ECE536 Computer Software Systems

Assignment #1 (5%)

Spring 2005, handout #536004

Due: Tuesday, 02/8/05, at the beginning of class

Objectives

• To publicize yourself via WWW
• To practice commonly used routines in software system
• To be able to control timing and measure time

Submittal

• A cover page to show your name and student number.
• Your source files
• Your test run (use "script")

Assignment

Part 1 (30%):

• Construct your own web page dedicated to ECE 536, required information:
  • Your name and picture, office, phone number, and affiliation
  • Your ECE computer user ID (needed by project deposit)
  • Your UNM CIRT computer user ID (needed by WebCT)
  • Your technical background (one paragraph description)
  • Topics in computer engineering you are particularly interested
• Submit a printout of the web page and upload (or link) your page to WebCT. Everyone in the class can know each other by reading your pages!
  
  

  Part 2 (70%)

• There are different time values maintained by UNIX systems.
  • Calendar time. This value counts the number of seconds since 00:00:00 January 1, 1970, Coordinated Universal Time (UTC). The primitive system data type time_t in timeval, as defined in < sys/time.h>, holds these time values.

    struct timeval {
            time_t          tv_sec;         /* seconds */
            suseconds_t     tv_usec;        /* and microseconds */
    };
    

    There are two major C Library calls to help you handle the calendar time:
    • gettimeofday // man -s 3C gettimeofday
    • ctime // man -s 3C ctime
  • Process time. This is also called CPU time and measures the central processor resources used by a process. Process time is measured in clock ticks, which have historically been 50,60, or 100 ticks per second. The primitive system data type clock_t holds these time values. There are many C Library calls and a system call to help you handle the CPU time:
    • clock // man -s 3C clock
    • times // man -s 2 times
    • getrusage // man -s 3C getrusage
    • sysconf // man -s 3C sysconf
    The process time in UNIX consists of two values:
    • user CPU time: the CPU time that is attributed to user instructions
    • system CPU time: the CPU time that is attributed to the kernel, when it executes on behalf of the process.
• There are some lib calls to suspend the calling processes/threads for a certain time period:
  • sleep // man -s 3C sleep
  • usleep // man -s 3C usleep, high resolution, but MT unsafe
  • nanosleep // man -s 3RT POSIX nanosleep, high resolution, MT-safe
• You are required to write a control program, in x steps of y microseconds, for total duration of 1 minute, that is, x · y = 60000000. The command format should be: yourprog -I y -C z where switch "-I" is used to specify the length of interval (in microsecond) for control steps; switch "-C" is used to indicate the scheme used for control:
  • z=1: use sleep or usleep
  • z=2: use nanosleep
  • z=3: use busy-wait
  • z=4: an optimal mix of all schemes
  The assumed control process is just to write the elapsed time in microseconds (taken from your computer's calendar time) relative to the start of the control process. At the end of 1 minute, print these collected time values and some data analysis.
  
  

  Part 2.1 (15%):

  • Write a paragraph to show your design for cases of z=1,2,3, and 4.
    
    

    Part 2.2 (30%):

  • Run your program and fill the following table:

    Y	Z=1		Z=2		Z=3		Z=4
    (in usecs)	avg offset	usr/sys T	avg offset	usr/sys T	avg offset	usr/sys T	avg offset	usr/sys T
    1000000
    100000
    10000
    1000

    
    
    

    Part 2.3 (15%):

    Redo Part 2.2 by forking a process to do some busy nonsense computation to consume CPU.
    
    

    Part 3.4 (10%):

    Discussion: Summerize what you have learn from the above three parts of programming.
  
  Assigned by Dr. Shu, shu@ece.unm.edu