--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.management/share/classes/java/lang/management/MemoryUsage.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,301 @@
+/*
+ * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.lang.management;
+
+import javax.management.openmbean.CompositeData;
+import sun.management.MemoryUsageCompositeData;
+
+/**
+ * A <tt>MemoryUsage</tt> object represents a snapshot of memory usage.
+ * Instances of the <tt>MemoryUsage</tt> class are usually constructed
+ * by methods that are used to obtain memory usage
+ * information about individual memory pool of the Java virtual machine or
+ * the heap or non-heap memory of the Java virtual machine as a whole.
+ *
+ * <p> A <tt>MemoryUsage</tt> object contains four values:
+ * <table summary="Describes the MemoryUsage object content">
+ * <tr>
+ * <td valign=top> <tt>init</tt> </td>
+ * <td valign=top> represents the initial amount of memory (in bytes) that
+ * the Java virtual machine requests from the operating system
+ * for memory management during startup. The Java virtual machine
+ * may request additional memory from the operating system and
+ * may also release memory to the system over time.
+ * The value of <tt>init</tt> may be undefined.
+ * </td>
+ * </tr>
+ * <tr>
+ * <td valign=top> <tt>used</tt> </td>
+ * <td valign=top> represents the amount of memory currently used (in bytes).
+ * </td>
+ * </tr>
+ * <tr>
+ * <td valign=top> <tt>committed</tt> </td>
+ * <td valign=top> represents the amount of memory (in bytes) that is
+ * guaranteed to be available for use by the Java virtual machine.
+ * The amount of committed memory may change over time (increase
+ * or decrease). The Java virtual machine may release memory to
+ * the system and <tt>committed</tt> could be less than <tt>init</tt>.
+ * <tt>committed</tt> will always be greater than
+ * or equal to <tt>used</tt>.
+ * </td>
+ * </tr>
+ * <tr>
+ * <td valign=top> <tt>max</tt> </td>
+ * <td valign=top> represents the maximum amount of memory (in bytes)
+ * that can be used for memory management. Its value may be undefined.
+ * The maximum amount of memory may change over time if defined.
+ * The amount of used and committed memory will always be less than
+ * or equal to <tt>max</tt> if <tt>max</tt> is defined.
+ * A memory allocation may fail if it attempts to increase the
+ * used memory such that <tt>used > committed</tt> even
+ * if <tt>used <= max</tt> would still be true (for example,
+ * when the system is low on virtual memory).
+ * </td>
+ * </tr>
+ * </table>
+ *
+ * Below is a picture showing an example of a memory pool:
+ *
+ * <pre>
+ * +----------------------------------------------+
+ * +//////////////// | +
+ * +//////////////// | +
+ * +----------------------------------------------+
+ *
+ * |--------|
+ * init
+ * |---------------|
+ * used
+ * |---------------------------|
+ * committed
+ * |----------------------------------------------|
+ * max
+ * </pre>
+ *
+ * <h3>MXBean Mapping</h3>
+ * <tt>MemoryUsage</tt> is mapped to a {@link CompositeData CompositeData}
+ * with attributes as specified in the {@link #from from} method.
+ *
+ * @author Mandy Chung
+ * @since 1.5
+ */
+public class MemoryUsage {
+ private final long init;
+ private final long used;
+ private final long committed;
+ private final long max;
+
+ /**
+ * Constructs a <tt>MemoryUsage</tt> object.
+ *
+ * @param init the initial amount of memory in bytes that
+ * the Java virtual machine allocates;
+ * or <tt>-1</tt> if undefined.
+ * @param used the amount of used memory in bytes.
+ * @param committed the amount of committed memory in bytes.
+ * @param max the maximum amount of memory in bytes that
+ * can be used; or <tt>-1</tt> if undefined.
+ *
+ * @throws IllegalArgumentException if
+ * <ul>
+ * <li> the value of <tt>init</tt> or <tt>max</tt> is negative
+ * but not <tt>-1</tt>; or</li>
+ * <li> the value of <tt>used</tt> or <tt>committed</tt> is negative;
+ * or</li>
+ * <li> <tt>used</tt> is greater than the value of <tt>committed</tt>;
+ * or</li>
+ * <li> <tt>committed</tt> is greater than the value of <tt>max</tt>
+ * <tt>max</tt> if defined.</li>
+ * </ul>
+ */
+ public MemoryUsage(long init,
+ long used,
+ long committed,
+ long max) {
+ if (init < -1) {
+ throw new IllegalArgumentException( "init parameter = " +
+ init + " is negative but not -1.");
+ }
+ if (max < -1) {
+ throw new IllegalArgumentException( "max parameter = " +
+ max + " is negative but not -1.");
+ }
+ if (used < 0) {
+ throw new IllegalArgumentException( "used parameter = " +
+ used + " is negative.");
+ }
+ if (committed < 0) {
+ throw new IllegalArgumentException( "committed parameter = " +
+ committed + " is negative.");
+ }
+ if (used > committed) {
+ throw new IllegalArgumentException( "used = " + used +
+ " should be <= committed = " + committed);
+ }
+ if (max >= 0 && committed > max) {
+ throw new IllegalArgumentException( "committed = " + committed +
+ " should be < max = " + max);
+ }
+
+ this.init = init;
+ this.used = used;
+ this.committed = committed;
+ this.max = max;
+ }
+
+ /**
+ * Constructs a <tt>MemoryUsage</tt> object from a
+ * {@link CompositeData CompositeData}.
+ */
+ private MemoryUsage(CompositeData cd) {
+ // validate the input composite data
+ MemoryUsageCompositeData.validateCompositeData(cd);
+
+ this.init = MemoryUsageCompositeData.getInit(cd);
+ this.used = MemoryUsageCompositeData.getUsed(cd);
+ this.committed = MemoryUsageCompositeData.getCommitted(cd);
+ this.max = MemoryUsageCompositeData.getMax(cd);
+ }
+
+ /**
+ * Returns the amount of memory in bytes that the Java virtual machine
+ * initially requests from the operating system for memory management.
+ * This method returns <tt>-1</tt> if the initial memory size is undefined.
+ *
+ * @return the initial size of memory in bytes;
+ * <tt>-1</tt> if undefined.
+ */
+ public long getInit() {
+ return init;
+ }
+
+ /**
+ * Returns the amount of used memory in bytes.
+ *
+ * @return the amount of used memory in bytes.
+ *
+ */
+ public long getUsed() {
+ return used;
+ };
+
+ /**
+ * Returns the amount of memory in bytes that is committed for
+ * the Java virtual machine to use. This amount of memory is
+ * guaranteed for the Java virtual machine to use.
+ *
+ * @return the amount of committed memory in bytes.
+ *
+ */
+ public long getCommitted() {
+ return committed;
+ };
+
+ /**
+ * Returns the maximum amount of memory in bytes that can be
+ * used for memory management. This method returns <tt>-1</tt>
+ * if the maximum memory size is undefined.
+ *
+ * <p> This amount of memory is not guaranteed to be available
+ * for memory management if it is greater than the amount of
+ * committed memory. The Java virtual machine may fail to allocate
+ * memory even if the amount of used memory does not exceed this
+ * maximum size.
+ *
+ * @return the maximum amount of memory in bytes;
+ * <tt>-1</tt> if undefined.
+ */
+ public long getMax() {
+ return max;
+ };
+
+ /**
+ * Returns a descriptive representation of this memory usage.
+ */
+ public String toString() {
+ StringBuilder buf = new StringBuilder();
+ buf.append("init = " + init + "(" + (init >> 10) + "K) ");
+ buf.append("used = " + used + "(" + (used >> 10) + "K) ");
+ buf.append("committed = " + committed + "(" +
+ (committed >> 10) + "K) " );
+ buf.append("max = " + max + "(" + (max >> 10) + "K)");
+ return buf.toString();
+ }
+
+ /**
+ * Returns a <tt>MemoryUsage</tt> object represented by the
+ * given <tt>CompositeData</tt>. The given <tt>CompositeData</tt>
+ * must contain the following attributes:
+ *
+ * <blockquote>
+ * <table border summary="The attributes and the types the given CompositeData contains">
+ * <tr>
+ * <th align=left>Attribute Name</th>
+ * <th align=left>Type</th>
+ * </tr>
+ * <tr>
+ * <td>init</td>
+ * <td><tt>java.lang.Long</tt></td>
+ * </tr>
+ * <tr>
+ * <td>used</td>
+ * <td><tt>java.lang.Long</tt></td>
+ * </tr>
+ * <tr>
+ * <td>committed</td>
+ * <td><tt>java.lang.Long</tt></td>
+ * </tr>
+ * <tr>
+ * <td>max</td>
+ * <td><tt>java.lang.Long</tt></td>
+ * </tr>
+ * </table>
+ * </blockquote>
+ *
+ * @param cd <tt>CompositeData</tt> representing a <tt>MemoryUsage</tt>
+ *
+ * @throws IllegalArgumentException if <tt>cd</tt> does not
+ * represent a <tt>MemoryUsage</tt> with the attributes described
+ * above.
+ *
+ * @return a <tt>MemoryUsage</tt> object represented by <tt>cd</tt>
+ * if <tt>cd</tt> is not <tt>null</tt>;
+ * <tt>null</tt> otherwise.
+ */
+ public static MemoryUsage from(CompositeData cd) {
+ if (cd == null) {
+ return null;
+ }
+
+ if (cd instanceof MemoryUsageCompositeData) {
+ return ((MemoryUsageCompositeData) cd).getMemoryUsage();
+ } else {
+ return new MemoryUsage(cd);
+ }
+
+ }
+}