【2014-11-23】《The Hardware/Software Interface》– Section 8 (continue)

• Exceptions:
• An exception is transfer of control to the operating system in response to some event.
• exception processing by exception handler
• 

1. Process(进程)
• Process abstraction provides an interface between the program and the underlying CPU + Memory.
• Definition: A process is an instance of a running program
• Process provides each program with two key abstractions:
• Logical control flow
• Each process seems to have exclusive use of the CPU
• Private virtual address space
• Each process seems to have exclusive use of main memory
2. Context Switching
• Processes are managed by a shared chunk of OS code called the kernel
• Control flow passes from one process to another via a context switch
• 
3. Creating New Processes & Programs