Computer Modeling of the Task Scheduler
Abstract
Purpose of the research is to simulate computer processes and the task scheduler of the operating system, to model process scheduling algorithms, to study the CPU load at different waiting times for I / O operations. Modern concepts of processes and task planning are presented, the states of processes and options for transitions between these states are considered. A process model is proposed, and the calculation of the process operation time is given for a known probability of waiting state. The method of changing the priority of the process is considered.
Methods. Processes are in one of three states: two active and one passive. Each process can be superseded by another when its time quantum expires. The order of displacement is determined by the priority of the process. The priority includes the basic part and the dynamic part, which changes over time, and can also change at the request of the user.
Results. As a result of computer simulation, an operating system was developed that implements the process model and the process scheduler. The process structure includes the process ID, state, processor context (register value), and memory card. The scheduler implements the round-robin algorithm. When a timer interrupt occurs, the context of the previous process is saved and the context of the next process is restored. As a result of the simulation, a relationship was obtained between the number of processes and CPU utilization at different I / O waiting times.
Conclusion. The resulting model can be used to model the operation of processes and the task scheduler of the operating system. It allows you to test scheduling algorithms to improve the performance of the operating system.
About the Authors
A. А. Chaplygin
Southwest State University
Russian Federation
Russian Federation
Aleksandr А. Chaplygin, Cand. of Sci. (Engineering), Associate Professor of the Department of Software Engeneering
50 Let Oktyabrya str. 94, Kursk 305040
E. А. Petrik
Southwest State University
Russian Federation
Russian Federation
Elena А. Petrik, Cand. of Sci. (Engineering), Associate Professor of Software Engineering Department
50 Let Oktyabrya str. 94, Kursk 305040
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Review
For citations:
Chaplygin A.А., Petrik E.А. Computer Modeling of the Task Scheduler. Proceedings of the Southwest State University. Series: IT Management, Computer Science, Computer Engineering. Medical Equipment Engineering. 2021;11(2):138-151. (In Russ.)
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