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?

What are the requirements for a swapper to work, The swapper work s on t...

The swapper work s on the biggest scheduling priority. Initially it will look for any sleeping process, if not get then it will see for the ready-to-run process for swapping. Bu

Explain two level directory, Two Level Directory This kind of structure...

Two Level Directory This kind of structure overcomes the problems of assigning unique names to the files. Thus there need not be any confusion among users. In this kind of s

Components of the r/e system, What components of the R/e system initiate th...

What components of the R/e system initiate the start of background jobs at the specified time? The batch scheduler initiates the begin of background job.  The dispatcher then s

Identify main functions of an operating system, Question: Introduction to ...

Question: Introduction to Operating Systems a) Define the term ‘Operating System' and identify main functions of an operating system. b) What are the characteristics of a go

Information system can be divided into three task areas, From hardware pers...

From hardware perspective, every information system can be divided into three task areas Presentation, Application Logic and Data Storage. The R/3 Basis software is extremely s

Find the parent process and the child process, Q. When a process creates a...

Q. When a process creates a fresh process using the fork() operation which of the following state is shared among the parent process and the child process? 1 Stack 2 Heap

What is erd, What is ERD? Entity Relationship Diagram is the graphical ...

What is ERD? Entity Relationship Diagram is the graphical representation of the object relationship pair. It is mostly used in database applications.

Define input - output operations, Q. Define Input - Output operations? ...

Q. Define Input - Output operations? Serial lines, Disks, tapes and other devices should be communicated with at a very low level. The user require only specify the device and

The key challenges of distributed systems, Question 1 Explain the followin...

Question 1 Explain the following with respect to Resource Management in Distributed Systems- Task assignment Approach Load - Balancing Approach Load - Sharing Approach

Essential properties of operating system, Essential Properties of Operating...

Essential Properties of Operating System 1. Batch: Jobs with similar needs are batched together and run through the computer as a group by an operator or automatic job sequen

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