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?

Interprocess communication, Now we consider the following questions: how ca...

Now we consider the following questions: how can the parent process communicate with its child? Or how can children processes communicate with other children? The exact answer depe

What are the methods for handling deadlocks?, What are the methods for hand...

What are the methods for handling deadlocks ? The technique for handling the deadlocks are: We are able to use protocol to prevent or avoid the deadlock, make sure tha

What are the typical elements of a process image, What are the typical elem...

What are the typical elements of a process image? User data: Modifiable part of user space. May have program data, user stack area, and programs that might be modified. User

Mechanism for code and data sharing, Q. Consider a system in which a progr...

Q. Consider a system in which a program is able to be separated into two parts: code and data. The CPU recognizes whether it wants an instruction (instruction fetch) or data (data

Thread, Explain thread in details

Explain thread in details

What are the issues in designing a network-scalability, Scalability : ...

Scalability : Scalability is the competence of the system to adapt to increased service load. A scalable system will respond more gracefully to increased load than a non-sc

Us constitution, what branch of goverment were the federal courts are?

what branch of goverment were the federal courts are?

Process creation, what is process creation and how to create a process

what is process creation and how to create a process

Lock revenue variable, Demonstrate that your program (include the program o...

Demonstrate that your program (include the program output as part of the final report) can produce the correct output with the following parameters. For each case comment if the ou

Benefits of virtual memory, Q.  When virtual memory is executed in a comput...

Q.  When virtual memory is executed in a computing system there are convinced costs associated with the technique and certain benefits. List the costs as well as the benefits. Is i

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