weka.core

Class Memory

java.lang.Object

weka.core.Memory

All Implemented Interfaces:

RevisionHandler

public class Memory
extends java.lang.Object
implements RevisionHandler

A little helper class for Memory management. The memory management can be disabled by using the setEnabled(boolean) method.

Version:

$Revision: 11271 $

Author:

FracPete (fracpete at waikato dot ac dot nz)

See Also:

setEnabled(boolean)

Field Summary

Fields

Modifier and Type	Field and Description
static long	LOW_MEMORY_MINIMUM
static long	MAX_SLEEP_TIME
static long	OUT_OF_MEMORY_THRESHOLD

Constructor Summary

Constructors

Constructor and Description
Memory() initializes the memory management without GUI support
Memory(boolean useGUI) initializes the memory management

Method Summary

Modifier and Type	Method and Description
long	getCurrent() returns the currently used size of the JVM heap, obtains a fresh MemoryUsage object to do so.
long	getInitial() returns the initial size of the JVM heap, obtains a fresh MemoryUsage object to do so.
long	getMax() returns the maximum size of the JVM heap, obtains a fresh MemoryUsage object to do so.
java.lang.String	getRevision() Returns the revision string.
boolean	getUseGUI() whether to display a dialog in case of a problem (= TRUE) or just print on stderr (= FALSE)
boolean	isEnabled() returns whether the memory management is enabled
boolean	isOutOfMemory() checks if there's still enough memory left by checking whether there is still a 50MB margin between getUsed() and getMax().
static void	main(java.lang.String[] args) prints only some statistics
boolean	memoryIsLow() Checks to see if memory is running low.
void	setEnabled(boolean value) sets whether the memory management is enabled
boolean	showMemoryIsLow() Prints a warning message if memoryIsLow (and if GUI is present a dialog).
void	showOutOfMemory() prints an error message if OutOfMemory (and if GUI is present a dialog), otherwise nothing happens.
void	stopThreads() stops all the current threads, to make a restart possible
static double	toMegaByte(long bytes) returns the amount of bytes as MB

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

OUT_OF_MEMORY_THRESHOLD

public static final long OUT_OF_MEMORY_THRESHOLD

See Also:

Constant Field Values

LOW_MEMORY_MINIMUM

public static final long LOW_MEMORY_MINIMUM

See Also:

Constant Field Values

MAX_SLEEP_TIME

public static final long MAX_SLEEP_TIME

See Also:

Constant Field Values

Constructor Detail

Memory

public Memory()

initializes the memory management without GUI support

Memory

public Memory(boolean useGUI)

initializes the memory management

Parameters:

useGUI - whether a GUI is present

Method Detail

isEnabled

public boolean isEnabled()

returns whether the memory management is enabled

Returns:

true if enabled

setEnabled

public void setEnabled(boolean value)

sets whether the memory management is enabled

Parameters:

value - true if the management should be enabled

getUseGUI

public boolean getUseGUI()

whether to display a dialog in case of a problem (= TRUE) or just print on stderr (= FALSE)

Returns:

true if the GUI is used

getInitial

public long getInitial()

returns the initial size of the JVM heap, obtains a fresh MemoryUsage object to do so.

Returns:

the initial size in bytes

getCurrent

public long getCurrent()

returns the currently used size of the JVM heap, obtains a fresh MemoryUsage object to do so.

Returns:

the used size in bytes

getMax

public long getMax()

returns the maximum size of the JVM heap, obtains a fresh MemoryUsage object to do so.

Returns:

the maximum size in bytes

isOutOfMemory

public boolean isOutOfMemory()

checks if there's still enough memory left by checking whether there is still a 50MB margin between getUsed() and getMax(). if ENABLED is true, then false is returned always. updates the MemoryUsage variable before checking.

Returns:

true if out of memory (only if management enabled, otherwise always false)

memoryIsLow

public boolean memoryIsLow()

Checks to see if memory is running low. Low is defined as available memory less than 20% of max memory.

Returns:

true if memory is running low

toMegaByte

public static double toMegaByte(long bytes)

returns the amount of bytes as MB

Returns:

the MB amount

showOutOfMemory

public void showOutOfMemory()

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 Also:

isOutOfMemory(), m_Enabled

showMemoryIsLow

public boolean showMemoryIsLow()

Prints a warning message if memoryIsLow (and if GUI is present a dialog).

Returns:

true if user opts to continue, disabled or GUI is not present.

stopThreads

public void stopThreads()

stops all the current threads, to make a restart possible

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision

main

public static void main(java.lang.String[] args)

prints only some statistics

Parameters:

args - the commandline arguments - ignored