Process Queues:
For each of the process states, the operating system manages multiple sorts of queues. The PCB for the procedure is likewise kept in the same state's queue. When a process is switched from one state to another, its PCB is likewise delinked from the queue that corresponds to the previous state and added to the queue for the new state.
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There are the following queues maintained by the Operating system.
1. Job Queue:
All processes are initially queued up in the job queue. It is kept in the auxiliary memory. Some of the jobs are chosen by the job scheduler and stored in the main memory.
2. Ready Queue:
Primary memory is used to manage the ready queue. The job is selected by the short-term scheduler and sent to the CPU for execution from the ready queue.
3. Waiting Queue:
The OS changes the process's status from running to waiting when some IO activity is required for it to finish running. When the process completes the IO, the context (PCB) associated with the process is saved on the waiting queue and used by the Processor.
