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 is segmentation?, SEGMENTATION In a memory management system that ...

SEGMENTATION In a memory management system that is properly a programmer views a program to be collection of program components called as segments . Every segment is a logical

Why page sizes always powers of 2, Q. Why page sizes always powers of 2? ...

Q. Why page sizes always powers of 2? Answer: Recall that paging is executed by breaking up an address into a page and offset number. It is most competent to break the address

What is indexed allocation, What is indexed allocation? Every file has ...

What is indexed allocation? Every file has its own block of pointers to the sectors of the file.

Assignment on Fork System Call, Parent process P creates three child proces...

Parent process P creates three child processes, C1, C2, and C3. Each child process executes a memory and CPU intensive application of your choice. Your choice should be such that

Define inter process communication (ipc), The term IPC (Inter-Process Commu...

The term IPC (Inter-Process Communication) defines several paths by which different process executing on some operating system interact between each other.

Palm os provides no signifies of concurrent processing, Q. Palm OS provides...

Q. Palm OS provides no signifies of concurrent processing. Discuss three major complications that concurrent processing adds to an operating system. Answer: a. A meth

Most-recently used algorithm, Evicting the most-recently used (MRU) page do...

Evicting the most-recently used (MRU) page does very well on LRU's worst case. In general, however, MRU is a bad idea, since many programs exhibit temporal locality in their memory

Explain segmentation hardware?, Explain segmentation hardware? We defin...

Explain segmentation hardware? We define an completion to map two-dimensional user-defined addresses into one-dimensional physical addresses. This mapping is affected by means

Ubuntu shell script - linux, Task 1 description: Design and implement the ...

Task 1 description: Design and implement the disableuser.sh script. Required script functionality: disableuser.sh -v : prints the script version number and exits dis

What are threads?, What are threads? A thread is alike to sequential pr...

What are threads? A thread is alike to sequential programs. Single threads have a beginning, sequence and end. At any given point in time during the runtime of the thread there

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