001/* CompilationMXBean.java - Interface for a compilation bean
002   Copyright (C) 2006 Free Software Foundation
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package java.lang.management;
039
040/**
041 * Provides access to information about the Just-In-Time
042 * (JIT) compiler provided by the virtual machine, if one
043 * exists.  An instance of this bean is obtainable by
044 * calling {@link ManagementFactory#getCompilationMXBean()}
045 * if a JIT is available.  Otherwise, the method returns
046 * <code>null</code>.
047 *
048 * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
049 * @since 1.5
050 */
051public interface CompilationMXBean
052{
053  
054  /**
055   * Returns the name of the Just-In-Time (JIT) compiler.
056   *
057   * @return the name of the JIT compiler.
058   */
059  String getName();
060
061  /**
062   * Returns true if the virtual machine's JIT compiler
063   * supports monitoring of the time spent compiling.
064   *
065   * @return true if the JIT compiler can be monitored
066   *         for time spent compiling.
067   */
068  boolean isCompilationTimeMonitoringSupported();
069
070  /**
071   * Returns the accumulated time, in milliseconds, that
072   * the JIT compiler has spent compiling Java bytecodes
073   * to native machine code.  This value represents a single
074   * time measurement for the whole virtual machine, including
075   * all multiple threads of operation.  The value is not
076   * intended as a performance measurement.
077   *
078   * @return the accumulated number of milliseconds the JIT
079   *         compiler has spent compiling.
080   * @throws UnsupportedOperationException if time monitoring
081   *                                       is not supported.
082   */
083  long getTotalCompilationTime();
084
085}