#processassociate

Process Management - What Is Process? What Is Process Control Block What Is Concurrent Processes? What Is Process Creation? What Is Process Termination?  

Process

A Program In Execution Is Called As Process. A System Can Be Viewed As A Collection Of Processes. Operating System Process Execute System Code And User Processes Execute User Code. A Process Needs Certain Resources Like CPU Time, Memory Files And I/O Devices To Accomplish Its Task. The Operating System Is Responsible For (1) Creation And Deletion Of User And User Processes (2) The Scheduling Of Processes. (2) Provision Of Mechanisms For Synchronisation Communication And Deadlock Handling For Processes.  

Process Control Block (PCB)

A PCB (Process Control Block) Is A Data Structure Containing Information Regarding A Specific Process Control Block.Each Process Is Represented In An Operating System By Its Own Process Control Block. This Includes- (a) Process State May Be New, Ready, Running, Waiting Or Halted. (b) Program Counter Indicates The Address Of The Next Instruction To Be Executed For This Process. (c) CPU Registers Include Accumulators, Index Registers, Stack Pointers, And General Purpose Registers. This Information Is Saved When An Interrupt Occurs. (d) CPU Scheduling Information Include Process, Priority, Pointers, For Scheduling Queues Etc.

Concurrent Processes

The Processes In A System Can Execute Concurrently. To Provide Concurrent Execution A Mechanism For Process Creation And Termination Is Required.

What Is Process Creation?

A Process May Create Several New Processes via a Create System Call. The Creating Process Is Called S Parent Process While New Processes Are Called Children Processes. A Parent May Execute Concurrently With Its Children Or It May Wait Until All Its Children Have Terminated.

Process Termination

A Process Terminates When It Finishes Executing Its Last Statement And Asks The Operating System To Delete The Process. A Process Can Also Cause The Termination Of Another Process via a System Call. Usually, Such A System Call Can Be Invoked By Only The Parent Of The Process That Is To Be Terminated.

Relation Between Processes

A Process Executing In The Operating System May Be Either Independent Process Or A Cooperating Process. 1.Independent Process  Such A Process Cannot Affect Or Be Affected By Other Processes Executing In The System. 2.Cooperating Process  Such A Process Can Be Affected Or Can Affect The  Other Processes Executing In The System.

Processor Scheduling