Testing Central Processing Unit scheduling algorithms using Metamorphic Testing

Central Processing Unit (CPU) scheduling is used to allocate CPU for multiple processes. CPU is one of the most important resources in the computer system, and its scheduling is vital and influential in operating systems. Thus, it is necessary to ensure the correctness of the CPU scheduling program. However, testing the correctness of a scheduling program is difficult because it is hard to verify the correctness of its output, which is known as the test oracle problem in software testing. Metamorphic Testing (MT) which has been recently proposed to alleviate the test oracle problem, is applied to test the CPU scheduling program. In this paper, we use MT to test the Highest Response Ratio Next (HRRN) scheduling algorithm. Two simulators of HRRN scheduler are used in the evaluation of our method. Surprisingly, some real life faults in one open source simulator are detected by MT. Further experiments are performed based on mutants, and the experimental results show that MT is an effective strategy to test CPU scheduler.