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Diffstat (limited to 'java/lang/management/MemoryNotificationInfo.java')
| -rw-r--r-- | java/lang/management/MemoryNotificationInfo.java | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/java/lang/management/MemoryNotificationInfo.java b/java/lang/management/MemoryNotificationInfo.java new file mode 100644 index 000000000..adb38b06f --- /dev/null +++ b/java/lang/management/MemoryNotificationInfo.java @@ -0,0 +1,215 @@ +/* MemoryNotificationInfo.java - Emitted memory notification info. + Copyright (C) 2006 Free Software Foundation + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package java.lang.management; + +import gnu.java.lang.management.MemoryMXBeanImpl; + +import javax.management.openmbean.CompositeData; +import javax.management.openmbean.CompositeType; +import javax.management.openmbean.SimpleType; + +/** + * <p> + * Represents the content of a notification emitted by the + * {@link MemoryMXBean}. Such notifications are emitted when + * one of the memory pools exceeds its usage or collection + * usage threshold. This object contains the following information, + * representing the state of the pool at the time of the + * notification: + * </p> + * <ul> + * <li>The name of the pool.</li> + * <li>The memory usage of the pool at the time of notification.</li> + * <li>The number of times the pool has exceeded this particular + * threshold in the past.</li> + * </ul> + * <p> + * Two types of notification are emitted by the {@link MemoryMXBean}: + * one for exceeding the usage threshold and one for exceeding the + * collection usage threshold. The value returned by {@link #getCount()} + * is dependent on this type; if the threshold exceeded is the usage + * threshold, then the usage threshold count is returned. If, instead, + * the collection usage threshold is exceeded, then the collection usage + * threshold count is returned. + * </p> + * <p> + * This data is held in the user data part of the notification (returned + * by {@link javax.management.Notification#getUserData()}) encapsulated in + * a {@link javax.management.openmbean.CompositeData} object. The + * {@link #from(javax.management.openmbean.CompositeData)} method may be + * used to unwrap the value and obtain an instance of this class. + * </p> + * + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + * @since 1.5 + */ +public class MemoryNotificationInfo +{ + + /** + * The type of notification emitted when the usage threshold is exceeded. + * After a notification is emitted, the usage level must drop below the + * threshold again before another notification is emitted. The value is + * <code>java.management.memory.threshold.exceeded</code>. + */ + public static final String MEMORY_THRESHOLD_EXCEEDED = + "java.management.memory.threshold.exceeded"; + + /** + * The type of notification emitted when the collection usage threshold + * is exceeded, following a garbage collection cycle. The value is + * <code>java.management.memory.collection.threshold.exceeded</code>. + */ + public static final String MEMORY_COLLECTION_THRESHOLD_EXCEEDED = + "java.management.memory.collection.threshold.exceeded"; + + /** + * The name of the memory pool which exceeded the threshold. + */ + private String poolName; + + /** + * The usage level of the memory pool at the time of notification. + */ + private MemoryUsage usage; + + /** + * The number of times the threshold has been crossed. + */ + private long count; + + /** + * Constructs a new {@link MemoryNotificationInfo} object using the + * specified pool name, usage level and threshold crossing count. + * + * @param poolName the name of the pool which has exceeded a threshold. + * @param usage the usage level of the pool at the time of notification. + * @param count the number of times the threshold has been crossed. + */ + public MemoryNotificationInfo(String poolName, MemoryUsage usage, long count) + { + this.poolName = poolName; + this.usage = usage; + this.count = count; + } + + /** + * <p> + * Returns a {@link MemoryNotificationInfo} instance using the values + * given in the supplied + * {@link javax.management.openmbean.CompositeData} object. + * The composite data instance should contain the following + * attributes with the specified types: + * </p> + * <table> + * <th><td>Name</td><td>Type</td></th> + * <tr><td>poolName</td><td>java.lang.String</td></tr> + * <tr><td>usage</td><td>javax.management.openmbean.CompositeData + * </td></tr> + * <tr><td>count</td><td>java.lang.Long</td></tr> + * </table> + * <p> + * The usage level is further described as: + * </p> + * <table> + * <th><td>Name</td><td>Type</td></th> + * <tr><td>init</td><td>java.lang.Long</td></tr> + * <tr><td>used</td><td>java.lang.Long</td></tr> + * <tr><td>committed</td><td>java.lang.Long</td></tr> + * <tr><td>max</td><td>java.lang.Long</td></tr> + * </table> + * + * @param data the composite data structure to take values from. + * @return a new instance containing the values from the + * composite data structure, or <code>null</code> + * if the data structure was also <code>null</code>. + * @throws IllegalArgumentException if the composite data structure + * does not match the structure + * outlined above. + */ + public static MemoryNotificationInfo from(CompositeData data) + { + if (data == null) + return null; + CompositeType type = data.getCompositeType(); + ThreadInfo.checkAttribute(type, "poolName", SimpleType.STRING); + ThreadInfo.checkAttribute(type, "usage", MemoryMXBeanImpl.usageType); + ThreadInfo.checkAttribute(type, "count", SimpleType.LONG); + MemoryUsage usage = MemoryUsage.from((CompositeData) data.get("usage")); + return new MemoryNotificationInfo(((String) data.get("poolName")), + usage, + ((Long) data.get("count")).longValue()); + } + + /** + * Returns the number of times the memory pool has crossed the usage + * threshold, as of the time of notification. If this is the notification + * represented by the type {@link #MEMORY_THRESHOLD_EXCEEDED}, then the + * count is the usage threshold count. If this is the notification + * represented by the type {@link #MEMORY_COLLECTION_THRESHOLD_EXCEEDED}, + * then the count is the collection usage threshold count. + * + * @return the number of times the appropriate threshold has been crossed. + */ + public long getCount() + { + return count; + } + + /** + * Returns the name of the pool which has crossed a threshold. + * + * @return the name of the pool. + */ + public String getPoolName() + { + return poolName; + } + + /** + * Returns the usage levels at the time of notification. + * + * @return the usage levels. + */ + public MemoryUsage getUsage() + { + return usage; + } + +} + |