001 /* OperatingSystemMXBean.java - Interface for an operating system 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 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 */ 048 public 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 }