Scheduler -- Why is my AI so much slower?!

[TrueBrain]

As of today, NoAI gained a scheduler. This beautiful piece of work by Morloth has several side-effects, of which most noticeable: your AI will perform a bit worse. What happens is this:

If your AI would contains:

Code: Select all

while (true) { }

Your AI would hang for ever, and worse: OpenTTD would too. As of today, this is no longer true. Every 4000 internal Squirrel commands, your AI is given a Sleep() for 1 tick. This makes sure the game keeps on responding no matter what. Also, it no longer allows you to scan the whole map in the first day, and fast pick all the good routes before any other AI can. You have to think a bit more now. All AIs are scheduled 'fair', and all get a piece to look at in the first game-day.

On a nice side-note: when you issue a Sleep() yourself, the counter is reset. This means if you add Sleep() at nice places in your code, the chances are that your AI performs better than when you remove them all.

Happy AI writing

[Ralph]

Cool, I have no idea how much slower this will make things, but seems like a good change.

Is there any way of accessing the internal command count? It may be useful for checking how expensive functions are so we know where to optimise.

[Zutty]

Excellent idea. Plus what Ralph said.... should be handy.

My AI is yet to be optimised, but it hangs terribly in places! I have nested loops with differing algorithms, so I'm never sure where to put the Sleep()s for the best results. This should help to ease that problem.

[Misha]

Also, it no longer allows you to scan the whole map in the first day, and fast pick all the good routes before any other AI can. You have to think a bit more now. All AIs are scheduled 'fair', and all get a piece to look at in the first game-day.

This looks very important for a fair competition between AI's. Good work. I have a few questions though.

Is it possible for an AI to detect which piece it can view?
What happens when an AI tries something on a tile it can't view?
From when will an AI be capable to view every tile on the map?

[Yexo]

Is it possible for an AI to detect which piece it can view?
What happens when an AI tries something on a tile it can't view?
From when will an AI be capable to view every tile on the map?

You're misunderstanding things here. There is a limit on the amount of commands an AI can execute every ingame day, not a limit on the amount of tiles the AI can use. Because of that command limit, it's not possible to do all pathfinding in one ingame day, since the AI will be paused every x opcodes.

[Misha]

Ah, that makes sense.