CSCI2467: Systems Programming Concepts

Transcription

1 CSCI2467: Systems Programming Concepts Slide set 0: Introduction to the course Instructor: Matthew A. Toups, ms Fall 2018

2 Today s Overview 1 Welcome What s new? Topics The labs Why systems? 2 Syllabus Administrivia Important Resources Student Responsibilities Student Evaluation Academic Integrity Student Support Culture 3 Lab 0 Welcome Prerequisites review Remote access with ssh The terminal Text editors Syllabus Lab 0

3 Welcome to CSCI 2467! In summer 2016 we revamped our Systems Programming Course (CSCI 2467) Goal: Better preparation for Operating Systems (CSCI 4401) Also: prepares you for many other courses and provides valuable experience Hands on! The course is centered on real lab assignments

4 Feedback from previous semesters this was the first time that I could honestly say I learned this much in a semester and actually had fun doing it This was tough but totally worth it This course challenged me to think and was difficult at times, but it made me learn a lot more than some easier courses have done. the labs were a great application of the course material. There s no reason a class about something boring like systems programming should be this fun In Fall 2017 evaluations, the word fun occurs 5 times, challenge occurs 4 times.

5 Our objective This course is an introduction to systems programming, specifically using the C programming language in the UNIX environment. Students in this course will become stronger computer scientists by mastering the basic concepts underlying all computer systems. You will learn what really happens under-the-hood when your programs run, so that when things (inevitably) go wrong you will have the intellectual tools to solve these problems.

6 Prerequisites CSCI 2120 (Software Design and Development II) CSCI 2450 (Machine Structure and Assembly Language Programming) In this course you will be expected to make use of your experience both in high-level programming (Java or other object-oriented languages) and low-level programming (machine instructions represented by assembly language). The course should strengthen your knowledge and skills in both of these areas, as well as give you insight into how computers actually work. This insight should serve you in many ways as you continue your studies in Computer Science and beyond.

7 Knowledge you will acquire 1 Low-level data representations (hands-on bit manipulation) 2 How C programs become machine instructions 3 How running programs really work (function call stack) 4 Exceptional control flow (signals and process control) 5 How programs interact with the Operating System (and run concurrently)

8 Skills you will develop 1 Using the Unix command-line: bash, make, text editors, gcc 2 Systems-level programming in C 3 Debugging using gdb 4 Executing a buffer overflow and using code injection to take control of a program 5 Mastering process control by writing your own shell!

9 Hands-on lab assignments will be the most important part of this course. Introductions The Data Lab The Bomb Lab The Attack Lab The Shell Lab

10 The work The workload for this class will be significant. Be prepared to invest many hours both in and outside of class. I expect this to be both challenging and fun for all students! Though it can be difficult, lots of help will be available and everyone willing to invest the time should be able to earn a good grade. Please talk to me after class if you are concerned about how this will work with your schedule this semester.

11 Why should we learn this stuff? Systems and related courses Operating Systems (2467 is a pre-requisite) Networks Compilers Databases Distributed systems Information Assurance Bioinformatics Deep knowledge of how machines work will serve you Software design Computer engineering IT Research... and elsewhere!

12 1 Welcome What s new? Topics The labs Why systems? 2 Syllabus Administrivia Important Resources Student Responsibilities Student Evaluation Academic Integrity Student Support Culture 3 Lab 0 Prerequisites review Remote access with ssh The terminal Text editors Part 1 Welcome Part 2 Syllabus Lab 0

13

14 The Syllabus Instructor: Matthew Toups, M.S. Office Math 335 Phone Class meetings: Tuesdays & Thursdays 3:30 4:45pm Math 209 (computer lab) Systems course hours! Monday/Wednesday 2-5pm Held weekly in GNOCIA (Math 329) web page: Contains class schedule, lecture slides, and other materials. AutoLab: Lab assignments are based around Autolab - more about this soon!

15 The Course Staff For most issues contact all of us: Course assistant: Jerod Dunbar Course assistant: Chase Lirette Systems course hours! Monday/Wednesday 2-5pm Held weekly in GNOCIA (Math 329) Additional help available from CS Tutoring Center (help desk) MATH 319 / M-F, schedule will be posted Evan and Christopher are both veterans of 2467 and very helpful Course staff staff@2467.cs.uno.edu This goes to all three of us!

16 Required textbook Primary, required textbook: Randal E. Bryant and David R. O Hallaron, Computer Systems: A Programmer s Perspective, Third Edition (CS:APP3e), Pearson, ISBN: X Get this book! How to solve labs Practice problems similar to or identical to exam problems. Worth keeping High resale value

17 Textbook access Available as course reserve at Earl Long Library. Must be during library hours, must not leave library. Maximum 4 hour checkout. (fine: 50 per hour!) Inquire at ciruclation desk, bring your UNO ID. 1st edition (2003) available in the stacks for longer checkout. Fine for Chapters 1 and 2 Chapter 3 is much different

18 Optional text Optional reference book: Brian W. Kernighan and Dennis M. Ritchie, The C Programming Language, Second Edition, Prentice Hall, ISBN: classic book commonly referred to as K & R authoritative standard co-written by one of the creators of C and UNIX not required for this course, but is widely considered an essential part of every computer scientist s library

19 Initial readings, free to download Finally, the following two PDF files are required downloads. They are freely available from Stanford University. The first is a concise primer on the C programming language. Most of what you ll need to know about the mechanics of the language should be found here. Parlante, Nick, Essential C, Stanford CS, 2003 http: // cslibrary. stanford. edu/ 101/ EssentialC. pdf The second is a similar short introduction to the tools used to compile and debug programs written in C in the UNIX environment. Parlante, Zelenski, et al., Unix Programming Tools, Stanford CS, 2001 http: // cslibrary. stanford. edu/ 107/ UnixProgrammingTools. pdf See links in syllabus or simply visit

20 How to succeed in this course 1 Attend class twice per week. 2 Read the text. 3 Do laboratory assignments. 4 Take exams.

21 Classroom etiquette Please silence telephones Only use computers (classroom or personal) for relevant activities (labs, slides, testing code) If you need to make a phone call/text/ /conversation, you may quietly leave the room

22 Grades Grading scale: A points B points C points D points F 239 points Final exam date: Tuesday December 11 3:00 5:00pm Assignments (50%): There are a total of five labs, each weighted 10%. Each lab contributes 40 points to your final score. Exams (50%): Midterm and final exam are weighted 25% each. Each exam contributes 100 points to your final score. Extra credit points will be available for particularly challenging sections, so >400 points will be available

23 Timeliness Late policy: 10 points (25 percent) will be deducted for each day after the due date. (See syllabus for specifics) This is a large penalty, so students should avoid this at all costs by staying ahead of deadlines. Don t fall behind! After each lab is due, the next one will be out. New this semester: 1 grace day per student per semester (automatically applied)

24 Academic integrity: no cheating, no plagarism

25 source:

26 Cheating has serious, real consequences source: Academic Dishonesty Report Form Please read document carefully. When complete it constitutes an agreement between you and the University community. To be completed by the complainant Complainant s Name (please print): Department: Telephone Number: Accused Student s Name (please print): and ID #: I believe the student named above has committed academic dishonesty, as I next describe (include documentation such as plagiarized sources, SafeAssign report, or similar documents when submitting to the Office of Student Accountability and Advocacy): Date of the offense: Course name & number: Check all that apply I have imposed a grade of Zero (or F) on the above assignment. I have assigned an F for the course. If a student is found guilty of academic dishonesty as a result of the student accountability process, an F will be recorded as that student s grade. I believe this act of Academic Dishonesty requires a greater sanction and I request a Resolution Conference. Because the act of Academic Dishonesty occurred at the end of the term, I am assigning a semester grade of I. It has not been feasible to show the accused student this report. The accused student has refused to complete his/her portion of this report. Complainant s Signature: Date: = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Welcome To be completed Syllabus by the accused student Lab 0

27 Totally not worth it

28 What is cheating? Copying an answer to a test question or lab assignment...from a classmate...from the web...from anywhere else Looking at a solution from any of these sources Verbally communicating answers or solutions Coaching: helping a friend with their lab line-by-line Cutting and pasting, retyping... doesn t matter All are easily detected!

29 What is not cheating? Using hints given in class (must be cited in code comments) Using help given by the course staff or textbook (again, must be cited) Asking a classmate for help logging in, using a text editor, or asking what an error message means Explaining how to use systems or tools Using google to look up a manual page for a C function, or for help using gdb

30 How to get help Everybody will get stuck at some point! The sooner you ask for help, the better. Ask questions in class Optional course study sessions: Tuesday/Thursday afternoons When appropriate, utilize ODS (see syllabus)

31 Use the lab in MATH 209! In-class activities Lab assignment work outside class time Can also work remotely via ssh to math209.cs.uno.edu

32 Support for students with disabilities Americans with Disabilities Act (ACA) affects everyone somehow, someday Talk to me or UNO Office of Disability Services (ODS)

33 Class culture Computer Science has a problem

34 Class culture

35 Class culture School culture impacts all of us It begins here: respect

36 Today s Overview 1 Welcome What s new? Topics The labs Why systems? 2 Syllabus Administrivia Important Resources Student Responsibilities Student Evaluation Academic Integrity Student Support Culture 3 Lab 0 Welcome Prerequisites review Remote access with ssh The terminal Text editors Syllabus Lab 0

37 3 Lab 0 Prerequisites review Remote access with ssh The terminal Text editors Part 1 Part 2 Part 3 Handin notes

38 Your first lab assignment CSCI 2467, Fall 2018 Lab 0: Introductions to C and Unix Due: Tuesday, August 28, 11:59PM 2467 Instructor: M. Toups mtoups@cs.uno.edu 1 Introductions The purpose of this assignment is to perform two introductions while getting you started in your exploration of Computers from a Systems perspective. Chapter 1 of Bryant & O Hallaron s CS:APP textbook will accompany this lab conceptually, and the tools we use will be explained further in the two PDF documents from Stanford s CS Library (Essential C and Unix Programming Tools). Please keep both the textbook and these two supplements handy as we work through this lab. The two introductions we will accomplish are:

39 Prerequisites A few notes on this process: bash shell, text editors, permissions Also: remote access via ssh Be sure to use your UNO username, and be aware there is a temporary block after a certain number (5-10) of failed login attempts.

40 Using PuTTY

41 Using PuTTY

42 Directories and permissions change directory with cd command create a directory with mkdir command change permissions with chmod command

43 Directories and permissions Source: Open Source GIS: A GRASS GIS Approach, First Edition, 2002

44 Terminal Shortcuts (bash shell) is an alias to your home directory: cp foo.txt ~. is an alias to your present directory: cp ~/foo.txt... is an alias to the parent directory: cp ~/foo.txt.. * will match as many characters as it can. cp ~/*.txt. Example: objdump -d * Example: rm *.c (be very very very careful!!) There is no trash with rm. It is gone.

45 More bash tricks Pressing tab will autocomplete filenames. Use the up & down arrow keys to scroll through your previous commands. Control+R lets you search your command history. Control+C terminates your current program. Control+D (on a blank line) exits the terminal.

46 Text editors Source: xkcd.com

47 nano Note command-key functions described at bottom

48 vi / vim see vimtutor command stateful or modal editor: can be in command, insert or visual mode.

49 emacs Described in Section 4 of Unix programming tools (optional reading)

50 gedit Nice GUI you can use in the lab Disadvantage: doesn t work (easily) via ssh Previous examples were all text-mode (terminal-based, work the same over ssh)

51 Notepad++ Haydar can show you the steps to get notepad++ to sync with our server.

52 Sublime Text

53 How to use Sublime Text for these labs From another school, but steps 5, 6 and 7 are of interest to us. (See resources section of class website) Start at step 5 and replace shark.ics.cs.cmu.edu with cook.cs.uno.edu

54 How to use notepad++ for these labs Written by Haydar specifically for us. (See resources section of class website)

55 Part 1: Who are you?

56 Part 1: Who are you?

57 Part 1: Who are you?

58 Part 1: Compiling and running Save (in text editor) Compile with gcc as given in lab manual Did compilation succeed? (No errors means yes) Run with./part1 Turn in by copying into /home/csci2467/handin/<userid>

59 Part 2: lifecycle of a C program A slightly modified hello.c

60 Part 2: lifecycle of a C program printf.o hello.c Source program (text) Pre- hello.i processor (cpp) source program (text) Compiler (cc1) hello.s Assembly program (text) Assembler (as) hello.o Relocatable object programs (binary) Linker (ld) hello Executable object program (binary) Source: Bryant & O Hallaron (2003)

61 Part 3: How long does it take to copy an array? Source: Bryant & O Hallaron (2003)

62 Part 3: How long does it take to copy an array? Source: Bryant & O Hallaron (2003)

63 Part 3: Memory mountain Bryant & O Hallaron (2003) Source:

64 Part 3: Memory hierarchy from Chapter 1 Smaller, faster, and costlier (per byte) storage devices Larger, slower, and cheaper (per byte) storage devices L5: L6: O Hallaron (2003) L4: L3: L2: L1: L0: Regs L1 cache (SRAM) L2 cache (SRAM) L3 cache (SRAM) Main memory (DRAM) Local secondary storage (local disks) Remote secondary storage CPU registers hold words retrieved from cache memory. L1 cache holds cache lines retrieved from the L2 cache. L2 cache holds cache lines retrieved from L3 cache L3 cache holds cache lines retrieved from memory. Main memory holds disk blocks retrieved from local disks. retrieved from disks on remote network servers. Source: Bryant &

65 Handing in your work Your work will be handed in using AutoLab (which we will demonstrate) You will do your work on math209, using a lab terminal or remotely using ssh.

66 Your first lab assignment Out today! CSCI 2467, Fall 2018 Lab 0: Introductions to C and Unix Due: Tuesday, August 28, 11:59PM 2467 Instructor: M. Toups mtoups@cs.uno.edu 1 Introductions The purpose of this assignment is to perform two introductions while getting you started in your exploration of Computers from a Systems perspective. Chapter 1 of Bryant & O Hallaron s CS:APP textbook will accompany this lab conceptually, and the tools we use will be explained further in the two PDF documents from Stanford s CS Library (Essential C and Unix Programming Tools). Welcome Please keep both Syllabus the textbook and these two supplements handy as we work Labthrough 0 this lab. The two introductions we will accomplish are:

67 Your first lab assignment Lab0: introlab Lab0: introductory skills, and background Before the next class: start Part 1 (Who am I?) We will discuss Parts 2 and 3 during the next classes. Reading: Chapter 1 (CS:APP by Bryant/O Hallaron)