bufferevent.c

   1 /*
   2  * Copyright (c) 2002-2007 Niels Provos <provos@citi.umich.edu>
   3  * Copyright (c) 2007-2012 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 "event2/event-config.h"
  29 #include "evconfig-private.h"
  30
  31 #include <sys/types.h>
  32
  33 #ifdef EVENT__HAVE_SYS_TIME_H
  34 #include <sys/time.h>
  35 #endif
  36
  37 #include <errno.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #ifdef EVENT__HAVE_STDARG_H
  42 #include <stdarg.h>
  43 #endif
  44
  45 #ifdef _WIN32
  46 #include <winsock2.h>
  47 #endif
  48 #include <errno.h>
  49
  50 #include "event2/util.h"
  51 #include "event2/buffer.h"
  52 #include "event2/buffer_compat.h"
  53 #include "event2/bufferevent.h"
  54 #include "event2/bufferevent_struct.h"
  55 #include "event2/bufferevent_compat.h"
  56 #include "event2/event.h"
  57 #include "event-internal.h"
  58 #include "log-internal.h"
  59 #include "mm-internal.h"
  60 #include "bufferevent-internal.h"
  61 #include "evbuffer-internal.h"
  62 #include "util-internal.h"
  63
  64 static void bufferevent_cancel_all_(struct bufferevent *bev);
  65 static void bufferevent_finalize_cb_(struct event_callback *evcb, void *arg_);
  66
  67 void
  68 bufferevent_suspend_read_(struct bufferevent *bufev, bufferevent_suspend_flags what)
  69 {
  70         struct bufferevent_private *bufev_private =
  71             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
  72         BEV_LOCK(bufev);
  73         if (!bufev_private->read_suspended)
  74                 bufev->be_ops->disable(bufev, EV_READ);
  75         bufev_private->read_suspended |= what;
  76         BEV_UNLOCK(bufev);
  77 }
  78
  79 void
  80 bufferevent_unsuspend_read_(struct bufferevent *bufev, bufferevent_suspend_flags what)
  81 {
  82         struct bufferevent_private *bufev_private =
  83             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
  84         BEV_LOCK(bufev);
  85         bufev_private->read_suspended &= ~what;
  86         if (!bufev_private->read_suspended && (bufev->enabled & EV_READ))
  87                 bufev->be_ops->enable(bufev, EV_READ);
  88         BEV_UNLOCK(bufev);
  89 }
  90
  91 void
  92 bufferevent_suspend_write_(struct bufferevent *bufev, bufferevent_suspend_flags what)
  93 {
  94         struct bufferevent_private *bufev_private =
  95             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
  96         BEV_LOCK(bufev);
  97         if (!bufev_private->write_suspended)
  98                 bufev->be_ops->disable(bufev, EV_WRITE);
  99         bufev_private->write_suspended |= what;
 100         BEV_UNLOCK(bufev);
 101 }
 102
 103 void
 104 bufferevent_unsuspend_write_(struct bufferevent *bufev, bufferevent_suspend_flags what)
 105 {
 106         struct bufferevent_private *bufev_private =
 107             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 108         BEV_LOCK(bufev);
 109         bufev_private->write_suspended &= ~what;
 110         if (!bufev_private->write_suspended && (bufev->enabled & EV_WRITE))
 111                 bufev->be_ops->enable(bufev, EV_WRITE);
 112         BEV_UNLOCK(bufev);
 113 }
 114
 115
 116 /* Callback to implement watermarks on the input buffer.  Only enabled
 117  * if the watermark is set. */
 118 static void
 119 bufferevent_inbuf_wm_cb(struct evbuffer *buf,
 120     const struct evbuffer_cb_info *cbinfo,
 121     void *arg)
 122 {
 123         struct bufferevent *bufev = arg;
 124         size_t size;
 125
 126         size = evbuffer_get_length(buf);
 127
 128         if (size >= bufev->wm_read.high)
 129                 bufferevent_wm_suspend_read(bufev);
 130         else
 131                 bufferevent_wm_unsuspend_read(bufev);
 132 }
 133
 134 static void
 135 bufferevent_run_deferred_callbacks_locked(struct event_callback *cb, void *arg)
 136 {
 137         struct bufferevent_private *bufev_private = arg;
 138         struct bufferevent *bufev = &bufev_private->bev;
 139
 140         BEV_LOCK(bufev);
 141         if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
 142             bufev->errorcb) {
 143                 /* The "connected" happened before any reads or writes, so
 144                    send it first. */
 145                 bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
 146                 bufev->errorcb(bufev, BEV_EVENT_CONNECTED, bufev->cbarg);
 147         }
 148         if (bufev_private->readcb_pending && bufev->readcb) {
 149                 bufev_private->readcb_pending = 0;
 150                 bufev->readcb(bufev, bufev->cbarg);
 151         }
 152         if (bufev_private->writecb_pending && bufev->writecb) {
 153                 bufev_private->writecb_pending = 0;
 154                 bufev->writecb(bufev, bufev->cbarg);
 155         }
 156         if (bufev_private->eventcb_pending && bufev->errorcb) {
 157                 short what = bufev_private->eventcb_pending;
 158                 int err = bufev_private->errno_pending;
 159                 bufev_private->eventcb_pending = 0;
 160                 bufev_private->errno_pending = 0;
 161                 EVUTIL_SET_SOCKET_ERROR(err);
 162                 bufev->errorcb(bufev, what, bufev->cbarg);
 163         }
 164         bufferevent_decref_and_unlock_(bufev);
 165 }
 166
 167 static void
 168 bufferevent_run_deferred_callbacks_unlocked(struct event_callback *cb, void *arg)
 169 {
 170         struct bufferevent_private *bufev_private = arg;
 171         struct bufferevent *bufev = &bufev_private->bev;
 172
 173         BEV_LOCK(bufev);
 174 #define UNLOCKED(stmt) \
 175         do { BEV_UNLOCK(bufev); stmt; BEV_LOCK(bufev); } while(0)
 176
 177         if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
 178             bufev->errorcb) {
 179                 /* The "connected" happened before any reads or writes, so
 180                    send it first. */
 181                 bufferevent_event_cb errorcb = bufev->errorcb;
 182                 void *cbarg = bufev->cbarg;
 183                 bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
 184                 UNLOCKED(errorcb(bufev, BEV_EVENT_CONNECTED, cbarg));
 185         }
 186         if (bufev_private->readcb_pending && bufev->readcb) {
 187                 bufferevent_data_cb readcb = bufev->readcb;
 188                 void *cbarg = bufev->cbarg;
 189                 bufev_private->readcb_pending = 0;
 190                 UNLOCKED(readcb(bufev, cbarg));
 191         }
 192         if (bufev_private->writecb_pending && bufev->writecb) {
 193                 bufferevent_data_cb writecb = bufev->writecb;
 194                 void *cbarg = bufev->cbarg;
 195                 bufev_private->writecb_pending = 0;
 196                 UNLOCKED(writecb(bufev, cbarg));
 197         }
 198         if (bufev_private->eventcb_pending && bufev->errorcb) {
 199                 bufferevent_event_cb errorcb = bufev->errorcb;
 200                 void *cbarg = bufev->cbarg;
 201                 short what = bufev_private->eventcb_pending;
 202                 int err = bufev_private->errno_pending;
 203                 bufev_private->eventcb_pending = 0;
 204                 bufev_private->errno_pending = 0;
 205                 EVUTIL_SET_SOCKET_ERROR(err);
 206                 UNLOCKED(errorcb(bufev,what,cbarg));
 207         }
 208         bufferevent_decref_and_unlock_(bufev);
 209 #undef UNLOCKED
 210 }
 211
 212 #define SCHEDULE_DEFERRED(bevp)                                         \
 213         do {                                                            \
 214                 if (event_deferred_cb_schedule_(                        \
 215                             (bevp)->bev.ev_base,                        \
 216                         &(bevp)->deferred))                             \
 217                         bufferevent_incref_(&(bevp)->bev);              \
 218         } while (0)
 219
 220
 221 void
 222 bufferevent_run_readcb_(struct bufferevent *bufev, int options)
 223 {
 224         /* Requires that we hold the lock and a reference */
 225         struct bufferevent_private *p =
 226             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 227         if (bufev->readcb == NULL)
 228                 return;
 229         if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 230                 p->readcb_pending = 1;
 231                 SCHEDULE_DEFERRED(p);
 232         } else {
 233                 bufev->readcb(bufev, bufev->cbarg);
 234         }
 235 }
 236
 237 void
 238 bufferevent_run_writecb_(struct bufferevent *bufev, int options)
 239 {
 240         /* Requires that we hold the lock and a reference */
 241         struct bufferevent_private *p =
 242             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 243         if (bufev->writecb == NULL)
 244                 return;
 245         if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 246                 p->writecb_pending = 1;
 247                 SCHEDULE_DEFERRED(p);
 248         } else {
 249                 bufev->writecb(bufev, bufev->cbarg);
 250         }
 251 }
 252
 253 #define BEV_TRIG_ALL_OPTS (                     \
 254                 BEV_TRIG_IGNORE_WATERMARKS|     \
 255                 BEV_TRIG_DEFER_CALLBACKS        \
 256         )
 257
 258 void
 259 bufferevent_trigger(struct bufferevent *bufev, short iotype, int options)
 260 {
 261         bufferevent_incref_and_lock_(bufev);
 262         bufferevent_trigger_nolock_(bufev, iotype, options&BEV_TRIG_ALL_OPTS);
 263         bufferevent_decref_and_unlock_(bufev);
 264 }
 265
 266 void
 267 bufferevent_run_eventcb_(struct bufferevent *bufev, short what, int options)
 268 {
 269         /* Requires that we hold the lock and a reference */
 270         struct bufferevent_private *p =
 271             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 272         if (bufev->errorcb == NULL)
 273                 return;
 274         if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 275                 p->eventcb_pending |= what;
 276                 p->errno_pending = EVUTIL_SOCKET_ERROR();
 277                 SCHEDULE_DEFERRED(p);
 278         } else {
 279                 bufev->errorcb(bufev, what, bufev->cbarg);
 280         }
 281 }
 282
 283 void
 284 bufferevent_trigger_event(struct bufferevent *bufev, short what, int options)
 285 {
 286         bufferevent_incref_and_lock_(bufev);
 287         bufferevent_run_eventcb_(bufev, what, options&BEV_TRIG_ALL_OPTS);
 288         bufferevent_decref_and_unlock_(bufev);
 289 }
 290
 291 int
 292 bufferevent_init_common_(struct bufferevent_private *bufev_private,
 293     struct event_base *base,
 294     const struct bufferevent_ops *ops,
 295     enum bufferevent_options options)
 296 {
 297         struct bufferevent *bufev = &bufev_private->bev;
 298
 299         if (!bufev->input) {
 300                 if ((bufev->input = evbuffer_new()) == NULL)
 301                         return -1;
 302         }
 303
 304         if (!bufev->output) {
 305                 if ((bufev->output = evbuffer_new()) == NULL) {
 306                         evbuffer_free(bufev->input);
 307                         return -1;
 308                 }
 309         }
 310
 311         bufev_private->refcnt = 1;
 312         bufev->ev_base = base;
 313
 314         /* Disable timeouts. */
 315         evutil_timerclear(&bufev->timeout_read);
 316         evutil_timerclear(&bufev->timeout_write);
 317
 318         bufev->be_ops = ops;
 319
 320         bufferevent_ratelim_init_(bufev_private);
 321
 322         /*
 323          * Set to EV_WRITE so that using bufferevent_write is going to
 324          * trigger a callback.  Reading needs to be explicitly enabled
 325          * because otherwise no data will be available.
 326          */
 327         bufev->enabled = EV_WRITE;
 328
 329 #ifndef EVENT__DISABLE_THREAD_SUPPORT
 330         if (options & BEV_OPT_THREADSAFE) {
 331                 if (bufferevent_enable_locking_(bufev, NULL) < 0) {
 332                         /* cleanup */
 333                         evbuffer_free(bufev->input);
 334                         evbuffer_free(bufev->output);
 335                         bufev->input = NULL;
 336                         bufev->output = NULL;
 337                         return -1;
 338                 }
 339         }
 340 #endif
 341         if ((options & (BEV_OPT_DEFER_CALLBACKS|BEV_OPT_UNLOCK_CALLBACKS))
 342             == BEV_OPT_UNLOCK_CALLBACKS) {
 343                 event_warnx("UNLOCK_CALLBACKS requires DEFER_CALLBACKS");
 344                 return -1;
 345         }
 346         if (options & BEV_OPT_UNLOCK_CALLBACKS)
 347                 event_deferred_cb_init_(
 348                     &bufev_private->deferred,
 349                     event_base_get_npriorities(base) / 2,
 350                     bufferevent_run_deferred_callbacks_unlocked,
 351                     bufev_private);
 352         else
 353                 event_deferred_cb_init_(
 354                     &bufev_private->deferred,
 355                     event_base_get_npriorities(base) / 2,
 356                     bufferevent_run_deferred_callbacks_locked,
 357                     bufev_private);
 358
 359         bufev_private->options = options;
 360
 361         evbuffer_set_parent_(bufev->input, bufev);
 362         evbuffer_set_parent_(bufev->output, bufev);
 363
 364         return 0;
 365 }
 366
 367 void
 368 bufferevent_setcb(struct bufferevent *bufev,
 369     bufferevent_data_cb readcb, bufferevent_data_cb writecb,
 370     bufferevent_event_cb eventcb, void *cbarg)
 371 {
 372         BEV_LOCK(bufev);
 373
 374         bufev->readcb = readcb;
 375         bufev->writecb = writecb;
 376         bufev->errorcb = eventcb;
 377
 378         bufev->cbarg = cbarg;
 379         BEV_UNLOCK(bufev);
 380 }
 381
 382 void
 383 bufferevent_getcb(struct bufferevent *bufev,
 384     bufferevent_data_cb *readcb_ptr,
 385     bufferevent_data_cb *writecb_ptr,
 386     bufferevent_event_cb *eventcb_ptr,
 387     void **cbarg_ptr)
 388 {
 389         BEV_LOCK(bufev);
 390         if (readcb_ptr)
 391                 *readcb_ptr = bufev->readcb;
 392         if (writecb_ptr)
 393                 *writecb_ptr = bufev->writecb;
 394         if (eventcb_ptr)
 395                 *eventcb_ptr = bufev->errorcb;
 396         if (cbarg_ptr)
 397                 *cbarg_ptr = bufev->cbarg;
 398
 399         BEV_UNLOCK(bufev);
 400 }
 401
 402 struct evbuffer *
 403 bufferevent_get_input(struct bufferevent *bufev)
 404 {
 405         return bufev->input;
 406 }
 407
 408 struct evbuffer *
 409 bufferevent_get_output(struct bufferevent *bufev)
 410 {
 411         return bufev->output;
 412 }
 413
 414 struct event_base *
 415 bufferevent_get_base(struct bufferevent *bufev)
 416 {
 417         return bufev->ev_base;
 418 }
 419
 420 int
 421 bufferevent_get_priority(const struct bufferevent *bufev)
 422 {
 423         if (event_initialized(&bufev->ev_read)) {
 424                 return event_get_priority(&bufev->ev_read);
 425         } else {
 426                 return event_base_get_npriorities(bufev->ev_base) / 2;
 427         }
 428 }
 429
 430 int
 431 bufferevent_write(struct bufferevent *bufev, const void *data, size_t size)
 432 {
 433         if (evbuffer_add(bufev->output, data, size) == -1)
 434                 return (-1);
 435
 436         return 0;
 437 }
 438
 439 int
 440 bufferevent_write_buffer(struct bufferevent *bufev, struct evbuffer *buf)
 441 {
 442         if (evbuffer_add_buffer(bufev->output, buf) == -1)
 443                 return (-1);
 444
 445         return 0;
 446 }
 447
 448 size_t
 449 bufferevent_read(struct bufferevent *bufev, void *data, size_t size)
 450 {
 451         return (evbuffer_remove(bufev->input, data, size));
 452 }
 453
 454 int
 455 bufferevent_read_buffer(struct bufferevent *bufev, struct evbuffer *buf)
 456 {
 457         return (evbuffer_add_buffer(buf, bufev->input));
 458 }
 459
 460 int
 461 bufferevent_enable(struct bufferevent *bufev, short event)
 462 {
 463         struct bufferevent_private *bufev_private =
 464             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 465         short impl_events = event;
 466         int r = 0;
 467
 468         bufferevent_incref_and_lock_(bufev);
 469         if (bufev_private->read_suspended)
 470                 impl_events &= ~EV_READ;
 471         if (bufev_private->write_suspended)
 472                 impl_events &= ~EV_WRITE;
 473
 474         bufev->enabled |= event;
 475
 476         if (impl_events && bufev->be_ops->enable(bufev, impl_events) < 0)
 477                 r = -1;
 478
 479         bufferevent_decref_and_unlock_(bufev);
 480         return r;
 481 }
 482
 483 int
 484 bufferevent_set_timeouts(struct bufferevent *bufev,
 485                          const struct timeval *tv_read,
 486                          const struct timeval *tv_write)
 487 {
 488         int r = 0;
 489         BEV_LOCK(bufev);
 490         if (tv_read) {
 491                 bufev->timeout_read = *tv_read;
 492         } else {
 493                 evutil_timerclear(&bufev->timeout_read);
 494         }
 495         if (tv_write) {
 496                 bufev->timeout_write = *tv_write;
 497         } else {
 498                 evutil_timerclear(&bufev->timeout_write);
 499         }
 500
 501         if (bufev->be_ops->adj_timeouts)
 502                 r = bufev->be_ops->adj_timeouts(bufev);
 503         BEV_UNLOCK(bufev);
 504
 505         return r;
 506 }
 507
 508
 509 /* Obsolete; use bufferevent_set_timeouts */
 510 void
 511 bufferevent_settimeout(struct bufferevent *bufev,
 512                        int timeout_read, int timeout_write)
 513 {
 514         struct timeval tv_read, tv_write;
 515         struct timeval *ptv_read = NULL, *ptv_write = NULL;
 516
 517         memset(&tv_read, 0, sizeof(tv_read));
 518         memset(&tv_write, 0, sizeof(tv_write));
 519
 520         if (timeout_read) {
 521                 tv_read.tv_sec = timeout_read;
 522                 ptv_read = &tv_read;
 523         }
 524         if (timeout_write) {
 525                 tv_write.tv_sec = timeout_write;
 526                 ptv_write = &tv_write;
 527         }
 528
 529         bufferevent_set_timeouts(bufev, ptv_read, ptv_write);
 530 }
 531
 532
 533 int
 534 bufferevent_disable_hard_(struct bufferevent *bufev, short event)
 535 {
 536         int r = 0;
 537         struct bufferevent_private *bufev_private =
 538             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 539
 540         BEV_LOCK(bufev);
 541         bufev->enabled &= ~event;
 542
 543         bufev_private->connecting = 0;
 544         if (bufev->be_ops->disable(bufev, event) < 0)
 545                 r = -1;
 546
 547         BEV_UNLOCK(bufev);
 548         return r;
 549 }
 550
 551 int
 552 bufferevent_disable(struct bufferevent *bufev, short event)
 553 {
 554         int r = 0;
 555
 556         BEV_LOCK(bufev);
 557         bufev->enabled &= ~event;
 558
 559         if (bufev->be_ops->disable(bufev, event) < 0)
 560                 r = -1;
 561
 562         BEV_UNLOCK(bufev);
 563         return r;
 564 }
 565
 566 /*
 567  * Sets the water marks
 568  */
 569
 570 void
 571 bufferevent_setwatermark(struct bufferevent *bufev, short events,
 572     size_t lowmark, size_t highmark)
 573 {
 574         struct bufferevent_private *bufev_private =
 575             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 576
 577         BEV_LOCK(bufev);
 578         if (events & EV_WRITE) {
 579                 bufev->wm_write.low = lowmark;
 580                 bufev->wm_write.high = highmark;
 581         }
 582
 583         if (events & EV_READ) {
 584                 bufev->wm_read.low = lowmark;
 585                 bufev->wm_read.high = highmark;
 586
 587                 if (highmark) {
 588                         /* There is now a new high-water mark for read.
 589                            enable the callback if needed, and see if we should
 590                            suspend/bufferevent_wm_unsuspend. */
 591
 592                         if (bufev_private->read_watermarks_cb == NULL) {
 593                                 bufev_private->read_watermarks_cb =
 594                                     evbuffer_add_cb(bufev->input,
 595                                                     bufferevent_inbuf_wm_cb,
 596                                                     bufev);
 597                         }
 598                         evbuffer_cb_set_flags(bufev->input,
 599                                       bufev_private->read_watermarks_cb,
 600                                       EVBUFFER_CB_ENABLED|EVBUFFER_CB_NODEFER);
 601
 602                         if (evbuffer_get_length(bufev->input) >= highmark)
 603                                 bufferevent_wm_suspend_read(bufev);
 604                         else if (evbuffer_get_length(bufev->input) < highmark)
 605                                 bufferevent_wm_unsuspend_read(bufev);
 606                 } else {
 607                         /* There is now no high-water mark for read. */
 608                         if (bufev_private->read_watermarks_cb)
 609                                 evbuffer_cb_clear_flags(bufev->input,
 610                                     bufev_private->read_watermarks_cb,
 611                                     EVBUFFER_CB_ENABLED);
 612                         bufferevent_wm_unsuspend_read(bufev);
 613                 }
 614         }
 615         BEV_UNLOCK(bufev);
 616 }
 617
 618 int
 619 bufferevent_getwatermark(struct bufferevent *bufev, short events,
 620     size_t *lowmark, size_t *highmark)
 621 {
 622         if (events == EV_WRITE) {
 623                 BEV_LOCK(bufev);
 624                 if (lowmark)
 625                         *lowmark = bufev->wm_write.low;
 626                 if (highmark)
 627                         *highmark = bufev->wm_write.high;
 628                 BEV_UNLOCK(bufev);
 629                 return 0;
 630         }
 631
 632         if (events == EV_READ) {
 633                 BEV_LOCK(bufev);
 634                 if (lowmark)
 635                         *lowmark = bufev->wm_read.low;
 636                 if (highmark)
 637                         *highmark = bufev->wm_read.high;
 638                 BEV_UNLOCK(bufev);
 639                 return 0;
 640         }
 641         return -1;
 642 }
 643
 644 int
 645 bufferevent_flush(struct bufferevent *bufev,
 646     short iotype,
 647     enum bufferevent_flush_mode mode)
 648 {
 649         int r = -1;
 650         BEV_LOCK(bufev);
 651         if (bufev->be_ops->flush)
 652                 r = bufev->be_ops->flush(bufev, iotype, mode);
 653         BEV_UNLOCK(bufev);
 654         return r;
 655 }
 656
 657 void
 658 bufferevent_incref_and_lock_(struct bufferevent *bufev)
 659 {
 660         struct bufferevent_private *bufev_private =
 661             BEV_UPCAST(bufev);
 662         BEV_LOCK(bufev);
 663         ++bufev_private->refcnt;
 664 }
 665
 666 #if 0
 667 static void
 668 bufferevent_transfer_lock_ownership_(struct bufferevent *donor,
 669     struct bufferevent *recipient)
 670 {
 671         struct bufferevent_private *d = BEV_UPCAST(donor);
 672         struct bufferevent_private *r = BEV_UPCAST(recipient);
 673         if (d->lock != r->lock)
 674                 return;
 675         if (r->own_lock)
 676                 return;
 677         if (d->own_lock) {
 678                 d->own_lock = 0;
 679                 r->own_lock = 1;
 680         }
 681 }
 682 #endif
 683
 684 int
 685 bufferevent_decref_and_unlock_(struct bufferevent *bufev)
 686 {
 687         struct bufferevent_private *bufev_private =
 688             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 689         int n_cbs = 0;
 690 #define MAX_CBS 16
 691         struct event_callback *cbs[MAX_CBS];
 692
 693         EVUTIL_ASSERT(bufev_private->refcnt > 0);
 694
 695         if (--bufev_private->refcnt) {
 696                 BEV_UNLOCK(bufev);
 697                 return 0;
 698         }
 699
 700         if (bufev->be_ops->unlink)
 701                 bufev->be_ops->unlink(bufev);
 702
 703         /* Okay, we're out of references. Let's finalize this once all the
 704          * callbacks are done running. */
 705         cbs[0] = &bufev->ev_read.ev_evcallback;
 706         cbs[1] = &bufev->ev_write.ev_evcallback;
 707         cbs[2] = &bufev_private->deferred;
 708         n_cbs = 3;
 709         if (bufev_private->rate_limiting) {
 710                 struct event *e = &bufev_private->rate_limiting->refill_bucket_event;
 711                 if (event_initialized(e))
 712                         cbs[n_cbs++] = &e->ev_evcallback;
 713         }
 714         n_cbs += evbuffer_get_callbacks_(bufev->input, cbs+n_cbs, MAX_CBS-n_cbs);
 715         n_cbs += evbuffer_get_callbacks_(bufev->output, cbs+n_cbs, MAX_CBS-n_cbs);
 716
 717         event_callback_finalize_many_(bufev->ev_base, n_cbs, cbs,
 718             bufferevent_finalize_cb_);
 719
 720 #undef MAX_CBS
 721         BEV_UNLOCK(bufev);
 722
 723         return 1;
 724 }
 725
 726 static void
 727 bufferevent_finalize_cb_(struct event_callback *evcb, void *arg_)
 728 {
 729         struct bufferevent *bufev = arg_;
 730         struct bufferevent *underlying;
 731         struct bufferevent_private *bufev_private =
 732             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 733
 734         BEV_LOCK(bufev);
 735         underlying = bufferevent_get_underlying(bufev);
 736
 737         /* Clean up the shared info */
 738         if (bufev->be_ops->destruct)
 739                 bufev->be_ops->destruct(bufev);
 740
 741         /* XXX what happens if refcnt for these buffers is > 1?
 742          * The buffers can share a lock with this bufferevent object,
 743          * but the lock might be destroyed below. */
 744         /* evbuffer will free the callbacks */
 745         evbuffer_free(bufev->input);
 746         evbuffer_free(bufev->output);
 747
 748         if (bufev_private->rate_limiting) {
 749                 if (bufev_private->rate_limiting->group)
 750                         bufferevent_remove_from_rate_limit_group_internal_(bufev,0);
 751                 mm_free(bufev_private->rate_limiting);
 752                 bufev_private->rate_limiting = NULL;
 753         }
 754
 755
 756         BEV_UNLOCK(bufev);
 757
 758         if (bufev_private->own_lock)
 759                 EVTHREAD_FREE_LOCK(bufev_private->lock,
 760                     EVTHREAD_LOCKTYPE_RECURSIVE);
 761
 762         /* Free the actual allocated memory. */
 763         mm_free(((char*)bufev) - bufev->be_ops->mem_offset);
 764
 765         /* Release the reference to underlying now that we no longer need the
 766          * reference to it.  We wait this long mainly in case our lock is
 767          * shared with underlying.
 768          *
 769          * The 'destruct' function will also drop a reference to underlying
 770          * if BEV_OPT_CLOSE_ON_FREE is set.
 771          *
 772          * XXX Should we/can we just refcount evbuffer/bufferevent locks?
 773          * It would probably save us some headaches.
 774          */
 775         if (underlying)
 776                 bufferevent_decref_(underlying);
 777 }
 778
 779 int
 780 bufferevent_decref(struct bufferevent *bufev)
 781 {
 782         BEV_LOCK(bufev);
 783         return bufferevent_decref_and_unlock_(bufev);
 784 }
 785
 786 void
 787 bufferevent_free(struct bufferevent *bufev)
 788 {
 789         BEV_LOCK(bufev);
 790         bufferevent_setcb(bufev, NULL, NULL, NULL, NULL);
 791         bufferevent_cancel_all_(bufev);
 792         bufferevent_decref_and_unlock_(bufev);
 793 }
 794
 795 void
 796 bufferevent_incref(struct bufferevent *bufev)
 797 {
 798         struct bufferevent_private *bufev_private =
 799             EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 800
 801         /* XXX: now that this function is public, we might want to
 802          * - return the count from this function
 803          * - create a new function to atomically grab the current refcount
 804          */
 805         BEV_LOCK(bufev);
 806         ++bufev_private->refcnt;
 807         BEV_UNLOCK(bufev);
 808 }
 809
 810 int
 811 bufferevent_enable_locking_(struct bufferevent *bufev, void *lock)
 812 {
 813 #ifdef EVENT__DISABLE_THREAD_SUPPORT
 814         return -1;
 815 #else
 816         struct bufferevent *underlying;
 817
 818         if (BEV_UPCAST(bufev)->lock)
 819                 return -1;
 820         underlying = bufferevent_get_underlying(bufev);
 821
 822         if (!lock && underlying && BEV_UPCAST(underlying)->lock) {
 823                 lock = BEV_UPCAST(underlying)->lock;
 824                 BEV_UPCAST(bufev)->lock = lock;
 825                 BEV_UPCAST(bufev)->own_lock = 0;
 826         } else if (!lock) {
 827                 EVTHREAD_ALLOC_LOCK(lock, EVTHREAD_LOCKTYPE_RECURSIVE);
 828                 if (!lock)
 829                         return -1;
 830                 BEV_UPCAST(bufev)->lock = lock;
 831                 BEV_UPCAST(bufev)->own_lock = 1;
 832         } else {
 833                 BEV_UPCAST(bufev)->lock = lock;
 834                 BEV_UPCAST(bufev)->own_lock = 0;
 835         }
 836         evbuffer_enable_locking(bufev->input, lock);
 837         evbuffer_enable_locking(bufev->output, lock);
 838
 839         if (underlying && !BEV_UPCAST(underlying)->lock)
 840                 bufferevent_enable_locking_(underlying, lock);
 841
 842         return 0;
 843 #endif
 844 }
 845
 846 int
 847 bufferevent_setfd(struct bufferevent *bev, evutil_socket_t fd)
 848 {
 849         union bufferevent_ctrl_data d;
 850         int res = -1;
 851         d.fd = fd;
 852         BEV_LOCK(bev);
 853         if (bev->be_ops->ctrl)
 854                 res = bev->be_ops->ctrl(bev, BEV_CTRL_SET_FD, &d);
 855         BEV_UNLOCK(bev);
 856         return res;
 857 }
 858
 859 evutil_socket_t
 860 bufferevent_getfd(struct bufferevent *bev)
 861 {
 862         union bufferevent_ctrl_data d;
 863         int res = -1;
 864         d.fd = -1;
 865         BEV_LOCK(bev);
 866         if (bev->be_ops->ctrl)
 867                 res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_FD, &d);
 868         BEV_UNLOCK(bev);
 869         return (res<0) ? -1 : d.fd;
 870 }
 871
 872 enum bufferevent_options
 873 bufferevent_get_options_(struct bufferevent *bev)
 874 {
 875         struct bufferevent_private *bev_p =
 876             EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
 877         enum bufferevent_options options;
 878
 879         BEV_LOCK(bev);
 880         options = bev_p->options;
 881         BEV_UNLOCK(bev);
 882         return options;
 883 }
 884
 885
 886 static void
 887 bufferevent_cancel_all_(struct bufferevent *bev)
 888 {
 889         union bufferevent_ctrl_data d;
 890         memset(&d, 0, sizeof(d));
 891         BEV_LOCK(bev);
 892         if (bev->be_ops->ctrl)
 893                 bev->be_ops->ctrl(bev, BEV_CTRL_CANCEL_ALL, &d);
 894         BEV_UNLOCK(bev);
 895 }
 896
 897 short
 898 bufferevent_get_enabled(struct bufferevent *bufev)
 899 {
 900         short r;
 901         BEV_LOCK(bufev);
 902         r = bufev->enabled;
 903         BEV_UNLOCK(bufev);
 904         return r;
 905 }
 906
 907 struct bufferevent *
 908 bufferevent_get_underlying(struct bufferevent *bev)
 909 {
 910         union bufferevent_ctrl_data d;
 911         int res = -1;
 912         d.ptr = NULL;
 913         BEV_LOCK(bev);
 914         if (bev->be_ops->ctrl)
 915                 res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_UNDERLYING, &d);
 916         BEV_UNLOCK(bev);
 917         return (res<0) ? NULL : d.ptr;
 918 }
 919
 920 static void
 921 bufferevent_generic_read_timeout_cb(evutil_socket_t fd, short event, void *ctx)
 922 {
 923         struct bufferevent *bev = ctx;
 924         bufferevent_incref_and_lock_(bev);
 925         bufferevent_disable(bev, EV_READ);
 926         bufferevent_run_eventcb_(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_READING, 0);
 927         bufferevent_decref_and_unlock_(bev);
 928 }
 929 static void
 930 bufferevent_generic_write_timeout_cb(evutil_socket_t fd, short event, void *ctx)
 931 {
 932         struct bufferevent *bev = ctx;
 933         bufferevent_incref_and_lock_(bev);
 934         bufferevent_disable(bev, EV_WRITE);
 935         bufferevent_run_eventcb_(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_WRITING, 0);
 936         bufferevent_decref_and_unlock_(bev);
 937 }
 938
 939 void
 940 bufferevent_init_generic_timeout_cbs_(struct bufferevent *bev)
 941 {
 942         event_assign(&bev->ev_read, bev->ev_base, -1, EV_FINALIZE,
 943             bufferevent_generic_read_timeout_cb, bev);
 944         event_assign(&bev->ev_write, bev->ev_base, -1, EV_FINALIZE,
 945             bufferevent_generic_write_timeout_cb, bev);
 946 }
 947
 948 int
 949 bufferevent_generic_adj_timeouts_(struct bufferevent *bev)
 950 {
 951         const short enabled = bev->enabled;
 952         struct bufferevent_private *bev_p =
 953             EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
 954         int r1=0, r2=0;
 955         if ((enabled & EV_READ) && !bev_p->read_suspended &&
 956             evutil_timerisset(&bev->timeout_read))
 957                 r1 = event_add(&bev->ev_read, &bev->timeout_read);
 958         else
 959                 r1 = event_del(&bev->ev_read);
 960
 961         if ((enabled & EV_WRITE) && !bev_p->write_suspended &&
 962             evutil_timerisset(&bev->timeout_write) &&
 963             evbuffer_get_length(bev->output))
 964                 r2 = event_add(&bev->ev_write, &bev->timeout_write);
 965         else
 966                 r2 = event_del(&bev->ev_write);
 967         if (r1 < 0 || r2 < 0)
 968                 return -1;
 969         return 0;
 970 }
 971
 972 int
 973 bufferevent_generic_adj_existing_timeouts_(struct bufferevent *bev)
 974 {
 975         int r = 0;
 976         if (event_pending(&bev->ev_read, EV_READ, NULL)) {
 977                 if (evutil_timerisset(&bev->timeout_read)) {
 978                             if (bufferevent_add_event_(&bev->ev_read, &bev->timeout_read) < 0)
 979                                     r = -1;
 980                 } else {
 981                         event_remove_timer(&bev->ev_read);
 982                 }
 983         }
 984         if (event_pending(&bev->ev_write, EV_WRITE, NULL)) {
 985                 if (evutil_timerisset(&bev->timeout_write)) {
 986                         if (bufferevent_add_event_(&bev->ev_write, &bev->timeout_write) < 0)
 987                                 r = -1;
 988                 } else {
 989                         event_remove_timer(&bev->ev_write);
 990                 }
 991         }
 992         return r;
 993 }
 994
 995 int
 996 bufferevent_add_event_(struct event *ev, const struct timeval *tv)
 997 {
 998         if (!evutil_timerisset(tv))
 999                 return event_add(ev, NULL);
1000         else
1001                 return event_add(ev, tv);
1002 }
1003
1004 /* For use by user programs only; internally, we should be calling
1005    either bufferevent_incref_and_lock_(), or BEV_LOCK. */
1006 void
1007 bufferevent_lock(struct bufferevent *bev)
1008 {
1009         bufferevent_incref_and_lock_(bev);
1010 }
1011
1012 void
1013 bufferevent_unlock(struct bufferevent *bev)
1014 {
1015         bufferevent_decref_and_unlock_(bev);
1016 }