An Overview Of Windows NT System

1. An Overview Of Windows NT System Student: Yifan Yang Student ID: 102525

2. #1. WindowsNTModels a>. Client / server model b>. Object model c>. Symmetric multiprocessing #2. WindowsNTStructure a>. Protected subsystems b>. Executive

3. #3. A Brief Tour a>. Logon session b>. Environment subsystems c>. Native services d>. Objects e>. Virtual memory f>. I/O and file systems #4. AdditionalWindows NT Architectures a>. Internationalization b>. Structured exception handling

4. #1. Windows NT Models • What is an OS Model? It is a broad framework that unifies the many features and services the system provides and the tasks it performs. • a>.Client / Server model • Windows NT system: Combination of Layered model and client / server model. • Layered model is one which divides the O/S into modules and layers them one on top of the other. Each module provides a set of functions that other modules can call. • Benefits for using client / server model • Simplifies the base OS, the executive. • Improves reliability. • Lends itself well to a distributed computing model.

5. ... Application Program Application Program User Mode Kernel Mode System Services File System Memory and I/O Device Management Processor Scheduling Hardware Layered Operating System

6. a>. Client /Server model • Is one which devices OS into several processes, each of which implements a single set of services. Client Application Network Server Memory Server Display Server Process Server File Server Reply Send Microkernel Hardware Client /Server Operating System

7. b>. Object model • Object model Is one that any system resources such as files, shared memory and physical devices is implemented as an object and manipulated by using object services so that resources can be shared by more than one process. • Benefits for using object model • OS can access and manipulate its resources uniformly. • Security is simplified because all objects are protected in the same way. • Objects provide a convenient and uniform paradigm for sharing resources between two or more processes.

8. c>. Symmetric multiprocessing • Symmetric multiprocessing is to allow OS running on any free processor or on all processors simultaneously, sharing memory among them. Memory Processor A Processor B Operating System User Thread User Thread User Thread User Thread Operating System I/O Devices Monitor Mouse Keyboard Symmetric Multiprocessing

9. Benefits for being multiprocessing system • Ability to run OS code on any available processor and on multiple processors at one time. • Multiple threads of execution within a single process. • Server processes that use multiple threads to process requests from more than one client simultaneously. • Convenient mechanisms for sharing objects between processes and flexible interposes communication capabilities, including shared memory and an optimized message-passing facility.

10. #2. Windows NT Structure • The Windows NT’s structure can roughly be divided into two parts: the user-mode portion (protected subsystems) and kernel-mode portion (NT executive).

11. a>. Protected subsystems (environment and integral) OS/2 Client POSIX Client Win32 Client Logon Process Applications OS/2 Subsystem POSIX Subsystem Protected Subsystems Security subsystem Win32 Subsystem (Servers) User Mode Kernel Mode System Services I/O Manager Object Security Process Virtual Local Memory Manager Reference Manager Procedure File Systems Manager Monitor NT Executive Call Facility Cache Manager Device Drivers Network Drivers Kernel Hardware Abstraction Layer (HAL) System Trap Message Passing Hardware Hardware Manipulation

12. b>. Executive Executive components and their responsibilities: Object Security Process Virtual Local I/O Manager Memory Manager Reference Manager Procedure File Systems Manager Monitor Call Facility Cache Manager Device Drivers Network Drivers Kernel Hardware Abstraction Layer System Services Internal Interfaces System Interfaces

13. #3. A Brief Tour a>.Logon session Logon Process Security Subsystem Win32 Subsystem User Mode Local Procedure Call (LPC) Logging On

14. b>.Environment subsystems Each of the environment subsystems supplies an API that its client applications use. Win32 Client Win32 Client POSIX Client OS/2 Client Virtual DOS Machines (VDMs) ………………………………….. 16-Bit Windows Environment OS/2 Subsystem POSIX Subsystem ……………... MS-DOS Client Graphical I/O Character I/O Win32 Subsystem …………………. Character I/O Character I/O User Mode Kernel Mode Local Procedure Call (LPC) Environment Subsystems and Client Applications

15. c>. Native services They are system services provided by individual components of the NT executive. Win32 Subsystem POSIX Subsystem OS/2 Subsystem User Mode Kernel Mode System Services Object Security Process Virtual Local I/O Manager Memory Manager Reference Manager Procedure File Systems Manager Monitor Call Facility Cache Manager Device Drivers Network Drivers Kernel Hardware Abstraction Layer System Trap Native System Service Call

16. d>. Objects Many NT native services are object services. Win32 Subsystem Create process Create file User Mode Kernel Mode System Services Create object I/O Manager Create object File Systems Security Cache Manager Process Virtual Local Object Reference Procedure Memory Manager Manager Device Drivers Manager Monitor Call Facility Network Drivers Kernel Hardware Abstraction Layer Creating NT Objects

17. e>.Virtual memory The NT memory architecture is virtual memory based on 32-bit addresses in a flat/linear address space. FFFFFFFFh Nonpaged System Paged (2 GB) ………………………. Physical Addressing Range Resident Operating 80000000h System Code 7FFFFFFFh User Code Paged And Data (2 GB) 00000000h NT Address Space Layout

18. f>. I/O and file systems Synchronous as well as asynchronous I/O. Windows NT supports FAT, HPFS and NTFS. User Mode Kernel Mode System Services Object Security Process Virtual Local Memory Manager Reference Manager Procedure Manager Monitor Call Facility I/O Manager Kernel FAT File System Driver NTFS Driver HPFS Driver ... Floppy Disk Driver Hard Disk Driver Layered Drivers

19. #4. Additional / Windows NT Architectures • a>. Internationalization • A Locale consists of a language, a country, a code set, the binary codes used to represent the characters of a particular language. • To facilitate localization, Windows NT’s Win32 subsystem provides a national language support (NLS) API. • Unicode, a 16-bit character-coding scheme, can represent 65,536 characters so that it is enough to include all languages in computer commerce today.

20. Punctuation Math/technical symbols Dingbats (graphical symbols) Arabic and Unified Hebrew scripts Private Chinese/Japanese/Korean Application use ideographs ASCII 0000h FFFFh Indic scripts Compatibility Others zone Chinese/Japanese/ Latin, Korean symbols Greek, (Bopomofo, Cyrillic, and Hiragana, Katakana, Armenian scripts Hangul,…) Future use Provides compatibility with standard, non-Unicode character sets Unicode Layout

21. b>.Structured exception handling • Structured exception handling is the met hod used in windows NT for processing both hardware and software exceptions, using the control structure of a programming language.

22. Thank you!