This shared state between original data and depsgraphs was added in
98a0bcd425. Other physics systems also share
the pointcache, but not the simulation state to this extent, which leads
to this kind of crash.
The mutex lock is not a great solution, you don't really want both render and viewport to be filling the same cache in parallel. However
this kind of problem also exists in other physics systems, and solving
that is certainly beyond the scope of 4.4, and probably needs to wait
for a bigger physics rewrite. In general the recommendation is to bake
everything before rendering.
Pull Request: https://projects.blender.org/blender/blender/pulls/134779
c988a04802