Assignment 2
Due:
February 15, 2001
For
this assignment, we will modify the first assignment to allow for different
scheduling algorithms for the three different types of queues: the Long-Term scheduler, the Short-Term
scheduler and the I/O schedulers. The
algorithms for the long-term scheduler will be Balance-I/O and
Smallest-Job-First. The algorithms for
the short-term scheduler will be Shortest-Job-First,
Predict-Shortest-Job-First, Round-Robin (quantum = 5) and Round-Robin (quantum
= 12). The algorithm for the I/O
schedulers will be First-Come-First-Serve.
Each
student will only have to write a program for a single set of algorithms. The algorithms used will be based on the
first letter of your EECS User ID.
Refer to the following table to determine which algorithms you must
use. Note: the First-Come-First-Serve algorithm is used for all the I/O
schedulers.
|
First Letter of EECS User ID |
Long-Term Scheduler |
Short-Term Scheduler |
|
A-F |
Smallest-Job-First |
Shortest-Job-First |
|
G-I |
Smallest-Job-First |
Predict-Shortest-Job-First |
|
J |
Smallest-Job-First |
Round-Robin(q=12) |
|
K-L |
Smallest-Job-First |
Round-Robin(q=5) |
|
M |
Balance-I/O |
Shortest-Job-First |
|
N-P |
Balance-I/O |
Predict-Shortest-Job-First |
|
R-S |
Balance-I/O |
Round-Robin(q=12) |
|
T-Z |
Balance-I/O |
Round-Robin(q=5) |
The
Balance-I/O algorithm for the long-term scheduler will select a process based
on which I/O device it will use. The
algorithm attempts to maintain an even usage (or balance) of the three I/O
devices. When processes are waiting, the
algorithm selects the process that will use the least busy I/O device. The "busyness" of an I/O device is
determined by the number of processes currently using that device. If no process is waiting for the least busy
I/O device, then select a process waiting for the second least busy I/O device
(if no process if waiting for this device, select for the most busy I/O
device). If there is a tie in the
"business" of the I/O devices, first select for the lower numbered
device (i.e. select a process for device 1 over devices 2 or 3, and device 2
over device 3). The processes for a
particular I/O device are to be selected in the order they arrive.
The
Smallest-Job-First algorithm for the long-term scheduler will select the
process that requires the smallest amount of memory.
The
Shortest-Job-First algorithm for the short-term scheduler will select the
process with the smallest next CPU burst size (this will give us the
theoretical shortest wait time).
The
Predict-Shortest-Job-First algorithm for the short-term scheduler will select
the process with the smallest result from the following equation:
Tn+1 = 0.5 * Tn + 0.5 * tn Where: Tn+1 is the
current prediction
Tn is the last prediction
tn is the last actual CPU burst
T0 is set to 4
The
Round-Robin algorithms for the short-term scheduler are the only preemptive algorithms that will be
used. These algorithms will return the
process to the CPU waiting queue if the process has not completed by end of the
time quantum. The time quantum will be
either 5 milliseconds or 12 milliseconds. Note: time quantum is the
same as time slice.
One
other change will be that the name of the data file is to be given as a command
line argument instead of using the hardcoded name of mp1.data. For command line arguments, your main()
function will take two parameters.
These parameters are most often called argc and argv.
The
remainder of the program will be exactly the same as what was required for the first machine problem.
The
assignment is expected to be the result of individual work. You will submit the project electronically
using the UNIX "turnin" command with the project name of mp2. As shown below, where <files> is a
list of all files that you wish to submit.
Refer to the man page on the system for more information about the
command.
$> turnin -c eecs371 -p
mp2 <files>
All
of your programs must be written in a good programming style. This is to
include in-line comments, a file header, function headers, blank lines,
indentation, meaningful variable names, readable output, etc. The first two lines of your file must
comments stating how you compiled your program on the EECS department's UNIX
machines and how you ran your program.
You must also submit a makefile with your program that will properly
compile your program.