Alexandre Lision | 8af73cb | 2013-12-10 14:11:20 -0500 | [diff] [blame] | 1 | /* $Id$ */ |
| 2 | /* |
| 3 | * Copyright (C) 2011-2011 Teluu Inc. (http://www.teluu.com) |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | */ |
| 19 | #include <pjmedia/event.h> |
| 20 | #include <pjmedia/errno.h> |
| 21 | #include <pj/assert.h> |
| 22 | #include <pj/list.h> |
| 23 | #include <pj/log.h> |
| 24 | #include <pj/os.h> |
| 25 | #include <pj/pool.h> |
| 26 | #include <pj/string.h> |
| 27 | |
| 28 | #define THIS_FILE "event.c" |
| 29 | |
| 30 | #define MAX_EVENTS 16 |
| 31 | |
| 32 | typedef struct esub esub; |
| 33 | |
| 34 | struct esub |
| 35 | { |
| 36 | PJ_DECL_LIST_MEMBER(esub); |
| 37 | |
| 38 | pjmedia_event_cb *cb; |
| 39 | void *user_data; |
| 40 | void *epub; |
| 41 | }; |
| 42 | |
| 43 | typedef struct event_queue |
| 44 | { |
| 45 | pjmedia_event events[MAX_EVENTS]; /**< array of events. */ |
| 46 | int head, tail; |
| 47 | pj_bool_t is_full; |
| 48 | } event_queue; |
| 49 | |
| 50 | struct pjmedia_event_mgr |
| 51 | { |
| 52 | pj_pool_t *pool; |
| 53 | pj_thread_t *thread; /**< worker thread. */ |
| 54 | pj_bool_t is_quitting; |
| 55 | pj_sem_t *sem; |
| 56 | pj_mutex_t *mutex; |
| 57 | event_queue ev_queue; |
| 58 | event_queue *pub_ev_queue; /**< publish() event queue. */ |
| 59 | esub esub_list; /**< list of subscribers. */ |
| 60 | esub free_esub_list; /**< list of subscribers. */ |
| 61 | esub *th_next_sub, /**< worker thread's next sub. */ |
| 62 | *pub_next_sub; /**< publish() next sub. */ |
| 63 | }; |
| 64 | |
| 65 | static pjmedia_event_mgr *event_manager_instance; |
| 66 | |
| 67 | static pj_status_t event_queue_add_event(event_queue* ev_queue, |
| 68 | pjmedia_event *event) |
| 69 | { |
| 70 | if (ev_queue->is_full) { |
| 71 | char ev_name[5]; |
| 72 | |
| 73 | /* This event will be ignored. */ |
| 74 | PJ_LOG(4, (THIS_FILE, "Lost event %s from publisher [0x%p] " |
| 75 | "due to full queue.", |
| 76 | pjmedia_fourcc_name(event->type, ev_name), |
| 77 | event->epub)); |
| 78 | |
| 79 | return PJ_ETOOMANY; |
| 80 | } |
| 81 | |
| 82 | pj_memcpy(&ev_queue->events[ev_queue->tail], event, sizeof(*event)); |
| 83 | ev_queue->tail = (ev_queue->tail + 1) % MAX_EVENTS; |
| 84 | if (ev_queue->tail == ev_queue->head) |
| 85 | ev_queue->is_full = PJ_TRUE; |
| 86 | |
| 87 | return PJ_SUCCESS; |
| 88 | } |
| 89 | |
| 90 | static pj_status_t event_mgr_distribute_events(pjmedia_event_mgr *mgr, |
| 91 | event_queue *ev_queue, |
| 92 | esub **next_sub, |
| 93 | pj_bool_t rls_lock) |
| 94 | { |
| 95 | pj_status_t err = PJ_SUCCESS; |
| 96 | esub * sub = mgr->esub_list.next; |
| 97 | pjmedia_event *ev = &ev_queue->events[ev_queue->head]; |
| 98 | |
| 99 | while (sub != &mgr->esub_list) { |
| 100 | *next_sub = sub->next; |
| 101 | |
| 102 | /* Check if the subscriber is interested in |
| 103 | * receiving the event from the publisher. |
| 104 | */ |
| 105 | if (sub->epub == ev->epub || !sub->epub) { |
| 106 | pjmedia_event_cb *cb = sub->cb; |
| 107 | void *user_data = sub->user_data; |
| 108 | pj_status_t status; |
| 109 | |
| 110 | if (rls_lock) |
| 111 | pj_mutex_unlock(mgr->mutex); |
| 112 | |
| 113 | status = (*cb)(ev, user_data); |
| 114 | if (status != PJ_SUCCESS && err == PJ_SUCCESS) |
| 115 | err = status; |
| 116 | |
| 117 | if (rls_lock) |
| 118 | pj_mutex_lock(mgr->mutex); |
| 119 | } |
| 120 | sub = *next_sub; |
| 121 | } |
| 122 | *next_sub = NULL; |
| 123 | |
| 124 | ev_queue->head = (ev_queue->head + 1) % MAX_EVENTS; |
| 125 | ev_queue->is_full = PJ_FALSE; |
| 126 | |
| 127 | return err; |
| 128 | } |
| 129 | |
| 130 | /* Event worker thread function. */ |
| 131 | static int event_worker_thread(void *arg) |
| 132 | { |
| 133 | pjmedia_event_mgr *mgr = (pjmedia_event_mgr *)arg; |
| 134 | |
| 135 | while (1) { |
| 136 | /* Wait until there is an event. */ |
| 137 | pj_sem_wait(mgr->sem); |
| 138 | |
| 139 | if (mgr->is_quitting) |
| 140 | break; |
| 141 | |
| 142 | pj_mutex_lock(mgr->mutex); |
| 143 | event_mgr_distribute_events(mgr, &mgr->ev_queue, |
| 144 | &mgr->th_next_sub, PJ_TRUE); |
| 145 | pj_mutex_unlock(mgr->mutex); |
| 146 | } |
| 147 | |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | PJ_DEF(pj_status_t) pjmedia_event_mgr_create(pj_pool_t *pool, |
| 152 | unsigned options, |
| 153 | pjmedia_event_mgr **p_mgr) |
| 154 | { |
| 155 | pjmedia_event_mgr *mgr; |
| 156 | pj_status_t status; |
| 157 | |
| 158 | mgr = PJ_POOL_ZALLOC_T(pool, pjmedia_event_mgr); |
| 159 | mgr->pool = pj_pool_create(pool->factory, "evt mgr", 500, 500, NULL); |
| 160 | pj_list_init(&mgr->esub_list); |
| 161 | pj_list_init(&mgr->free_esub_list); |
| 162 | |
| 163 | if (!(options & PJMEDIA_EVENT_MGR_NO_THREAD)) { |
| 164 | status = pj_sem_create(mgr->pool, "ev_sem", 0, MAX_EVENTS + 1, |
| 165 | &mgr->sem); |
| 166 | if (status != PJ_SUCCESS) |
| 167 | return status; |
| 168 | |
| 169 | status = pj_thread_create(mgr->pool, "ev_thread", |
| 170 | &event_worker_thread, |
| 171 | mgr, 0, 0, &mgr->thread); |
| 172 | if (status != PJ_SUCCESS) { |
| 173 | pjmedia_event_mgr_destroy(mgr); |
| 174 | return status; |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | status = pj_mutex_create_recursive(mgr->pool, "ev_mutex", &mgr->mutex); |
| 179 | if (status != PJ_SUCCESS) { |
| 180 | pjmedia_event_mgr_destroy(mgr); |
| 181 | return status; |
| 182 | } |
| 183 | |
| 184 | if (!event_manager_instance) |
| 185 | event_manager_instance = mgr; |
| 186 | |
| 187 | if (p_mgr) |
| 188 | *p_mgr = mgr; |
| 189 | |
| 190 | return PJ_SUCCESS; |
| 191 | } |
| 192 | |
| 193 | PJ_DEF(pjmedia_event_mgr*) pjmedia_event_mgr_instance(void) |
| 194 | { |
| 195 | return event_manager_instance; |
| 196 | } |
| 197 | |
| 198 | PJ_DEF(void) pjmedia_event_mgr_set_instance(pjmedia_event_mgr *mgr) |
| 199 | { |
| 200 | event_manager_instance = mgr; |
| 201 | } |
| 202 | |
| 203 | PJ_DEF(void) pjmedia_event_mgr_destroy(pjmedia_event_mgr *mgr) |
| 204 | { |
| 205 | if (!mgr) mgr = pjmedia_event_mgr_instance(); |
| 206 | PJ_ASSERT_ON_FAIL(mgr != NULL, return); |
| 207 | |
| 208 | if (mgr->thread) { |
| 209 | mgr->is_quitting = PJ_TRUE; |
| 210 | pj_sem_post(mgr->sem); |
| 211 | pj_thread_join(mgr->thread); |
| 212 | } |
| 213 | |
| 214 | if (mgr->sem) { |
| 215 | pj_sem_destroy(mgr->sem); |
| 216 | mgr->sem = NULL; |
| 217 | } |
| 218 | |
| 219 | if (mgr->mutex) { |
| 220 | pj_mutex_destroy(mgr->mutex); |
| 221 | mgr->mutex = NULL; |
| 222 | } |
| 223 | |
| 224 | if (mgr->pool) |
| 225 | pj_pool_release(mgr->pool); |
| 226 | |
| 227 | if (event_manager_instance == mgr) |
| 228 | event_manager_instance = NULL; |
| 229 | } |
| 230 | |
| 231 | PJ_DEF(void) pjmedia_event_init( pjmedia_event *event, |
| 232 | pjmedia_event_type type, |
| 233 | const pj_timestamp *ts, |
| 234 | const void *src) |
| 235 | { |
| 236 | pj_bzero(event, sizeof(*event)); |
| 237 | event->type = type; |
| 238 | if (ts) |
| 239 | event->timestamp.u64 = ts->u64; |
| 240 | event->epub = event->src = src; |
| 241 | } |
| 242 | |
| 243 | PJ_DEF(pj_status_t) pjmedia_event_subscribe( pjmedia_event_mgr *mgr, |
| 244 | pjmedia_event_cb *cb, |
| 245 | void *user_data, |
| 246 | void *epub) |
| 247 | { |
| 248 | esub *sub; |
| 249 | |
| 250 | PJ_ASSERT_RETURN(cb, PJ_EINVAL); |
| 251 | |
| 252 | if (!mgr) mgr = pjmedia_event_mgr_instance(); |
| 253 | PJ_ASSERT_RETURN(mgr, PJ_EINVAL); |
| 254 | |
| 255 | pj_mutex_lock(mgr->mutex); |
| 256 | /* Check whether callback function with the same user data is already |
| 257 | * subscribed to the publisher. This is to prevent the callback function |
| 258 | * receiving the same event from the same publisher more than once. |
| 259 | */ |
| 260 | sub = mgr->esub_list.next; |
| 261 | while (sub != &mgr->esub_list) { |
| 262 | esub *next = sub->next; |
| 263 | if (sub->cb == cb && sub->user_data == user_data && |
| 264 | sub->epub == epub) |
| 265 | { |
| 266 | pj_mutex_unlock(mgr->mutex); |
| 267 | return PJ_SUCCESS; |
| 268 | } |
| 269 | sub = next; |
| 270 | } |
| 271 | |
| 272 | if (mgr->free_esub_list.next != &mgr->free_esub_list) { |
| 273 | sub = mgr->free_esub_list.next; |
| 274 | pj_list_erase(sub); |
| 275 | } else |
| 276 | sub = PJ_POOL_ZALLOC_T(mgr->pool, esub); |
| 277 | sub->cb = cb; |
| 278 | sub->user_data = user_data; |
| 279 | sub->epub = epub; |
| 280 | pj_list_push_back(&mgr->esub_list, sub); |
| 281 | pj_mutex_unlock(mgr->mutex); |
| 282 | |
| 283 | return PJ_SUCCESS; |
| 284 | } |
| 285 | |
| 286 | PJ_DEF(pj_status_t) |
| 287 | pjmedia_event_unsubscribe(pjmedia_event_mgr *mgr, |
| 288 | pjmedia_event_cb *cb, |
| 289 | void *user_data, |
| 290 | void *epub) |
| 291 | { |
| 292 | esub *sub; |
| 293 | |
| 294 | PJ_ASSERT_RETURN(cb, PJ_EINVAL); |
| 295 | |
| 296 | if (!mgr) mgr = pjmedia_event_mgr_instance(); |
| 297 | PJ_ASSERT_RETURN(mgr, PJ_EINVAL); |
| 298 | |
| 299 | pj_mutex_lock(mgr->mutex); |
| 300 | sub = mgr->esub_list.next; |
| 301 | while (sub != &mgr->esub_list) { |
| 302 | esub *next = sub->next; |
| 303 | if (sub->cb == cb && (sub->user_data == user_data || !user_data) && |
| 304 | (sub->epub == epub || !epub)) |
| 305 | { |
| 306 | /* If the worker thread or pjmedia_event_publish() API is |
| 307 | * in the process of distributing events, make sure that |
| 308 | * its pointer to the next subscriber stays valid. |
| 309 | */ |
| 310 | if (mgr->th_next_sub == sub) |
| 311 | mgr->th_next_sub = sub->next; |
| 312 | if (mgr->pub_next_sub == sub) |
| 313 | mgr->pub_next_sub = sub->next; |
| 314 | pj_list_erase(sub); |
| 315 | pj_list_push_back(&mgr->free_esub_list, sub); |
| 316 | if (user_data && epub) |
| 317 | break; |
| 318 | } |
| 319 | sub = next; |
| 320 | } |
| 321 | pj_mutex_unlock(mgr->mutex); |
| 322 | |
| 323 | return PJ_SUCCESS; |
| 324 | } |
| 325 | |
| 326 | PJ_DEF(pj_status_t) pjmedia_event_publish( pjmedia_event_mgr *mgr, |
| 327 | void *epub, |
| 328 | pjmedia_event *event, |
| 329 | pjmedia_event_publish_flag flag) |
| 330 | { |
| 331 | pj_status_t err = PJ_SUCCESS; |
| 332 | |
| 333 | PJ_ASSERT_RETURN(epub && event, PJ_EINVAL); |
| 334 | |
| 335 | if (!mgr) mgr = pjmedia_event_mgr_instance(); |
| 336 | PJ_ASSERT_RETURN(mgr, PJ_EINVAL); |
| 337 | |
| 338 | event->epub = epub; |
| 339 | |
| 340 | pj_mutex_lock(mgr->mutex); |
| 341 | if (flag & PJMEDIA_EVENT_PUBLISH_POST_EVENT) { |
| 342 | if (event_queue_add_event(&mgr->ev_queue, event) == PJ_SUCCESS) |
| 343 | pj_sem_post(mgr->sem); |
| 344 | } else { |
| 345 | /* For nested pjmedia_event_publish() calls, i.e. calling publish() |
| 346 | * inside the subscriber's callback, the function will only add |
| 347 | * the event to the event queue of the first publish() call. It |
| 348 | * is the first publish() call that will be responsible to |
| 349 | * distribute the events. |
| 350 | */ |
| 351 | if (mgr->pub_ev_queue) { |
| 352 | event_queue_add_event(mgr->pub_ev_queue, event); |
| 353 | } else { |
| 354 | static event_queue ev_queue; |
| 355 | pj_status_t status; |
| 356 | |
| 357 | ev_queue.head = ev_queue.tail = 0; |
| 358 | ev_queue.is_full = PJ_FALSE; |
| 359 | mgr->pub_ev_queue = &ev_queue; |
| 360 | |
| 361 | event_queue_add_event(mgr->pub_ev_queue, event); |
| 362 | |
| 363 | do { |
| 364 | status = event_mgr_distribute_events(mgr, mgr->pub_ev_queue, |
| 365 | &mgr->pub_next_sub, |
| 366 | PJ_FALSE); |
| 367 | if (status != PJ_SUCCESS && err == PJ_SUCCESS) |
| 368 | err = status; |
| 369 | } while(ev_queue.head != ev_queue.tail || ev_queue.is_full); |
| 370 | |
| 371 | mgr->pub_ev_queue = NULL; |
| 372 | } |
| 373 | } |
| 374 | pj_mutex_unlock(mgr->mutex); |
| 375 | |
| 376 | return err; |
| 377 | } |