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1: /* MemoryNotificationInfo.java - Emitted memory notification info. 2: Copyright (C) 2006 Free Software Foundation 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: package java.lang.management; 39: 40: import gnu.java.lang.management.MemoryMXBeanImpl; 41: 42: import javax.management.openmbean.CompositeData; 43: import javax.management.openmbean.CompositeType; 44: import javax.management.openmbean.SimpleType; 45: 46: /** 47: * <p> 48: * Represents the content of a notification emitted by the 49: * {@link MemoryMXBean}. Such notifications are emitted when 50: * one of the memory pools exceeds its usage or collection 51: * usage threshold. This object contains the following information, 52: * representing the state of the pool at the time of the 53: * notification: 54: * </p> 55: * <ul> 56: * <li>The name of the pool.</li> 57: * <li>The memory usage of the pool at the time of notification.</li> 58: * <li>The number of times the pool has exceeded this particular 59: * threshold in the past.</li> 60: * </ul> 61: * <p> 62: * Two types of notification are emitted by the {@link MemoryMXBean}: 63: * one for exceeding the usage threshold and one for exceeding the 64: * collection usage threshold. The value returned by {@link #getCount()} 65: * is dependent on this type; if the threshold exceeded is the usage 66: * threshold, then the usage threshold count is returned. If, instead, 67: * the collection usage threshold is exceeded, then the collection usage 68: * threshold count is returned. 69: * </p> 70: * <p> 71: * This data is held in the user data part of the notification (returned 72: * by {@link javax.management.Notification#getUserData()}) encapsulated in 73: * a {@link javax.management.openmbean.CompositeData} object. The 74: * {@link #from(javax.management.openmbean.CompositeData)} method may be 75: * used to unwrap the value and obtain an instance of this class. 76: * </p> 77: * 78: * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 79: * @since 1.5 80: */ 81: public class MemoryNotificationInfo 82: { 83: 84: /** 85: * The type of notification emitted when the usage threshold is exceeded. 86: * After a notification is emitted, the usage level must drop below the 87: * threshold again before another notification is emitted. The value is 88: * <code>java.management.memory.threshold.exceeded</code>. 89: */ 90: public static final String MEMORY_THRESHOLD_EXCEEDED = 91: "java.management.memory.threshold.exceeded"; 92: 93: /** 94: * The type of notification emitted when the collection usage threshold 95: * is exceeded, following a garbage collection cycle. The value is 96: * <code>java.management.memory.collection.threshold.exceeded</code>. 97: */ 98: public static final String MEMORY_COLLECTION_THRESHOLD_EXCEEDED = 99: "java.management.memory.collection.threshold.exceeded"; 100: 101: /** 102: * The name of the memory pool which exceeded the threshold. 103: */ 104: private String poolName; 105: 106: /** 107: * The usage level of the memory pool at the time of notification. 108: */ 109: private MemoryUsage usage; 110: 111: /** 112: * The number of times the threshold has been crossed. 113: */ 114: private long count; 115: 116: /** 117: * Constructs a new {@link MemoryNotificationInfo} object using the 118: * specified pool name, usage level and threshold crossing count. 119: * 120: * @param poolName the name of the pool which has exceeded a threshold. 121: * @param usage the usage level of the pool at the time of notification. 122: * @param count the number of times the threshold has been crossed. 123: */ 124: public MemoryNotificationInfo(String poolName, MemoryUsage usage, long count) 125: { 126: this.poolName = poolName; 127: this.usage = usage; 128: this.count = count; 129: } 130: 131: /** 132: * <p> 133: * Returns a {@link MemoryNotificationInfo} instance using the values 134: * given in the supplied 135: * {@link javax.management.openmbean.CompositeData} object. 136: * The composite data instance should contain the following 137: * attributes with the specified types: 138: * </p> 139: * <table> 140: * <th><td>Name</td><td>Type</td></th> 141: * <tr><td>poolName</td><td>java.lang.String</td></tr> 142: * <tr><td>usage</td><td>javax.management.openmbean.CompositeData 143: * </td></tr> 144: * <tr><td>count</td><td>java.lang.Long</td></tr> 145: * </table> 146: * <p> 147: * The usage level is further described as: 148: * </p> 149: * <table> 150: * <th><td>Name</td><td>Type</td></th> 151: * <tr><td>init</td><td>java.lang.Long</td></tr> 152: * <tr><td>used</td><td>java.lang.Long</td></tr> 153: * <tr><td>committed</td><td>java.lang.Long</td></tr> 154: * <tr><td>max</td><td>java.lang.Long</td></tr> 155: * </table> 156: * 157: * @param data the composite data structure to take values from. 158: * @return a new instance containing the values from the 159: * composite data structure, or <code>null</code> 160: * if the data structure was also <code>null</code>. 161: * @throws IllegalArgumentException if the composite data structure 162: * does not match the structure 163: * outlined above. 164: */ 165: public static MemoryNotificationInfo from(CompositeData data) 166: { 167: if (data == null) 168: return null; 169: CompositeType type = data.getCompositeType(); 170: ThreadInfo.checkAttribute(type, "poolName", SimpleType.STRING); 171: ThreadInfo.checkAttribute(type, "usage", MemoryMXBeanImpl.usageType); 172: ThreadInfo.checkAttribute(type, "count", SimpleType.LONG); 173: MemoryUsage usage = MemoryUsage.from((CompositeData) data.get("usage")); 174: return new MemoryNotificationInfo(((String) data.get("poolName")), 175: usage, 176: ((Long) data.get("count")).longValue()); 177: } 178: 179: /** 180: * Returns the number of times the memory pool has crossed the usage 181: * threshold, as of the time of notification. If this is the notification 182: * represented by the type {@link #MEMORY_THRESHOLD_EXCEEDED}, then the 183: * count is the usage threshold count. If this is the notification 184: * represented by the type {@link #MEMORY_COLLECTION_THRESHOLD_EXCEEDED}, 185: * then the count is the collection usage threshold count. 186: * 187: * @return the number of times the appropriate threshold has been crossed. 188: */ 189: public long getCount() 190: { 191: return count; 192: } 193: 194: /** 195: * Returns the name of the pool which has crossed a threshold. 196: * 197: * @return the name of the pool. 198: */ 199: public String getPoolName() 200: { 201: return poolName; 202: } 203: 204: /** 205: * Returns the usage levels at the time of notification. 206: * 207: * @return the usage levels. 208: */ 209: public MemoryUsage getUsage() 210: { 211: return usage; 212: } 213: 214: }