Implementation and validation of dynamic scheduler based on LST on FreeRTOS

The main concern of real time systems is to deliver logically correct results within the given timing constraints. This requires scheduling algorithms which can use the processor in the most efficient manner possible. The current paper presents the implementation of a least slack time first dynamic scheduling algorithm to support number of real time applications on a single processor. The proposed implementation of algorithm is adaptable to different kinds of tasks - periodic, aperiodic and sporadic tasks and later for different types of real time applications. Mutex and semaphore concepts are used to illustrate the working of designed scheduler to support resource sharing and task synchronization. The algorithm is implemented on an ARM Cortex M4 based platform with real time applications. It is tested using numerous test cases and results are verified. The results obtained from simulation meet desired requirements of a robust scheduler.