Queue scheduling

[sean-gilliam]

With multiple people playing and general network latency, there's a near absolute chance that individual players could issue multiple commands within the game server's tick. Take for example the following:

Player 1: issues 3 commands
Player 2: issues 4 commands
Player 3: issues 2 commands

with the following message order placed on the queue

p2 | p2 | p3 | p1 | p1 | p2 | p3 | p1 | p2

If processed in order, that would give p2 an unfair advantage, as they would have more actions per tick than the rest.

I see one of two ways of handling it. There may be more, but this is what I see.

• create an in-memory queue and a re-sequencer to intersperse the commands (maintaining FIFO) like such

p2 | p3 | p1 | p2 | p1 | p3 | p2 | p1 | p2

• or we create individual in-memory queues for each player and a router. We then iterate over the first elements of their queues per server tick.

p2 | p2 | p2 | p2
p3 | p3
p1 | p1 | p1

process p2, then process p3, then process p1 ....

I'm leaning towards the latter, as the logic would be simpler.

Thoughts @rezalas?