30-05-2012, 12:19 PM
RESOURCE ABSTRACTION IN OPERATING SYSTEM
RESOURCE ABSTRACTION.ppt (Size: 693.5 KB / Downloads: 112)
Introduction
System software hides the details of how the underlying machinery operates.
The techniques for the system software to provide an abstract model of the operation of hardware components.
Abstractions are implemented within the system software.
The lowest level abstractions- the ones that deal directly with the hardware are implemented in non-OS system software.
Object-Oriented programmers use abstraction at multiple levels when they work with class hierarchies.
A base class defines the most abstract operations for objects, and subclasses refine the operations for more specific members of the family.
OS Requirements
Provide resource abstractions
Process abstraction of CPU/memory use
Address space
Thread abstraction of CPU within address space
Resource abstraction
“Anything a process can request that can block the process if it is unavailable”
NT uses “object abstraction” to reference resources
File abstraction of secondary storage use
Resource abstraction
Operating System (System Software) hides the details of how underlying machinery operates.
Like An Automobile – Ignition, Gear, accelerator, brake, Steering, Wipers, Light ….
Modern Automobile – Push button, auto transmission abstraction ( P, D, R), GPRS, IVR Cell
Disadvantages of Abstraction : While simplifying the way application programmer controls hardware, it limits the flexibility by which specific H/W can be manipulated.
While some operations are easy to perform, other operations may be impossible to achieve using abstraction.