CSC 415 - Consumer Producer Problem
Project 5
Total Points: 175 Points
Description
Project ve will introduce you to POSIX synchronization primitives. You will rst x your
code from homework four using the correct synchronization primitive. Now the correct
output of the program should be 100.
For part two, you will need to implement the consumer-producer problem. In essence this
problem is simply maintaining a shared resource that is going to be used by many threads.
Some threads will add items and some will consume. It is your job to make sure each thread
doesn’t negatively e ect the others.
Part 1 - Modifying pthread race.c
For the rst part of assignment ve you will add synchronization to your solution to HW
#4 to eliminate all the race conditions. You should not remove any of the nanosleep com-
mands that you used to produce the race conditions, but simply add the necessary mutex
synchronization calls for Linux threads. Your implementation should use the synchroniza-
tion primitives of the programming API you are working with (Posix). Your code must be
put into the pthread race.c le inside the part1 folder. NO OTHER FILES WILL BE
GRADED
Part 2 - Implementing Consumer Producer Problem
Part two of the assignment is (very roughly) based on Programming Project 6.40 in Sil-
bershatz. You will be implementing a Producer-Consumer program with a bounded bu er
queue of N elements, P producer threads and C consumer threads (N, P and C should be
command line arguments to your program, along with three additional parameters, X, Ptime
and Ctime, that are described below). Each Producer thread should Enqueue X di erent
numbers onto the queue (sleeping for Ptime cycles in between each call to Enqueue). Each
Consumer thread should Dequeue P*X/C (be careful when P*X/C is not evenly divisible)
items from the queue (sleeping for Ctime cycles in between each call to Dequeue). The main
program should create/initialize the Bounded Bu er Queue, print a timestamp, spawn o C
consumer threads P producer threads, wait for all of the threads to nish and then print
o another timestamp the duration of execution.
Step 1. Write high level pseudocode for the Producer and Consumer threads, as well as for the
Bounded Bu er Queue (Init, Enqueue, Dequeue). Use semaphores to describe synchro-
1
nization logic in your pseudocode, and put all of the calls to P/V in the Enqueue/D-
equeue implementations. Submit this pseudocode in a le called pandcpseudo.txt .
Design a testing strategy for verifying that all of the threads are collectively execut-
ing correctly. One possible testing strategy is to have a single atomic counter (i.e. a
counter with mutex synchronization so it is guaranteed to produce di erent numbers)
to generate numbers for Producer threads, then have the main routine combine the
output from all of the Consumer threads, sort it and verify that all of the input numbers
appeared as output. Submit this testing strategy as part of your design documentation.
Step 2. Implement your Producer-Consumer program using Linux threads.
For step 2, you will take your pandcpseudo.txt and implement it in C using the appro-
priate synchronization primitives(mutex locks and/or signal semaphores and/or count
semaphores) so that your code always executes correctly. Submit well-commented
source code and annotated output to demonstrate that your code is executing cor-
rectly.
The implementation has the the following requirements:
{ Your implementation must be stored in pandc.c NO OTHER .C FILES WILL
BE CHECKED OR GRADED FOR ANY REASON
{ Your program must accept 6 command like arguments N,P,C,X,Ptime,Ctime
Where each arguments is :
N is the number of bu ers to maintain.
P is the number of producer threads.
C is the number of consumer threads.
X is the number of items each producer thread will produce.
Ptime is the how long each producer thread will sleep after producing an
item.
Ctime is the how long each consumer thread will sleep after consuming an
item.
{ Your implementation must maintain N bu ers. Size of these bu ers can be one
which store one integer.
{ Your implementation must generate a unique sequence of numbers for the Pro-
ducer threads and the Consumer threads should consume the same sequence.
{ Your implementation must handle when P*X/C is not evenly divisible. For ex-
ample if P = 3 and X = 5 and C = 2 then P*X/C is 15/2 which is 7.5. This
means one producer thread and one consumer thread will produce and consume
1 extra item then the other thread.
{ Each consumer thread must print their thread id and which item they have con-
sumed.
{ Each consumer thread must sleep for Ctime after consuming each item.
2
{ Each producer thread must print their thread id and which item they have pro-
duced.
{ Each producer thread must sleep for Ptime after producing each item.
{ Your implementation must implement a test strategy that shows your program
works. A simple approach is to maintain a consumer array and a producer array.
If everything works out these two arrays should be identical and in order(Given
enqueue and dequeue are implemented correctly).
Sample Output:
N = 7 P = 5 C = 3 X = 15 Ptime = 1 Ctime = 1
Current time: Sun Apr 1 20:49:12 2018
1 was produced by producer-> 1
2 was produced by producer-> 2
3 was produced by producer-> 3
4 was produced by producer-> 4
5 was produced by producer-> 5
6 was produced by producer-> 1
1 was consumed by consumer-> 1
7 was produced by producer-> 2
2 was consumed by consumer-> 1
3 was consumed by consumer-> 3
8 was produced by producer-> 3
4 was consumed by consumer-> 1
9 was produced by producer-> 4
5 was consumed by consumer-> 1
6 was consumed by consumer-> 3
7 was consumed by consumer-> 2
10 was produced by producer-> 1
8 was consumed by consumer-> 2
11 was produced by producer-> 2
12 was produced by producer-> 3
13 was produced by producer-> 4
14 was produced by producer-> 5
9 was consumed by consumer-> 1
10 was consumed by consumer-> 3
15 was produced by producer-> 1
11 was consumed by consumer-> 3
16 was produced by producer-> 2
12 was consumed by consumer-> 3
3
13 was consumed by consumer-> 1
14 was consumed by consumer-> 2
17 was produced by producer-> 4
15 was consumed by consumer-> 1
18 was produced by producer-> 5
16 was consumed by consumer-> 1
19 was produced by producer-> 2
20 was produced by producer-> 3
17 was consumed by consumer-> 2
18 was consumed by consumer-> 3
21 was produced by producer-> 4
19 was consumed by consumer-> 2
22 was produced by producer-> 5
20 was consumed by consumer-> 1
23 was produced by producer-> 2
21 was consumed by consumer-> 1
22 was consumed by consumer-> 3
24 was produced by producer-> 1
23 was consumed by consumer-> 1
24 was consumed by consumer-> 2
25 was produced by producer-> 5
26 was produced by producer-> 5
27 was produced by producer-> 2
28 was produced by producer-> 1
29 was produced by producer-> 4
25 was consumed by consumer-> 1
30 was produced by producer-> 3
26 was consumed by consumer-> 1
27 was consumed by consumer-> 2
28 was consumed by consumer-> 3
31 was produced by producer-> 2
29 was consumed by consumer-> 3
32 was produced by producer-> 1
30 was consumed by consumer-> 3
33 was produced by producer-> 3
31 was consumed by consumer-> 3
32 was consumed by consumer-> 2
33 was consumed by consumer-> 1
34 was produced by producer-> 2
34 was consumed by consumer-> 1
35 was produced by producer-> 1
35 was consumed by consumer-> 1
4
36 was produced by producer-> 3
36 was consumed by consumer-> 1
37 was produced by producer-> 4
37 was consumed by consumer-> 1
38 was produced by producer-> 5
38 was consumed by consumer-> 1
39 was produced by producer-> 2
39 was consumed by consumer-> 1
40 was produced by producer-> 1
40 was consumed by consumer-> 1
41 was produced by producer-> 3
41 was consumed by consumer-> 1
42 was produced by producer-> 4
43 was produced by producer-> 1
44 was produced by producer-> 5
45 was produced by producer-> 3
46 was produced by producer-> 2
47 was produced by producer-> 4
42 was consumed by consumer-> 2
48 was produced by producer-> 1
43 was consumed by consumer-> 2
44 was consumed by consumer-> 1
49 was produced by producer-> 5
45 was consumed by consumer-> 1
50 was produced by producer-> 3
46 was consumed by consumer-> 1
47 was consumed by consumer-> 2
48 was consumed by consumer-> 3
51 was produced by producer-> 4
49 was consumed by consumer-> 2
52 was produced by producer-> 1
50 was consumed by consumer-> 2
53 was produced by producer-> 3
51 was consumed by consumer-> 2
54 was produced by producer-> 2
52 was consumed by consumer-> 2
55 was produced by producer-> 5
53 was consumed by consumer-> 2
54 was consumed by consumer-> 3
56 was produced by producer-> 3
55 was consumed by consumer-> 3
57 was produced by producer-> 2
5
56 was consumed by consumer-> 3
58 was produced by producer-> 5
57 was consumed by consumer-> 3
59 was produced by producer-> 3
58 was consumed by consumer-> 3
60 was produced by producer-> 2
59 was consumed by consumer-> 3
61 was produced by producer-> 5
62 was produced by producer-> 5
63 was produced by producer-> 4
64 was produced by producer-> 3
65 was produced by producer-> 2
66 was produced by producer-> 1
60 was consumed by consumer-> 2
61 was consumed by consumer-> 3
67 was produced by producer-> 5
62 was consumed by consumer-> 2
63 was consumed by consumer-> 3
68 was produced by producer-> 4
64 was consumed by consumer-> 3
69 was produced by producer-> 1
65 was consumed by consumer-> 3
70 was produced by producer-> 3
66 was consumed by consumer-> 3
67 was consumed by consumer-> 2
71 was produced by producer-> 1
68 was consumed by consumer-> 3
72 was produced by producer-> 4
Producer Thread joined: 1
Producer Thread joined: 2
Producer Thread joined: 3
69 was consumed by consumer-> 3
73 was produced by producer-> 5
74 was produced by producer-> 4
75 was produced by producer-> 4
70 was consumed by consumer-> 2
Producer Thread joined: 4
Producer Thread joined: 5
Consumer Thread joined: 1
71 was consumed by consumer-> 2
72 was consumed by consumer-> 2
73 was consumed by consumer-> 2
6
74 was consumed by consumer-> 2
75 was consumed by consumer-> 2
Consumer Thread joined: 2
Consumer Thread joined: 3
Current time: Sun Apr 1 20:50:33 2018
Consume and Produce Arrays Match!
Total Runtime: 81 secs
What to submit
1. Updated source code for pthread race.c for part 1.
2. pandcpseudo.txt le containing pseudo code from step 1 of Part 2.
3. Copy-n-paste program output from completed Part 2 stored in output.txt
4. Please ll in readme.txt le given for both Parts 1 and 2.
5. Push all completed code to your given repository by the deadline.
How to submit
git add .
git commit -m " message"
git push
Point Breakdown
part1 ! 50 points.
part2 step1 ! 25 points.
part2 step2 ! 100 points.