2006-07-16 Andrew John Hughes <gnu_andrew@member.fsf.org>

	* java/lang/management/MemoryNotificationInfo.java:
	New file.

2 files changed, 244 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 0294abe3b..cb2fb9afd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2006-07-16  Andrew John Hughes  <gnu_andrew@member.fsf.org>
+
+	* java/lang/management/MemoryNotificationInfo.java:
+	New file.
+	
 2006-07-16  Audrius Meskauskas  <AudriusA@Bioinformatics.org>
 
 	PR 28392
diff --git a/java/lang/management/MemoryNotificationInfo.java b/java/lang/management/MemoryNotificationInfo.java
new file mode 100644
index 000000000..c97fe6bb5
--- /dev/null
+++ b/java/lang/management/MemoryNotificationInfo.java
@@ -0,0 +1,239 @@
+/* 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 javax.management.openmbean.CompositeData;
+import javax.management.openmbean.CompositeType;
+import javax.management.openmbean.OpenDataException;
+import javax.management.openmbean.OpenType;
+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);
+    try
+      {
+	CompositeType uType = 
+	  new CompositeType(MemoryUsage.class.getName(),
+			    "Describes the usage levels of a pool",
+			    new String[] { "init", "used",
+					   "committed", "max"
+			    },
+			    new String[] { "Initial level",
+					   "Used level",
+					   "Committed level",
+					   "Maximum level"
+			    },
+			    new OpenType[] {
+			      SimpleType.LONG, SimpleType.LONG,
+			      SimpleType.LONG, SimpleType.LONG
+			    });
+	ThreadInfo.checkAttribute(type, "usage", uType);
+      }
+    catch (OpenDataException e)
+      {
+	throw new IllegalStateException("Something went wrong in creating " +
+					"the composite data type for the " +
+					"memory usage element.", e);
+      }
+    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;
+  }
+
+}
+