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wpilibsuite / allwpilib

Official Repository of WPILibJ and WPILibC
https://wpilib.org/
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Simulation consumes all CPU #6336

Open truher opened 7 months ago

truher commented 7 months ago

When I run simulation of our Java robot on my Linux machine, it pegs all the cores.

VisualVM says the process isn't doing much except waiting on notifiers. Maybe those are spinning?

It doesn't seem to hurt anything unless I want to do anything else, like run AdvantageScope.

My machine is Ubuntu 22.04, I'm using 2024.2.1.

PeterJohnson commented 7 months ago

The Simulation GUI is a single thread but runs continuously—you can set a max frame rate in the GUI to try to help with that. The robot code is pretty much single threaded as well. I’m not sure why you’re seeing all cores very active, as you’re right, things should be waiting on notifiers. What vendor deps are you using?

truher commented 7 months ago

we have rev, phoenix, navx, and choreo, but none of that is used for simulation, we use simple fakes in java-land.

turning the frame rate down from 60fps to 30fps reduces the load from 4 cores to 3.

i guess looking more closely java isn't consuming all CPU, just most of it (there are 6 cores on this machine).

also i think my concern about advantagescope might be more about the 3d field implementation? it goes at like 2 fps.