Comment by _dps

I don't know what kind of latency vs throughput tradeoff you're facing, but given these constraints (and being on windows) I might try running multiple python processes each with the C++ structure in shared memory, and then broker any inter-python shared state through something like Redis on localhost (so as long as the inter-python shared state is small and rarely updated, you only pay a small IPC cost to get it from Redis instead of having it in-process).