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| 1 | +/* | |
| 2 | + * Copyright (c) 2003, 2006, 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 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 | +} | |