/* VMGarbageCollectorMXBeanImpl.java - VM interface for a GC 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.

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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 gnu.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
 */
final class VMGarbageCollectorMXBeanImpl
{

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

  /**
   * 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.
   * 
   * @param name the name of the garbage collector.
   * @return the accumulated number of milliseconds spent collecting,
   *         or -1 if this is undefined.
   */
  static native long getCollectionTime(String name);

}
