Operating Systems
Project- A Four Level Priority Dispatcher
This project is to write a C program who implement four level priority process dispatcher operating within the constraints of finite available memory and I/O resources.
The dispatcher operates at four priority levels:
• Real-Time processes must be run immediately on a First Come First Served (FCFS) basis, pre-empting any other process running with lower priority. These processes are run till completion.
• Normal user processes are run on a time sliced three level feedback dispatcher. The basic timing quantum of the dispatcher is 1 second. This is also the value for the time quantum of the feedback scheduler.
The dispatcher controls the following resources:
• 2 Printers
• 1 Scanner
• 1 Modem
¦ 2 CD Drives
• 1024 MByte Memory available for processes
The dispatcher is presented with a list of processes along with their arrival times, priority, and requested resources. The dispatcher ensures that each requested resource is solely available to that process throughout its lifetime in the 'ready-to-run' dispatch queues: from the initial transfer from the job queue through to process completion, including any intervening idle time quanta.
The executing process is emulated by a supplied program that repot any signals sent to it and `ticks' once a second while it is running.
Programming Language and Environment:
• Language: C
• Platform: Sloop
• Shell: tcsh.