/*
* Copyright © 2003 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*/
package java.lang;
/**
* Every Java application has a single instance of class
* <code>Runtime</code> that allows the application to interface with
* the environment in which the application is running. The current
* runtime can be obtained from the <code>getRuntime</code> method.
* <p>
* An application cannot create its own instance of this class.
*
* @author unascribed
* @version 12/17/01 (CLDC 1.1)
* @see java.lang.Runtime#getRuntime()
* @since JDK1.0, CLDC 1.0
*/
public class Runtime {
private static Runtime currentRuntime = new Runtime();
/**
* Returns the runtime object associated with the current Java application.
* Most of the methods of class <code>Runtime</code> are instance
* methods and must be invoked with respect to the current runtime object.
*
* @return the <code>Runtime</code> object associated with the current
* Java application.
*/
public static Runtime getRuntime() {
return currentRuntime;
}
/** Don't let anyone else instantiate this class */
private Runtime() {}
/* Helper for exit
*/
private native void exitInternal(int status);
/**
* Terminates the currently running Java application. This
* method never returns normally.
* <p>
* The argument serves as a status code; by convention, a nonzero
* status code indicates abnormal termination.
*
* @param status exit status.
* @since JDK1.0
*/
public void exit(int status) {
exitInternal(status);
}
/**
* Returns the amount of free memory in the system. Calling the
* <code>gc</code> method may result in increasing the value returned
* by <code>freeMemory.</code>
*
* @return an approximation to the total amount of memory currently
* available for future allocated objects, measured in bytes.
*/
public native long freeMemory();
/**
* Returns the total amount of memory in the Java Virtual Machine.
* The value returned by this method may vary over time, depending on
* the host environment.
* <p>
* Note that the amount of memory required to hold an object of any
* given type may be implementation-dependent.
*
* @return the total amount of memory currently available for current
* and future objects, measured in bytes.
*/
public native long totalMemory();
/**
* Runs the garbage collector.
* Calling this method suggests that the Java Virtual Machine expend
* effort toward recycling unused objects in order to make the memory
* they currently occupy available for quick reuse. When control
* returns from the method call, the Java Virtual Machine has made
* its best effort to recycle all discarded objects.
* <p>
* The name <code>gc</code> stands for "garbage
* collector". The Java Virtual Machine performs this recycling
* process automatically as needed even if the
* <code>gc</code> method is not invoked explicitly.
* <p>
* The method {@link System#gc()} is the conventional and convenient
* means of invoking this method.
*/
public native void gc();
}
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