Description
Objectives:
1. Complete the source code to simulate producer/consumer problem.
2. Understand the basics of the POSIX thread library.
3. Build a binary program on a Linux machine.
4. Run the program and record the result of the simulation.
Requirements:
• Each student should independently accomplish this project assignment. You may
discuss with other students to solve the coding problems.
• Important! Read and follow the I/O format specification carefully. We are using an autograde script to grade this project. It is very important for your final grade of this project!
Any submission violating the format may not be correctly recognized.
• You are highly recommended to use a Linux operating system, because “pthread.h” is a
header for the Unix/Linux (POSIX) API for threads.
1. Introduction to producer and consumer model
The producer and consumer model is to schedule how concurrent processes and threads access
the resources. It contains:
1. Producer: One or multiple processes/threads that produce data or release hardware
resource.
2. Consumer: The one process/thread that takes in data or uses hardware resource to do
computations.
A producer could also be relatively a consumer to the output of another producer and vice versa.
3. Buffer: The destination to store the output from producers or resources and later
accessed by another consumer.
Other concepts involved in our project:
4. POSIX thread: Threads mechanism that satisfy POSIX standard (most operating system).
5. Mutex: A “lock” that guarantee that only one person has the access.
In this project we use POSIX threads. The “pthread” is a POSIX thread library written in C++ and
provides the basic functions.
To simplify our simulation, we assume there are only 2 POSIX threads. One is the consumer, the
other is the producer. The producer generates 1 unit data each time to the buffer, and the
consumer takes 1 unit data from the buffer each time. The size of the buffer is 1. One unit data is
just one integer. The producer generates integers 7, 14, 21 …. into the buffer and consumer read
them out from the buffer.
2. Follow the Format Specification (10 Points)
In the source file “project5_LastName_UserID.cpp”, you will find first four comment lines:
// #0#BEGIN# DO NOT MODIFY THIS COMMENT LINE!
// Firstname
// Lastname
// #0#END# DO NOT MODIFY THIS COMMENT LINE!
Your first task is modifying the two lines between the beginning line and end line. Change them
into your first name and last name. Remember the strings are case-sensitive, so capitalize the
first letter of the word and follow exactly the syntax of the example.
You can see lots of similar code blocks in the file. You are supposed to fill your answer between
those special beginning and ending comment lines. You can insert and edit multiple lines between
special comment lines in anyways, however (Important!), as the comment indicated, do not modify
the special begin and comment lines themselves!
Let’s do the second task. Scroll down to the bottom of the file and find those lines (press “shift +
g” if you are using vi/vim):
// #8#BEGIN# DO NOT MODIFY THIS COMMENT LINE!
int banner_id = 0;
// #8#END# DO NOT MODIFY THIS COMMENT LINE!
Look at your student ID card, check your banner ID. Again, change ZERO to your own ID. Your
unique student id will be compiled into the program, and the input of the experiment also uniquely
depends on your ID.
Warning: Since every student has a unique id number, the later compiled binary file is also unique.
Copy binary file from other students will be easily detected!
3. Complete Source Code (70 Points)
Read the source code and the rest comments, try to understand the function of each line of code,
the basic usage of “pthread” library function and semaphore from the example code of producer
and from the main function.
Follow the instructions in the comments and insert proper code into the rest 7 blocks to implement
a producer/consumer model.
4. Run and Record Simulation Result (10 Points)
Your correct file name should be: project5_LastName_UserID.cpp
For example, project5_Liu_tzl0031.cpp. Please remember to change the lastname and userID
to your own ones before you continue the following steps.
Compile your source code into a binary program. For example, use following command to include
the pthread library:
$ g++ project5_Lastname_UserID.cpp -o project5_LastName_UserID -lpthread
After you compile the C++ source code successfully, please use the script command to record
the running result of the program Firstname_Lastname:
$ script project5_LastName_UserID.script
Script started, file is project5_LastName_UserID.script
./project5_LastName_UserID
After you run the program, you will have the following results:
Banner id: 90…….
producer produce item 7
consumer consume item 7
producer produce item 14
consumer consume item 14
producer produce item 21
consumer consume item 21
producer produce item 28
consumer consume item 28
producer produce item 35
consumer consume item 35
producer produce item 42
consumer consume item 42
…
You should have the same result except the different in the banner ID. Then exit recording and
save it into typescript file “project5_LastName_UserID.script” by the following command:
$ exit
exit Script done, file is project5_LastName_UserID.script
Warning: Since every student has a unique id number, the result of the simulation is also unique.
Copy simulation results from other students will be easily detected!
5. Deliverables (10 Points)
Since you have generated multiple script files, please save all the script files in one
directory. Make sure all the three files are into this folder. You should have those following files
inside the folder:
1. Commands recording file: project5_LastName_UserID.script
2. Executable binary file: project5_LastName_UserID
3. Source code file: project5_LastName_UserID.cpp
Change the folder name to “project5_LastName_UserID”. Note: It is better to change the
name of the folder after the above three files moved into the folder, because of the name
conflict. Please make sure the folder name is in a correct form. You can use the command mv
to rename the folder:
$ mv your-current-folder-name project5_LastName_UserID
Achieve all the folder into a single tarred and compressed file with a tar command.
tar -zcvf project5_LastName_UserID.tar.gz project5_LastName_UserID
You need to submit one tarred file with a format project5_LastName_UserID.tar.gz through
Canvas.
Grading Criteria:
1. Follow the format specification: 10%
a. Do not break the special comments.
b. Input your name properly (mark #0).
c. Input your banner id properly (mark #8).
2. Complete the source code: 70%
a. Each blank is worth 10%, in total 70% (mark #1 ~ #7).
b. See detailed specification for each blank in the source code file.
3. Compiling and running result: 10%
a. Compile the code successfully.
b. Record the running results.
4. Deliverables: 10%
a. Contains all the files.
b. Naming all the files properly.
Late Submission Penalty:
– Late submissions will not be accepted and will result in a ZERO without valid excuses, in
which case you should talk to Dr. Li to explain your situation.
– GTA/Instructor will not accept any late submission caused by internet latency.
Rebuttal Period:
You will be given two business days to read and respond to the comments and grades of your
homework or project assignment. The TA may use this opportunity to address any concern and
question you have. The TA also may ask for additional information from you regarding your
homework or project.
