A computer system consists of hardware, system programs, and application programs figs 11

2.1 PROCESSES 2.2 THREADS 2.3 INTERPROCESS COMMUNICATION 2.4 CLASSICAL IPC PROBLEMS 2.5 SCHEDULING 2.6 RESEARCH ON PROCESSES AND THREADS 2.7 SUMMARY

11CASE STUDY 2: WINDOWS 2000

Win32 application program

Win32 Application Programming Interface

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HKEY3LOCAL3MACHINE Properties of the hardware and software

HARDWARE Hardware description and mapping of hardware to driversSAM Security and account information for users

SECURITY System-wide security policies

SOFTWARE Generic information about installed application programsSYSTEM Information for booting the system

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HKEY3USERS Information about the users; one subkey per user

USER-AST-ID User AST’s profile

AppEvents Which sound to make when (incoming email/fax, error, etc.)Console Command prompt settings (colors, fonts, history, etc.)

Control Panel Desktop appearance, screensaver, mouse sensitivity, etc.Environment Environment variables

Keyboard Layout Which keyboard: 102-key US, AZERTY, Dvorak, etc

Printers Information about installed printers

Software User preferences for Microsoft and third party software

POSIX program POSIX subsystem

Win32 program Win32 subsystem

OS/2 program OS/2 subsystem

Kernel File sys

I/O mgr

Object

mgr

Process mgr

Memory mgr

Security mgr

Cache mgr

PnP mgr

Power mgr

Config mgr

LPC mgr

Win32 GDI Video driver

registers

Device addresses Interrupts DMA Timers

Spin locks BIOS

Disk RAM

Hardware abstraction layer

Fig 11-8 Some of the hardware functions the HAL manages.

Reference countsPointer to the type object

Type nameAccess typesAccess rightsQuota chargesSynchronizable?PageableOpen methodClose methodDelete methodQuery name methodParse methodSecurity method

Fig 11-9 The structure of an object.

Thread 1

Mutex 1

Mutex 2

Mutex 3

Thread 2

Thread 3

Thread 4

Thread type object

Mutex type object

Handle

table for

process A

Handle table for process B

1010

1011

1110 1111 0101

Fig 11-11 The relationship between handle tables, objects, and type objects.

Gdi32.dll User32.dll Kernel32.dll

Call Call Call

Operating system

User process

Enviroment

subsystem

process (csrss.exe)

Win32 subsys

Kernel mode thread stackAccess token

priori-Next thread to run Priority

Idle thread

Fig 11-19 Windows 2000 supports 32 priorities for threads.

48

12Does a down on the

semaphore and blocks

MS–DOS program 1

2 3

4 Trampoline

Operating system Ntvdm

Fig 11-21 How old MS-DOS programs are run under Windows 2000.

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idle Not really a process, but home to the idle thread

system Creates smss.exe & paging files; reads registry; opens DLLssmss.exe First real proc; much initialization; creates csrss & winlogoncsrss.exe Win32 subsystem process

winlogon.exe Login daemon

lsass.exe Authentication manager

services.exe Looks in registry and starts services

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Printer server Allows remote jobs to use the printer

File server Serves requests for local files

Telnet daemon Allows remote logins

Incoming email handler Accepts and stores inbound email

Incoming fax handler Accepts and prints inbound faxes

DNS resolver Internet domain name system server

Event logger Logs various system events

Plug-and-play manager Monitors hardware to see what is out there

Fig 11-22 The processes starting up during the boot phase The

ones above the line are always started The ones below it are

examples of services that could be started.

A's page tables

Stacks, data, etc

Process B'sprivate codeand data

Process C

Nonpaged poolPaged poolC's page tablesStacks, data, etcHAL + OSSystem data

Process C'sprivate codeand data

Bottom and top

64 KB are invalid

Fig 11-23 Virtual address space layout for three user processes The white areas are private per process The shaded areas are shared among all processes.

Shared

library

Data

StackStack

Data

Region

Fig 11-24 Mapped regions with their shadow pages on disk The

lib.dll file is mapped into two address spaces at the same time.

vir-20 3

G

1L

1D

1A

1

CWt

1U

11W

1V

1Page frame

Notused

Fig 11-26 A page table entry for a mapped page on the Pentium.

Mod-Standby page list

Free page list

Zeroed page list

Bad RAM page list Top

Bottom

Modified page writer(4)

Dealloc(5) Zero

page thread (7)

Page evicted from a working set (1) Process exist (3)

Fig 11-27 The various page lists and the transitions between them.

XX

State Cnt WS Other PT Next

CleanDirtyCleanActiveCleanDirtyActiveDirtyFreeFreeZeroedActiveActiveZeroed

1312

10

7654

User process

User program

Win32

Rest of windows

Hardware abstraction layer

Controller Controller Controller

Driver stack

Fig 11-30 Windows 2000 allows drivers to be stacked.

/ * Open files for input and output * /

do {

if (s && count > 0) WriteFile(outhandle, buffer, count, &ocnt, NULL);

} while (s > 0 && count > 0);

CloseHandle(inhandle);

CloseHandle(outhandle);

Fig 11-32 A program fragment for copying a file using the

Win-dows 2000 API functions.

Fig 11-33 The principal Win32 API functions for directory

management The second column gives the nearest UNIX

equivalent, when one exists.

$Extend Extentions: quotas,etc

$Upcase Case conversion table

$Secure Security descriptors for all files

$BadClus List of bad blocks

$Bitmap Bitmap of blocks used

$AttrDef Attribute definitions

$Volume Volume file

$LogFile Log file to recovery

$MftMirr Mirror copy of MFT

Fig 11-34 The NTFS master file table.

Data header

Info about data blocks Run #1 Run #2 Run #3

Standard info File name 0 9 20 4 64 2 80 3 Unused

Disk blocks Blocks numbers 20-23 64-65 80-82

Second extension record

First extension record

Base record101

104

107

Fig 11-37 A file that requires three MFT records to store all its runs.

Fig 11-38 The MFT record for a small directory.

D:

Harddisk Volume 1

\Devices

2 Follow symbolic link

to get disk portion

\?? Directory

1 Look up C: in \??

Root directory maria web.htm MFT for HD volume 1

3 Look up path name

4 Create new file object

5 Return handle

to calling process Handle

Fig 11-39 Steps in looking up the file C:\maria\web.htm.

7 0

Original uncompressed file

Compressed Uncompressed

Fig 11-40 (a) An example of a 48-block file being compressed to

32 blocks (b) The MFT record for the file after compression.

K retrieved

by applyinguser's privatekey to storedkey on diskDisk

ModifiedDES

C = Encrypted file

K encrypted withuser's public key

DecryptionEncryption

DESC

Fig 11-41 Operating of the encrypting file system.

UserSID

GroupSID

RestrictedSIDs

Security descriptor Header Owner's SID Group SID DACL SACL

Header Audit Marilyn 111111

Security descriptor Header

Allow Everyone

Deny Elvis 111111 Allow Cathy 110000 Allow Ida

ACE

ACE

File

100000 111111

Fig 11-43 An example security descriptor for a file.

Kernel32.dllntdll.dll

Cache mangerI/O managerNTFS FAT–32SCSI IDE

Disk Disk

User process reads from a file

Call is handled in shared libraryActual system call is made

Call is caught by cache manager

If block is absent, page faultCall to file system to get blockCall to disk driver to read block

Fig 11-45 The path through the cache to the hardware.