This adds the MemoryPoolMXBean interface. Implementation, VM stuff, doc updates and example to follow as usual.
Changelog:
2006-07-03 Andrew John Hughes <[EMAIL PROTECTED]>
* java/lang/management/MemoryPoolMXBean.java:
New file.
--
Andrew :-)
Escape the Java Trap with GNU Classpath!
http://www.gnu.org/philosophy/java-trap.html
public class gcj extends Freedom implements Java { ... }
Index: java/lang/management/MemoryPoolMXBean.java
===================================================================
RCS file: java/lang/management/MemoryPoolMXBean.java
diff -N java/lang/management/MemoryPoolMXBean.java
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ java/lang/management/MemoryPoolMXBean.java 3 Jul 2006 20:19:46 -0000
@@ -0,0 +1,310 @@
+/* MemoryPoolMXBean.java - Interface for a memory pool bean
+ 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;
+
+/**
+ * <p>
+ * Provides access to information about one of the memory
+ * resources or pools used by the virtual machine. Instances
+ * of this bean are obtained by calling
+ * [EMAIL PROTECTED] ManagementFactory#getMemoryPoolMXBeans()}. One
+ * bean is returned for each memory pool provided.
+ * </p>
+ * <p>
+ * The memory pool bean allows the usage of the pool to be
+ * monitored. The bean can provide statistics on the current
+ * and peak usage of the pool, and on the threshold levels the
+ * pool uses.
+ * </p>
+ * <p>
+ * [EMAIL PROTECTED] getUsage()} returns an approximation of the current
+ * usage of the pool. Calls to this method are expected to be
+ * generally quick to perform; if the call is expensive, the
+ * documentation of the bean should specify so. For memory
+ * pool beans that represent the memory used by garbage
+ * collectors, the usage level includes both referenced and
+ * unreferenced objects.
+ * </p>
+ * <p>
+ * [EMAIL PROTECTED] getPeakUsage()} and [EMAIL PROTECTED] resetPeakUsage()}
enable
+ * the retrieval of the peak usage level and setting it to the
+ * current usage level, respectively. Initially, the peak usage
+ * level is relative to the start of the virtual machine.
+ * </p>
+ * <p>
+ * Memory pools may also include optional support for usage thresholds.
+ * The usage threshold is a particular level of memory usage. When this
+ * value is crossed (the current memory usage becomes equal to or greater
+ * than this threshold level), the usage threshold count is increased.
+ * This feature is designed for monitoring the trend in memory usage.
+ * Support for a collection usage threshold is also provided, for
+ * particular garbage collectors. This is used to monitor the amount
+ * of memory left uncollected after a garbage collection cycle. There
+ * is no need to make special garbage collection runs to support this;
+ * the level following collection just needs to be monitored.
+ * </p>
+ *
+ * @author Andrew John Hughes ([EMAIL PROTECTED])
+ * @since 1.5
+ */
+public interface MemoryPoolMXBean
+{
+
+ /**
+ * Returns memory usage statistics after a best-effort attempt
+ * has been made to remove unused objects from the pool. This
+ * method is designed for use by the pools of garbage collectors,
+ * in order to monitor the amount of memory used after collections.
+ * It will return <code>null</code> if such functionality is
+ * unsupported by the memory pool represented by this bean.
+ *
+ * @return the memory usage of the memory pool after the most
+ * recent garbage collection cycle, or <code>null</code>
+ * if this operation is not supported.
+ */
+ MemoryUsage getCollectionUsage();
+
+ /**
+ * Returns the collection usage threshold level in bytes. This
+ * value is initially zero.
+ *
+ * @return the collection usage threshold in bytes.
+ * @throws UnsupportedOperationException if the collection usage
+ * threshold is not supported.
+ * @see #getCollectionUsageThresholdCount()
+ * @see #isCollectionUsageThresholdExceeded()
+ * @see #isCollectionUsageThresholdSupported()
+ * @see #setCollectionUsageThreshold(long)
+ */
+ long getCollectionUsageThreshold();
+
+ /**
+ * Returns the number of times the usage level has matched or
+ * exceeded the collection usage threshold.
+ *
+ * @return the number of times the usage level has matched
+ * or exceeded the collection usage threshold.
+ * @throws UnsupportedOperationException if the collection usage
+ * threshold is not supported.
+ * @see #getCollectionUsageThreshold()
+ * @see #isCollectionUsageThresholdExceeded()
+ * @see #isCollectionUsageThresholdSupported()
+ * @see #setCollectionUsageThreshold(long)
+ */
+ long getCollectionUsageThresholdCount();
+
+ /**
+ * Returns the names of the memory managers associated with this
+ * pool. Each pool has at least one memory manager.
+ *
+ * @return an array containing the name of each memory manager
+ * responsible for this pool.
+ */
+ String[] getMemoryManagerNames();
+
+ /**
+ * Returns the name of the memory pool.
+ *
+ * @return the memory pool name.
+ */
+ String getName();
+
+ /**
+ * Returns memory usage statistics for the peak memory usage
+ * of the pool. The peak is the maximum memory usage occurring
+ * since the virtual machine was started or since the peak
+ * was reset by [EMAIL PROTECTED] #resetPeakUsage()}. The return value
+ * may be <code>null</code> if this pool is no longer valid.
+ *
+ * @return the memory usage of the memory pool at its peak,
+ * or <code>null</code> if this pool is no longer valid.
+ */
+ MemoryUsage getPeakUsage();
+
+ /**
+ * Returns memory usage statistics for the current memory usage
+ * of the pool. The return value may be <code>null</code> if
+ * this pool is no longer valid. Obtaining these values is
+ * expected to be a relatively quick operation; if this will
+ * instead be an expensive operation to perform, the documentation
+ * of the implementating bean should specify that this is the
+ * case. The values are intended to be an estimate for monitoring
+ * purposes.
+ *
+ * @return the memory usage of the memory pool at present,
+ * or <code>null</code> if this pool is no longer valid.
+ */
+ MemoryUsage getUsage();
+
+ /**
+ * Returns the usage threshold level in bytes. This
+ * value is initially defined by the virtual machine.
+ *
+ * @return the usage threshold in bytes.
+ * @throws UnsupportedOperationException if the usage threshold
+ * is not supported.
+ * @see #getUsageThresholdCount()
+ * @see #isUsageThresholdExceeded()
+ * @see #isUsageThresholdSupported()
+ * @see #setUsageThreshold(long)
+ */
+ long getUsageThreshold();
+
+ /**
+ * Returns the number of times the usage level has matched or
+ * exceeded the usage threshold.
+ *
+ * @return the number of times the usage level has matched
+ * or exceeded the usage threshold.
+ * @throws UnsupportedOperationException if the usage threshold
+ * is not supported.
+ * @see #getUsageThreshold()
+ * @see #isUsageThresholdExceeded()
+ * @see #isUsageThresholdSupported()
+ * @see #setUsageThreshold(long)
+ */
+ long getUsageThresholdCount();
+
+ /**
+ * Returns true if the collection usage level is equal to
+ * or greater than the collection usage threshold.
+ *
+ * @return true if the collection usage threshold has been
+ * matched or exceeded.
+ * @throws UnsupportedOperationException if the collection usage
+ * threshold is not supported.
+ * @see #getCollectionUsageThreshold()
+ * @see #getCollectionUsageThresholdCount()
+ * @see #isCollectionUsageThresholdSupported()
+ * @see #setCollectionUsageThreshold(long)
+ */
+ boolean isCollectionUsageThresholdExceeded();
+
+ /**
+ * Returns true if this memory pool supports a collection usage
+ * level threshold.
+ *
+ * @return true if a collection usage level threshold is supported.
+ * @see #getCollectionUsageThreshold()
+ * @see #getCollectionUsageThresholdCount()
+ * @see #isCollectionUsageThresholdExceeded()
+ * @see #setCollectionUsageThreshold(long)
+ */
+ boolean isCollectionUsageThresholdSupported();
+
+ /**
+ * Returns true if the usage level is equal to
+ * or greater than the usage threshold.
+ *
+ * @return true if the usage threshold has been
+ * matched or exceeded.
+ * @throws UnsupportedOperationException if the usage threshold
+ * is not supported.
+ * @see #getUsageThreshold()
+ * @see #getUsageThresholdCount()
+ * @see #isUsageThresholdSupported()
+ * @see #setUsageThreshold(long)
+ */
+ boolean isUsageThresholdExceeded();
+
+ /**
+ * Returns true if this memory pool supports a usage level threshold.
+ *
+ * @return true if a usage level threshold is supported.
+ * @see #getUsageThreshold()
+ * @see #getUsageThresholdCount()
+ * @see #isUsageThresholdExceeded()
+ * @see #setUsageThreshold(long)
+ */
+ boolean isUsageThresholdSupported();
+
+ /**
+ * Returns true if this memory pool is still valid. A memory pool
+ * becomes invalid when it is removed by the virtual machine and
+ * no longer used.
+ *
+ * @return true if this memory pool is valid.
+ */
+ boolean isValid();
+
+ /**
+ * Resets the peak memory usage level to the current memory usage
+ * level.
+ *
+ * @throws SecurityException if a security manager exists and
+ * denies ManagementPermission("control").
+ */
+ void resetPeakUsage();
+
+ /**
+ * Sets the collection threshold usage level to the given value.
+ * A value of zero disables the collection threshold.
+ *
+ * @param threshold the new threshold level.
+ * @throws IllegalArgumentException if the threshold hold level
+ * is negative.
+ * @throws UnsupportedOperationException if the collection usage
+ * threshold is not supported.
+ * @throws SecurityException if a security manager exists and
+ * denies ManagementPermission("control").
+ * @see #getCollectionUsageThreshold()
+ * @see #getCollectionUsageThresholdCount()
+ * @see #isCollectionUsageThresholdExceeded()
+ * @see #isCollectionUsageThresholdSupported()
+ */
+ void setCollectionUsageThreshold(long threshold);
+
+ /**
+ * Sets the threshold usage level to the given value. A value of
+ * zero disables the threshold.
+ *
+ * @param threshold the new threshold level.
+ * @throws IllegalArgumentException if the threshold hold level
+ * is negative.
+ * @throws UnsupportedOperationException if the usage threshold
+ * is not supported.
+ * @throws SecurityException if a security manager exists and
+ * denies ManagementPermission("control").
+ * @see #getUsageThreshold()
+ * @see #getUsageThresholdCount()
+ * @see #isUsageThresholdExceeded()
+ * @see #isUsageThresholdSupported()
+ */
+ void setUsageThreshold(long threshold);
+
+}
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