cse 5343/7343windows case study1 cse 5343/7343 fall 2006 case studies windows history/processes ms...

CSE 5343/7343 Windows Case Study 1

CSE 5343/7343Fall 2006

Case Studies

Windows History/ProcessesMS DOS to Windows NT


Windows Case Study Outline• History

– MS-DOS– Windows 3.xx– Windows NT– Windows 2000– Windows XP

• Design Philosophy• Process Management


CAUTION:

There are so many variations of Windows. Each version is

different. Some are drastically different (even if the GUI is

similar.)


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.


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


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.


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


Windows History ([3],[4])

• Early Windows– Not true OS just a new GUI layer with “fixes”

to address memory constraints.


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


Windows Question

Who invented windows?

Who invented the mouse?

ANSWER: XEROX PARC


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


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


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


Windows NT Design([3],[5],[6])• New Technology

DEC (RSX & VMS & ELN) – NTVMS +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


Windows NT Design (cont’d)

• Preemptive multi-tasking

• Supports multiple processors

• Used on many architectures

• Backward compatibility

• Fully reentrant code

• Object oriented


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


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


Windows XP Design ([7])

• 32/64 bit

• Preemptive multitasking

• October 2001 released

• Client-server architecture for multiple processors


Win32 Subsystem ([6])

• Used in most Windows OSs

• Window manager

• Process/Thread

• CreateFile

• GetMessage


Windows Process

Management


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


Early Windows Processes([2])

• Cooperative multitasking:– Windows program voluntarily yields control at

certain times (Windows 4 and 6.2)


Windows NT Processes ([6])

• Executable program (code and data)

• Private virtual address space

• System resources (semaphores, ports, etc)

• Process ID

• Threads


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


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


Windows NT PCB ([6])

• Executive (EPROCESS) blocks

• ETHREAD blocks

• Process Environment Block (PEB)

• Thread Environment Block (TEB)


Windows NT Fibers ([6])

• NT 3.51

• Subsets of threads

• “Lightweight” threads

• User level threads

• Scheduled to run by programmers not OS


Windows NT Process States ([6])

• Ready

• Standby – Next to run

• Running

• Waiting

• Transition – Ready to run but kernel stack paged out

• Terminated


Windows NT Quantums ([6])

• Default:– 6 on Windows NT Workstation– 36 on Windows NT Server– Units are not time values, but relative

• At clock interrupt, 3 is deducted from quantum if it is 0 then another thread may run.


Windows NT Thread Scheduling ([6])

• Preemptive priority• Multilevel queues – RR within queue• Scheduling independent of process• Threads have processor affinity• If thread is preempted, it is put at the front of

the ready queue for that priority. When scheduled it receives the rest of its quantum.


Windows NT Priorities ([6])• 32 priority levels

– 16-31 real time

– 1-15 variable levels

– 0 system level

• Priority classes

– Real time, High, Normal, Idle

• Threads (Type with Class)

– Time critical, Highest, Above normal, Normal, Below normal, Lowest, Idle


Windows NT Priorities ([6])

• Default base priority level within class• Thread has base and current priority• Priorities raised (1-15 range never above)

– After wait state– Entering wait state– Threads not getting CPU time– Priority goes down after each quantum until

base is reached


IPC([3],[4],[7])

• Windows 95– Thunking:

• Allows 16bit modules to communicate with 32bit

• Routine that maps addresses


IPC (cont’d)

• Messages– Queue per thread

• Semaphores– Win16 mutex– Used to prevent to Win16 applications from

executing the same code– Ignored by Win32 applications– Limits multitasking


IPC (cont’d)

• Clipboard– Actually shared memory

• OLE (Object Linking and Embedding)– Windows 95

– Drag & Drop

– Enhancement to DDE

– Embed or link data from one application to another.

– Link – pointer to data

– Embed – actually move


IPC (cont’d)

• DDE (Dynamic Data Exchange)– Windows 3.1– Protocol that allows Windows applications to

share data.


IPC (cont’d)

• Deferred Procedure Call (DPC)– Windows NT/2000– System function will be (ultimately) executed– IRQL (Interrupt Queue Level)

• Asynchronous Procedure Call (APC)– Like DPC but for users– Nonblocking

• Both are viewed as software interrupts


References1. Harvey M. Deitel, Operating Systems Second Edition, Addison-

Wesley, 1990.2. Mark Minasi, etal., Inside MS-DOS 6.2 Second Edition, New Riders

Publishing, 1993.3. Jime Boyce, etal., Inside Windows 95, New Riders Publishing, 1995.4. Richard Wagner, Jim Boyce, Forrest Houlette, Randall Kennedy, and

Keven Stoltz, Ultimate Windows 3.1, New Riders publishing, 1993.5. John Savill, The Windows NT and Windows 2000 Answer Book A

Colmplete Resource from the Desktop to the Enterprise, Addison-Wesley, 1999.

6. David A. Solomon, Inside Windows NT Second Edition, Microsoft Press, 1998.

7. Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne, Windows XP Update Operating System Concepts Sixth Edition, 2003, John Wiley & Sons.

cse 5343/7343windows case study1 cse 5343/7343 fall 2006 case studies windows history/processes ms...

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