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 the term system software, Question: (a) Define the term system ...

Question: (a) Define the term system software and application software, giving an example for each. (b) Draw a diagram to represent the abstract view of a computer system i

What is multiprogramming, What is Multiprogramming? Multiprogramming is...

What is Multiprogramming? Multiprogramming is the capability of am operating system to support multiple applications running concurrently. Multiprogramming simply means that an

Illustrate the function of loader, Q. Illustrate the function of Loader? ...

Q. Illustrate the function of Loader? A loader is a routine which loads an object program and prepares it for execution. There are many loading schemes: relocating, absolute an

Protection, protection in operating system

protection in operating system

What is an acyclic graph, What is an acyclic graph? A tree that has bee...

What is an acyclic graph? A tree that has been corrupted by links to other branches, but does not have any cyclic paths in it.

History of operating systems, Operating Systems have evolved tremendously i...

Operating Systems have evolved tremendously in the last few decades. The first approach for building Operating Systems, taken during the 40s through early 60s, was to allow only on

Assignment, Ask question #Minimum 100 words accDefine Hashing System. Descr...

Ask question #Minimum 100 words accDefine Hashing System. Describe the Hashed page table with example and mapping figure.

Parent process: why not finishing and how to make finish, #include #inclu...

#include #include #include #include #include int main(void) { int pchan[2], pid, rval, cvar; char buf[20]; if (pipe(pchan) == -1){

Explain drawbacks of fixed partitioning, The drawbacks of fixed partitionin...

The drawbacks of fixed partitioning are: The number of partitions are précised at system generation time limits the number of active processes in the system. For the re

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