void start_pointer(struct fsm_pointer *pointer) {
    if ( pointer->started != 0 ){
        printf("CRITICAL : A pointer must be started only once");
        return;
    }
    pthread_create(&pointer->thread, NULL, &pointer_loop, (void *)pointer);
    pointer->started = 1;
}

void *pointer_loop(void * _pointer) {
    struct fsm_pointer * pointer = _pointer; // cast void pointer
    struct fsm_context init_context = {
        .event = event,
        .fnct_args = step.args,
    };
    // call pointer structure member => SEGFAULT
    pointer->current_step.fnct(&init_context);
    return NULL;
}

struct fsm_pointer{
    pthread_t thread;
    pthread_mutex_t mutex_event;
    pthread_cond_t cond_event;
    struct fsm_event input_event;
    struct fsm_step current_step;
    unsigned short started;
};

struct fsm_step{
    void (*fnct)(const struct fsm_context *);
    void * args;
    struct fsm_trans transition;
};