What are scheduling queues?, Operating System

Assignment Help:

What are scheduling queues?

Since the processes enter the system they are put into job queue. This queue contains all processes in the system. The processes that are exist in main memory and are ready and waiting to execute are kept on a list called as the ready queue. The queue is in general stored in as a linked list. A ready queue header consist pointer to the first and final PCBs in the list. We extend every PCB to include a pointer that points to the next PCB in the ready queue.

When the process is assigned the CPU, it implements for a while and executes for a while and eventually quits is interrupted or waits for the occurrence of a particular event such as the completion of a request for example the completion of an I/O request. In the case of an I/O request such a request perhaps dedicated tape drive and so on. since the system has several processes, the disk perhaps busy with the I/O request of some other processes.  The process afterward has to wait for the disk. The listing of processes waiting for a particular I/O device queue is called as a device queue.

A new process is originally put in the ready queue. It waits in the ready in anticipation of it is selected fro execution. Formerly the process is assigned to the CPU and is executing one of several events could take place:

  •  
    1. The process could issues I/O request, after that be placed in an i/o queue.
    2. The process could create a new sub process in addition to wait for its termination.
    3. The process could be detached forcibly from the CPU as a result of an interrupt and be put back in the ready queue.

In the first two cases the process finally switches from the waiting state to the ready state and is then put back in the ready queue. A process keep going this cycle until it terminates this cycle until it terminates at which time is removed from all queues and has its PCB and resources deallocated.


Related Discussions:- What are scheduling queues?

Define what is dispatcher, Define what is Dispatcher In the Worker Mode...

Define what is Dispatcher In the Worker Model, it is the task of the Dispatcher to spawn a thread for every client-to-server connection. The Dispatcher acts as the go-between o

Can indefinite blocking take place, Consider the subsequent resource-alloca...

Consider the subsequent resource-allocation policy. Requests as well as releases for resources are allowed at any time. If a request for resources can't be satisfied because the re

Define lru page replacement policy, Define ‘LRU’ page replacement policy ...

Define ‘LRU’ page replacement policy LRU is Least Recently Used page replacement policy.

Ipc, Explain in detail about ipc in linux

Explain in detail about ipc in linux

Explain about deadlock detection, Explain about deadlock detection? In ...

Explain about deadlock detection? In deadlock situation, the system must provide An algorithm that verifies the state of the system to verify whether a deadlock has occu

Dual mode operation, WHAT ARE THE ADVANTAGES AND DISADVANTAGES OF DUAL MODE...

WHAT ARE THE ADVANTAGES AND DISADVANTAGES OF DUAL MODE OPERATION OF OPERATING SYSTEM>?

For what reason would such a scheme be useful, Q. A Burroughs B7000/B6000 ...

Q. A Burroughs B7000/B6000 MCP file is able to be tagged as sensitive data. When such a file is removed its storage area is overwritten by some random bits. For what reason would

What is contiguous allocation, What is contiguous allocation? Allocati...

What is contiguous allocation? Allocation of a group of consecutive sectors for a one file.

Briefly explain the process management in unix., Briefly explain the proces...

Briefly explain the process management in UNIX. UNIX makes use of the easy but powerful process facility that is visible to the user. UNIX follows the model in which the majori

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd