OPERATING SYSTEM : PROCESS AND DEADLOCK

OPERATING SYSTEM :  
                 ~ PROCESS AND DEADLOCK ~

* PARTS OF PROCESS MANAGEMENT

Process Management can be divided into

following parts

1. PROCESS CONCEPT

2. CPU SCHEDULING

3. PROCESS SYNCHRONIZATION

4. DEADLOCKS

* PROCESS CONCEPT :)

A process is more than the program code 

(same as the text section). It also includes

the current activity, as represented by the

value of the program counter and the

contents ot the processor's regi sters. 

A includes the process stack, containing temporary data (such as subroutine parameters, return address, and temporary variables), 

and a data section containing global variables.

* PROCESS STATE :)

As a process executes, it changes state.

state of a process is defined in various part by the

current activity of that process. process in one following states :

1) New The process is being created.

2) Running Instructions are being executed.

3) Waiting The process is waiting for some event to occur (such as an I/0 completion or reception of a signal).

4) Ready process is waiting in assigned to  processor.

5) Terminated The process has finished

execution.

* STATE DIAGRAM OF A PROCESS

A process goes through various states with

respect to CPU. It is depicted in following

figure :

a) Initial State A process/program/job starts in a state in which it has no resources at all. It is called initial state.

b) Hold State A process is said to be hold

state if it lies in the secondary storage.

c) Ready State A job in ready state is in

the main memory. It is ready to use CPU

but CPU is not available.

d) Run State : A process is said to be in

Run state if it is using the CPU. Hence a

process wanting to reach RUN state

goes through the ready state first.

e) Wait State : A process is said to be in

Wait state if it is waiting for something

to happen and it is not in a position to

use the CPU (e. g. There may be page fault).

f) Complete State In this state, the

process completes its erection. It does

not need any resources.

* PROCESS CONTROL BLOCK

Each process is represented in the

operating system by a process control

block (PCB)-also called a task control block.

A PCB is shown in the figure  :

* PROCESS SCHEDULING

The objective of multiprogramming is to

have some process running to all times, to

maxi mize, CPU utilization.

* SCHEDULING QUEUES :)

As processes enter the sys tem, they are put

into a job queue. The queue consists of all

processes in the system. The processes that

are residing in main memory and are ready

are kept on a list A common representation for a discussion of process scheduling is a queuing diagram, such as shown in Figure and waiting to execute called the ready queue.

FURTHER TOPIC WILL BE SOON....

THANK YOU :)