Operating System
1 Introduction to Operating System
Definition: Special layer of software that provides application software access to hardware resources.
What is an Operating System?
Illusionist: Provide clean, easy-to-use abstractions of physical resources.
Referee: Manage protection, isolation, and sharing of resources.
Glue: Common services.
1.1 Operating System as Illusionist - Provide clean, easy-to-use abstractions of physical resources
Application's "machine" is the process abstraction provided by OS.
Each running program runs in its own process.
Processes provide nicer interfaces than raw hardware.
A process consists of:
Address Space
One or more threads of control executing in that address space
Additional system state associated with it, e.g., open files, open sockets, etc.
OS translates from hardware interface to application interface.
OS provides each running program with its own process.
1.2 Operating System as Referee - Manage protection, isolation, and sharing of resources
Last modified: 25 November 2024