| /* $Id$ */ |
| /* |
| * Copyright (C) 2011-2011 Teluu Inc. (http://www.teluu.com) |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program 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 General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| #include <pjmedia/event.h> |
| #include <pjmedia/errno.h> |
| #include <pj/assert.h> |
| #include <pj/list.h> |
| #include <pj/log.h> |
| #include <pj/os.h> |
| #include <pj/pool.h> |
| #include <pj/string.h> |
| |
| #define THIS_FILE "event.c" |
| |
| #define MAX_EVENTS 16 |
| |
| typedef struct esub esub; |
| |
| struct esub |
| { |
| PJ_DECL_LIST_MEMBER(esub); |
| |
| pjmedia_event_cb *cb; |
| void *user_data; |
| void *epub; |
| }; |
| |
| typedef struct event_queue |
| { |
| pjmedia_event events[MAX_EVENTS]; /**< array of events. */ |
| int head, tail; |
| pj_bool_t is_full; |
| } event_queue; |
| |
| struct pjmedia_event_mgr |
| { |
| pj_pool_t *pool; |
| pj_thread_t *thread; /**< worker thread. */ |
| pj_bool_t is_quitting; |
| pj_sem_t *sem; |
| pj_mutex_t *mutex; |
| event_queue ev_queue; |
| event_queue *pub_ev_queue; /**< publish() event queue. */ |
| esub esub_list; /**< list of subscribers. */ |
| esub free_esub_list; /**< list of subscribers. */ |
| esub *th_next_sub, /**< worker thread's next sub. */ |
| *pub_next_sub; /**< publish() next sub. */ |
| }; |
| |
| static pjmedia_event_mgr *event_manager_instance; |
| |
| static pj_status_t event_queue_add_event(event_queue* ev_queue, |
| pjmedia_event *event) |
| { |
| if (ev_queue->is_full) { |
| char ev_name[5]; |
| |
| /* This event will be ignored. */ |
| PJ_LOG(4, (THIS_FILE, "Lost event %s from publisher [0x%p] " |
| "due to full queue.", |
| pjmedia_fourcc_name(event->type, ev_name), |
| event->epub)); |
| |
| return PJ_ETOOMANY; |
| } |
| |
| pj_memcpy(&ev_queue->events[ev_queue->tail], event, sizeof(*event)); |
| ev_queue->tail = (ev_queue->tail + 1) % MAX_EVENTS; |
| if (ev_queue->tail == ev_queue->head) |
| ev_queue->is_full = PJ_TRUE; |
| |
| return PJ_SUCCESS; |
| } |
| |
| static pj_status_t event_mgr_distribute_events(pjmedia_event_mgr *mgr, |
| event_queue *ev_queue, |
| esub **next_sub, |
| pj_bool_t rls_lock) |
| { |
| pj_status_t err = PJ_SUCCESS; |
| esub * sub = mgr->esub_list.next; |
| pjmedia_event *ev = &ev_queue->events[ev_queue->head]; |
| |
| while (sub != &mgr->esub_list) { |
| *next_sub = sub->next; |
| |
| /* Check if the subscriber is interested in |
| * receiving the event from the publisher. |
| */ |
| if (sub->epub == ev->epub || !sub->epub) { |
| pjmedia_event_cb *cb = sub->cb; |
| void *user_data = sub->user_data; |
| pj_status_t status; |
| |
| if (rls_lock) |
| pj_mutex_unlock(mgr->mutex); |
| |
| status = (*cb)(ev, user_data); |
| if (status != PJ_SUCCESS && err == PJ_SUCCESS) |
| err = status; |
| |
| if (rls_lock) |
| pj_mutex_lock(mgr->mutex); |
| } |
| sub = *next_sub; |
| } |
| *next_sub = NULL; |
| |
| ev_queue->head = (ev_queue->head + 1) % MAX_EVENTS; |
| ev_queue->is_full = PJ_FALSE; |
| |
| return err; |
| } |
| |
| /* Event worker thread function. */ |
| static int event_worker_thread(void *arg) |
| { |
| pjmedia_event_mgr *mgr = (pjmedia_event_mgr *)arg; |
| |
| while (1) { |
| /* Wait until there is an event. */ |
| pj_sem_wait(mgr->sem); |
| |
| if (mgr->is_quitting) |
| break; |
| |
| pj_mutex_lock(mgr->mutex); |
| event_mgr_distribute_events(mgr, &mgr->ev_queue, |
| &mgr->th_next_sub, PJ_TRUE); |
| pj_mutex_unlock(mgr->mutex); |
| } |
| |
| return 0; |
| } |
| |
| PJ_DEF(pj_status_t) pjmedia_event_mgr_create(pj_pool_t *pool, |
| unsigned options, |
| pjmedia_event_mgr **p_mgr) |
| { |
| pjmedia_event_mgr *mgr; |
| pj_status_t status; |
| |
| mgr = PJ_POOL_ZALLOC_T(pool, pjmedia_event_mgr); |
| mgr->pool = pj_pool_create(pool->factory, "evt mgr", 500, 500, NULL); |
| pj_list_init(&mgr->esub_list); |
| pj_list_init(&mgr->free_esub_list); |
| |
| if (!(options & PJMEDIA_EVENT_MGR_NO_THREAD)) { |
| status = pj_sem_create(mgr->pool, "ev_sem", 0, MAX_EVENTS + 1, |
| &mgr->sem); |
| if (status != PJ_SUCCESS) |
| return status; |
| |
| status = pj_thread_create(mgr->pool, "ev_thread", |
| &event_worker_thread, |
| mgr, 0, 0, &mgr->thread); |
| if (status != PJ_SUCCESS) { |
| pjmedia_event_mgr_destroy(mgr); |
| return status; |
| } |
| } |
| |
| status = pj_mutex_create_recursive(mgr->pool, "ev_mutex", &mgr->mutex); |
| if (status != PJ_SUCCESS) { |
| pjmedia_event_mgr_destroy(mgr); |
| return status; |
| } |
| |
| if (!event_manager_instance) |
| event_manager_instance = mgr; |
| |
| if (p_mgr) |
| *p_mgr = mgr; |
| |
| return PJ_SUCCESS; |
| } |
| |
| PJ_DEF(pjmedia_event_mgr*) pjmedia_event_mgr_instance(void) |
| { |
| return event_manager_instance; |
| } |
| |
| PJ_DEF(void) pjmedia_event_mgr_set_instance(pjmedia_event_mgr *mgr) |
| { |
| event_manager_instance = mgr; |
| } |
| |
| PJ_DEF(void) pjmedia_event_mgr_destroy(pjmedia_event_mgr *mgr) |
| { |
| if (!mgr) mgr = pjmedia_event_mgr_instance(); |
| PJ_ASSERT_ON_FAIL(mgr != NULL, return); |
| |
| if (mgr->thread) { |
| mgr->is_quitting = PJ_TRUE; |
| pj_sem_post(mgr->sem); |
| pj_thread_join(mgr->thread); |
| } |
| |
| if (mgr->sem) { |
| pj_sem_destroy(mgr->sem); |
| mgr->sem = NULL; |
| } |
| |
| if (mgr->mutex) { |
| pj_mutex_destroy(mgr->mutex); |
| mgr->mutex = NULL; |
| } |
| |
| if (mgr->pool) |
| pj_pool_release(mgr->pool); |
| |
| if (event_manager_instance == mgr) |
| event_manager_instance = NULL; |
| } |
| |
| PJ_DEF(void) pjmedia_event_init( pjmedia_event *event, |
| pjmedia_event_type type, |
| const pj_timestamp *ts, |
| const void *src) |
| { |
| pj_bzero(event, sizeof(*event)); |
| event->type = type; |
| if (ts) |
| event->timestamp.u64 = ts->u64; |
| event->epub = event->src = src; |
| } |
| |
| PJ_DEF(pj_status_t) pjmedia_event_subscribe( pjmedia_event_mgr *mgr, |
| pjmedia_event_cb *cb, |
| void *user_data, |
| void *epub) |
| { |
| esub *sub; |
| |
| PJ_ASSERT_RETURN(cb, PJ_EINVAL); |
| |
| if (!mgr) mgr = pjmedia_event_mgr_instance(); |
| PJ_ASSERT_RETURN(mgr, PJ_EINVAL); |
| |
| pj_mutex_lock(mgr->mutex); |
| /* Check whether callback function with the same user data is already |
| * subscribed to the publisher. This is to prevent the callback function |
| * receiving the same event from the same publisher more than once. |
| */ |
| sub = mgr->esub_list.next; |
| while (sub != &mgr->esub_list) { |
| esub *next = sub->next; |
| if (sub->cb == cb && sub->user_data == user_data && |
| sub->epub == epub) |
| { |
| pj_mutex_unlock(mgr->mutex); |
| return PJ_SUCCESS; |
| } |
| sub = next; |
| } |
| |
| if (mgr->free_esub_list.next != &mgr->free_esub_list) { |
| sub = mgr->free_esub_list.next; |
| pj_list_erase(sub); |
| } else |
| sub = PJ_POOL_ZALLOC_T(mgr->pool, esub); |
| sub->cb = cb; |
| sub->user_data = user_data; |
| sub->epub = epub; |
| pj_list_push_back(&mgr->esub_list, sub); |
| pj_mutex_unlock(mgr->mutex); |
| |
| return PJ_SUCCESS; |
| } |
| |
| PJ_DEF(pj_status_t) |
| pjmedia_event_unsubscribe(pjmedia_event_mgr *mgr, |
| pjmedia_event_cb *cb, |
| void *user_data, |
| void *epub) |
| { |
| esub *sub; |
| |
| PJ_ASSERT_RETURN(cb, PJ_EINVAL); |
| |
| if (!mgr) mgr = pjmedia_event_mgr_instance(); |
| PJ_ASSERT_RETURN(mgr, PJ_EINVAL); |
| |
| pj_mutex_lock(mgr->mutex); |
| sub = mgr->esub_list.next; |
| while (sub != &mgr->esub_list) { |
| esub *next = sub->next; |
| if (sub->cb == cb && (sub->user_data == user_data || !user_data) && |
| (sub->epub == epub || !epub)) |
| { |
| /* If the worker thread or pjmedia_event_publish() API is |
| * in the process of distributing events, make sure that |
| * its pointer to the next subscriber stays valid. |
| */ |
| if (mgr->th_next_sub == sub) |
| mgr->th_next_sub = sub->next; |
| if (mgr->pub_next_sub == sub) |
| mgr->pub_next_sub = sub->next; |
| pj_list_erase(sub); |
| pj_list_push_back(&mgr->free_esub_list, sub); |
| if (user_data && epub) |
| break; |
| } |
| sub = next; |
| } |
| pj_mutex_unlock(mgr->mutex); |
| |
| return PJ_SUCCESS; |
| } |
| |
| PJ_DEF(pj_status_t) pjmedia_event_publish( pjmedia_event_mgr *mgr, |
| void *epub, |
| pjmedia_event *event, |
| pjmedia_event_publish_flag flag) |
| { |
| pj_status_t err = PJ_SUCCESS; |
| |
| PJ_ASSERT_RETURN(epub && event, PJ_EINVAL); |
| |
| if (!mgr) mgr = pjmedia_event_mgr_instance(); |
| PJ_ASSERT_RETURN(mgr, PJ_EINVAL); |
| |
| event->epub = epub; |
| |
| pj_mutex_lock(mgr->mutex); |
| if (flag & PJMEDIA_EVENT_PUBLISH_POST_EVENT) { |
| if (event_queue_add_event(&mgr->ev_queue, event) == PJ_SUCCESS) |
| pj_sem_post(mgr->sem); |
| } else { |
| /* For nested pjmedia_event_publish() calls, i.e. calling publish() |
| * inside the subscriber's callback, the function will only add |
| * the event to the event queue of the first publish() call. It |
| * is the first publish() call that will be responsible to |
| * distribute the events. |
| */ |
| if (mgr->pub_ev_queue) { |
| event_queue_add_event(mgr->pub_ev_queue, event); |
| } else { |
| static event_queue ev_queue; |
| pj_status_t status; |
| |
| ev_queue.head = ev_queue.tail = 0; |
| ev_queue.is_full = PJ_FALSE; |
| mgr->pub_ev_queue = &ev_queue; |
| |
| event_queue_add_event(mgr->pub_ev_queue, event); |
| |
| do { |
| status = event_mgr_distribute_events(mgr, mgr->pub_ev_queue, |
| &mgr->pub_next_sub, |
| PJ_FALSE); |
| if (status != PJ_SUCCESS && err == PJ_SUCCESS) |
| err = status; |
| } while(ev_queue.head != ev_queue.tail || ev_queue.is_full); |
| |
| mgr->pub_ev_queue = NULL; |
| } |
| } |
| pj_mutex_unlock(mgr->mutex); |
| |
| return err; |
| } |