Engine "Parallel" is Dangerously unstable (ALL)

[KyleSanderson]

A few years ago, the 'parallel' convars were turned on by default for servers.

sv_parallel_packentities 1
sv_parallel_sendsnapshot 1

Both of these convars, at their default values, will cause crashes due to not locking properly and allowing the gamethread to succeed the other two threads. If you miss no frames, they're a nice performance improvement. However, if your server were to suddenly start missing frames (an overloaded CPU/core), there's a high probability you will crash. The default response has typically been to just disable these options, but that isn't the greatest option. I was hoping this could be fixed, which would prevent many crashes.