Some ComputeShortPath 700ms simulation lagspike over 40 seconds

[elexis]

Between turn 1920 and turn 2000 in this r22504 replay, computing the turn took more than the average 80ms, even 5 times more than the otherwise maximum of 140ms - 700ms.

Notice that this is quite long - from 16:00 to 16:40.

The part that is slow is ComputeShortPath and Process Short Requests.

replay at ​https://code.wildfiregames.com/F1008256
profile1 json at ​https://code.wildfiregames.com/F1008316

What is particularly surprising is that there are not many units walking around, maybe < 200 that werent gathering?

Perhaps this isn't a regression, and perhaps it is a duplicate ticket.

In early 2018 temple looked a bit at lagspikes and mentioned that one type of lagspike occurs when every path is obstructed (all gates closed) and there was a gate-lock-command in this replay. (But does it have to be that bad for performance?)