What is the use of queue ready queue and device queue?

Job queue contains the set of all processes in the system and ready queue contains the set of all processes residing in main memory and awaiting execution. Job queue consists of all the processes where ready queue contains processes which are waiting for execution is the major difference.

What is a job queue in OS?

A job queue contains an ordered list of jobs waiting to be processed by a subsystem. The job queue is the first place that a submitted batch job goes before becoming active in a subsystem.

What is a waiting queue in OS?

Waiting Queue When the process needs some IO operation in order to complete its execution, OS changes the state of the process from running to waiting. The context (PCB) associated with the process gets stored on the waiting queue which will be used by the Processor when the process finishes the IO.

What is the function of device queue?

Device or IO Queue Device queue contains the processes which are waiting for the completion of I/O request. Each device has its own device queue. Devices usually have device controller hardware and device driver software that work as part of the OS to control it.

What do you mean by scheduler?

A scheduler is a software product that allows an enterprise to schedule and track computer batch tasks. These units of work include running a security program or updating software. A scheduler is one of the main components of IT infrastructure. A scheduler may also be known as a job scheduler.

What is meant by ready queue?

The ready queue is a simplified version of a kernel data structure consisting of a queue with one entry per priority. Each entry in turn consists of another queue of the threads that are READY at the priority. Any threads that aren’t READY aren’t in any of the queues — but they will be when they become READY.

What is process queue?

A queueing process is a model of waiting lines, constructed so that queue length and waiting times can be predicted. The symbolic representation of a queueing process makes it easy to simulate its behavior, estimate its parameters from data, and compute state probabilities at finite and infinite time horizons.

Where does job queue reside?

Conventional Operating Systems like Batch System tend to place new created processes in a secondary storage device in the job queue. Later on these processed are loaded in the main memory(RAM) and placed in the ready queue. So, In batch Systems, job queue resides in Secondary Storage.

What is scheduler and its types?

A scheduler is a type of system software that allows you to handle process scheduling. Three types of the scheduler are 1) Long term 2) Short term 3) Medium-term. Long term scheduler regulates the program and select process from the queue and loads them into memory for execution.