1. Pertemuan 26 Proses dan Threads pada Sistem Operasi Windows
Matakuliah : T0316/sistem Operasi
Tahun : 2005
Versi/Revisi : 5
Pertemuan 26 Proses dan Threads pada Sistem Operasi Windows

2. Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
membandingkan sistem operasi Linux dan Windows 2000 (C4)

3. Outline Materi Proses dan threads pada windows 2000
Komunikasi inter proses
Penjadwalan
Proses booting pada windows 2000
Pengaturan memory
Pengaturan I/O
Device driver
Sistem file pada windows 2000
Securiti pada windows 2000

4. Processes and Threads (1)
Basic concepts used for CPU and resource management

5. Share quota dan resource limit
Job
Sekumpulan proses
Share quota dan resource limit
Jumlah proses
CPU time
dll

6. Container for resources
Process
Container for resources
Created via Win32 call
CreateProcess (Win32 API function di dalam library kernel32.dll)
NTCreateprocess (system call)
Minimal satu thread
Serangkaian handles
Access token  for security information
4 GB adress space

7. Thread Entity scheduled by kernel Created via Win32 call
Created using CreateThread (Win32 API function di dalam library kernel32.dll)
NTCreateThread (system call)
State: ready, running, block
Normal vs daemod threads (in user and kernel space, respectively)
Thread switching
(between user and kernel mode)
Dapat memiliki beberapa fibers

8. Fiber
Lightweight thread
Lightweight pseudo-parallelism
Scheduled in user space  faster
Tidak termasuk executive object
Melalui Win32 API tanpa system call

9. Komunikasi antar process
Threads komunikasi lewat
Pipes
Named pipes (dengan network)
Mailslot
only on Windows 2000
One-way, un-guaranteed delivery, allow broadcast
Socket  connect processes on different machine
Similar to pipe
Remote procedure calls
Shared files

10. Synchronization mechanism
Komunikasi (2)
Synchronization mechanism
Semaphore
Mutexes
Critical sections
Events
Set or cleared
Eg. Set  waiting threads are released

11. Scheduler diaktifkan ketika
Penjadwalan
Scheduler diaktifkan ketika
Threads terhalang (blocked) misal oleh semaphore
Thread memberi signal (misal up on semaphore) pada suatu object
Quantum habis
Operasi IO selesai
Batas waktu menunggu habis

12. Run as many MSDOS programs as prossible NT vitual DOS machine  ntvdm
Emulasi MS-DOS
Run as many MSDOS programs as prossible
NT vitual DOS machine  ntvdm
Monitor MSDOS program and carry out its system calls
Trampoline
Emulation to bounce back MSDOS IO request

13. How old MS-DOS programs are run under Windows 2000
MS-DOS Emulation
How old MS-DOS programs are run under Windows 2000

14. Booting Windows 2000 Processes starting up during boot phase
Those above the line are always started
Those below are examples of services which could be started

15. Process Booting
Baca master boot record  sektor pertama dari disk pertama
Assembly language program
Baca partition table
Cari boot sector  sektor pertama dalam partisi yang berisi bootable OS
Baca root directory
Cari dan execute file ntldr (nt loader)
Baca file boot.ini
Baca files hal.dll, ntoskrnl.exe, bootvid.dll (video driver)

16. Process Booting (2)
First user process  session manager (smss.exe)
Aktifkan win32 environment subsytem (crss.exe)
Baca registry  hives
Login daemon  winlogon.exe
Authentication manager  lsass.exe
Services.exe  parent process of all services

17. Pengaturan Memory Memory Virtual
Proses  32 bit virtual address (4GB virtual address space)
Upper 2GB  untuk OS, shareable
4KB page size (Pentium), atau 8/16KB (Itanium)
Demand paged
States dari virtual page
Free, reserved, committed

18. Pengaturan Memory (2) Memory manager Balance Set Manager
Berkaitan dengan proses, bukan thread (scheduler)
Virtual Address Descriptor (VAD)
Contains list of range of address mapped, backing store file and offset, protection code
Balance Set Manager
Kernel daemon thread
Kontrol ketersediaan free pages

19. Pengaturan Memory (3) Working set manager Win32 API
Thread yang mengatur working set bagi proses
Berdasarkan parameter min dan max size of working set
Local allocation strategy
Win32 API
To allocate, free, protect and query Virtual Address Space (VAS)
Pengaturan memory-mapped files

20. Pengaturan Physical Memory
Page lists
Standby page list
Modified (dirty) page list
Free list
Zeroed page list
Page frame databases
Banyaknya entries  banyaknya pages dalam RAM
Index menurut physical page frame #

21. Pengaturan Input/Output
Plug and Play Manager
Enumerable bus  allows request to the slot for self identification of devices
Mengalokasikan H/W resource (eg interrupt level)
Memilih driver yang sesuai
Load ke memory & create driver object
Win32 API
Utama pada window management
Management of text  colour, size, width, typeface
clipboard

22. Pengaturan IO (2) Device Drivers Windows driver model
IO request dengan format standar
Object based
Support plug-and-play
Support power management
Configurable
Reentrant
Portable
Stacked drivers  request must pass a sequence of drivers
Filter drivers  perform transformation on the data

23. Support FAT-16, FAT-32, dan NTFS NTFS
File System
Support FAT-16, FAT-32, dan NTFS
NTFS
64 bit disk address
Long file name (255 chars)
Volume (partition) terdiri dari
Files, directories, bitmaps, and data structures
Block (cluster) size  512 bytes hingga 64 KB  compromised 4 KB
Master File Table (MFT)
Each describe one file/directoriy

24. File System (2) Win32 API NTFS File name Lookup
File  create, delete, open, close, read, write, etc
Mutual exclusion  lock file, unlock file
Directory  create, remove, find first file, etc
NTFS File name Lookup
Dimulai dari root object manager name space
Directory \??
Contains the disk letter (eg. A, C, D …)
??  read first in ASCII
Support hard link
Support symbolic links (reparse point)

25. File System (3) NTFS File Compression NTFS File Encryption
Transparent file compression
Compressed mode  compress blocks as written and uncompress as read
Run compression algorithm
NTFS File Encryption
Option to encrypt files
Done by EFS (Encrypting File Standard) driver
A variant of DES (Data Encryption Standard)
Generates a random 128 bit file key

26. File System Structure (1)
The NTFS master file table

27. File System Structure (2)
The attributes used in MFT records

28. File System Structure (3)
An MFT record for a three-run, nine-block file

29. Steps in looking up the file C:\maria\web.htm
File Name Lookup
Steps in looking up the file C:\maria\web.htm

30. File Compression
(a) An example of a 48-block file being compressed to 32 blocks
(b) The MFT record for the file after compression

31. Security Mewarisi security dari Win NT
Identifikasi user dan group dengan Security ID (SID)
Access token  for each process
DACL (Discretionary Access Control List)
contains who may use the object
ACE (Access Control Elements)
Access or deny
Security Descriptor
Header + DACL + one or more ACEs
Win32 API
Berbasis security descriptor
Menggunakan security dan SAM (Security Account Manager) keys di dalam registry

32. Caching
Cache manager
Untuk keperluan kinerja sistem
Menyimpan blok-blok file yang baru digunakan untuk kegunaan berikutnya
Berdasarkan virtual block (bukan physical block)
Diacu (referenced) dengan (file, offset)
Sebesar 256 KB VAS dipetakan (mapped) ke file

33. The path through the cache to the hardware
Caching in Windows 2000
The path through the cache to the hardware