Civ4 end-of-turn processing order

can someone point me to, or be so kind as to break down for me, what the end-of-turn processing order is? I'm trying to understand whether the game sweeps through tiles first, then tile stacks, one at a time or if there are parallel operations, such that off-screen tiles/units are processed at the same time ?

I'll sort of re-word that to show more of my thinking here;
Is tile/unit processing serial, meaning each tile or unit must output it's action/turn result before any other unit can act, or can multiple units process their turns in parallel (under the right/any conditions?)

Thanks very much!

I had a similar question and couldn't solve it, I tried to find out which deal i. e. gets cancelled when trading 2 resources to 2 different AIs and pillaging one of the resources so that one deal must be cancelled, so basically the GPT-trick only slightly more complicated. I couldn't find that out via a testgame, in my test-game the deal with the AI I traded the 1st resource to got cancelled, in my real game however the deal towards the AI that I traded to 2nd got cancelled, I conducted both deals on the same on turn so both had a 10T timer. I couldn't find out any logical solution, if not the oldest deal gets cancelled if 2 deals have the same timer and if it's not based on the order that one selected when setting up the game, what exactly is the order in which the deals with the AIs get processed? Any definite info would help.

TIA .

As a wild guess...wouldn't those deals process in the order that the AIs take their turns? So when one takes their turn the deal is intact, but when the other takes their turn there is no goods left so it cancels. Wouldn't make any difference what order you made the deals in.