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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 | } | ||