info.rolandkrueger.roklib.system
Class MemorySwappingDetectionThread

java.lang.Object
  java.lang.Thread
      info.rolandkrueger.roklib.system.MemorySwappingDetectionThread

All Implemented Interfaces:

Runnable

Direct Known Subclasses:

VMStatSwappingDetectionThread

public abstract class MemorySwappingDetectionThread
extends Thread

Abstract class for implementations of threads that are able to detect memory paging events on the local system. Subclasses of this class can implement their own specific methods for detecting memory paging by providing an implementation for the abstract method isSwapEventDetected(). This method is repeatedly called during the lifetime of the detection thread.

Author:

Roland Krueger

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

private MemorySwappingEventListener	mListener
private boolean	mStopRequest

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

MemorySwappingDetectionThread(MemorySwappingEventListener listener)
Constructor.

Method Summary

protected abstract boolean	isSwapEventDetected() Returns true if a memory paging event was detected
protected void	notifyListenerOfSwappingEvent() If a swapping event was detected, this method notifies the MemorySwappingEventListener of that.
void	run() During its execution, the swapping detection thread will repeatedly call isSwapEventDetected() and check if a swapping event was detected.
void	stopThread() Stop this thread.
protected abstract void	stopThreadImpl() Implementations of this method define the actions that have to be taken prior to stopping this thread.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

mListener

private MemorySwappingEventListener mListener

mStopRequest

private boolean mStopRequest

Constructor Detail

MemorySwappingDetectionThread

public MemorySwappingDetectionThread(MemorySwappingEventListener listener)

Constructor.

Parameters:

listener - class implementing the MemorySwappingEventListener interface which will be notified of swapping events

Method Detail

isSwapEventDetected

protected abstract boolean isSwapEventDetected()

Returns true if a memory paging event was detected

Returns:

true if a memory paging event was detected

stopThreadImpl

protected abstract void stopThreadImpl()

Implementations of this method define the actions that have to be taken prior to stopping this thread.

run

public void run()

During its execution, the swapping detection thread will repeatedly call isSwapEventDetected() and check if a swapping event was detected. If so, the listener will be notified of this event.

Important: Since isSwapEventDetected() will be called within a loop, you must take care that the implementation of this method will block the thread for a reasonable amount of time (e.g., via Thread.sleep(long). Otherwise this thread will consume too much CPU time through the 'busy wait'.

Specified by:

run in interface Runnable

Overrides:

run in class Thread

notifyListenerOfSwappingEvent

protected void notifyListenerOfSwappingEvent()

If a swapping event was detected, this method notifies the MemorySwappingEventListener of that.

stopThread

public final void stopThread()

Stop this thread.