1. CGS 3763 Operating Systems Concepts Spring 2013
Dan C. Marinescu
Office: HEC 304
Office hours: M-Wd 11: :30 AM

2. Lecture 4 – Monday, January 14, 2013
Last time:
State and events; Event-driven-software
Discussion of problems from the textbook
Today:
Types of systems
User access; user interfaces
OS services
The management of computer resources: CPU, memory, I/O devices
Next time
Protection – user and kernel mode execution
System calls
Kernel data structures
Reading assignments:
Chapter 2 of the text book
The computer architecture material
11/30/2018

3. Questions Why there are different types of operating systems?
Why do we need to distinguish the mode in which an OS and an application run?
What is a process?
What is a thread?
Why do we need to share the CPU of a system among multiple processes/threads?
What do we mean by a memory hierarchy?
Why do we need a hierarchy of memory?
What is virtualization?
What is virtual memory?
What is an interrupt?
What types of interrupts can you identify?
11/30/2018

4. User-computer relationship
Many-to-one  time-shared systems
One-to-one  PCs
One-to-many  Computational grids, network computers
Many-to-many  Computing clouds
Different resources and OS for each class of systems
11/30/2018

5. Kernel functions Program execution: Interrupt handling:
Error handling:
Job sequencing:
Input/Output operations:
File system manipulation:
Scheduling:
Resource Allocation:
Accounting of computer resources:
Protection:
11/30/2018

6. Management of system resources
Processor
Memory hierarchy
I/O devices
11/30/2018