001/* OperatingSystemMXBean.java - Interface for an operating system 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 underlying operating 042 * system. An instance of this bean is obtained by calling 043 * {@link ManagementFactory#getOperatingSystemMXBean()}. 044 * 045 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 046 * @since 1.5 047 */ 048public interface OperatingSystemMXBean 049{ 050 051 /** 052 * Returns the name of the underlying system architecture. This 053 * is equivalent to obtaining the <code>os.arch</code> property 054 * via {@link System#getProperty(String)}. 055 * 056 * @return the name of the underlying system architecture on which 057 * the VM is running. 058 * @throws SecurityException if a security manager exists which 059 * prevents access to the name property. 060 * @see java.lang.System#getProperty(String) 061 * @see java.lang.SecurityManager#checkPropertyAccess(String) 062 */ 063 String getArch(); 064 065 /** 066 * Returns the number of processors currently available to the 067 * virtual machine. This number is subject to change during 068 * execution of the virtual machine, and will always be >= 1. 069 * The call is equivalent to {@link Runtime#availableProcessors()}. 070 * 071 * @return the number of processors available to the VM. 072 */ 073 int getAvailableProcessors(); 074 075 /** 076 * Returns the name of the underlying operating system. This 077 * is equivalent to obtaining the <code>os.name</code> property 078 * via {@link System#getProperty(String)}. 079 * 080 * @return the name of the operating system on which the VM 081 * is running. 082 * @throws SecurityException if a security manager exists which 083 * prevents access to the name property. 084 * @see java.lang.System#getProperty(String) 085 * @see java.lang.SecurityManager#checkPropertyAccess(String) 086 */ 087 String getName(); 088 089 /** 090 * Returns the system load average for the last minute, or -1 091 * if this is unavailable. The availability and calculation 092 * of the load average is system-dependent, but is usually 093 * a damped time-dependent average obtained by monitoring the 094 * number of queued and running processes. It is expected 095 * that this method will be called frequently to monitor the 096 * average over time, so it may not be implemented on systems 097 * where such a call is expensive. 098 * 099 * @return the system load average for the last minute, or -1 100 * if this is unavailable. 101 * @since 1.6 102 */ 103 double getSystemLoadAverage(); 104 105 /** 106 * Returns the version of the underlying operating system. This 107 * is equivalent to obtaining the <code>os.version</code> property 108 * via {@link System#getProperty(String)}. 109 * 110 * @return the version of the operating system on which the VM 111 * is running. 112 * @throws SecurityException if a security manager exists which 113 * prevents access to the name property. 114 * @see java.lang.System#getProperty(String) 115 * @see java.lang.SecurityManager#checkPropertyAccess(String) 116 */ 117 String getVersion(); 118 119}