CS341 Lecture 12: CS 341 full notes

• School: University of Waterloo
• Department: Computer Science
• Course: CS341
• Professor: David R.Cheriton

Document Summary

What is an operating system: three views of an operating system. An operating system is part cop, part facilitator. Application view of an operating system: the os provides an execution environment for running programs. The execution environment provides a program with the processor time and memory space that it needs to run. The execution environment provides interfaces through which a program can use networks, storage, i/o devices, and other system hardware components. Interfaces provide a simpli ed, abstract view of hardware to application programs. The execution environment isolates running programs from one another and prevents undesirable interactions among them. It controls the sharing of resources among programs: the os itself also uses resources, which it must share with application programs. Implementation view: the os is a concurrent, real-time program: concurrency arises naturally in an os when it supports concurrent applications, and because it must interact directly with the hardware, hardware interactions also impose timing constraints.