pt.ua.concurrent

Class Actor

java.lang.Object

java.lang.Thread

pt.ua.concurrent.Actor

All Implemented Interfaces:

java.lang.Runnable

public class Actor
extends java.lang.Thread

An actor module (object-oriented approach for message passing concurrent programming).

This class implements, in an object-oriented way, the message passing thread communication mechanism.
Important Note: external synchronization is not yet implemented.

This class follows DbC(tm) methodology (Wikipedia). Where possible, contracts are implement with native's Java assert.

Version:

0.5, November 2011, 0.6, November 2012

Author:

Miguel Oliveira e Silva (mos@ua.pt)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	Actor.Routine ADT of actor's routines closure.

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

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.Queue<Actor.Routine>	pending routine calls pending for execution
protected java.util.Queue<Actor.Routine>	pendingCSync routine calls pending due to conditional synchronization
protected boolean	runUniqueInvocation
protected boolean	terminated

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
Actor() Constructs a new Actor (note that its attached thread is not started here).

Method Summary

Modifier and Type	Method and Description
protected void	futureDone(pt.ua.concurrent.Future future) Indicates that the routine attached to future is done.
protected void	inPendingRoutine(Actor.Routine r) Queue's a routine for execution by the actor.
void	run() The actor's message handling routine.
protected boolean	runUniqueInvocation() Has run not executed yet? (This method is only for internal usage to ensure that run method is executed only by the thread's start method.)
void	terminate() Terminate te execution of actor.
boolean	terminated() Is the actor terminated?

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, 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

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

Field Detail

pending

protected final java.util.Queue<Actor.Routine> pending

routine calls pending for execution

pendingCSync

protected final java.util.Queue<Actor.Routine> pendingCSync

routine calls pending due to conditional synchronization

terminated

protected boolean terminated

runUniqueInvocation

protected boolean runUniqueInvocation

Constructor Detail

Actor

public Actor()

Constructs a new Actor (note that its attached thread is not started here).

Method Detail

futureDone

protected void futureDone(pt.ua.concurrent.Future future)

Indicates that the routine attached to future is done. (This method is to be used by actor descendant classes.)

requires: future != null
requires: isAlive()

Parameters:

future - the future object

inPendingRoutine

protected void inPendingRoutine(Actor.Routine r)

Queue's a routine for execution by the actor. (This method is to be used by actor descendant classes.)

requires: r != null

Parameters:

r - the routine object

terminate

public void terminate()

Terminate te execution of actor. The actor will terminate as soon as its pending queue is empty.

requires: isAlive()

terminated

public boolean terminated()

Is the actor terminated?

Returns:

boolean true if the actor has finished, false otherwise

runUniqueInvocation

protected boolean runUniqueInvocation()

Has run not executed yet? (This method is only for internal usage to ensure that run method is executed only by the thread's start method.)

Returns:

boolean true if run has not yet started execution, false otherwise

run

public void run()

The actor's message handling routine. (This method is to be executed only by thread's start method.)

Specified by:

run in interface java.lang.Runnable

Overrides:

run in class java.lang.Thread