OS (BSC-IT 3rd)

SECTION A

Introduction: Application programs and system programs; functions of an operating

system; classification of operating systems-Multi-user, multiprogramming,

multiprocessing, time sharing, multi-threaded. Subsystems – Top Layer, Middle Layer,

Bottom Layer, Bootstrap, Protection and security.

Processes and Threads: Program vs. Process; Process context, address space,

identification, transition, state & management. Thread management-benefits,

synchronization issues; applications of threads.

SECTION B

CPU Management: Objectives, Pre-emptive vs. Non-pre-emptive, context switching,

scheduling schemes; multi-processor scheduling, thread scheduling.

Inter-process Communications: Introduction, message passing model, shared

memory model. Pipe, FIFO and Socket.

SECTION C

Memory Management: Introduction, address binding, relocation, loading, linking,

memory sharing and protection; Paging and segmentation; Virtual memory: basic

concepts of demand paging, performance, page replacement. Thrashing.

I/O Device Management: I/O devices and controllers, device drivers; disk storage,

scheduling and management.

SECTION D

File Management: Basic concepts, file operations, access methods, directory

structures and management, remote file systems; file protection.

Protection & Security: Need, environments: software, hardware, unauthorized use,

denial of services, access control and authentication. Application security, attacks, virus

& anti-virus, firewall.