/* GarbageCollectorMXBean.java - Interface for a garbage collector 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
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any later version.

GNU Classpath is distributed in the hope that it will be useful, but
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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along with GNU Classpath; see the file COPYING.  If not, write to the
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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
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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
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independent module, the terms and conditions of the license of that
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this exception to your version of the library, but you are not
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exception statement from your version. */

package java.lang.management;

/**
 * Provides access to information about the garbage collectors
 * of the virtual machine.  Garbage collectors are responsible
 * for removing unreferenced objects from memory.  A garbage
 * collector is a type of memory manager, so this interface
 * is combined with that of generic memory managers.  An instance
 * of this bean for each garbage collector is obtained by calling
 * {@link ManagementFactory#getGarbageCollectorMXBeans()}.
 *
 * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
 * @since 1.5
 */
public interface GarbageCollectorMXBean
  extends MemoryManagerMXBean
{

  /**
   * Returns the number of collections the garbage collector
   * represented by this bean has made.  -1 is returned if the
   * collection count is undefined.
   *
   * @return the number of collections made, or -1 if this is
   *         undefined.
   */
  long getCollectionCount();

  /**
   * Returns the accumulated number of milliseconds this garbage
   * collector has spent freeing the memory used by unreferenced
   * objects.  -1 is returned if the collection time is undefined.
   * Note that the accumulated time may not change, even when the
   * collection count increases, if the time taken is sufficiently
   * short; this depends on the resolution of the timer used.
   * 
   * @return the accumulated number of milliseconds spent collecting,
   *         or -1 if this is undefined.
   */
  long getCollectionTime();

}