rice.selector
Class SelectorManager

java.lang.Object
  java.lang.Thread
      rice.selector.SelectorManager

All Implemented Interfaces:

java.lang.Runnable, Timer

Direct Known Subclasses:

ProfileSelector

public class SelectorManager

extends java.lang.Thread

implements Timer

This class is the class which handles the selector, and listens for activity. When activity occurs, it figures out who is interested in what has happened, and hands off to that object.

Version:

$Id: SelectorManager.java,v 1.27 2005/05/17 15:42:18 jeffh Exp $

Author:

Alan Mislove

Field Summary

protected java.util.HashSet	cancelledKeys DESCRIBE THE FIELD
protected java.util.LinkedList	invocations DESCRIBE THE FIELD
protected java.util.HashSet	modifyKeys DESCRIBE THE FIELD
protected java.nio.channels.Selector	selector DESCRIBE THE FIELD
static int	TIMEOUT DESCRIBE THE FIELD
protected java.util.TreeSet	timerQueue DESCRIBE THE FIELD
protected long	wakeupTime DESCRIBE THE FIELD

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

protected

SelectorManager(boolean profile) Constructor, which is private since there is only one selector per JVM.

Method Summary

void	addLoopObserver(LoopObserver lo) Adds a feature to the LoopObserver attribute of the SelectorManager object
void	cancel(java.nio.channels.SelectionKey key) Method which asks the Selector Manager to add the given key to the cancelled set.
protected void	doInvocations() Method which invokes all pending invocations.
protected void	doSelections() DESCRIBE THE METHOD
protected void	executeDueTasks() Internal method which finds all due tasks and executes them.
protected java.lang.Runnable	getInvocation() Method which synchroniously returns the first element off of the invocations list.
java.nio.channels.SelectionKey	getKey(java.nio.channels.SelectableChannel channel) Utility method which returns the SelectionKey attached to the given channel, if one exists
protected java.nio.channels.SelectionKey	getModifyKey() Method which synchroniously returns on element off of the modifyKeys list
int	getNumInvocations() Debug method which returns the number of pending invocations
static SelectorManager	getSelectorManager() Returns the SelectorManager applications should use.
Timer	getTimer() Returns the timer associated with this SelectorManager (in this case, it is this).
void	invoke(java.lang.Runnable d) This method schedules a runnable task to be done by the selector thread during the next select() call.
static boolean	isSelectorThread() Returns whether or not this thread of execution is the selector thread
void	modifyKey(java.nio.channels.SelectionKey key) Adds a selectionkey handler into the list of handlers which wish to change their keys.
protected void	notifyLoopListeners() DESCRIBE THE METHOD
protected void	onLoop() This method is to be implemented by a subclass to do some task each loop.
java.nio.channels.SelectionKey	register(java.nio.channels.SelectableChannel channel, SelectionKeyHandler handler, int ops) Registers a new channel with the selector, and attaches the given SelectionKeyHandler as the handler for the newly created key.
void	removeLoopObserver(LoopObserver lo) DESCRIBE THE METHOD
void	run() This method starts the socket manager listening for events.
void	schedule(TimerTask task, java.util.Date time) Method which schedules a task to run at a specified time
void	schedule(TimerTask task, java.util.Date firstTime, long period) Method which schedules a task to run repeatedly first at a specified time and period
void	schedule(TimerTask task, long delay) Method which schedules a task to run after a specified number of millis
void	schedule(TimerTask task, long delay, long period) Method which schedules a task to run repeatedly after a specified delay and period
void	scheduleAtFixedRate(TimerTask task, java.util.Date firstTime, long period) Method which schedules a task to run repeatedly (at a fixed rate) after a specified delay and period
void	scheduleAtFixedRate(TimerTask task, long delay, long period) Method which schedules a task to run repeatedly (at a fixed rate) after a specified delay and period
protected java.nio.channels.SelectionKey[]	selectedKeys() Selects all of the currenlty selected keys on the selector and returns the result as an array of keys.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, 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

selector

protected java.nio.channels.Selector selector

DESCRIBE THE FIELD

invocations

protected java.util.LinkedList invocations

DESCRIBE THE FIELD

modifyKeys

protected java.util.HashSet modifyKeys

DESCRIBE THE FIELD

cancelledKeys

protected java.util.HashSet cancelledKeys

DESCRIBE THE FIELD

timerQueue

protected java.util.TreeSet timerQueue

DESCRIBE THE FIELD

wakeupTime

protected long wakeupTime

DESCRIBE THE FIELD

TIMEOUT

public static int TIMEOUT

DESCRIBE THE FIELD

Constructor Detail

SelectorManager

protected SelectorManager(boolean profile)

Constructor, which is private since there is only one selector per JVM.

Parameters:

profile - DESCRIBE THE PARAMETER

Method Detail

getKey

public java.nio.channels.SelectionKey getKey(java.nio.channels.SelectableChannel channel)

Utility method which returns the SelectionKey attached to the given channel, if one exists

Parameters:

channel - The channel to return the key for

Returns:

The key

getNumInvocations

public int getNumInvocations()

Debug method which returns the number of pending invocations

Returns:

The number of pending invocations

getInvocation

protected java.lang.Runnable getInvocation()

Method which synchroniously returns the first element off of the invocations list.

Returns:

An item from the invocations list

getModifyKey

protected java.nio.channels.SelectionKey getModifyKey()

Method which synchroniously returns on element off of the modifyKeys list

Returns:

An item from the invocations list

getTimer

public Timer getTimer()

Returns the timer associated with this SelectorManager (in this case, it is this).

Returns:

The associated timer

cancel

public void cancel(java.nio.channels.SelectionKey key)

Method which asks the Selector Manager to add the given key to the cancelled set. If noone calls register on this key during the rest of this select() operation, the key will be cancelled. Otherwise, it will be returned as a result of the register operation.

Parameters:

key - The key to cancel

register

public java.nio.channels.SelectionKey register(java.nio.channels.SelectableChannel channel,
                                               SelectionKeyHandler handler,
                                               int ops)
                                        throws java.io.IOException

Registers a new channel with the selector, and attaches the given SelectionKeyHandler as the handler for the newly created key. Operations which the hanlder is interested in will be called as available.

Parameters:

channel - The channel to regster with the selector

handler - The handler to use for the callbacks

ops - The initial interest operations

Returns:

The SelectionKey which uniquely identifies this channel

Throws:

java.io.IOException - DESCRIBE THE EXCEPTION

invoke

public void invoke(java.lang.Runnable d)

This method schedules a runnable task to be done by the selector thread during the next select() call. All operations which modify the selector should be done using this method, as they must be done in the selector thread.

Parameters:

d - The runnable task to invoke

modifyKey

public void modifyKey(java.nio.channels.SelectionKey key)

Adds a selectionkey handler into the list of handlers which wish to change their keys. Thus, modifyKeys() will be called on the next selection operation

Parameters:

key - The key which is to be chanegd

onLoop

protected void onLoop()

This method is to be implemented by a subclass to do some task each loop.

run

public void run()

This method starts the socket manager listening for events. It is designed to be started when this thread's start() method is invoked.

Specified by:

run in interface java.lang.Runnable

notifyLoopListeners

protected void notifyLoopListeners()

DESCRIBE THE METHOD

addLoopObserver

public void addLoopObserver(LoopObserver lo)

Adds a feature to the LoopObserver attribute of the SelectorManager object

Parameters:

lo - The feature to be added to the LoopObserver attribute

removeLoopObserver

public void removeLoopObserver(LoopObserver lo)

DESCRIBE THE METHOD

Parameters:

lo - DESCRIBE THE PARAMETER

doSelections

protected void doSelections()
                     throws java.io.IOException

DESCRIBE THE METHOD

Throws:

java.io.IOException - DESCRIBE THE EXCEPTION

doInvocations

protected void doInvocations()

Method which invokes all pending invocations. This method should *only* be called by the selector thread.

selectedKeys

protected java.nio.channels.SelectionKey[] selectedKeys()
                                                 throws java.io.IOException

Selects all of the currenlty selected keys on the selector and returns the result as an array of keys.

Returns:

The array of keys

Throws:

java.io.IOException - DESCRIBE THE EXCEPTION

schedule

public void schedule(TimerTask task,
                     long delay)

Method which schedules a task to run after a specified number of millis

Specified by:

schedule in interface Timer

Parameters:

task - The task to run

delay - The delay

schedule

public void schedule(TimerTask task,
                     java.util.Date time)

Method which schedules a task to run at a specified time

Parameters:

task - The task to run

time - The time to run

schedule

public void schedule(TimerTask task,
                     long delay,
                     long period)

Method which schedules a task to run repeatedly after a specified delay and period

Specified by:

schedule in interface Timer

Parameters:

task - The task to run

delay - The delay

period - The period with which to run

schedule

public void schedule(TimerTask task,
                     java.util.Date firstTime,
                     long period)

Method which schedules a task to run repeatedly first at a specified time and period

Parameters:

task - The task to run

firstTime - The first time

period - The period with which to run

scheduleAtFixedRate

public void scheduleAtFixedRate(TimerTask task,
                                long delay,
                                long period)

Method which schedules a task to run repeatedly (at a fixed rate) after a specified delay and period

Specified by:

scheduleAtFixedRate in interface Timer

Parameters:

task - The task to run

delay - The delay

period - The period with which to run

scheduleAtFixedRate

public void scheduleAtFixedRate(TimerTask task,
                                java.util.Date firstTime,
                                long period)

Method which schedules a task to run repeatedly (at a fixed rate) after a specified delay and period

Parameters:

task - The task to run

period - The period with which to run

firstTime - DESCRIBE THE PARAMETER

executeDueTasks

protected void executeDueTasks()

Internal method which finds all due tasks and executes them.

getSelectorManager

public static SelectorManager getSelectorManager()

Returns the SelectorManager applications should use.

Returns:

The SelectorManager which applications should use

isSelectorThread

public static boolean isSelectorThread()

Returns whether or not this thread of execution is the selector thread

Returns:

Whether or not this is the selector thread