Figure 4 shows a program that tries to solve the dining philosophers' problem given that it only includes 3 philosophers who want to eat, where only 3 forks are available and each philosopher needs two forks. The outputs after running the program are given . In the outputs, it seems that the program never finishes executing; thus, (a) explain the reasons why it never finishes

Computer Networking: A Top-Down Approach (7th Edition)
7th Edition
ISBN:9780133594140
Author:James Kurose, Keith Ross
Publisher:James Kurose, Keith Ross
Chapter1: Computer Networks And The Internet
Section: Chapter Questions
Problem R1RQ: What is the difference between a host and an end system? List several different types of end...
icon
Related questions
Question

Figure 4 shows a program that tries to solve the dining philosophers' problem given that it
only includes 3 philosophers who want to eat, where only 3 forks are available and each
philosopher needs two forks. The outputs after running the program are given .
In the outputs, it seems that the program never finishes executing; thus,

(a) explain the reasons why it never finishes 

Philosopher
Philosopher
Philosopher
2 wants to eat
1 wants to eat
wants to eat
Transcribed Image Text:Philosopher Philosopher Philosopher 2 wants to eat 1 wants to eat wants to eat
1 #include<stdio.h>
2 #include<pthread.h>
3 #include<semaphore.h>
4 #include<unistd.h>
5 sem_t fork [3];
6
7 void eat (int phil) {
8
9
10}
11 void
12
13
14
15
16
17
18
19
20}
21 int main() {
22
23
24
25
26
27
28
29
30
31
223 M M
Nt06
32}
printf("Philosopher %d is eating\n", phil);
sleep (2); //time eating
philosopher (void * num) {
int phil=*(int *)num;
printf("Philosopher %d wants to eat\n",phil);
sem_wait (&fork[phil]);
sem_wait (&fork [(phil+1)]);
eat (phil);
printf("Philosopher %d has finished eating\n", phil);
sem_post(&fork[(phil+1)]);
sem_post(&fork[phil]);
int i, a[3];
pthread_t tid [3];
for(i=0; i<3; i++)
sem_init(&fork[i],0,1);
for(i=0; i<3; i++) {
a[i]=i;
pthread_create(&tid[i], NULL, philosopher, (void *)&a[i]);
}
for(i=0; i<3; i++)
pthread_join(tid[i],NULL);
Transcribed Image Text:1 #include<stdio.h> 2 #include<pthread.h> 3 #include<semaphore.h> 4 #include<unistd.h> 5 sem_t fork [3]; 6 7 void eat (int phil) { 8 9 10} 11 void 12 13 14 15 16 17 18 19 20} 21 int main() { 22 23 24 25 26 27 28 29 30 31 223 M M Nt06 32} printf("Philosopher %d is eating\n", phil); sleep (2); //time eating philosopher (void * num) { int phil=*(int *)num; printf("Philosopher %d wants to eat\n",phil); sem_wait (&fork[phil]); sem_wait (&fork [(phil+1)]); eat (phil); printf("Philosopher %d has finished eating\n", phil); sem_post(&fork[(phil+1)]); sem_post(&fork[phil]); int i, a[3]; pthread_t tid [3]; for(i=0; i<3; i++) sem_init(&fork[i],0,1); for(i=0; i<3; i++) { a[i]=i; pthread_create(&tid[i], NULL, philosopher, (void *)&a[i]); } for(i=0; i<3; i++) pthread_join(tid[i],NULL);
Expert Solution
steps

Step by step

Solved in 2 steps

Blurred answer
Recommended textbooks for you
Computer Networking: A Top-Down Approach (7th Edi…
Computer Networking: A Top-Down Approach (7th Edi…
Computer Engineering
ISBN:
9780133594140
Author:
James Kurose, Keith Ross
Publisher:
PEARSON
Computer Organization and Design MIPS Edition, Fi…
Computer Organization and Design MIPS Edition, Fi…
Computer Engineering
ISBN:
9780124077263
Author:
David A. Patterson, John L. Hennessy
Publisher:
Elsevier Science
Network+ Guide to Networks (MindTap Course List)
Network+ Guide to Networks (MindTap Course List)
Computer Engineering
ISBN:
9781337569330
Author:
Jill West, Tamara Dean, Jean Andrews
Publisher:
Cengage Learning
Concepts of Database Management
Concepts of Database Management
Computer Engineering
ISBN:
9781337093422
Author:
Joy L. Starks, Philip J. Pratt, Mary Z. Last
Publisher:
Cengage Learning
Prelude to Programming
Prelude to Programming
Computer Engineering
ISBN:
9780133750423
Author:
VENIT, Stewart
Publisher:
Pearson Education
Sc Business Data Communications and Networking, T…
Sc Business Data Communications and Networking, T…
Computer Engineering
ISBN:
9781119368830
Author:
FITZGERALD
Publisher:
WILEY