com.prosyst.mbs.framework.event
Class EventThread

java.lang.Object
  com.prosyst.mbs.framework.event.EventThread

All Implemented Interfaces:

java.lang.Runnable

public abstract class EventThread
extends java.lang.Object
implements java.lang.Runnable

Abstract class for asynchronous event dispatching

Field Summary

java.lang.Object	bad The last callbacked listener.
protected java.lang.String	baseName
protected int	counter Instancies counter.
protected java.lang.Object	element The event to be dispatched
protected java.lang.ThreadGroup	group
protected java.lang.String	name
protected Queue	queue The event queue.
protected int	state The state of the thread.
protected java.lang.Thread	thread
protected long	time The time spent in the current callback, or 0 if the thread is not in a callback

Constructor Summary

protected	EventThread(EventThread old) Constructs a new EventThread, after the old event thread has stopped responding
	EventThread(java.lang.ThreadGroup group, java.lang.String name, int size) Constructs the first instance of the EventThread
	EventThread(java.lang.ThreadGroup group, java.lang.String name, Queue queue) Constructs the first instance of the EventThread

Method Summary

void	addEvent(java.lang.Object event, boolean check) Adds an event in the event queue.
abstract boolean	checkTime() Checks if the thread is still active.
java.lang.String	getName()
java.lang.Thread	getThread()
abstract int	getThreadPriority() Returns the desired thread priority.
abstract void	newEventDispatcher() The method must create a new EventThread instance, using super.EventThread(this) and start it.
abstract void	print(java.lang.Throwable t) Logs the error.
abstract void	processEvent() Performs the actual event delivery.
void	run() Processes the event queue.
void	start()

Methods inherited from class java.lang.Object

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

Field Detail

bad

public java.lang.Object bad

The last callbacked listener. If the events thread is not responding, subclasses can take the appropriate actions - remove the listener for example

queue

protected Queue queue

The event queue. This object must be used for synchronization with the events thread's state

state

protected int state

The state of the thread.

bit 0: 0 = started / 1 = stopped;

bit 1: 0 not waiting / 1 = waiting

time

protected long time

The time spent in the current callback, or 0 if the thread is not in a callback

counter

protected int counter

Instancies counter. Subclasses must not modify it.

element

protected java.lang.Object element

The event to be dispatched

baseName

protected java.lang.String baseName

name

protected java.lang.String name

thread

protected java.lang.Thread thread

group

protected java.lang.ThreadGroup group

Constructor Detail

EventThread

public EventThread(java.lang.ThreadGroup group,
                   java.lang.String name,
                   int size)

Constructs the first instance of the EventThread

Parameters:

group - The ThreadGroup of the thread, or null for the current thread group

name - The base name of the thread. The counter value will be added at the end of the string to construct the full name.

size - The initial number of elements of the events queue

EventThread

public EventThread(java.lang.ThreadGroup group,
                   java.lang.String name,
                   Queue queue)

Constructs the first instance of the EventThread

Parameters:

group - The ThreadGroup of the thread, or null for the current thread group

name - The base name of the thread. The counter value will be added at the end of the string to construct the full name.

queue - The events queue

EventThread

protected EventThread(EventThread old)

Constructs a new EventThread, after the old event thread has stopped responding

Parameters:

old - The previous instance

Method Detail

start

public void start()

addEvent

public void addEvent(java.lang.Object event,
                     boolean check)

Adds an event in the event queue. The method must be synchronized outside, on the queue field.

Parameters:

event - The event to add

check - If true, the method will check if the EventThread is still responding

run

public void run()

Processes the event queue. Sets the event to be dispathed in the element field and calls processEvent

Specified by:

run in interface java.lang.Runnable

getThread

public java.lang.Thread getThread()

getName

public java.lang.String getName()

getThreadPriority

public abstract int getThreadPriority()

Returns the desired thread priority. Called in the constructors of the class in order to set the returned value to the thread.

Returns:

processEvent

public abstract void processEvent()

Performs the actual event delivery. The event is stored in the element field. The method is supposed to perform the following for every listener:

synchronized on queue check the state of the thread - if it si closed - return

set the fields bad and time

callback

set bad to null and time to 0

checkTime

public abstract boolean checkTime()

Checks if the thread is still active. The fields time and bad must be used. The method is called from the addEvent method - thus should be synchronizes on the queue field outside and additional synchronization is not needed.

newEventDispatcher

public abstract void newEventDispatcher()

The method must create a new EventThread instance, using super.EventThread(this) and start it.

print

public abstract void print(java.lang.Throwable t)

Logs the error.

Parameters:

t -