libevent/bufferevent.c

   1 /*
   2  * Copyright (c) 2002-2007 Niels Provos <provos@citi.umich.edu>
   3  * Copyright (c) 2007-2010 Niels Provos, Nick Mathewson
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include <sys/types.h>
  29
  30 #include "event2/event-config.h"
  31
  32 #ifdef _EVENT_HAVE_SYS_TIME_H
  33 #include <sys/time.h>
  34 #endif
  35
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #ifdef _EVENT_HAVE_STDARG_H
  41 #include <stdarg.h>
  42 #endif
  43
  44 #ifdef WIN32
  45 #include <winsock2.h>
  46 #endif
  47 #include <errno.h>
  48
  49 #include "event2/util.h"
  50 #include "event2/buffer.h"
  51 #include "event2/buffer_compat.h"
  52 #include "event2/bufferevent.h"
  53 #include "event2/bufferevent_struct.h"
  54 #include "event2/bufferevent_compat.h"
  55 #include "event2/event.h"
  56 #include "log-internal.h"
  57 #include "mm-internal.h"
  58 #include "bufferevent-internal.h"
  59 #include "evbuffer-internal.h"
  60 #include "util-internal.h"
  61
  62 void
  63 bufferevent_suspend_read(struct bufferevent *bufev, bufferevent_suspend_flags what)
  64 {
  65         struct bufferevent_private *bufev_private =
  66             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
  67         BEV_LOCK(bufev);
  68         if (!bufev_private->read_suspended)
  69                 bufev->be_ops->disable(bufev, EV_READ);
  70         bufev_private->read_suspended |= what;
  71         BEV_UNLOCK(bufev);
  72 }
  73
  74 void
  75 bufferevent_unsuspend_read(struct bufferevent *bufev, bufferevent_suspend_flags what)
  76 {
  77         struct bufferevent_private *bufev_private =
  78             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
  79         BEV_LOCK(bufev);
  80         bufev_private->read_suspended &= ~what;
  81         if (!bufev_private->read_suspended && (bufev->enabled & EV_READ))
  82                 bufev->be_ops->enable(bufev, EV_READ);
  83         BEV_UNLOCK(bufev);
  84 }
  85
  86 void
  87 bufferevent_suspend_write(struct bufferevent *bufev, bufferevent_suspend_flags what)
  88 {
  89         struct bufferevent_private *bufev_private =
  90             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
  91         BEV_LOCK(bufev);
  92         if (!bufev_private->write_suspended)
  93                 bufev->be_ops->disable(bufev, EV_WRITE);
  94         bufev_private->write_suspended |= what;
  95         BEV_UNLOCK(bufev);
  96 }
  97
  98 void
  99 bufferevent_unsuspend_write(struct bufferevent *bufev, bufferevent_suspend_flags what)
 100 {
 101         struct bufferevent_private *bufev_private =
 102             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 103         BEV_LOCK(bufev);
 104         bufev_private->write_suspended &= ~what;
 105         if (!bufev_private->write_suspended && (bufev->enabled & EV_WRITE))
 106                 bufev->be_ops->enable(bufev, EV_WRITE);
 107         BEV_UNLOCK(bufev);
 108 }
 109
 110
 111 /* Callback to implement watermarks on the input buffer.  Only enabled
 112  * if the watermark is set. */
 113 static void
 114 bufferevent_inbuf_wm_cb(struct evbuffer *buf,
 115     const struct evbuffer_cb_info *cbinfo,
 116     void *arg)
 117 {
 118         struct bufferevent *bufev = arg;
 119         size_t size;
 120
 121         size = evbuffer_get_length(buf);
 122
 123         if (size >= bufev->wm_read.high)
 124                 bufferevent_wm_suspend_read(bufev);
 125         else
 126                 bufferevent_wm_unsuspend_read(bufev);
 127 }
 128
 129 static void
 130 bufferevent_run_deferred_callbacks_locked(struct deferred_cb *_, void *arg)
 131 {
 132         struct bufferevent_private *bufev_private = arg;
 133         struct bufferevent *bufev = &bufev_private->bev;
 134
 135         BEV_LOCK(bufev);
 136         if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
 137             bufev->errorcb) {
 138                 /* The "connected" happened before any reads or writes, so
 139                    send it first. */
 140                 bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
 141                 bufev->errorcb(bufev, BEV_EVENT_CONNECTED, bufev->cbarg);
 142         }
 143         if (bufev_private->readcb_pending && bufev->readcb) {
 144                 bufev_private->readcb_pending = 0;
 145                 bufev->readcb(bufev, bufev->cbarg);
 146         }
 147         if (bufev_private->writecb_pending && bufev->writecb) {
 148                 bufev_private->writecb_pending = 0;
 149                 bufev->writecb(bufev, bufev->cbarg);
 150         }
 151         if (bufev_private->eventcb_pending && bufev->errorcb) {
 152                 short what = bufev_private->eventcb_pending;
 153                 int err = bufev_private->errno_pending;
 154                 bufev_private->eventcb_pending = 0;
 155                 bufev_private->errno_pending = 0;
 156                 EVUTIL_SET_SOCKET_ERROR(err);
 157                 bufev->errorcb(bufev, what, bufev->cbarg);
 158         }
 159         _bufferevent_decref_and_unlock(bufev);
 160 }
 161
 162 static void
 163 bufferevent_run_deferred_callbacks_unlocked(struct deferred_cb *_, void *arg)
 164 {
 165         struct bufferevent_private *bufev_private = arg;
 166         struct bufferevent *bufev = &bufev_private->bev;
 167
 168         BEV_LOCK(bufev);
 169 #define UNLOCKED(stmt) \
 170         do { BEV_UNLOCK(bufev); stmt; BEV_LOCK(bufev); } while(0)
 171
 172         if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
 173             bufev->errorcb) {
 174                 /* The "connected" happened before any reads or writes, so
 175                    send it first. */
 176                 bufferevent_event_cb errorcb = bufev->errorcb;
 177                 void *cbarg = bufev->cbarg;
 178                 bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
 179                 UNLOCKED(errorcb(bufev, BEV_EVENT_CONNECTED, cbarg));
 180         }
 181         if (bufev_private->readcb_pending && bufev->readcb) {
 182                 bufferevent_data_cb readcb = bufev->readcb;
 183                 void *cbarg = bufev->cbarg;
 184                 bufev_private->readcb_pending = 0;
 185                 UNLOCKED(readcb(bufev, cbarg));
 186         }
 187         if (bufev_private->writecb_pending && bufev->writecb) {
 188                 bufferevent_data_cb writecb = bufev->writecb;
 189                 void *cbarg = bufev->cbarg;
 190                 bufev_private->writecb_pending = 0;
 191                 UNLOCKED(writecb(bufev, cbarg));
 192         }
 193         if (bufev_private->eventcb_pending && bufev->errorcb) {
 194                 bufferevent_event_cb errorcb = bufev->errorcb;
 195                 void *cbarg = bufev->cbarg;
 196                 short what = bufev_private->eventcb_pending;
 197                 int err = bufev_private->errno_pending;
 198                 bufev_private->eventcb_pending = 0;
 199                 bufev_private->errno_pending = 0;
 200                 EVUTIL_SET_SOCKET_ERROR(err);
 201                 UNLOCKED(errorcb(bufev,what,cbarg));
 202         }
 203         _bufferevent_decref_and_unlock(bufev);
 204 #undef UNLOCKED
 205 }
 206
 207 #define SCHEDULE_DEFERRED(bevp)                                         \
 208         do {                                                            \
 209                 bufferevent_incref(&(bevp)->bev);                       \
 210                 event_deferred_cb_schedule(                             \
 211                         event_base_get_deferred_cb_queue((bevp)->bev.ev_base), \
 212                         &(bevp)->deferred);                             \
 213         } while (0)
 214
 215
 216 void
 217 _bufferevent_run_readcb(struct bufferevent *bufev)
 218 {
 219         /* Requires that we hold the lock and a reference */
 220         struct bufferevent_private *p =
 221             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 222         if (bufev->readcb == NULL)
 223                 return;
 224         if (p->options & BEV_OPT_DEFER_CALLBACKS) {
 225                 p->readcb_pending = 1;
 226                 if (!p->deferred.queued)
 227                         SCHEDULE_DEFERRED(p);
 228         } else {
 229                 bufev->readcb(bufev, bufev->cbarg);
 230         }
 231 }
 232
 233 void
 234 _bufferevent_run_writecb(struct bufferevent *bufev)
 235 {
 236         /* Requires that we hold the lock and a reference */
 237         struct bufferevent_private *p =
 238             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 239         if (bufev->writecb == NULL)
 240                 return;
 241         if (p->options & BEV_OPT_DEFER_CALLBACKS) {
 242                 p->writecb_pending = 1;
 243                 if (!p->deferred.queued)
 244                         SCHEDULE_DEFERRED(p);
 245         } else {
 246                 bufev->writecb(bufev, bufev->cbarg);
 247         }
 248 }
 249
 250 void
 251 _bufferevent_run_eventcb(struct bufferevent *bufev, short what)
 252 {
 253         /* Requires that we hold the lock and a reference */
 254         struct bufferevent_private *p =
 255             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 256         if (bufev->errorcb == NULL)
 257                 return;
 258         if (p->options & BEV_OPT_DEFER_CALLBACKS) {
 259                 p->eventcb_pending |= what;
 260                 p->errno_pending = EVUTIL_SOCKET_ERROR();
 261                 if (!p->deferred.queued)
 262                         SCHEDULE_DEFERRED(p);
 263         } else {
 264                 bufev->errorcb(bufev, what, bufev->cbarg);
 265         }
 266 }
 267
 268 int
 269 bufferevent_init_common(struct bufferevent_private *bufev_private,
 270     struct event_base *base,
 271     const struct bufferevent_ops *ops,
 272     enum bufferevent_options options)
 273 {
 274         struct bufferevent *bufev = &bufev_private->bev;
 275
 276         if (!bufev->input) {
 277                 if ((bufev->input = evbuffer_new()) == NULL)
 278                         return -1;
 279         }
 280
 281         if (!bufev->output) {
 282                 if ((bufev->output = evbuffer_new()) == NULL) {
 283                         evbuffer_free(bufev->input);
 284                         return -1;
 285                 }
 286         }
 287
 288         bufev_private->refcnt = 1;
 289         bufev->ev_base = base;
 290
 291         /* Disable timeouts. */
 292         evutil_timerclear(&bufev->timeout_read);
 293         evutil_timerclear(&bufev->timeout_write);
 294
 295         bufev->be_ops = ops;
 296
 297         /*
 298          * Set to EV_WRITE so that using bufferevent_write is going to
 299          * trigger a callback.  Reading needs to be explicitly enabled
 300          * because otherwise no data will be available.
 301          */
 302         bufev->enabled = EV_WRITE;
 303
 304 #ifndef _EVENT_DISABLE_THREAD_SUPPORT
 305         if (options & BEV_OPT_THREADSAFE) {
 306                 if (bufferevent_enable_locking(bufev, NULL) < 0) {
 307                         /* cleanup */
 308                         evbuffer_free(bufev->input);
 309                         evbuffer_free(bufev->output);
 310                         bufev->input = NULL;
 311                         bufev->output = NULL;
 312                         return -1;
 313                 }
 314         }
 315 #endif
 316         if ((options & (BEV_OPT_DEFER_CALLBACKS|BEV_OPT_UNLOCK_CALLBACKS))
 317             == BEV_OPT_UNLOCK_CALLBACKS) {
 318                 event_warnx("UNLOCK_CALLBACKS requires DEFER_CALLBACKS");
 319                 return -1;
 320         }
 321         if (options & BEV_OPT_DEFER_CALLBACKS) {
 322                 if (options & BEV_OPT_UNLOCK_CALLBACKS)
 323                         event_deferred_cb_init(&bufev_private->deferred,
 324                             bufferevent_run_deferred_callbacks_unlocked,
 325                             bufev_private);
 326                 else
 327                         event_deferred_cb_init(&bufev_private->deferred,
 328                             bufferevent_run_deferred_callbacks_locked,
 329                             bufev_private);
 330         }
 331
 332         bufev_private->options = options;
 333
 334         evbuffer_set_parent(bufev->input, bufev);
 335         evbuffer_set_parent(bufev->output, bufev);
 336
 337         return 0;
 338 }
 339
 340 void
 341 bufferevent_setcb(struct bufferevent *bufev,
 342     bufferevent_data_cb readcb, bufferevent_data_cb writecb,
 343     bufferevent_event_cb eventcb, void *cbarg)
 344 {
 345         BEV_LOCK(bufev);
 346
 347         bufev->readcb = readcb;
 348         bufev->writecb = writecb;
 349         bufev->errorcb = eventcb;
 350
 351         bufev->cbarg = cbarg;
 352         BEV_UNLOCK(bufev);
 353 }
 354
 355 struct evbuffer *
 356 bufferevent_get_input(struct bufferevent *bufev)
 357 {
 358         return bufev->input;
 359 }
 360
 361 struct evbuffer *
 362 bufferevent_get_output(struct bufferevent *bufev)
 363 {
 364         return bufev->output;
 365 }
 366
 367 struct event_base *
 368 bufferevent_get_base(struct bufferevent *bufev)
 369 {
 370         return bufev->ev_base;
 371 }
 372
 373 int
 374 bufferevent_write(struct bufferevent *bufev, const void *data, size_t size)
 375 {
 376         if (evbuffer_add(bufev->output, data, size) == -1)
 377                 return (-1);
 378
 379         return 0;
 380 }
 381
 382 int
 383 bufferevent_write_buffer(struct bufferevent *bufev, struct evbuffer *buf)
 384 {
 385         if (evbuffer_add_buffer(bufev->output, buf) == -1)
 386                 return (-1);
 387
 388         return 0;
 389 }
 390
 391 size_t
 392 bufferevent_read(struct bufferevent *bufev, void *data, size_t size)
 393 {
 394         return (evbuffer_remove(bufev->input, data, size));
 395 }
 396
 397 int
 398 bufferevent_read_buffer(struct bufferevent *bufev, struct evbuffer *buf)
 399 {
 400         return (evbuffer_add_buffer(buf, bufev->input));
 401 }
 402
 403 int
 404 bufferevent_enable(struct bufferevent *bufev, short event)
 405 {
 406         struct bufferevent_private *bufev_private =
 407             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 408         short impl_events = event;
 409         int r = 0;
 410
 411         _bufferevent_incref_and_lock(bufev);
 412         if (bufev_private->read_suspended)
 413                 impl_events &= ~EV_READ;
 414         if (bufev_private->write_suspended)
 415                 impl_events &= ~EV_WRITE;
 416
 417         bufev->enabled |= event;
 418
 419         if (impl_events && bufev->be_ops->enable(bufev, impl_events) < 0)
 420                 r = -1;
 421
 422         _bufferevent_decref_and_unlock(bufev);
 423         return r;
 424 }
 425
 426 int
 427 bufferevent_set_timeouts(struct bufferevent *bufev,
 428                          const struct timeval *tv_read,
 429                          const struct timeval *tv_write)
 430 {
 431         int r = 0;
 432         BEV_LOCK(bufev);
 433         if (tv_read) {
 434                 bufev->timeout_read = *tv_read;
 435         } else {
 436                 evutil_timerclear(&bufev->timeout_read);
 437         }
 438         if (tv_write) {
 439                 bufev->timeout_write = *tv_write;
 440         } else {
 441                 evutil_timerclear(&bufev->timeout_write);
 442         }
 443
 444         if (bufev->be_ops->adj_timeouts)
 445                 r = bufev->be_ops->adj_timeouts(bufev);
 446         BEV_UNLOCK(bufev);
 447
 448         return r;
 449 }
 450
 451
 452 /* Obsolete; use bufferevent_set_timeouts */
 453 void
 454 bufferevent_settimeout(struct bufferevent *bufev,
 455                        int timeout_read, int timeout_write)
 456 {
 457         struct timeval tv_read, tv_write;
 458         struct timeval *ptv_read = NULL, *ptv_write = NULL;
 459
 460         memset(&tv_read, 0, sizeof(tv_read));
 461         memset(&tv_write, 0, sizeof(tv_write));
 462
 463         if (timeout_read) {
 464                 tv_read.tv_sec = timeout_read;
 465                 ptv_read = &tv_read;
 466         }
 467         if (timeout_write) {
 468                 tv_write.tv_sec = timeout_write;
 469                 ptv_write = &tv_write;
 470         }
 471
 472         bufferevent_set_timeouts(bufev, ptv_read, ptv_write);
 473 }
 474
 475
 476 int
 477 bufferevent_disable(struct bufferevent *bufev, short event)
 478 {
 479         int r = 0;
 480
 481         BEV_LOCK(bufev);
 482         bufev->enabled &= ~event;
 483
 484         if (bufev->be_ops->disable(bufev, event) < 0)
 485                 r = -1;
 486
 487         BEV_UNLOCK(bufev);
 488         return r;
 489 }
 490
 491 /*
 492  * Sets the water marks
 493  */
 494
 495 void
 496 bufferevent_setwatermark(struct bufferevent *bufev, short events,
 497     size_t lowmark, size_t highmark)
 498 {
 499         struct bufferevent_private *bufev_private =
 500             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 501
 502         BEV_LOCK(bufev);
 503         if (events & EV_WRITE) {
 504                 bufev->wm_write.low = lowmark;
 505                 bufev->wm_write.high = highmark;
 506         }
 507
 508         if (events & EV_READ) {
 509                 bufev->wm_read.low = lowmark;
 510                 bufev->wm_read.high = highmark;
 511
 512                 if (highmark) {
 513                         /* There is now a new high-water mark for read.
 514                            enable the callback if needed, and see if we should
 515                            suspend/bufferevent_wm_unsuspend. */
 516
 517                         if (bufev_private->read_watermarks_cb == NULL) {
 518                                 bufev_private->read_watermarks_cb =
 519                                     evbuffer_add_cb(bufev->input,
 520                                                     bufferevent_inbuf_wm_cb,
 521                                                     bufev);
 522                         }
 523                         evbuffer_cb_set_flags(bufev->input,
 524                                       bufev_private->read_watermarks_cb,
 525                                       EVBUFFER_CB_ENABLED|EVBUFFER_CB_NODEFER);
 526
 527                         if (evbuffer_get_length(bufev->input) > highmark)
 528                                 bufferevent_wm_suspend_read(bufev);
 529                         else if (evbuffer_get_length(bufev->input) < highmark)
 530                                 bufferevent_wm_unsuspend_read(bufev);
 531                 } else {
 532                         /* There is now no high-water mark for read. */
 533                         if (bufev_private->read_watermarks_cb)
 534                                 evbuffer_cb_clear_flags(bufev->input,
 535                                     bufev_private->read_watermarks_cb,
 536                                     EVBUFFER_CB_ENABLED);
 537                         bufferevent_wm_unsuspend_read(bufev);
 538                 }
 539         }
 540         BEV_UNLOCK(bufev);
 541 }
 542
 543 int
 544 bufferevent_flush(struct bufferevent *bufev,
 545     short iotype,
 546     enum bufferevent_flush_mode mode)
 547 {
 548         int r = -1;
 549         BEV_LOCK(bufev);
 550         if (bufev->be_ops->flush)
 551                 r = bufev->be_ops->flush(bufev, iotype, mode);
 552         BEV_UNLOCK(bufev);
 553         return r;
 554 }
 555
 556 void
 557 _bufferevent_incref_and_lock(struct bufferevent *bufev)
 558 {
 559         struct bufferevent_private *bufev_private =
 560             BEV_UPCAST(bufev);
 561         BEV_LOCK(bufev);
 562         ++bufev_private->refcnt;
 563 }
 564
 565 #if 0
 566 static void
 567 _bufferevent_transfer_lock_ownership(struct bufferevent *donor,
 568     struct bufferevent *recipient)
 569 {
 570         struct bufferevent_private *d = BEV_UPCAST(donor);
 571         struct bufferevent_private *r = BEV_UPCAST(recipient);
 572         if (d->lock != r->lock)
 573                 return;
 574         if (r->own_lock)
 575                 return;
 576         if (d->own_lock) {
 577                 d->own_lock = 0;
 578                 r->own_lock = 1;
 579         }
 580 }
 581 #endif
 582
 583 int
 584 _bufferevent_decref_and_unlock(struct bufferevent *bufev)
 585 {
 586         struct bufferevent_private *bufev_private =
 587             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 588         struct bufferevent *underlying;
 589
 590         EVUTIL_ASSERT(bufev_private->refcnt > 0);
 591
 592         if (--bufev_private->refcnt) {
 593                 BEV_UNLOCK(bufev);
 594                 return 0;
 595         }
 596
 597         underlying = bufferevent_get_underlying(bufev);
 598
 599         /* Clean up the shared info */
 600         if (bufev->be_ops->destruct)
 601                 bufev->be_ops->destruct(bufev);
 602
 603         /* XXX what happens if refcnt for these buffers is > 1?
 604          * The buffers can share a lock with this bufferevent object,
 605          * but the lock might be destroyed below. */
 606         /* evbuffer will free the callbacks */
 607         evbuffer_free(bufev->input);
 608         evbuffer_free(bufev->output);
 609
 610         if (bufev_private->rate_limiting) {
 611                 if (bufev_private->rate_limiting->group)
 612                         bufferevent_remove_from_rate_limit_group_internal(bufev,0);
 613                 if (event_initialized(&bufev_private->rate_limiting->refill_bucket_event))
 614                         event_del(&bufev_private->rate_limiting->refill_bucket_event);
 615                 event_debug_unassign(&bufev_private->rate_limiting->refill_bucket_event);
 616                 mm_free(bufev_private->rate_limiting);
 617                 bufev_private->rate_limiting = NULL;
 618         }
 619
 620         event_debug_unassign(&bufev->ev_read);
 621         event_debug_unassign(&bufev->ev_write);
 622
 623         BEV_UNLOCK(bufev);
 624         if (bufev_private->own_lock)
 625                 EVTHREAD_FREE_LOCK(bufev_private->lock,
 626                     EVTHREAD_LOCKTYPE_RECURSIVE);
 627
 628         /* Free the actual allocated memory. */
 629         mm_free(((char*)bufev) - bufev->be_ops->mem_offset);
 630
 631         /* Release the reference to underlying now that we no longer need the
 632          * reference to it.  We wait this long mainly in case our lock is
 633          * shared with underlying.
 634          *
 635          * The 'destruct' function will also drop a reference to underlying
 636          * if BEV_OPT_CLOSE_ON_FREE is set.
 637          *
 638          * XXX Should we/can we just refcount evbuffer/bufferevent locks?
 639          * It would probably save us some headaches.
 640          */
 641         if (underlying)
 642                 bufferevent_decref(underlying);
 643
 644         return 1;
 645 }
 646
 647 int
 648 bufferevent_decref(struct bufferevent *bufev)
 649 {
 650         BEV_LOCK(bufev);
 651         return _bufferevent_decref_and_unlock(bufev);
 652 }
 653
 654 void
 655 bufferevent_free(struct bufferevent *bufev)
 656 {
 657         BEV_LOCK(bufev);
 658         bufferevent_setcb(bufev, NULL, NULL, NULL, NULL);
 659         _bufferevent_decref_and_unlock(bufev);
 660 }
 661
 662 void
 663 bufferevent_incref(struct bufferevent *bufev)
 664 {
 665         struct bufferevent_private *bufev_private =
 666             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 667
 668         BEV_LOCK(bufev);
 669         ++bufev_private->refcnt;
 670         BEV_UNLOCK(bufev);
 671 }
 672
 673 int
 674 bufferevent_enable_locking(struct bufferevent *bufev, void *lock)
 675 {
 676 #ifdef _EVENT_DISABLE_THREAD_SUPPORT
 677         return -1;
 678 #else
 679         struct bufferevent *underlying;
 680
 681         if (BEV_UPCAST(bufev)->lock)
 682                 return -1;
 683         underlying = bufferevent_get_underlying(bufev);
 684
 685         if (!lock && underlying && BEV_UPCAST(underlying)->lock) {
 686                 lock = BEV_UPCAST(underlying)->lock;
 687                 BEV_UPCAST(bufev)->lock = lock;
 688                 BEV_UPCAST(bufev)->own_lock = 0;
 689         } else if (!lock) {
 690                 EVTHREAD_ALLOC_LOCK(lock, EVTHREAD_LOCKTYPE_RECURSIVE);
 691                 if (!lock)
 692                         return -1;
 693                 BEV_UPCAST(bufev)->lock = lock;
 694                 BEV_UPCAST(bufev)->own_lock = 1;
 695         } else {
 696                 BEV_UPCAST(bufev)->lock = lock;
 697                 BEV_UPCAST(bufev)->own_lock = 0;
 698         }
 699         evbuffer_enable_locking(bufev->input, lock);
 700         evbuffer_enable_locking(bufev->output, lock);
 701
 702         if (underlying && !BEV_UPCAST(underlying)->lock)
 703                 bufferevent_enable_locking(underlying, lock);
 704
 705         return 0;
 706 #endif
 707 }
 708
 709 int
 710 bufferevent_setfd(struct bufferevent *bev, evutil_socket_t fd)
 711 {
 712         union bufferevent_ctrl_data d;
 713         int res = -1;
 714         d.fd = fd;
 715         BEV_LOCK(bev);
 716         if (bev->be_ops->ctrl)
 717                 res = bev->be_ops->ctrl(bev, BEV_CTRL_SET_FD, &d);
 718         BEV_UNLOCK(bev);
 719         return res;
 720 }
 721
 722 evutil_socket_t
 723 bufferevent_getfd(struct bufferevent *bev)
 724 {
 725         union bufferevent_ctrl_data d;
 726         int res = -1;
 727         d.fd = -1;
 728         BEV_LOCK(bev);
 729         if (bev->be_ops->ctrl)
 730                 res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_FD, &d);
 731         BEV_UNLOCK(bev);
 732         return (res<0) ? -1 : d.fd;
 733 }
 734
 735 short
 736 bufferevent_get_enabled(struct bufferevent *bufev)
 737 {
 738         short r;
 739         BEV_LOCK(bufev);
 740         r = bufev->enabled;
 741         BEV_UNLOCK(bufev);
 742         return r;
 743 }
 744
 745 struct bufferevent *
 746 bufferevent_get_underlying(struct bufferevent *bev)
 747 {
 748         union bufferevent_ctrl_data d;
 749         int res = -1;
 750         d.ptr = NULL;
 751         BEV_LOCK(bev);
 752         if (bev->be_ops->ctrl)
 753                 res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_UNDERLYING, &d);
 754         BEV_UNLOCK(bev);
 755         return (res<0) ? NULL : d.ptr;
 756 }
 757
 758 static void
 759 bufferevent_generic_read_timeout_cb(evutil_socket_t fd, short event, void *ctx)
 760 {
 761         struct bufferevent *bev = ctx;
 762         _bufferevent_incref_and_lock(bev);
 763         bufferevent_disable(bev, EV_READ);
 764         _bufferevent_run_eventcb(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_READING);
 765         _bufferevent_decref_and_unlock(bev);
 766 }
 767 static void
 768 bufferevent_generic_write_timeout_cb(evutil_socket_t fd, short event, void *ctx)
 769 {
 770         struct bufferevent *bev = ctx;
 771         _bufferevent_incref_and_lock(bev);
 772         bufferevent_disable(bev, EV_WRITE);
 773         _bufferevent_run_eventcb(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_WRITING);
 774         _bufferevent_decref_and_unlock(bev);
 775 }
 776
 777 void
 778 _bufferevent_init_generic_timeout_cbs(struct bufferevent *bev)
 779 {
 780         evtimer_assign(&bev->ev_read, bev->ev_base,
 781             bufferevent_generic_read_timeout_cb, bev);
 782         evtimer_assign(&bev->ev_write, bev->ev_base,
 783             bufferevent_generic_write_timeout_cb, bev);
 784 }
 785
 786 int
 787 _bufferevent_del_generic_timeout_cbs(struct bufferevent *bev)
 788 {
 789         int r1,r2;
 790         r1 = event_del(&bev->ev_read);
 791         r2 = event_del(&bev->ev_write);
 792         if (r1<0 || r2<0)
 793                 return -1;
 794         return 0;
 795 }
 796
 797 int
 798 _bufferevent_generic_adj_timeouts(struct bufferevent *bev)
 799 {
 800         const short enabled = bev->enabled;
 801         struct bufferevent_private *bev_p =
 802             EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
 803         int r1=0, r2=0;
 804         if ((enabled & EV_READ) && !bev_p->read_suspended &&
 805             evutil_timerisset(&bev->timeout_read))
 806                 r1 = event_add(&bev->ev_read, &bev->timeout_read);
 807         else
 808                 r1 = event_del(&bev->ev_read);
 809
 810         if ((enabled & EV_WRITE) && !bev_p->write_suspended &&
 811             evutil_timerisset(&bev->timeout_write) &&
 812             evbuffer_get_length(bev->output))
 813                 r2 = event_add(&bev->ev_write, &bev->timeout_write);
 814         else
 815                 r2 = event_del(&bev->ev_write);
 816         if (r1 < 0 || r2 < 0)
 817                 return -1;
 818         return 0;
 819 }
 820
 821 int
 822 _bufferevent_add_event(struct event *ev, const struct timeval *tv)
 823 {
 824         if (tv->tv_sec == 0 && tv->tv_usec == 0)
 825                 return event_add(ev, NULL);
 826         else
 827                 return event_add(ev, tv);
 828 }
 829
 830 /* For use by user programs only; internally, we should be calling
 831    either _bufferevent_incref_and_lock(), or BEV_LOCK. */
 832 void
 833 bufferevent_lock(struct bufferevent *bev)
 834 {
 835         _bufferevent_incref_and_lock(bev);
 836 }
 837
 838 void
 839 bufferevent_unlock(struct bufferevent *bev)
 840 {
 841         _bufferevent_decref_and_unlock(bev);
 842 }