001 /* ClassLoadingMXBean.java - Interface for a class loading 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 class loading 042 * behaviour of the current invocation of the virtual 043 * machine. An instance of this bean is obtained by calling 044 * {@link ManagementFactory#getClassLoadingMXBean()}. 045 * 046 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 047 * @since 1.5 048 */ 049 public interface ClassLoadingMXBean 050 { 051 052 /** 053 * Returns the number of classes currently loaded by 054 * the virtual machine. 055 * 056 * @return the number of loaded classes. 057 */ 058 int getLoadedClassCount(); 059 060 /** 061 * Returns the total number of classes loaded by the 062 * virtual machine since it was started. This is the 063 * sum of the currently loaded classes and those that 064 * have been unloaded. 065 * 066 * @return the total number of classes that have been 067 * loaded by the virtual machine since it started. 068 */ 069 long getTotalLoadedClassCount(); 070 071 /** 072 * Returns the number of classes that have been unloaded 073 * by the virtual machine since it was started. 074 * 075 * @return the number of unloaded classes. 076 */ 077 long getUnloadedClassCount(); 078 079 /** 080 * Returns true if the virtual machine will emit additional 081 * information when classes are loaded and unloaded. The 082 * format of the output is left up to the virtual machine. 083 * 084 * @return true if verbose class loading output is on. 085 */ 086 boolean isVerbose(); 087 088 /** 089 * Turns on or off the emission of additional information 090 * when classes are loaded and unloaded. The format of the 091 * output is left up to the virtual machine. This method 092 * may be called by multiple threads concurrently, but there 093 * is only one global setting of verbosity that is affected. 094 * 095 * @param verbose the new setting for verbose class loading 096 * output. 097 * @throws SecurityException if a security manager exists and 098 * denies ManagementPermission("control"). 099 */ 100 void setVerbose(boolean verbose); 101 102 } 103