Thursday, October 2, 2008

Process management in operating system

Hello friends from now onwards i am going to discuss various concepts of operating systems that are very necessary to grasp the fundamentals of operating systems.In the post i am going to discuss the process management in operating system.

Before i begin with process management first of all we have to understand what is a process.In simple words we can say that a process is a program that is running on our computer.Now this process may be running either in frontend or in backend of the computer.Each and every process is composed of one or more than one thread.It is possible that an operating system may contain more processes running than actual programs because some processes are running in the backend of the operating systems.Now we came to our main issue of process management.As all we know a process needs some resources like cpu time,memory files and I/O devices for the execution of its instructions.Sometimes these resources are allocated to the processes when they are created or sometime when they are in running state.Sometimes in addition to these resources we have also pass some initialization data that is known as input for the process.

To understand the concept of process management we have to very much clear about the terms process and program.The main difference between these two terms is that process is an active entity while program is a passive entity.Generally the management of each process is done with the help of program counter,in case of a single threaded process it has one program counter that specifies the execution of the next instruction.The execution of these process are sequential in nature.The CPU executes next instruction only when it successfully executed the previous instruction.In case of multi threaded process they have multiple program counters each pointing to the next instruction to execute a given thread.

A process is a unit of work in the system.These types of systems are collection of the process some of which are them operating system process that execute system code and some of them are user system process that executes the user code.In addition to process management, operating system is also engaged in various activities like:
-->Creating and deleting both user and system process.
-->Suspending and resuming process.
-->Providing mechanism for process synchronization.
-->Providing mechanism for deadlock handling.

1 comments:

shaurya said...

hello, i have seen the diagram of process management. in this i have a query that you using double sided arrow between the waiting state and running state. so my question is that the process which is in running state how can it come to waiting state directly?......
please reply soon i am waiting