《操作系统教学资料》2013-CHAP1.pptVIP

OS Design Hierarchy(操作系统层次结构) Level Name Objects Example Operations 13 Shell User programming environment Statements in shell language 12 User processes User processes Quit, kill, suspend, resume 11 Directories Directories Create, destroy, attach, detach, search, list 10 Devices External devices, such as printer, displays keyboards Open, close, read, write 9 File system Files Create, destroy, open, close read, write 8 Communications Pipes Create, destroy, open, close, read, write 7 Virtual Memory Segments, pages Read, write, fetch 6 Local secondary store Blocks of data, device channels Read, write, allocate, free 5 Primitive processes Primitive process, semaphores, ready list Suspend, resume, wait, signal Introduction(绪论) OS Design Hierarchy(操作系统层次结构) Introduction(绪论) Level Name Objects Example Operations 4 Interrupts Interrupt-handling programs Invoke, mask, unmask, retry 3 Procedures Procedures, call stack, display Mark stack, call, return 2 Instruction Set Evaluation stack, micro-program interpreter, scalar and array data Load, store, add, subtract, branch 1 Electronic circuits Registers, gates, buses, etc. Clear, transfer, activate, complement OS Architectures: Microkernel(操作系统微内核结构) Introduction(绪论) 1.8 Characteristics of Modern OS(现代操作系统的特征) Microkernel architecture assigns only a few essential functions to the kernel a. address space b. interprocess communication (IPC) c. basic scheduling Introduction(绪论) 1.8 Characteristics of Modern OS(现代操作系统的特征) Multithreading process is divided into threads that can run simultaneously Thread： dispatchable unit of work； executes sequentially and is interruptable Process is a collection of one or more threads Introduction(绪论) Symmetric multiprocessing there are multiple processors these processors share same main memory and I/O facilities All processors can perform the same functions Distributed operating systems provides the illusion of a si