Explain the need of a process table in a timesharing system

Explain the need of a process table in a timesharing system. Do we also need the process table in a UNIX or Windows based personal computer with a single user? Justify your answer.

Solution

a)

Process table is needed in a timesharing system because it holds all the processes in the machine - that are either \'waiting\' or \'ready\' state to be processed.

We know time-sharing system gives processes a time-slice or quantum, and these Processes can only be executed within this time frame, once it expires, the CPU receives an interrupt signal, the CPU saves its current state in the current process and focuses on the interrupting entity (another process).

The scheduler adds/removes new processes to/from the process table as it goes.