | * {@link javax.management.Notification#setUserData user data} |
| 59 | * of a {@link javax.management.Notification notification}. |
| 60 | * The {@link #from from} method is provided to convert from |
| 61 | * a <tt>CompositeData</tt> to a <tt>MemoryNotificationInfo</tt> |
| 62 | * object. For example: |
| 63 | * |
| 64 | * <blockquote><pre> |
| 65 | * Notification notif; |
| 66 | * |
| 67 | * // receive the notification emitted by MemoryMXBean and set to notif |
| 68 | * ... |
| 69 | * |
| 70 | * String notifType = notif.getType(); |
| 71 | * if (notifType.equals(MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED) || |
| 72 | * notifType.equals(MemoryNotificationInfo.MEMORY_COLLECTION_THRESHOLD_EXCEEDED)) { |
| 73 | * // retrieve the memory notification information |
| 74 | * CompositeData cd = (CompositeData) notif.getUserData(); |
| 75 | * MemoryNotificationInfo info = MemoryNotificationInfo.from(cd); |
| 76 | * .... |
| 77 | * } |
| 78 | * </pre></blockquote> |
| 79 | * |
| 80 | * <p> |
| 81 | * The types of notifications emitted by <tt>MemoryMXBean</tt> are: |
| 82 | * <ul> |
| 83 | * <li>A {@link #MEMORY_THRESHOLD_EXCEEDED |
| 84 | * usage threshold exceeded notification}. |
| 85 | * <br>This notification will be emitted when |
| 86 | * the memory usage of a memory pool is increased and has reached |
| 87 | * or exceeded its |
| 88 | * <a href="MemoryPoolMXBean.html#UsageThreshold"> usage threshold</a> value. |
| 89 | * Subsequent crossing of the usage threshold value does not cause |
| 90 | * further notification until the memory usage has returned |
| 91 | * to become less than the usage threshold value. |
| 92 | * <p></li> |
| 93 | * <li>A {@link #MEMORY_COLLECTION_THRESHOLD_EXCEEDED |
| 94 | * collection usage threshold exceeded notification}. |
| 95 | * <br>This notification will be emitted when |
| 96 | * the memory usage of a memory pool is greater than or equal to its |
| 97 | * <a href="MemoryPoolMXBean.html#CollectionThreshold"> |
| 98 | * collection usage threshold</a> after the Java virtual machine |
| 99 | * has expended effort in recycling unused objects in that |
| 100 | * memory pool.</li> |
| 101 | * </ul> |
| 102 | * |
| 103 | * @author Mandy Chung |
| 104 | * @since 1.5 |
| 105 | * |
| 106 | */ |
| 107 | public class MemoryNotificationInfo { |
| 108 | private final String poolName; |
| 109 | private final MemoryUsage usage; |
| 110 | private final long count; |
| 111 | |
| 112 | /** |
| 113 | * Notification type denoting that |
| 114 | * the memory usage of a memory pool has |
| 115 | * reached or exceeded its |
| 116 | * <a href="MemoryPoolMXBean.html#UsageThreshold"> usage threshold</a> value. |
| 117 | * This notification is emitted by {@link MemoryMXBean}. |
| 118 | * Subsequent crossing of the usage threshold value does not cause |
| 119 | * further notification until the memory usage has returned |
| 120 | * to become less than the usage threshold value. |
| 121 | * The value of this notification type is |
| 122 | * <tt>java.management.memory.threshold.exceeded</tt>. |
| 123 | */ |
| 124 | public static final String MEMORY_THRESHOLD_EXCEEDED = |
| 125 | "java.management.memory.threshold.exceeded"; |
| 126 | |
| 127 | /** |
| 128 | * Notification type denoting that |
| 129 | * the memory usage of a memory pool is greater than or equal to its |
| 130 | * <a href="MemoryPoolMXBean.html#CollectionThreshold"> |
| 131 | * collection usage threshold</a> after the Java virtual machine |
| 132 | * has expended effort in recycling unused objects in that |
| 133 | * memory pool. |
| 134 | * This notification is emitted by {@link MemoryMXBean}. |
| 135 | * The value of this notification type is |
| 136 | * <tt>java.management.memory.collection.threshold.exceeded</tt>. |
| 137 | */ |
| 138 | public static final String MEMORY_COLLECTION_THRESHOLD_EXCEEDED = |
| 139 | "java.management.memory.collection.threshold.exceeded"; |
| 140 | |
| 141 | /** |
| 142 | * Constructs a <tt>MemoryNotificationInfo</tt> object. |
| 143 | * |
| 144 | * @param poolName The name of the memory pool which triggers this notification. |
| 145 | * @param usage Memory usage of the memory pool. |
| 146 | * @param count The threshold crossing count. |
| 147 | */ |
| 148 | public MemoryNotificationInfo(String poolName, |
| 149 | MemoryUsage usage, |
| 150 | long count) { |
| 151 | if (poolName == null) { |
| 152 | throw new NullPointerException("Null poolName"); |
| 153 | } |
| 154 | if (usage == null) { |
| 155 | throw new NullPointerException("Null usage"); |
| 156 | } |
| 157 | |
| 158 | this.poolName = poolName; |
| 159 | this.usage = usage; |
| 160 | this.count = count; |
| 161 | } |
| 162 | |
| 163 | MemoryNotificationInfo(CompositeData cd) { |
| 164 | MemoryNotifInfoCompositeData.validateCompositeData(cd); |
| 165 | |
| 166 | this.poolName = MemoryNotifInfoCompositeData.getPoolName(cd); |
| 167 | this.usage = MemoryNotifInfoCompositeData.getUsage(cd); |
| 168 | this.count = MemoryNotifInfoCompositeData.getCount(cd); |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Returns the name of the memory pool that triggers this notification. |
| 173 | * The memory pool usage has crossed a threshold. |
| 174 | * |
| 175 | * @return the name of the memory pool that triggers this notification. |
| 176 | */ |
| 177 | public String getPoolName() { |
| 178 | return poolName; |
| 179 | } |
| 180 | |
| 181 | /** |
| 182 | * Returns the memory usage of the memory pool |
| 183 | * when this notification was constructed. |
| 184 | * |
| 185 | * @return the memory usage of the memory pool |
| 186 | * when this notification was constructed. |
| 187 | */ |
| 188 | public MemoryUsage getUsage() { |
| 189 | return usage; |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * Returns the number of times that the memory usage has crossed |
| 194 | * a threshold when the notification was constructed. |
| 195 | * For usage threshold notifications, this count will be the |
| 196 | * {@link MemoryPoolMXBean#getUsageThresholdCount threshold |
| 197 | * count}. For collection threshold notifications, |
| 198 | * this count will be the |
| 199 | * {@link MemoryPoolMXBean#getCollectionUsageThresholdCount |
| 200 | * collection usage threshold count}. |
| 201 | * |
| 202 | * @return the number of times that the memory usage has crossed |
| 203 | * a threshold when the notification was constructed. |
| 204 | */ |
| 205 | public long getCount() { |
| 206 | return count; |
| 207 | } |
| 208 | |
| 209 | /** |
| 210 | * Returns a <tt>MemoryNotificationInfo</tt> object represented by the |
| 211 | * given <tt>CompositeData</tt>. |
| 212 | * The given <tt>CompositeData</tt> must contain |
| 213 | * the following attributes: |
| 214 | * <blockquote> |
| 215 | * <table border> |
| 216 | * <tr> |
| 217 | * <th align=left>Attribute Name</th> |
| 218 | * <th align=left>Type</th> |
| 219 | * </tr> |
| 220 | * <tr> |
| 221 | * <td>poolName</td> |
| 222 | * <td><tt>java.lang.String</tt></td> |
| 223 | * </tr> |
| 224 | * <tr> |
| 225 | * <td>usage</td> |
| 226 | * <td><tt>javax.management.openmbean.CompositeData</tt></td> |
| 227 | * </tr> |
| 228 | * <tr> |
| 229 | * <td>count</td> |
| 230 | * <td><tt>java.lang.Long</tt></td> |
| 231 | * </tr> |
| 232 | * </table> |
| 233 | * </blockquote> |
| 234 | * |
| 235 | * @param cd <tt>CompositeData</tt> representing a |
| 236 | * <tt>MemoryNotificationInfo</tt> |
| 237 | * |
| 238 | * @throws IllegalArgumentException if <tt>cd</tt> does not |
| 239 | * represent a <tt>MemoryNotificationInfo</tt> object. |
| 240 | * |
| 241 | * @return a <tt>MemoryNotificationInfo</tt> object represented |
| 242 | * by <tt>cd</tt> if <tt>cd</tt> is not <tt>null</tt>; |
| 243 | * <tt>null</tt> otherwise. |
| 244 | */ |
| 245 | public static MemoryNotificationInfo from(CompositeData cd) { |
| 246 | if (cd == null) { |
| 247 | return null; |
| 248 | } |
| 249 | |
| 250 | if (cd instanceof MemoryNotifInfoCompositeData) { |
| 251 | return ((MemoryNotifInfoCompositeData) cd).getMemoryNotifInfo(); |
| 252 | } else { |
| 253 | return new MemoryNotificationInfo(cd); |
| 254 | } |
| 255 | } |
| 256 | } |