+// programme philosophe.c
+#include <stdio.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <semaphore.h>
+
+#define N 5
+// nombre de philosophes
+#define G (i + 1) % N
+// fourchette gauche du philosophe i
+#define D i
+// fourchette droite du philosophe i
+
+#define penser 0
+#define faim 1
+#define manger 2
+static int phiState[N] = { penser };
+
+sem_t mutex;
+sem_t semPhil[N];
+
+void test(int i)
+{
+ if (phiState[i] == faim && phiState[G] != manger
+ && phiState[D] != manger) {
+ phiState[i] = manger;
+ sem_post(&semPhil[i]);
+ }
+}
+
+void *philosophe(void *num)
+{
+ int i = *(int *)num, nb = 2;
+ while (nb) {
+ /* penser */
+ sem_wait(&mutex);
+ phiState[i] = penser;
+ sem_post(&mutex);
+ sleep(1);
+ /* essayer de manger */
+ sem_wait(&mutex);
+ phiState[i] = faim;
+ test(i);
+ sem_post(&mutex);
+ /* attendre son tour */
+ sem_wait(&semPhil[i]);
+ /* à nous de manger */
+ printf("philosophe[%d] mange\n", i);
+ sleep(1);
+ printf("philosophe[%d] a fini\n", i);
+ /* laisser manger ses voisins */
+ sem_wait(&mutex);
+ phiState[i] = penser;
+ test(G);
+ test(D);
+ sem_post(&mutex);
+ nb--;
+ }
+ return NULL;
+}
+
+int main()
+{
+ int i, NumPhi[N] = { 0, 1, 2, 3, 4 };
+ pthread_t th[N];
+ sem_init(&mutex, 0, 1);
+ for (int i = 0; i < N; i++) {
+ sem_init(&semPhil[i], 0, 1);
+ }
+ // création des N philosophes
+ for (i = 0; i < N; i++)
+ pthread_create(&th[i], NULL, philosophe, &NumPhi[i]);
+ // attendre la fin des threads
+ for (i = 0; i < N; i++)
+ pthread_join(th[i], NULL);
+ printf("fin des threads\n");
+ return 0;
+}