/* * Ouroboros - Copyright (C) 2016 - 2018 * * Notifier event system using callbacks * * Dimitri Staessens <dimitri.staessens@ugent.be> * Sander Vrijders <sander.vrijders@ugent.be> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * version 2.1 as published by the Free Software Foundation. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., http://www.fsf.org/about/contact/. */ #include <ouroboros/errno.h> #include <ouroboros/notifier.h> #include <ouroboros/list.h> #include <pthread.h> #include <stdlib.h> struct listener { struct list_head next; notifier_fn_t callback; void * obj; }; struct { struct list_head listeners; pthread_mutex_t lock; } notifier; int notifier_init(void) { if (pthread_mutex_init(¬ifier.lock, NULL)) return -1; list_head_init(¬ifier.listeners); return 0; } void notifier_fini(void) { struct list_head * p; struct list_head * h; pthread_mutex_lock(¬ifier.lock); list_for_each_safe(p, h, ¬ifier.listeners) { struct listener * l = list_entry(p, struct listener, next); list_del(&l->next); free(l); } pthread_mutex_unlock(¬ifier.lock); pthread_mutex_destroy(¬ifier.lock); } void notifier_event(int event, const void * o) { struct list_head * p; pthread_mutex_lock(¬ifier.lock); list_for_each(p, ¬ifier.listeners) { struct listener * l = list_entry(p, struct listener, next); l->callback(l->obj, event, o); } pthread_mutex_unlock(¬ifier.lock); } int notifier_reg(notifier_fn_t callback, void * obj) { struct listener * l; struct list_head * p; pthread_mutex_lock(¬ifier.lock); list_for_each(p, ¬ifier.listeners) { struct listener * l = list_entry(p, struct listener, next); if (l->callback == callback) { pthread_mutex_unlock(¬ifier.lock); return -EPERM; } } l = malloc(sizeof(*l)); if (l == NULL) { pthread_mutex_unlock(¬ifier.lock); return -ENOMEM; } l->callback = callback; l->obj = obj; list_add_tail(&l->next, ¬ifier.listeners); pthread_mutex_unlock(¬ifier.lock); return 0; } void notifier_unreg(notifier_fn_t callback) { struct list_head * p; struct list_head * h; pthread_mutex_lock(¬ifier.lock); list_for_each_safe(p, h, ¬ifier.listeners) { struct listener * l = list_entry(p, struct listener, next); if (l->callback == callback) { list_del(&l->next); free(l); break; } } pthread_mutex_unlock(¬ifier.lock); }