001    /* CompilationMXBean.java - Interface for a compilation bean
002       Copyright (C) 2006 Free Software Foundation
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package 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     */
051    public 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    }