X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=philosophe-famine%2Fphilosophe.c;fp=philosophe-famine%2Fphilosophe.c;h=69e1fe8e7ca9bb8a648ce01849e88c2bd4dae1c8;hb=fa1b4804896b3db52c1e9b614cd00162fcfb8754;hp=0000000000000000000000000000000000000000;hpb=e5997403e61f46f23255becf22ce8e05a4982405;p=TD_SE.git

diff --git a/philosophe-famine/philosophe.c b/philosophe-famine/philosophe.c
new file mode 100644
index 0000000..69e1fe8
--- /dev/null
+++ b/philosophe-famine/philosophe.c
@@ -0,0 +1,78 @@
+// 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;
+}