Assignment 4: Multi-threaded Producer Consumer Counter

Assignment 4: Multi-threaded Producer Consumer
Counter
 Points 75 Submitting a file upload

Introduction
In this assignment, you'll write a C program called "myCounter" that will get you familiar
with the use of threads, mutual exclusion and condition variables.
Learning Outcomes
Describe what is mutual exclusion and why is it an important property to maintain when
developing programs that may concurrently access shared resources (MLO 2)
Describe the API you can use to create threads and wait for the termination of a thread (MLO 4)
Describe what are condition variables and the API related to their use (MLO 4)
Instructions
Use slides 50 and 51 from Lecture 2.3 to create a program that uses two threads: one thread (the
one that your program starts out with) will be the Producer, while the other thread (that you'll create)
will be the Consumer.
Your program must use these 2 threads to communicate with each other using a ProducerConsumer approach, as described in this lecture.
Objective and Variables
Both threads must share one mutex and two condition variables to control and protect the counting
of a number. The number must count from a starting value of 0 to 10, by ones, at which point the
program will end. You get to decide which parts of the incrementation and printing go in each
thread.
Your variables must be named as follows:
Your mutex must be named "myMutex".
Your two conditions variables must be named "myCond1" and "myCond2".
Your counting variable must be named "myCount".
Output
Your program must output lines that contain the following text exactly as written, at the following
times. No other lines are allowed to be in the output:
6/27/23, 5:04 PM Assignment 4: Multi-threaded Producer Consumer Counter
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When your program begins:
PROGRAM START
When thread 2 is created:
CONSUMER THREAD CREATED
When myCount changes value:
myCount: <PREVIOUS#> -> <NEW#>
Example:
myCount: 1 -> 2
When myMutex is unlocked:
<THREAD>: myMutex unlocked
Example:
CONSUMER: myMutex unlocked
When myMutex is locked:
<THREAD>: myMutex locked
Example:
CONSUMER: myMutex locked
When myCond1 or myCond2 has pthread_cond_wait() called on it:
<THREAD>: waiting on <CONDITION VAR>
Example:
PRODUCER: waiting on myCond1
When myCond1 or myCond2 has pthread_cond_signal() called on it:
<THREAD>: signaling <CONDITION VAR>
Example:
CONSUMER: signaling myCond1
When your program ends:
PROGRAM END
What to turn in?
You can only use C for coding this assignment and you must use the gcc compiler.
You can use C99 or GNU99 standard or the default standard used by the gcc installation on
os1.
6/27/23, 5:04 PM Assignment 4: Multi-threaded Producer Consumer Counter
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Assignment 4 - Counter
Your assignment will be graded on os1.
Submit a single zip file with all your code, which can be in as many different files as you want.
This zip file must be named youronid_program4.zip where youronid must be replaced by your
own ONID.
E.g., if chaudhrn was submitting the assignment, the file must be named
chaudhrn_program4.zip .
In the zip file, you must include a text file called README.txt that contains instructions on how to
compile your code using gcc to create an executable file that must be named myCounter .
When you resubmit a file in Canvas, Canvas can attach a suffix to the file, e.g., the file name
may become chaudhrn_program4-1.zip . Don't worry about this name change as no points will be
deducted because of this.
Grading Criteria
The points for the assignment and the break-up for items is described in the grading rubric.
The "waiting on" lines can be missing, or only sporadically appear, as the code doesn't always
need to use pthread_cond_wait(). This can happen because your own internal logic might cause
the wait to be unnecessary at least some of the time, and potentially all of the time.
The order of the lines displaying the mutex and condition variables changing is allowed to
change, and extra lines displaying these changes as the program initializes are acceptable.
6/27/23, 5:04 PM Assignment 4: Multi-threaded Producer Consumer Counter
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Total Points: 75
Criteria Ratings Pts
5 pts
5 pts
20 pts
20 pts
20 pts
5 pts
PROGRAM
START
5 pts
Full Marks
The very first line of output is exactly:
PROGRAM START
0 pts
No Marks
The very first line of output is NOT
exactly: PROGRAM START
CONSUMER
THREAD
CREATED
5 pts
Full Marks
The second line of output is exactly:
CONSUMER THREAD CREATED
0 pts
No Marks
The second line of output is NOT exactly:
CONSUMER THREAD CREATED
Counter
Changes
20 pts
Full Marks
Each counter change is displayed using the provided
example. All counter changes are displayed,
including the 9 -> 10 change. All counter changes
are done in concert between the two threads, mutex,
and two condition variables.
0 pts
No Marks
Any one counter change is
not displayed, or the
changes are being done
without the required
methods.
mutex Locking 20 pts
Full Marks
The mutex is locked before the count is updated, each time,
and the mutex is after the count is updated, each time.
Exception: you do not have to display the final mutex unlock
line, if you do not want to (i.e. your program terminates as
soon as myCount = 10).
0 pts
No Marks
At least once, the
mutex is NOT
locked before the
count is updated.
condition
Variables
20 pts
Full Marks
The two condition variables are toggled on
and off as per the Lectures, in a way that
protects the counter. This will be demonstrated
by your code displaying the "...waiting on..."
and "...signaling..." lines, and by examining
your code.
0 pts
No Marks
At least once, your code alters the
counting variable without using the
two condition variables, and/or
your program doesn't display the
state of these condition variables
correctly.
PROGRAM
END
5 pts
Full Marks
The very last line of output is exactly:
PROGRAM END
0 pts
No Marks
The very last line of output is NOT exactly:
PROGRAM END