CS-502 Fall 2006Introduction1 CS-502 Operating Systems Hugh C. Lauer Adjunct Professor

CS-502 Fall 2006Introduction2 Why an Operating Systems course? WPI CS requirements – “core area” for grads Understanding of inner workings of “systems” Exposure to diversity of operating systems OS-related assignments you may see in real life:– “Design and develop an operating system to do THIS” (not probable) “Select an operating system for a product that will do THAT” (probable) “Design and develop this application on THAT system to exploit its special features” (likely)

CS-502 Fall 2006Introduction3 Textbook and Web Text Book: –(required) Operating Systems Concepts, 7 th edition, by Silberschatz, Galvin, and Gagne, John Wiley and Sons, 2005 –(very useful) Linux Kernel Design, 2 nd edition, by Robert Love, Novell Press, 2005 –(supplemental) Modern Operating Systems, 2 nd edition, by Andrew S. Tanenbaum, Prentice Hall, 2001 Course Information: –

CS-502 Fall 2006Introduction4 Prerequisites Prerequisites: –C/C++ programming –Data structures –Unix/Linux user experience and access –Computer Organization Reading assignment –Silbershatz Chapter 1 and §2.8

CS-502 Fall 2006Introduction5 Schedule & Logistics Schedule –Fuller Labs – Room 320 –6:00 PM to 8:50 PM –Approx two 5 minute breaks around 7PM, 8PM –14 classes –No break for Thanksgiving! –Term Project & Final Exam – Monday, December 11, Programming Projects –2-3 weeks each Mobile Phones, pagers and other similar devices OFF during class If you need to eat during class –Please be QUIET –Avoid spicy or savory aromas (pot stickers, curries, etc.) Office Hours –by appointment –will try to be in Adjunct Office, Fuller 239, by 4 PM on Monday afternoons Contact cs.wpi.edu –Adjunct office phone: (508) (shared)

CS-502 Fall 2006Introduction6 Grading –Exams & quizzes – 35% –Programming Projects (4-5) – 35% –Term Project – 15% –Class participation and written homework – 15% Unless otherwise noted, assignments are to be completed individually, not groups Late Policy – 10%/day –But contact Professor for extenuating circumstances WPI Academic Honesty policy

CS-502 Fall 2006Introduction7 Ground Rule There are no “stupid” questions. It is a waste of your time and the class’s time to proceed when you don’t understand the basic terms. If you don’t understand it, someone else probably doesn’t it, either.

CS-502 Fall 2006Introduction8 Programming Projects This term we embark on an experiment in CS-502 projects Each student will get a “virtual machine” What is a virtual machine? ( §2.8 in Silbershatz) Build, modify, install Linux kernel on your virtual machine Debug, analyze, crash Restore, try again

CS-502 Fall 2006Introduction9 Programming Projects (continued) Similar to Fossil Lab Shares VMware server resource in CS Dept However, Does not require physical presence on campus Does require you to install VMware client application on your home or office PC No Macintosh version of client is available

CS-502 Fall 2006Introduction10 Action items Sign up for CS Department logins – See instructions for setting up your virtual machine –See course web page for links to instructions. (Alternative) Acquire and install VMware Workstation at home or office –See course web page for links to instructions.

CS-502 Fall 2006Introduction11 Introductions Who are you? –Name, year, degree, major –Full time student? Work experience in computing, etc.? Employer? C & C++ experience –Other programming experience Previous degree and where Why CS502 – Operating Systems? Anything else relevant?

CS-502 Fall 2006Introduction12 Instructor — Hugh C. Lauer Adjunct Professor Ph. D. Carnegie-Mellon –Dissertation “Correctness in Operating Systems” Lecturer: University of Newcastle upon Tyne, UK Approximately 30 years in industry in USA Research topics –Operating Systems –Proofs of Correctness –Computer Architecture –Networks and Distributed Computing –Real-time networking –3D Volume Rendering –Surgical Simulation –…

CS-502 Fall 2006Introduction13 Systems Experience University of Newcastle Systems Development Corporation Xerox Corporation (Palo Alto) Software Arts, Inc. Apollo Computer Eastman Kodak Company Mitsubishi Electric Research Labs (MERL) Real-Time Visualization Founded and spun out from MERL Acquired by TeraRecon, Inc. SensAble Technologies, Inc.

CS-502 Fall 2006Introduction14 VolumePro™ Interactive volume rendering of 3D data such as MRI scans CT scans Seismic scans Two generations of ASICs, boards, software VolumePro 500 – 1999 VolumePro 1000 – 2001 CTO, Chief Architect of VolumePro million gate, high-performance ASIC 10 9 Phong-illuminated samples per second

CS-502 Fall 2006Introduction15 Sample images from VolumePro

CS-502 Fall 2006Introduction16 Operating Systems I have known IBSYS (IBM 7090) OS/360 (IBM 360) TSS/360 (360 mod 67) Michigan Terminal System (MTS) CP/CMS & VM 370 MULTICS (GE 645) Alto (Xerox PARC) Pilot (Xerox STAR) CP/M MACH Apollo DOMAIN Unix (System V & BSD) Apple Mac (v.1 – v.9) MS-DOS Windows NT, 2000, XP various embedded systems …

CS-502 Fall 2006Introduction17 Class Discussion What is an Operating System?

CS-502 Fall 2006Introduction18 What is an Operating System? Characteristics –Large, complex set of programs –Long-lived, evolutionary –Worked on by many people over many years Functions –Creates abstractions –Multiplexes concurrent activities –Manages resources Also –Mediates access to hardware devices –Provides a variety of services to users and applications

CS-502 Fall 2006Introduction19 What is an operating system? (cont’d) Abstractions:– –Implements processes & threads –Implements virtual memory & manages memory –Provides interprocess communication (IPC) –Implements file system. Manages persistent storage of information Controls I/O Implements networking & communications Definition — Same as judicial definition of pornography “I cannot define it, but I sure can recognize one when I see it!”

CS-502 Fall 2006Introduction20 What is an Operating System Hardware Interfaces – Registers, etc. OS Kernel Prog. ToolsServicesUI/Shell XYZ OfficeMedia PlayerBusiness Appl. CPUI/O Controllers Traditional OS Practical OS

CS-502 Fall 2006Introduction21 Major OS Issues structure: how is the OS organized? sharing: how are resources shared across users? naming: how are resources named (by users or programs)? security: how is the integrity of the OS and its resources ensured? protection: how is one user/program protected from another? performance: how do we make it all go fast? reliability: what happens if something goes wrong – hardware or software extensibility: can we add new features? communication: how do programs exchange information concurrency: how are parallel activities created and controlled? scale: what happens as demands or resources increase? persistence: how do you make data last longer than program executions? distribution: how do multiple computers interact with each other? accounting: how do we keep track of resource usage, and charge for it?

CS-502 Fall 2006Introduction22 Operating Systems Large, complex programs Typically –Long-lived –Frequently extended and updated –Worked on by a number of developers –Used and, maybe abused by a variety of users with varying expertise and expectations Essential to create an acceptable computing environment to create and execute other programs that achieve business or personal goals

CS-502 Fall 2006Introduction23 Kinds of operating systems Stand-alone machines – no OS Simple batch monitors Concurrent I/O and programs Time-sharing, multiple users, interactive Servers, non-stop systems, transaction processing PC’s, workstations Multiple processor systems Real-time systems Embedded systems

CS-502 Fall 2006Introduction24 Kinds of operating systems (1) Stand-alone machines – no OS Manually scheduled “jobs,” reset between jobs Early business computers –E.g., IBM 1401/1460 Early mini-computers –E.g., PDP1, PDP5, PDP8, etc. Simple batch monitors Simple “monitor routine” switches between jobs Input loaded onto tape off-line Output to tape is punched and/or printed off-line Typical university computing centers –IBM 7090, Univac, etc.

CS-502 Fall 2006Introduction25 Kinds of operating systems (2) Concurrent I/O and programs SPOOL-ing (Simultaneous Peripheral Operation On Line) –Allows direct input & output Multiple programs resident in memory at once –Keeps processor busy On-line file storage Some support for terminals, telecommunications Early business computers –E.g., IBM 7070, IBM 360 & 370 Scientific computing –E.g., Control Data 6600, IBM 360/91

CS-502 Fall 2006Introduction26 Kinds of operating systems (3) Time-sharing, multiple users, interactive Many concurrent users “logged on” Interactive editing and computing Self submission of batch jobs Protection among users, protection among jobs Fair allocation of resources All university computing centers since about 1970 –E.g., MULTICS, IBM 360/67, DEC PDP-10, PDP-20 Advanced minicomputers –DEC, Data General, Prime, etc. –Unix

CS-502 Fall 2006Introduction27 Kinds of operating systems (4) Servers, non-stop systems, transaction processing Banking, airline reservation Online databases Many very short “transactions” Tandem, Stratus, Sequoia Unix, Linux, Solaris, HP-UX Windows Server 2000, 2003 Oracle, SAP (?)

CS-502 Fall 2006Introduction28 Kinds of operating systems (5) PC’s, workstations CP/M, DOS, MS-DOS Apollo Domain Unix, Solaris, HP-UX Mac OS Windows 95, 98, Me Windows 2000, XP Linux Multiple processor systems Beowulf clusters Unix, Solaris, HP-UX, Linux

CS-502 Fall 2006Introduction29 Kinds of operating systems (6) Real-time systems SAGE (North American air defense) Process control (steel mills, refineries, etc.) Large and small; computers you never heard of VxWorks, etc. Embedded systems Auto ignition Cell phone, PDA Appliances …

CS-502 Fall 2006Introduction30 OS History – Unix & Linux Unix –Descendant of Multics –First “C” version in 1973 (DEC PDP-11) Timesharing for < 10 users on 32K Memory Many Unix versions at BTL – different goals Source code made available to Universities – BSD –Posix (start 1981) defines standard Unix system calls –AT&T licensing!

CS-502 Fall 2006Introduction31 OS History - Linux Open Source – Linux.org First Version 1991, Linus Torvalds, processor –v.01, limited devices, no networking, –with proper Unix process support! 1994, v1.0 –networking (Internet) –enhanced file system –many devices, dynamic kernel modules

CS-502 Fall 2006Introduction32 OS History - Linux 1996, v2.0 –multiple architectures, multiple processors –threads, memory management …. Gnome UI – introduced in 1999 Recent –V million lines of code –7-10 million users –Growth by 25%/year through 2003 –Growing use in business server market Note - Development convention –Odd numbered minor versions “development” –Even numbered minor versions “stable”

CS-502 Fall 2006Introduction33 OS History – Windows NT/2000/XP Key designer – David Cutler also designed VAX/VMS 1988, v1 - Win32 API – “microkernel” 1990, v3.1- Server and Workstation versions 1996, v4 –Win95 interface –Graphics to kernel –More NT licenses sold than all Unix combined –Microkernel de-emphasized

CS-502 Fall 2006Introduction34 OS History – Windows NT/2000/XP Windows 2000 – NT5.0 –Multi-user (with terminal services) –Professional - desktop –Server and Advanced Server - Client-server application servers –Datacenter Server - Up to 32 processors, 64 GB RAM Windows XP –Windows 2000 code base –Revised UI –EOL for DOS/Windows line

CS-502 Fall 2006Introduction35 OS History – Windows NT/2000/XP Microsoft has 80% to 90% of OS market Wintel – Windows + X86 WinNT 4.x is 12 million lines of code Win2000 is 18 million lines of code

CS-502 Fall 2006Introduction36 OS and Hardware OS mediates programs’ access to hardware –Computation – CPU –Storage – volatile (memory) and persistent (disk) –Networks – NIC, protocols –I/O devices – sound cards, keyboards, displays OS creates uniform abstractions –Processes –Files –Sockets –Streams

CS-502 Fall 2006Introduction37 Break (next topic)