You can use the usual BSD socket API (in which case the context switches to/from the kernel for calling read() puts the contemplated workload out of reach) or a

You can use the usual BSD socket API (in which case the context switches to/from the kernel for calling read() puts the contemplated workload out of reach) or any number of vendor-specific userland network stacks. There is no need to context switch. (Function calls and function returns are not context switches.)