Big waves.
This function wraps the operation of getting a stimframe from
the SpMcRingBuffer, and then eventually assigning it a
SimultaneityStamp. For now we just always pass in the first
stim frame and we don't get any simulstamps.
Its callOriginalCallback() automatically calls
allowNextStimulusFrame() to ensure that it doesn't deadlock future
timeslices.
We implemented the feature to fill unassembled slots w/dummy header
values for the livox pcloud header.
We also fixed a bug where io uring was writing into the last slot
only because we were using the same iovec for every SQE.
This is in preparation for re-using StagingBuffer to also serve
as the collation buffer that we'll use as the intermediate stage
for producing the final output mesh.
Invoke it instimFrameProductionTimesliceInd.
Also, we discovered:
* stream_descriptor::release() doesn't fully release all metadata
from the fd it was assigned. This suggests that we should go
through the codebase and do: release()=>reset() whenever we
wish to release().
* We've confirmed that spinlocks can be used to prevent race
conditions between stop() and handler methods.