Page 52 - DCAP403_Operating System

Unit 3: Operating System Structure

An error is one part of the system may cause malfunctioning of the complete system. To Notes
avoid such a situation the operating system constantly monitors the system for detecting
the errors.
System calls provide an interface between the process and the operating system. These
types of system calls are used to control the processes.
A signal is a limited form of inter-process communication used in UNIX, UNIX-like, and
other POSIX-compliant operating systems. The number of signals available is system
dependent. File Management System Calls are used to manage fi les.
Device Management System Calls are used to manage devices. System programs provide a
convenient environment for program development and execution. Communications are the
programs that provide the mechanism for creating virtual connections among processes,
users, and different computer systems.
3.8 Keywords

Device Management System Calls: These types of system calls are used to manage devices.
Error Detection: This is a process where the operating system constantly monitors the system for
detecting the malfunctioning of it.
File Management System Calls: These types of system calls are used to manage fi les.
File System Manipulation: Creation, deletion, modification or updation of files is known as File

System Manipulation.
I/O Operations: It refers to the communication between an information processing system and
the outside world - possibly a human, or another information processing system.

File: A file is a collected of related information defined by its creator. Computer can store fi les on

the disk (secondary storage), which provide long term storage.
Operating System: An operating system is itself a computer program which must be executed.
Primary-Memory: Primary-Memory or Main-Memory is a large array of words or bytes and it
provides storage that can be access directly by the CPU.
Process Communication: A processes need to communicate with other process or with the user
to exchange the information, this is known as Process Communication.
Process: A process is only one instant of a program in execution.

Processes Control System Calls: These types of system calls are used to control the processes.
Program Execution: Program execution is a method in which user given commands call up a
processes and pass data to them.

Protection: It refers to mechanism for controlling the access of programs, processes, or users to

the resources defined by a computer system.
Signal: A signal is a limited form of inter-process communication used in some operating
systems.
System calls: It provides an interface between the process and the operating system.

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