jason.asSemantics
Class ConcurrentInternalAction

java.lang.Object
  jason.asSemantics.ConcurrentInternalAction

All Implemented Interfaces:

InternalAction

public abstract class ConcurrentInternalAction
extends java.lang.Object
implements InternalAction

This class can be used in place of DefaultInternalAction to create an IA that suspend the intention while it is being executed. Example: a plan may ask something to an user and wait the answer. If DefaultInternalAction is used for that, all the agent thread is blocked until the answer. With ConcurrentInternalAction, only the intention using the IA is suspended. See demos/gui/gui1. The code of an internal action that extends this class looks like:

  public class ...... extends ConcurrentInternalAction {

    public Object execute(final TransitionSystem ts, Unifier un, final Term[] args) throws Exception {
        ....

        final String key = suspendInt(ts, "gui", 5000); // suspend the intention (max 5 seconds) 

        startInternalAction(ts, new Runnable() { // to not block the agent thread, start a thread that performs the task and resume the intention latter
            public void run() {

                .... the code of the IA .....

                if ( ... all Ok ...)
                    resumeInt(ts, key); // resume the intention with success
                else
                    failInt(ts, key); // resume the intention with fail
            }
        });

        ...
    }

    public void timeout(TransitionSystem ts, String intentionKey) { // called back when the intention should be resumed/failed by timeout (after 5 seconds in this example)
        ... this method have to decide what to do with actions finished by timeout: resume or fail
        ... to call resumeInt(ts,intentionKey) or failInt(ts, intentionKey)
    }
  }
  

Constructor Summary

ConcurrentInternalAction()

Method Summary

boolean	canBeUsedInContext() Return true if the internal action can be used in plans' context
java.lang.Object	execute(TransitionSystem ts, Unifier un, Term[] args) Executes the internal action.
void	failInt(TransitionSystem ts, java.lang.String intentionKey) fails the intention identified by intentionKey
Term[]	prepareArguments(Literal body, Unifier un) Prepare body's terms to be used in 'execute', normally it consist of cloning and applying each term
static void	resume(TransitionSystem ts, java.lang.String intentionKey, boolean abort, java.util.List<Term> failAnnots)
void	resumeInt(TransitionSystem ts, java.lang.String intentionKey) resume the intention identified by intentionKey
void	startInternalAction(TransitionSystem ts, java.lang.Runnable code)
java.lang.String	suspendInt(TransitionSystem ts, java.lang.String basekey, int timeout) Suspend the current intention, put it in the PendingIntention (PI) structure and assigns it to a key.
boolean	suspendIntention() Returns true if the internal action (IA) should suspend the intention where the IA is called
abstract void	timeout(TransitionSystem ts, java.lang.String intentionKey) called back when some intention should be resumed/failed by timeout

Methods inherited from class java.lang.Object

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

Constructor Detail

ConcurrentInternalAction

public ConcurrentInternalAction()

Method Detail

canBeUsedInContext

public boolean canBeUsedInContext()

Description copied from interface: InternalAction

Return true if the internal action can be used in plans' context

Specified by:

canBeUsedInContext in interface InternalAction

suspendIntention

public boolean suspendIntention()

Description copied from interface: InternalAction

Returns true if the internal action (IA) should suspend the intention where the IA is called

Specified by:

suspendIntention in interface InternalAction

prepareArguments

public Term[] prepareArguments(Literal body,
                               Unifier un)

Description copied from interface: InternalAction

Prepare body's terms to be used in 'execute', normally it consist of cloning and applying each term

Specified by:

prepareArguments in interface InternalAction

execute

public java.lang.Object execute(TransitionSystem ts,
                                Unifier un,
                                Term[] args)
                         throws java.lang.Exception

Description copied from interface: InternalAction

Executes the internal action. It should return a Boolean or an Iterator. A true boolean return means that the IA was successfully executed. An Iterator result means that there is more than one answer for this IA (e.g. see member internal action).

Specified by:

execute in interface InternalAction

Throws:

java.lang.Exception

suspendInt

public java.lang.String suspendInt(TransitionSystem ts,
                                   java.lang.String basekey,
                                   int timeout)

Suspend the current intention, put it in the PendingIntention (PI) structure and assigns it to a key.

Parameters:

ts - the "engine" of the agent

basekey - the base key to form final key used to get the intention back from PI (e.g. "moise", "cartago", ...)

timeout - the max time the intention will be in PI, the value 0 means until "resume"

Returns:

the final key used to store the intention in PI, this key is used the resume the intention

startInternalAction

public void startInternalAction(TransitionSystem ts,
                                java.lang.Runnable code)

timeout

public abstract void timeout(TransitionSystem ts,
                             java.lang.String intentionKey)

called back when some intention should be resumed/failed by timeout

resumeInt

public void resumeInt(TransitionSystem ts,
                      java.lang.String intentionKey)

resume the intention identified by intentionKey

failInt

public void failInt(TransitionSystem ts,
                    java.lang.String intentionKey)

fails the intention identified by intentionKey

resume

public static void resume(TransitionSystem ts,
                          java.lang.String intentionKey,
                          boolean abort,
                          java.util.List<Term> failAnnots)