Operations on Processes-R.D.Sivakumar

1. OPERATIONS ON PROCESSESOPERATIONS ON PROCESSES
Video Lecture and E-Content Created byVideo Lecture and E-Content Created by
R.D.SIVAKUMAR,M.Sc.,M.Phil.,M.Tech.,R.D.SIVAKUMAR,M.Sc.,M.Phil.,M.Tech.,
Assistant Professor of Computer Science &Assistant Professor of Computer Science &
Assistant Professor and Head, Department of M.Com.(CA),Assistant Professor and Head, Department of M.Com.(CA),
Ayya Nadar Janaki Ammal College,Ayya Nadar Janaki Ammal College,
Sivakasi – 626 124.Sivakasi – 626 124.
Mobile: 099440-42243Mobile: 099440-42243
e-mail :e-mail : sivamsccsit@gmail.comsivamsccsit@gmail.com website:website: www.rdsivakumar.blogspot.inwww.rdsivakumar.blogspot.in

2. PROCESS CREATIONPROCESS CREATION
• When a user executes a program, the operatingWhen a user executes a program, the operating
system creates a process.system creates a process.
• A process may create several new process viaA process may create several new process via
a create-process system call.a create-process system call.
• The creating process is called a parent processThe creating process is called a parent process
and the new processes are called the childrenand the new processes are called the children
of that process.of that process.

3. TREE OF PROCESSTREE OF PROCESS
• Each of these processes may create otherEach of these processes may create other
process, forming tree of processes.process, forming tree of processes.
• Operating systems identify processes accordingOperating systems identify processes according
to a unique Process Identification (PID).to a unique Process Identification (PID).
• The children process obtain its resourcesThe children process obtain its resources
(memory, files, I/O devices, CPU) directly(memory, files, I/O devices, CPU) directly
from the OS or it uses the resources of thefrom the OS or it uses the resources of the
parent.parent.

4. PROCESS TERMINATION
• A process terminates when it finishes
executing its final statement.
• The operating system terminates a process by
using the exit system call.
• Termination can occur in other circumstances
as well.
»Time slot expired
»I/O failure
»Parent termination.