Real-Time Scheduler Simulator - A Software Development Project in C++

In this project, a software called the Scheduler Simulator was created to simulate task executions given a specified real-time scheduler. Existing similar simulators were examined and evaluated, reusable functionality best fitted to be adopted by this projects simulator software was identified. Whereas all the existing solutions have strengths and weaknesses, the following properties were extracted: limit the end-users responsibilities, create thorough documentation, use Gantt charts with clearly marked deadline misses, and provide relevant and readable simulation results. Best practices related to software development, such as software development methods, documentation development and software design, have been researched. In addition, other relevant theory related to real-time systems and schedulers was also examined. To develop the Scheduler Simulator, the best practices were evaluated. For the Scheduler Simulator project, the development was conducted using mainly iterative and incremental methods, influenced by sprints from Scrum development, emphasizing the flexibility and simplicity described by Agile development methodologies. The Scheduler Simulator allows a user to implement new scheduling policies, create and generate task sets and conduct simulations to generate relevant reports. The resulting reports contain CPU idle time, the number of reached and missed deadlines, the number of completed tasks, and a Gantt chart, visually presenting the simulated task executions. Four schedulers were implemented in the software: FIFO, RR, RM and EDF. A series of test runs of the Scheduler Simulator were conducted and evaluated. The simulator behaved as expected. It was discovered that when simulating more than 20 tasks, the Gantt chart overshot the page size of the result report. As a reaction to this, the simulator was altered to not produce Gantt charts for simulations where the task set exceeded 20 tasks. The documentation created for the system consists of three main parts; one for requirements, one describing the architectural design of the software, and one for the users. "The users" here refers to both maintenance personnel and end-users. As the project was conducted by one person, the social benefits from using Scrum and other Agile development methodologies diminished greatly. Instead, the development work converged towards a waterfall shaped structure, as a sequential work model can be more appealing and natural when working alone than a parallel and cyclic model. The iterative way of working still helped the developer to learn from mistakes along the way and create a functional system