The slack sharing server for embedded microcontrollers

An embedded real-time microcontroller usually has both hard and soft real-time tasks. The slack sharing server (SSS) allows soft real-time tasks to share the time slack left by hard real-time tasks. This paper evaluated the SSS and found that some tasks may be treated unfairly if the number of consecutive time slacks is not greater than the number of soft real-time tasks. An improved SSS was proposed to tackle this problem. An embedded controller for a sports training machine was designed and developed using the SSS and presented in this paper. The successful field test proved that the SSS is simple and efficient for slow speed and small memory embedded systems.