Event driven state machines: simple TCP-server

Hi, I’ve made one more example of using event driven state machines approach (simple echo server). This example shows how to organize a program as a hierarchical team of interacting machines. Specifically, this server includes 4 kinds of state machines:

  • listener (one instance)
  • worker (many instances, in a pool)
  • rx/tx machines (many instances, also in pools)

Some excerpts from server output (I used nc for testing) to get a feel of how it is doing it’s job:

  • client connected
LISTENER-1 @ WORK got 'D0' from OS
WORKER-4 @ IDLE got 'M1' from LISTENER-1
WORKER-4 @ IDLE got 'M0' from SELF
RX-4 @ IDLE got 'M1' from WORKER-4
RX-4 @ IDLE got 'M0' from SELF
  • client suddenly disconnected
RX-4 @ IDLE got 'M0' from SELF
RX-4 @ WORK got 'D2' from OS
RX-4 @ WORK got 'M0' from SELF
WORKER-4 @ RECV got 'M2' from RX-4
WORKER-4 @ FAIL got 'M0' from SELF
LISTENER-1 @ WORK got 'M0' from WORKER-4
  • request-reply
RX-4 @ IDLE got 'M0' from SELF
RX-4 @ WORK got 'D0' from OS
<<< 4 bytes: { 49, 50, 51, 10 }
RX-4 @ WORK got 'M0' from SELF
WORKER-4 @ RECV got 'M1' from RX-4
WORKER-4 @ RECV got 'M0' from SELF
TX-4 @ IDLE got 'M1' from WORKER-4
TX-4 @ IDLE got 'M0' from SELF
TX-4 @ WORK got 'D1' from OS
TX-4 @ WORK got 'M0' from SELF
WORKER-4 @ SEND got 'M1' from TX-4
WORKER-4 @ SEND got 'M0' from SELF
  • request timeout
RX-4 @ IDLE got 'M0' from SELF
RX-4 @ WORK got 'T0' from OS
RX-4 @ WORK got 'M0' from SELF
WORKER-4 @ RECV got 'M2' from RX-4
WORKER-4 @ FAIL got 'M0' from SELF
LISTENER-1 @ WORK got 'M0' from WORKER-4
3 Likes

I’ve added client example:

  • multiple connections in single thread
  • asynchronous connect