/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* Memory.java
* Copyright (C) 2005 University of Waikato, Hamilton, New Zealand
*
*/
package weka.core;
import javax.swing.JOptionPane;
/**
* A little helper class for Memory management. Very crude, since JDK 1.4
* doesn't offer real Memory Management.<p/>
* The memory management can be disabled by using the setEnabled(boolean)
* method.
*
* @author FracPete (fracpete at waikato dot ac dot nz)
* @version $Revision: 5953 $
* @see #setEnabled(boolean)
*/
public class Memory
implements RevisionHandler {
/** whether memory management is enabled */
protected static boolean m_Enabled = true;
/** whether a GUI is present */
protected boolean m_UseGUI = false;
/** the initial size of the JVM */
protected static long m_Initial = Runtime.getRuntime().totalMemory();
/** the total memory that is used */
protected long m_Total;
/** the maximum amount of memory that can be used */
protected long m_Max;
/** the current runtime variable */
protected Runtime m_Runtime;
/**
* initializes the memory management without GUI support
*/
public Memory() {
this(false);
}
/**
* initializes the memory management
* @param useGUI whether a GUI is present
*/
public Memory(boolean useGUI) {
m_UseGUI = useGUI;
m_Runtime = Runtime.getRuntime();
m_Max = m_Runtime.maxMemory();
m_Total = m_Runtime.totalMemory();
}
/**
* returns whether the memory management is enabled
*
* @return true if enabled
*/
public boolean isEnabled() {
return m_Enabled;
}
/**
* sets whether the memory management is enabled
*
* @param value true if the management should be enabled
*/
public void setEnabled(boolean value) {
m_Enabled = value;
}
/**
* whether to display a dialog in case of a problem (= TRUE) or just print
* on stderr (= FALSE)
*
* @return true if the GUI is used
*/
public boolean getUseGUI() {
return m_UseGUI;
}
/**
* returns the initial size of the JVM
*
* @return the initial size in bytes
*/
public long getInitial() {
return m_Initial;
}
/**
* returns the current memory consumption
*
* @return the current size in bytes
*/
public long getCurrent() {
m_Runtime = Runtime.getRuntime();
m_Total = m_Runtime.totalMemory();
return m_Total;
}
/**
* returns the maximum amount of memory that can be assigned
*
* @return the maximum size in bytes
*/
public long getMax() {
return m_Max;
}
/**
* checks if there's still enough memory left. if ENABLED is true, then
* false is returned always
*
* @return true if out of memory (only if management enabled,
* otherwise always false)
*/
public boolean isOutOfMemory() {
if (isEnabled())
return ((getMax() - getCurrent()) < (getInitial() + 200000));
else
return false;
}
/**
* returns the amount of bytes as MB
*
* @return the MB amount
*/
public static double toMegaByte(long bytes) {
return (bytes / (double) (1024 * 1024));
}
/**
* prints an error message if OutOfMemory (and if GUI is present a dialog),
* otherwise nothing happens. isOutOfMemory() has to be called beforehand,
* since it sets all the memory parameters.
* @see #isOutOfMemory()
* @see #m_Enabled
*/
public void showOutOfMemory() {
if (!isEnabled())
return;
System.gc();
String msg = "Not enough memory. Please load a smaller "
+ "dataset or use larger heap size.\n"
+ "- initial JVM size: "
+ Utils.doubleToString(toMegaByte(m_Initial), 1) + "MB\n"
+ "- total memory used: "
+ Utils.doubleToString(toMegaByte(m_Total), 1) + "MB\n"
+ "- max. memory avail.: "
+ Utils.doubleToString(toMegaByte(m_Max), 1) + "MB\n"
+ "\n"
+ "Note:\n"
+ "The Java heap size can be specified with the -Xmx option.\n"
+ "E.g., to use 128MB as heap size, the command line looks like this:\n"
+ " java -Xmx128m -classpath ...\n"
+ "This does NOT work in the SimpleCLI, the java command refers\n"
+ "to the one with which Weka is started.";
System.err.println(msg);
if (getUseGUI())
JOptionPane.showMessageDialog(
null, msg, "OutOfMemory", JOptionPane.WARNING_MESSAGE);
}
/**
* stops all the current threads, to make a restart possible
*/
public void stopThreads() {
int i;
Thread[] thGroup;
Thread t;
thGroup = new Thread[Thread.activeCount()];
Thread.enumerate(thGroup);
for (i = 0; i < thGroup.length; i++) {
t = thGroup[i];
if (t != null) {
if (t != Thread.currentThread()) {
if (t.getName().startsWith("Thread"))
t.stop();
else if (t.getName().startsWith("AWT-EventQueue"))
t.stop();
}
}
}
thGroup = null;
System.gc();
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 5953 $");
}
/**
* prints only some statistics
*
* @param args the commandline arguments - ignored
*/
public static void main(String[] args) {
Memory mem = new Memory();
System.out.println(
"Initial memory: "
+ Utils.doubleToString(Memory.toMegaByte(mem.getInitial()), 1) + "MB"
+ " (" + mem.getInitial() + ")");
System.out.println(
"Max memory: "
+ Utils.doubleToString(Memory.toMegaByte(mem.getMax()), 1) + "MB"
+ " (" + mem.getMax() + ")");
}
}