An Overview Of Windows NT System

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An Overview Of Windows NT System

• Student Yifan Yang
• Student ID 102525

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1. Windows NT Models agt. Client / server
model bgt. Object model cgt. Symmetric
multiprocessing 2. Windows NT Structure
agt. Protected subsystems bgt. Executive
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3. A Brief Tour agt. Logon session bgt.
Environment subsystems cgt. Native services
dgt. Objects egt. Virtual memory fgt.
I/O and file systems

• 4. Additional Windows NT Architectures
• agt. Internationalization
• bgt. Structured exception handling

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• 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.
• agt. 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.

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

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• cgt. 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
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• 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.

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

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agt. 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
Local
Virtual
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
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bgt. Executive
Executive components and their responsibilities
Object
Security
Process
Local
Virtual
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
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3. A Brief Tour
agt. Logon session
Logon Process
Security Subsystem
Win32 Subsystem
User Mode
Local Procedure Call (LPC)
Logging On
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bgt. 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
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cgt. 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
Local
Virtual
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
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dgt. 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
Process
Virtual
Cache Manager
Local
Object
Reference
Procedure
Memory
Manager
Manager
Device Drivers
Monitor
Call Facility
Manager
Network Drivers
Kernel
Hardware Abstraction Layer
Creating NT Objects
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egt. 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
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fgt. 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
Local
Virtual
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
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• 4. Additional / Windows NT Architectures
• agt. 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 NTs 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.

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Punctuation
Math/technical symbols
Dingbats (graphical symbols)
Arabic and
Hebrew scripts
Unified
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
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• bgt.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.

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Thank you!