Object Pooling in Board Game AI

Question

I was asked to create a Board Game AI(The game is pretty similar to the checkers). So far I finish a basic implementation of NegaScout with a bitboard and, within 5sec, I can go to 10 half-plies deep. The category of the game lies in EXPTIME-complete. In other word, there are almost more moves than atoms in the entire universe. NegaScout help me to reduce this number but I still need to deal with a big number of possible moves.

My board is already static with do/undo function. But for every new boards configurations I need to generate all allowed moves and it cost a lot time even if my class is simple as :

public class Move
{
    private final byte startIndex;
    private final byte endIndex;
    private byte endPawn;
    public Move(final byte start,final byte end){startIndex = start; endIndex = end;}
    public final void setEndPawn(byte pawn){endPawn = pawn;}
    //OTHER FUNCTIONS.. (ONLY FOR DISPLAY/DEBUG)
}

So I have two questions.

FIRST = Is object pooling (on Move) will improve my performance ?

Second = if(FIRST) then Can you tell me how to implement it?(link & small code sample will be really appreciate!!)

Have you already researched object pooling? I'm sure you would get your answer faster. — Josh, Jun 21 '12 at 14:04
The answer to your first question is yes, object pooling is always used to enhance performance. The answer to your second question is no, we cannot tell you even if it can be implemented on your project, given the limited code snippet you have posted — ControlAltDel, Jun 21 '12 at 14:11
@Josh I'm not familiar with object-pooling so I ask the question to have someone who know more than I on this subject tell me if it can apply to my problem and, in the case it is, give me good reference on the subject. — Jean-Christophe Fortin, Jun 21 '12 at 14:11
@ControlAltDel I can put the code where the moves are generate if it can help you ? — Jean-Christophe Fortin, Jun 21 '12 at 14:22
That's still a little silly. A quick Google search should answer your first question, and, like ControlAltDel has proven, it would be hard for anyone to apply it directly to your case without looking at more of your code. You should research yourself and apply what you can to your project and come back with specific implementation questions. — Josh, Jun 22 '12 at 03:26

Stephen C · Accepted Answer · 2012-06-21T14:25:21.620

1

Is object pooling (on Move) will improve my performance ?

Object pooling is often used in an attempt* to improve performance. Whether it will actually succeed in improving performance is another matter entirely.

If you are running on a platform with plenty of memory and a decent garbage collector, then discarding an object and creating a new one is often going to be faster than attempting to recycle. It really depends how expensive it is to initialize an object.

If you've got a slow platform or limited memory, the equation may tilt in favour of object pooling. However, the downside is that memory pooling will make your code more complicated. Furthermore, you need to guard against the pool being a sort of memory leak.

All in all, I'd advise against implementing memory pooling until you've got some hard profiling figures that say it is likely to help.

Reference:

The Object Pool Design Pattern

edited Jun 21 '12 at 14:25

answered Jun 21 '12 at 14:20

Stephen C

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my computer is an i5 3.2ghz/8gig ram/ubuntu 12.04/jdk 1.6. like i said so far I go 10 half-plies and the game have an average of 20 possible move at each half-plies so 10^20 possible move. That is all i can give you right now. If you want more information it will take little more time.. – Jean-Christophe Fortin Jun 21 '12 at 14:30
That tells me that memory is unlikely to be a problem. The rest of the equation depends on the details of your program. My advice is still "profile it first". – Stephen C Jun 22 '12 at 04:59
I'll do as you said and profile my project, I was hoping for a categorical answer but like many thing this isn't that easy. Thank you to pointing me out some potentials problems with that solution ! – Jean-Christophe Fortin Jun 22 '12 at 13:06

Object Pooling in Board Game AI

1 Answers1