createFAction, which Zone?

[Lourens van der Meij]

I just started out getting to know swarm;I am trying to give some
assistance to a swarm-user here (Fred Wan)
My first job was solving a memory leak, i.e. following
the "Memory exhausion" thread of  december last year.

I managed to solve the memory problems. They were
programming errors (i.e. not dropping attached EmptyProbeMapImpl
by dying agent).The sugestion of using xprint proved very useful.

In a later version there was another memory leak, which I traced back
to usage of MapImpl. I noticed that the new Integer() java keys
and the java object values did not get garbage collected.

By more closely reading the FAQ I now think I understand
that if one would like to use Objective-C datastructures,
one should only use java objects that are sub-objects of
SwarmObject (more precise Drop interface?). Is this correct?

Anyhow, I advised the user to use the java HashMap instead.

Another point:
Marcus Daniels suggested using createFAction instead of
createActionTo$message and createFActionForEachHeterogeneous$call
instead of createActionForEach$message.
A number of points:
1)There was no effect on memory consumption but performance
  increased dramatically (factor of 10 for GUI-less simple simulation).
2)I could not find out what the appropriate Zone was in some calls, i.e.
  in an "ObserverSwarm" there was code:

        displayActions.createActionTo$message
                (Globals.env.probeDisplayManager,
                new Selector(Globals.env.probeDisplayManager.getClass(),
                        "update", false));
        which I tried to replace with
                Zone z = ???
                        tried z = Globals.env.probeDisplayManager.getZone();
                        tried z= getZone();
                        tried z = Globals.env.globalZone;
                Selector sel = new Selector(Globals.env.probeDisplayManager.
                                getClass(),
                        "update", false);
                FArguments fa = new FArgumentsImpl(z, sel);
                FCall fc = new FCallImpl(z, this, sel, fa);
                displayActions.createFAction(fc);

        I got exceptions, whatever Zone I tried.

        The same problem with
                displayActions.createActionTo$message(
                        getActionCache(),
                        new Selector (getActionCache().getClass(),
                                "doTkEvents", true));
        What zone to use in the FCall version?
3)As there was such a performance increase I started wondering whether
        other calls could be improved as well.
        There are obvious candidates which I replaced,i.e. all classes having
        FActionCreating interface. (used it in a ActionGroup and Schedule).
        But I also noticed:

        modelSchedule = new ScheduleImpl(getZone(), 1);
        modelSchedule.at$createAction(0, modelActions);
        There is an equivalent modelSchedule.at$createFAction(1, ??)
        I suppose it is only useful if the Object anActionType
        is a java method call, i.e. there is a Selector involved?
        In the source that I am currently inspecting I only find
        a candidate in
        targetDisplay = new Object2dDisplayImpl
        (getZone(), worldRaster, modelSwarm.getTargetSpace(),
        new Selector(Class.forName("TargetBug"),"drawSelfOn", false));

        but there seems to be no FCall access there.

Thanks for reading,

Lourens



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