Commit | Line | Data |
---|---|---|
fa1b4804 JB |
1 | // programme philosophe.c |
2 | #include <stdio.h> | |
3 | #include <unistd.h> | |
4 | #include <pthread.h> | |
5 | #include <semaphore.h> | |
6 | ||
7 | #define N 5 | |
8 | // nombre de philosophes | |
9 | #define G (i + 1) % N | |
10 | // fourchette gauche du philosophe i | |
11 | #define D i | |
12 | // fourchette droite du philosophe i | |
13 | ||
14 | #define penser 0 | |
15 | #define faim 1 | |
16 | #define manger 2 | |
17 | static int phiState[N] = { penser }; | |
18 | ||
19 | sem_t mutex; | |
20 | sem_t semPhil[N]; | |
21 | ||
4ed359e8 | 22 | static void test(int i) |
fa1b4804 JB |
23 | { |
24 | if (phiState[i] == faim && phiState[G] != manger | |
25 | && phiState[D] != manger) { | |
26 | phiState[i] = manger; | |
27 | sem_post(&semPhil[i]); | |
28 | } | |
29 | } | |
30 | ||
4ed359e8 | 31 | static void *philosophe(void *num) |
fa1b4804 JB |
32 | { |
33 | int i = *(int *)num, nb = 2; | |
34 | while (nb) { | |
35 | /* penser */ | |
36 | sem_wait(&mutex); | |
37 | phiState[i] = penser; | |
38 | sem_post(&mutex); | |
39 | sleep(1); | |
40 | /* essayer de manger */ | |
41 | sem_wait(&mutex); | |
42 | phiState[i] = faim; | |
43 | test(i); | |
44 | sem_post(&mutex); | |
45 | /* attendre son tour */ | |
46 | sem_wait(&semPhil[i]); | |
47 | /* à nous de manger */ | |
48 | printf("philosophe[%d] mange\n", i); | |
49 | sleep(1); | |
50 | printf("philosophe[%d] a fini\n", i); | |
51 | /* laisser manger ses voisins */ | |
52 | sem_wait(&mutex); | |
53 | phiState[i] = penser; | |
54 | test(G); | |
55 | test(D); | |
56 | sem_post(&mutex); | |
57 | nb--; | |
58 | } | |
59 | return NULL; | |
60 | } | |
61 | ||
62 | int main() | |
63 | { | |
64 | int i, NumPhi[N] = { 0, 1, 2, 3, 4 }; | |
65 | pthread_t th[N]; | |
66 | sem_init(&mutex, 0, 1); | |
e2317121 | 67 | for (i = 0; i < N; i++) { |
fa1b4804 JB |
68 | sem_init(&semPhil[i], 0, 1); |
69 | } | |
70 | // création des N philosophes | |
71 | for (i = 0; i < N; i++) | |
72 | pthread_create(&th[i], NULL, philosophe, &NumPhi[i]); | |
73 | // attendre la fin des threads | |
74 | for (i = 0; i < N; i++) | |
75 | pthread_join(th[i], NULL); | |
76 | printf("fin des threads\n"); | |
77 | return 0; | |
78 | } |