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 throughput of a system, Define the “Throughput” of a system  ...

Define the “Throughput” of a system  Throughput is Number of programs processed by it per unit time

Page fault handling , Page Fault Handling conditions like, where the copy...

Page Fault Handling conditions like, where the copy on write bit of a page is set and that page is send by more than one process, the Kernel assign new page and copies the conten

Socket, socket based fortune teller sever.your program should create a serv...

socket based fortune teller sever.your program should create a server that listens to a specific port when a client receives a connection the server should respond with a random fo

Explain lru additional reference bits algorithm, Additional Reference bits...

Additional Reference bits algorithm Here we keep an 8-bit byte for every page in memory. At standard intervals the reference bit is shifted by the OS. If a shift register conta

Disk scheduling algorithms-first come, FCFS (First Come, First Served) Per...

FCFS (First Come, First Served) Perform operations in order requested No reordering of work queue No starvation every demand is serviced Poor performance

Define properties of real time operating system, Define properties of Real ...

Define properties of Real time operating system Real time :- Often used in a dedicated application, this system reads information from sensors and must respond within a fixed a

Explain what is semaphores, Explain what semaphores are, their usage, imple...

Explain what semaphores are, their usage, implementation given to avoid busy waiting and binary semaphores. Semaphore definition Usage for mutual exclusion and process synch

Explain the communications of request or response interface, Explain the Co...

Explain the Communications of Request or Response Interface The inter-application communication must provide four specific interface to the CSInterface() components. A client m

Digital circuits and design , 1. Draw a schematic diagram of a CMOS inverte...

1. Draw a schematic diagram of a CMOS inverter and explain its operation. 2. Draw schematic diagrams of CMOS NAND and NOR gates, and explain their operation. 3. Explain what

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