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* Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package java.lang.management;
/**
* The management interface for the operating system on which
* the Java virtual machine is running.
*
* <p> A Java virtual machine has a single instance of the implementation
* class of this interface. This instance implementing this interface is
* an <a href="ManagementFactory.html#MXBean">MXBean</a>
* that can be obtained by calling
* the {@link ManagementFactory#getOperatingSystemMXBean} method or
* from the {@link ManagementFactory#getPlatformMBeanServer
* platform <tt>MBeanServer</tt>} method.
*
* <p>The <tt>ObjectName</tt> for uniquely identifying the MXBean for
* the operating system within an MBeanServer is:
* <blockquote>
* {@link ManagementFactory#OPERATING_SYSTEM_MXBEAN_NAME
* <tt>java.lang:type=OperatingSystem</tt>}
* </blockquote>
*
* <p> This interface defines several convenient methods for accessing
* system properties about the operating system on which the Java
* virtual machine is running.
*
* @see <a href="../../../javax/management/package-summary.html">
* JMX Specification.</a>
* @see <a href="package-summary.html#examples">
* Ways to Access MXBeans</a>
*
* @author Mandy Chung
* @since 1.5
*/
public interface OperatingSystemMXBean {
/**
* Returns the operating system name.
* This method is equivalent to <tt>System.getProperty("os.name")</tt>.
*
* @return the operating system name.
*
* @throws java.lang.SecurityException
* if a security manager exists and its
* <code>checkPropertiesAccess</code> method doesn't allow access
* to this system property.
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
* @see java.lang.System#getProperty
*/
public String getName();
/**
* Returns the operating system architecture.
* This method is equivalent to <tt>System.getProperty("os.arch")</tt>.
*
* @return the operating system architecture.
*
* @throws java.lang.SecurityException
* if a security manager exists and its
* <code>checkPropertiesAccess</code> method doesn't allow access
* to this system property.
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
* @see java.lang.System#getProperty
*/
public String getArch();
/**
* Returns the operating system version.
* This method is equivalent to <tt>System.getProperty("os.version")</tt>.
*
* @return the operating system version.
*
* @throws java.lang.SecurityException
* if a security manager exists and its
* <code>checkPropertiesAccess</code> method doesn't allow access
* to this system property.
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
* @see java.lang.System#getProperty
*/
public String getVersion();
/**
* Returns the number of processors available to the Java virtual machine.
* This method is equivalent to the {@link Runtime#availableProcessors()}
* method.
* <p> This value may change during a particular invocation of
* the virtual machine.
*
* @return the number of processors available to the virtual
* machine; never smaller than one.
*/
public int getAvailableProcessors();
/**
* Returns the system load average for the last minute.
* The system load average is the sum of the number of runnable entities
* queued to the {@linkplain #getAvailableProcessors available processors}
* and the number of runnable entities running on the available processors
* averaged over a period of time.
* The way in which the load average is calculated is operating system
* specific but is typically a damped time-dependent average.
* <p>
* If the load average is not available, a negative value is returned.
* <p>
* This method is designed to provide a hint about the system load
* and may be queried frequently.
* The load average may be unavailable on some platform where it is
* expensive to implement this method.
*
* @return the system load average; or a negative value if not available.
*
* @since 1.6
*/
public double getSystemLoadAverage();
}