Hi Guido,

That was my first thought. But I didn't understand why this remapping was there. Christian said in a previous mail that removing the mapping will break all propagators that are used for integer as well as for boolean variables! If I pass the pc unchanged, will it break something in Gecode ? I don't want to break something, I would like to add safely my piece of code.

If removing it doesn't break anything, will this mapping be still there in the future versions ?

Thank you again, I really appreciate the time you spent to answer my questions :)

Cheers,
Vincent

Le 1 déc. 09 à 16:30, Guido Tack a écrit :

Hi Vincent,

the rewriting is currently done in int/var-imp/bool.hpp. Just remove the rewriting there and pass the pc unchanged, add rewriting to all the normal Gecode BoolView classes, and then add your own BoolView class that doesn't rewrite.

Cheers,
        Guido

Vincent Barichard wrote:

Dear Christian,

Thank you very much for your mail. I'm sorry, I don't understand your answer. Why having other BoolView classes will help me ? I added member functions in the BoolViews classes. I didn't change the existing ones,
I only added member functions which notify the ME_BOOL_SAME event.

In my own propagator (let's call it M) I call the recently added functions in the BoolViews. So the ME_BOOL_SAME
event is sent.

I also modified one propagator of Gecode (let's call it P') and make it subscribe to the PC_BOOL_SAME propagation condition (I only added "x1.subscribe(home, *this, PC_BOOL_SAME)" in constructor). In the "propagate" function of P' I added instructions which are only relevant if a ME_BOOL_SAME event has been sent before.

So when M is woke up (because it subscribe to PC_BOOL_VAL propagation condition) it may call the new member functions in the BoolViews classes which sent the ME_BOOL_SAME event. I would like that propagators which subscribe to the PC_BOOL_SAME propagation condition and only these ones, be scheduled to wake up (for example P' will be scheduled if it shares a variable with M). As no assignment has been made by the M propagator, I don't want that other propagators wake up except if a ME_BOOL_VAL event has been sent from elsewhere.

Unfortunately, as all propagation condition subscribings for Boleans variables are remapped to PC_BOOL_VAL, P' will not awake if a ME_BOOL_SAME event is sent.

May have I another choice but to use the ME_BOOL_VAL event instead of ME_BOOL_SAME in my new member functions of the BoolView classes ? As a result, all propagators will be awaken even if they can't propagate removal, indeed no assignment has been made.

Don't hesitate to ask me if I'm not clear enough.

Cheers,
Vincent

Le 30 nov. 09 à 16:35, Christian Schulte a écrit :

Actually what you have to do is the following: you define two classes for Boolean views, one that rewrites its propagation conditions and the other one that does not. Then your propagators can use the views without rewriting
while the other propagators can use the variables with rewriting.

Christian

--
Christian Schulte, www.ict.kth.se/~cschulte/


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Vincent Barichard
Sent: Monday, November 30, 2009 9:33 AM
To: Christian Schulte
Cc: 'Guido Tack'; 'gecode list'
Subject: Re: [gecode-users] Remapping of BoolVar propagation conditions

Hi,

Thank you both for your answers. As I don't want to break all propagators that are used for integer as well as boolean variables, I see no choice but
to use PC_BOOL_VAL.

Maybe one of you may see another way ? I make new functions on Boolean variables (and associated views) which don't set domain to 1 or 0 (I copied "ModEvent BoolVarImp::one_none(Space& home)" and removed the unwanted instructions). These functions notify new events (called ME_BOOL_SAME in
bool.vis file (see attached file)). I mapped this new event to the
PC_BOOL_SAME propagation condition.

Now I change an existing propagator (like the "Or" propagator), and I want it to be awaken when ME_BOOL_SAME is emitted. As the variable is not yet assigned, I didn't want to emit the ME_BOOL_VAL event because I didn't want to wake up propagators which only subscribed to the PC_BOOL_VAL condition.

So during propagation, I call my new functions on Boolean variables, the
ME_BOOL_SAME event is sent and propagators which subscribe to the
PC_BOOL_SAME condition are wake up. Other propagators are not awaken (except
if a ME_BOOL_VAL event has also been sent). Is it possible ?
Should I use ME_BOOL_VAL ? If I use ME_BOOL_VAL other propagators will be
awaken for nothing.

Thanks for your help.

Cheers,
Vincent

Vincent Barichard         Université d'Angers (LERIA)
Tel: 02 41 73 52 06      Département Informatique
Fax: 02 41 73 50 73     H203


Vincent Barichard         Université d'Angers (LERIA)
Tel: 02 41 73 52 06      Département Informatique
Fax: 02 41 73 50 73     H203


_______________________________________________
Gecode users mailing list
[email protected]
https://www.gecode.org/mailman/listinfo/gecode-users

Reply via email to