1.  
2. #include <stdio.h>
3. #include <unistd.h>
4. #include <semaphore.h>
5.  
6. sem_t mutex, fullBuffer, emptyBuffer;
7. int buffer = 0; // Represents the number of cokes in the machine
8.  
9. int main() {
10.     sem_init(&mutex;, 0, 1);
11.     sem_init(&fullBuffer;, 0, 0);
12.     sem_init(&emptyBuffer;, 0, 10);
13.  
14.     if (fork() == 0) { // Child process represents the delivery person
15.         for (int i = 0; i < 5; i++) { // The delivery person delivers 5 cokes
16.             sem_wait(&emptyBuffer;);
17.             sem_wait(&mutex;);
18.  
19.             // Place a coke in the machine (critical section)
20.             buffer++;
21.             printf("Delivery person delivered a coke. Current cokes in the machine: %d\n", buffer);
22.  
23.             sem_post(&mutex;);
24.             sem_post(&fullBuffer;);
25.         }
26.     } else { // Parent process represents the student
27.         for (int i = 0; i < 3; i++) { // The student wants 3 cokes
28.             sem_wait(&fullBuffer;);
29.             sem_wait(&mutex;);
30.  
31.             // Take a coke from the machine (critical section)
32.             buffer--;
33.             printf("Student took a coke. Current cokes in the machine: %d\n", buffer);
34.  
35.             sem_post(&mutex;);
36.             sem_post(&emptyBuffer;);
37.         }
38.     }
39.  
40.     sem_destroy(&mutex;);
41.     sem_destroy(&fullBuffer;);
42.     sem_destroy(&emptyBuffer;);
43.  
44.     return 0;
45. }
46.  
47.        
48. Consider a coke machine that has 10 slots. The producer is the delivery person and the consumer is the student who is thirsty and wants to use the machine to get a coke. We use the following three semaphores:
49.  
50. semaphore mutex
51. semaphore fullBuffer
52. semaphore emptyBuffer
53.  
54. The following operations are available on the semaphores:
55.  
56. wait(semaphore s), signal(semaphore s)
57.  
58. Write a solution that guarantees mutual exclusion and no deadlocks. Use two functions in your code:
59. 1. delivery_person() 2. student()
60.  
61. What will be the initial values of semaphores. Write code in C.
62.  
63.