System View - The OS as a Resource Manager
- From the computer's point of view, the OS is the program most intimately involved with the hardware. In this context, we can view an OS as a resource allocator.
- Resource - ``Something valuable'' e.g. CPU time, memory space (RAM), file-storage space, I/O devices (disk), and so on.
- The OS acts as the manager of these resources. Includes multiplexing (sharing) resources in two different ways. Each program gets
- time with the resource
- space on the resource
- Multiple users/applications can share, why share:
- devices are expensive,
- there is need to share data as well as communicate
- Facing numerous and possibly conflicting requests for resources, the OS must decide
- how to allocate them to specific programs (processes, jobs)
- how to protect applications from one another,
- how to provide fair and efficient access to resources,
- how to operate and control the various I/O devices.