Add mutex

programmation-multitaches-temps-reel/exemples/mutex.c

@@ -0,0 +1,55 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <unistd.h>
+
+static pthread_mutex_t my_mutex;
+static int tab[5];
+
+void *read_tab_process(void * arg) {
+    int i;
+
+    pthread_mutex_lock(&my_mutex);
+
+    for (i = 0 ; i != 5 ; i++)
+        printf("read_process, tab[%d] vaut %d\n", i, tab[i]);
+
+    pthread_mutex_unlock(&my_mutex);
+    pthread_exit(0);
+}
+
+void *write_tab_process(void * arg) {
+    int i;
+
+    pthread_mutex_lock(&my_mutex);
+
+    for (i = 0 ; i != 5 ; i++) {
+        tab[i] = 2 * i;
+        printf ("write_process, tab[%d] vaut %d\n", i, tab[i]);
+        sleep (1); /* Relentit le thread d'ecriture... */
+    }
+
+    pthread_mutex_unlock(&my_mutex);
+    pthread_exit(0);
+}
+
+int main (int ac, char **av) {
+    pthread_t th1, th2;
+    void *ret;
+
+    pthread_mutex_init(&my_mutex, NULL);
+
+    if (pthread_create(&th1, NULL, write_tab_process, NULL) < 0) {
+        fprintf(stderr, "pthread_create error for thread 1\n");
+        exit (1);
+    }
+    if (pthread_create(&th2, NULL, read_tab_process, NULL) < 0) {
+        fprintf(stderr, "pthread_create error for thread 2\n");
+        exit (1);
+    }
+
+    (void) pthread_join(th1, &ret);
+    (void) pthread_join(th2, &ret);
+
+    return 0;
+}