Unit 521: Operating Systems

1. Introduction to Operating Systems

• Definition and purpose
• Functions of an operating system
  • Resource management
  • User interface
  • File management
• Types of operating systems
  • Batch, Time-sharing, Distributed, Real-time
• Role in managing hardware and software

2. Operating System Structures

• Overview of OS architecture
• Monolithic Systems
  • Characteristics
  • Advantages and disadvantages
• Layered Systems
  • Design principles
  • Benefits and limitations
• Microkernel Systems
  • Structure and components
  • Pros and cons
• Hybrid Systems
  • Combination of approaches
  • Use cases and trade-offs

3. Process Management

• Concept of a process
• Process states and transitions
• Process creation and termination
• CPU scheduling
  • Scheduling criteria
  • Algorithms: FCFS, SJF, Round Robin, Priority
• Process synchronization
  • Critical section problem
  • Semaphores and mutexes
• Interprocess communication (IPC)
  • Shared memory
  • Message passing

4. Memory Management

• Memory hierarchy and management goals
• Partitioning
  • Fixed and dynamic partitioning
• Paging
  • Page tables and frame allocation
• Segmentation
  • Segment tables and addresses
• Virtual memory
  • Demand paging, page replacement algorithms
• Memory allocation and deallocation techniques

5. File Systems

• File concepts and attributes
• File organization methods
• Directory structures
  • Single-level, two-level, tree-structured directories
• File access methods
  • Sequential, direct, indexed
• File system implementation
  • Allocation methods: contiguous, linked, indexed
  • Free space management

6. Input/Output Management

• I/O devices and their characteristics
• Device drivers
  • Functions and design
• I/O scheduling algorithms
• Buffering techniques
• Spooling and its advantages
• Error handling in I/O operations

7. Security and Protection

• Importance of security in OS
• Authentication methods
• Access control mechanisms
  • ACLs, capabilities
• Encryption basics
• Firewalls and antivirus software
• Security policies and best practices

8. Distributed Operating Systems

• Characteristics and goals
• Design principles
• Distributed file systems
• Distributed process management
• Distributed synchronization
• Challenges and solutions

9. Real-Time Operating Systems

• Definition and requirements
• Hard vs. soft real-time systems
• Scheduling algorithms
  • Rate monotonic, earliest deadline first
• Applications in aerospace, healthcare, telecommunications

10. Case Studies in Operating Systems

• Analysis of popular OS (e.g., Windows, Linux, macOS)
• Design decisions and rationale
• Performance and scalability considerations
• Security implementations
• Impact on computing industry