CSCI 340 – Operating Systems Assignment 6 solved




In this assignment you will develop a small software application that simulates the dining philosophers
problem. This assignment will allow you to gain experience, or extend your knowledge, in the following
• More ’C’ Programming: This includes variable declaration, data types, arrays, pointers, operators, expressions, selection statements, looping statements, functions, structs, and header files.
• Thread: Learn how to create, run, join, and terminate multiple threads.
• Mutex: Learn how to create, lock, and unlock a mutex.
• Sleep: Learn how to put a thread to sleep for a given number of nanoseconds.
System and Standard Lib Functions
In this assignment you will use the system and standard library functions listed below. Please become
familiar with the syntax and usage of these calls. Detailed information about each function listed below
can be found using the man command from the console: i.e. man pthread create, will show the man
page (short for manual page) for the pthread create function.
• Thread Creation: int pthread create(pthread t
∗ thread, const pthread attr t

attr, void∗ (
∗start routine) (void∗), void∗ arg)
• Thread Join: int pthread join(pthread t thread, void∗∗ retval)
• Thread Exit: void pthread exit(void∗ retval)
• Thread Kill: int pthread kill(pthread t thread, int sig)
• Mutex Lock: int pthread mutex lock(pthread mutex t
∗ mutex)
• Mutex Unlock: int pthread mutex unlock(pthread mutex t
∗ mutex)
Provided Files
The three files listed below are provided to you.
• dpsim.h: Header file that defines the function prototypes used in this assignment. Please note:
You may not modify or add new function definitions to this header file.
• dpsim.c: A file that provides the implementation of each function prototype listed in dpsim.h. You
are to fully implement the th main, th phil, and eat functions. Please see TODO comments.
• hw6.c: Source code file that includes a stubbed out main function to be completed by you.
Many comments are provided above each function in the hw6.c and dpsim.h files. The provided comments
give detailed instructions that are meant to guide you through this assignment. Please read them carefully
and follow the instructions. For reference purposes, Fig. 1 shows which chopsticks can be used by each
philosopher. For instance, philosopher one (P1) can only pickup chopstick one (c1) followed by chopstick
two (c2). Your implementation must follow this chopstick ordering (i.e. right chopstick first then left
chopstick) as illustrated in this diagram.
P0 P2
P4 c4 P3
c0 c3
c1 c2
c = chopstick
P = philosopher
Figure 1: Table with five philosopers and five chopsticks. Each philosopher can only pickup the chopstick
to his/her immediate right or left. For instance, philosopher one (P1) can only pickup chopstick one (c1)
first and then chopstick two (c2)
Collaboration and Plagiarism
This is an individual assignment, i.e. no collaboration is permitted. Plagiarism will not be tolerated.
Submitted solutions that are very similar (determined by the instructor) will be given a grade of zero. Please
do your own work, and everything will be OK.
Create a compressed tarball, i.e. tar.gz, that only contains the completed hw6.c and dpsim.c files. The
name of the compressed tarball must be your last name. For example, ritchie.tar.gz would be correct if the
original co-developer of UNIX (Dennis Ritchie) submitted the assignment. Only assignments submitted
in the correct format will be accepted (no exceptions). Submit the compressed tarball (via OAKS) to the
Dropbox setup for this assignment. You may resubmit the compressed tarball as many times as you like,
Dropbox will only keep the newest submission.
To be fair to everyone, late assignments will not be accepted. Exceptions will only be made for extenuating
circumstances, i.e. death in the family, health related problems, etc. You will be given a week to complete
this assignment. Poor time management is not excuse. Please do not email assignment after the due date,
it will not be accepted. Please feel free to setup an appointment to discuss the assigned coding problem. I
will be more than happy to listen to your approach and make suggestions. However, I cannot tell you how
to code the solution. Additionally, code debugging is your job. You may use the debugger (gdb) or print
statements to help understand why your solution is not working correctly, your choice.
Grading Rubric
For this assignment the grading rubric is provided in the table shown below.
Program Compiles 10 points
Program Runs with no errors 10 points
main() function implementation 10 points
th main() function implementation 20 points
th phil() function implementation 10 points
eat() function implementation 20 points
In particular, the assignment will be graded as follows, if the submitted solution
• does not compile: 0 of 80 points
• compiles but does not run: 10 of 80 points
• compiles and runs with errors: 15 of 80 points
• compiles and runs without errors: 20 of 80 points
• All functions correctly implemented: 80 of 80 points