CSE 5343 7343 Fall 2006 Case Studies Windows History Processes MS DOS to Windows NT CSE 5343 7343 Windows Case Study 1 Windows Case Study Outline History MS DOS Windows 3 xx Windows NT Windows 2000 Windows XP Design Philosophy Process Management CSE 5343 7343 Windows Case Study 2 CAUTION There are so many variations of Windows Each version is different Some are drastically different even if the GUI is similar CSE 5343 7343 Windows Case Study 3 MS DOS History 1 pp 633 639 1975 First real PC Altair developed by Micro Instrumentation Telemetry Systems based on Intel 8080 8 bit microprocessor with 256 bytes of memory Bill Gates and Paul Allen of Microsoft develop a version of Basic for Altair CP M was dominant OS IBM asked Microsoft to develop a ROM BASIC IBM chose Intel 8088 Gates suggested IBM use CP M 86 IBM met with Digital Research and CP M 86 was running late Microsoft decided to write its own OS Microsoft purchased 86 DOS from Seattle Computer Products CSE 5343 7343 Windows Case Study 4 MS DOS History cont d 1981 MS DOS prototype running in February and appeared in IBM PC announcement MS DOS 1 0 in August 4000 lines of assembly code 12K memory CP M compatible Device independent I O treated as files in Unix Command processor had a resident and transient part CSE 5343 7343 Windows Case Study 5 MS DOS History cont d MS DOS 2 0 March 1983 20 000 lines of code IBM PC XT with 10M hard disk Hierarchical file system as in Unix Device drivers Users wanted multi tasking but instead Microsoft added the ability for a print spooler to run concurrently with other tasks in background mode as time permits When MS DOS has nothing to do an interrupt is generated to run the print spooler CSE 5343 7343 Windows Case Study 6 MS DOS History cont d MS DOS 3 0 August 1984 40 000 lines of code PBM PC AT with 20M hard and 1 2 floppy Intel 80286 16M address space 24 bit addresses Ring protection mechanism Cooperative multitasking Virtual memory Real address mode 1 MB address space acts as fast 8086 Protected mode All 16 MB CSE 5343 7343 Windows Case Study 7 Windows History 3 4 Early Windows Not true OS just a new GUI layer with fixes to address memory constraints CSE 5343 7343 Windows Case Study 8 Windows History cont d Problems with DOS Windows 3 1 16 bits Can t access all of memory 1M barrier for memory Cooperative multitasking Nonreentrant Lost system resources Win16 applications overwriting memory of another CSE 5343 7343 Windows Case Study 9 Windows Question Who invented windows Who invented the mouse ANSWER XEROX PARC CSE 5343 7343 Windows Case Study 10 Windows 95 Design 3 Design Goals Less than 4MB Backward compatible Support Win16 and DOS Increased stability Fault handler is not part of application Three major portions User I O manager Windows manager GDI GD manager Kernel Memory Files Task managers CSE 5343 7343 Windows Case Study 11 Windows 95 Design cont d Registry Central information including startup and init Supports plug and play Virtual Machine used to run Win16 applications User mode kernel mode Long file names CSE 5343 7343 Windows Case Study 12 OS 2 Design 5 Microsoft IBM designed to replace DOS on Intel machines Early 1990s Microsoft released Windows 3 0 which took over the market IBM viewed Windows as stepping stone to OS 2 Microsoft wanted to have Windows compete with OS 2 IBM Microsoft split CSE 5343 7343 Windows Case Study 13 Windows NT Design 3 5 6 New Technology DEC RSX VMS ELN NT VMS 1 WNT HAL 1 IBM All major designs of David Cutler 1993 versions 3 1 3 5 3 51 4 0 Mostly C C 3 1 had same GUI as Windows 32 bit OS CSE 5343 7343 Windows Case Study 14 Windows NT Design cont d Preemptive multi tasking Supports multiple processors Used on many architectures Backward compatibility Fully reentrant code Object oriented CSE 5343 7343 Windows Case Study 15 Windows NT Design cont d NTFS NT File System Permissions for file directory and all objects Security Domain Set of machines with similar uses and authorizations Registry contains information about OS and application configurations Hardware Installed software Applications and file types Current user Actively loaded user profiles CSE 5343 7343 Windows Case Study 16 Windows 2000 Design 5 7 AKA Windows NT 5 0 Distributed File System Multiple monitors Objects Event Mutant Mutex Semaphore Thread Timer Interrupt Asynchronous Procedure Call APC Process Subsystems provide backward compatibility Like virtual machines CSE 5343 7343 Windows Case Study 17 Windows XP Design 7 32 64 bit Preemptive multitasking October 2001 released Client server architecture for multiple processors CSE 5343 7343 Windows Case Study 18 Win32 Subsystem 6 Used in most Windows OSs Window manager Process Thread CreateFile GetMessage CSE 5343 7343 Windows Case Study 19 Windows Process Management CSE 5343 7343 Windows Case Study 20 MS DOS Processes 2 Single tasking since functions are nonreentrant Only real multitasking is background for printing Can change time slice for this EXEC function used by COMMAND COM Allocate memory Write program segment prefix Load program into memory Transfer control to program Child may in turn use EXEC CSE 5343 7343 Windows Case Study 21 Early Windows Processes 2 Cooperative multitasking Windows program voluntarily yields control at certain times Windows 4 and 6 2 CSE 5343 7343 Windows Case Study 22 Windows NT Processes 6 Executable program code and data Private virtual address space System resources semaphores ports etc Process ID Threads CSE 5343 7343 Windows Case Study 23 Windows NT Threads 6 Registers Stacks kernel user Private storage used by subsystems Thread ID client ID Mode transition switch from user mode to kernel mode does not require a context switch Test Windows Task Manager Performance Control Panel Administrative Tools Performance CSE 5343 7343 Windows Case Study 24 Windows NT Handles 6 Provides ability to access an object at a certain level of priviledge Handle Table entry in EPROCESS block Standardized interface to objects CSE 5343 7343 Windows Case Study 25 Windows NT PCB 6 Executive EPROCESS blocks ETHREAD blocks Process Environment Block PEB Thread Environment Block TEB CSE 5343 7343 Windows Case Study 26 Windows NT Fibers 6 NT 3 51 Subsets of threads Lightweight threads User level threads Scheduled to run by programmers not OS CSE 5343 7343 Windows Case Study 27 Windows NT Process States 6 Ready Standby Next to run Running Waiting Transition Ready to run but kernel stack paged out Terminated CSE 5343 7343 Windows Case