What is the fastest technology to send messages between C++ application processes, on Linux? I am vaguely aware that the following techniques are on the table:
are there any more ways and what is the fastest?
I would suggest looking at this also: How to use shared memory with Linux in C.
Basically, I'd drop network protocols such as TCP and UDP when doing IPC on a single machine. These have packeting overhead and are bound to even more resources (e.g. ports, loopback interface).