Explanation of the Iperf State Machine

Introduction

This document describes the flow of control of Iperf at a very high level.

Client State Machine

TEST_START -> TEST_RUNNING -> TEST_END -> TEST_COMPLETE

TEST_START

1. open control channel to the server
2. exchange parameters with the server
3. create and open test_streams
4. -> TEST_RUNNING

TEST_RUNNING

1. generate data on each stream (either n bytes or n seconds)
2. service the periodic callback
3. when all data has been sent close stream
4. when all streams closed -> TEST_END

TEST_END

1. request results from server
2. close control channel
3. -> TEST_COMPLETE

TEST_COMPLETE

1. all connections closed
2. structs are kept in tact for reporting and analysis

Server State Machine

TEST_WAIT -> TEST_START -> TEST_RUNNING -> TEST_END -> TEST_WAIT

TEST_WAIT

1. listen for a control channel connection
2. -> TEST_START

TEST_START

1. wait for parameter exchange
2. -> TEST_RUNNING

TEST_RUNNING

1. create new streams as the arrive
2. receive and discard data for each stream
3. service results requests
4. when no streams remain -> TEST_END
5. if no new data after timeout seconds, then close all streams and control channel -> TEST_WAIT

TEST_END

1. wait for results request or control channel closure
2. if nothing happens after timeout seconds -> TEST_WAIT
3. when control channel closed -> TEST_WAIT