Chapter 3 Operating System Structures

Chapter 3 Operating System Structures

1. Operating System Service

   • User interface
   • Program execution
   • I/O operation
   • File-system manipulation
   • Communication
   • Error detection

2. Additional Operating System Function

   • Resource allocation
   • Accounting
   • Protection and security

3. System call

   • To be used by an application program to invoke a function provided by OS
   • Types
     • Process control
     • File management
     • Device management
     • Information maintenance
     • Communication
     • Protection

4. Communication Models

   • Message passing
     • Communication takes place by a means of message exchanged between the process
   • Shared memory
     • A region of memory that is shared by the processes is established
     • Processes may exchange information by reading and writing data into the shared memory region

5. Microkernel

   • Small operation system core
   • Contains only essential core operating system function
   • External subsystem
     • Device drivers
     • File systems
     • Virtual memory manager
     • Windowing system
     • Security services
   • Benefits
     • Extensibility
     • Flexibility
     • Reliability
     • Portability

6. Operating System Design Goals

   • System Goals
     • Operating system should be easy to design, implement, and maintain, as well as flexible, reliable, error-free and efficient
   • User Goals
     • Operating system should be convenient to use, easy to learn, reliable, safe and fast.