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
  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 "event-internal.h"
  57 #include "log-internal.h"
  58 #include "mm-internal.h"
  59 #include "bufferevent-internal.h"
  60 #include "evbuffer-internal.h"
  61 #include "util-internal.h"
  62
  63 static void bufferevent_cancel_all_(struct bufferevent *bev);
  64 static void bufferevent_finalize_cb_(struct event_callback *evcb, void *arg_);
  65
  66 void
  67 bufferevent_suspend_read_(struct bufferevent *bufev, bufferevent_suspend_flags what)
  68 {
  69         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
  70         BEV_LOCK(bufev);
  71         if (!bufev_private->read_suspended)
  72                 bufev->be_ops->disable(bufev, EV_READ);
  73         bufev_private->read_suspended |= what;
  74         BEV_UNLOCK(bufev);
  75 }
  76
  77 void
  78 bufferevent_unsuspend_read_(struct bufferevent *bufev, bufferevent_suspend_flags what)
  79 {
  80         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
  81         BEV_LOCK(bufev);
  82         bufev_private->read_suspended &= ~what;
  83         if (!bufev_private->read_suspended && (bufev->enabled & EV_READ))
  84                 bufev->be_ops->enable(bufev, EV_READ);
  85         BEV_UNLOCK(bufev);
  86 }
  87
  88 void
  89 bufferevent_suspend_write_(struct bufferevent *bufev, bufferevent_suspend_flags what)
  90 {
  91         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
  92         BEV_LOCK(bufev);
  93         if (!bufev_private->write_suspended)
  94                 bufev->be_ops->disable(bufev, EV_WRITE);
  95         bufev_private->write_suspended |= what;
  96         BEV_UNLOCK(bufev);
  97 }
  98
  99 void
 100 bufferevent_unsuspend_write_(struct bufferevent *bufev, bufferevent_suspend_flags what)
 101 {
 102         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
 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  * Sometimes bufferevent's implementation can overrun high watermarks
 112  * (one of examples is openssl) and in this case if the read callback
 113  * will not handle enough data do over condition above the read
 114  * callback will never be called again (due to suspend above).
 115  *
 116  * To avoid this we are scheduling read callback again here, but only
 117  * from the user callback to avoid multiple scheduling:
 118  * - when the data had been added to it
 119  * - when the data had been drained from it (user specified read callback)
 120  */
 121 static void bufferevent_inbuf_wm_check(struct bufferevent *bev)
 122 {
 123         if (!bev->wm_read.high)
 124                 return;
 125         if (!(bev->enabled & EV_READ))
 126                 return;
 127         if (evbuffer_get_length(bev->input) < bev->wm_read.high)
 128                 return;
 129
 130         bufferevent_trigger(bev, EV_READ, BEV_OPT_DEFER_CALLBACKS);
 131 }
 132
 133 /* Callback to implement watermarks on the input buffer.  Only enabled
 134  * if the watermark is set. */
 135 static void
 136 bufferevent_inbuf_wm_cb(struct evbuffer *buf,
 137     const struct evbuffer_cb_info *cbinfo,
 138     void *arg)
 139 {
 140         struct bufferevent *bufev = arg;
 141         size_t size;
 142
 143         size = evbuffer_get_length(buf);
 144
 145         if (size >= bufev->wm_read.high)
 146                 bufferevent_wm_suspend_read(bufev);
 147         else
 148                 bufferevent_wm_unsuspend_read(bufev);
 149 }
 150
 151 static void
 152 bufferevent_run_deferred_callbacks_locked(struct event_callback *cb, void *arg)
 153 {
 154         struct bufferevent_private *bufev_private = arg;
 155         struct bufferevent *bufev = &bufev_private->bev;
 156
 157         BEV_LOCK(bufev);
 158         if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
 159             bufev->errorcb) {
 160                 /* The "connected" happened before any reads or writes, so
 161                    send it first. */
 162                 bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
 163                 bufev->errorcb(bufev, BEV_EVENT_CONNECTED, bufev->cbarg);
 164         }
 165         if (bufev_private->readcb_pending && bufev->readcb) {
 166                 bufev_private->readcb_pending = 0;
 167                 bufev->readcb(bufev, bufev->cbarg);
 168                 bufferevent_inbuf_wm_check(bufev);
 169         }
 170         if (bufev_private->writecb_pending && bufev->writecb) {
 171                 bufev_private->writecb_pending = 0;
 172                 bufev->writecb(bufev, bufev->cbarg);
 173         }
 174         if (bufev_private->eventcb_pending && bufev->errorcb) {
 175                 short what = bufev_private->eventcb_pending;
 176                 int err = bufev_private->errno_pending;
 177                 bufev_private->eventcb_pending = 0;
 178                 bufev_private->errno_pending = 0;
 179                 EVUTIL_SET_SOCKET_ERROR(err);
 180                 bufev->errorcb(bufev, what, bufev->cbarg);
 181         }
 182         bufferevent_decref_and_unlock_(bufev);
 183 }
 184
 185 static void
 186 bufferevent_run_deferred_callbacks_unlocked(struct event_callback *cb, void *arg)
 187 {
 188         struct bufferevent_private *bufev_private = arg;
 189         struct bufferevent *bufev = &bufev_private->bev;
 190
 191         BEV_LOCK(bufev);
 192 #define UNLOCKED(stmt) \
 193         do { BEV_UNLOCK(bufev); stmt; BEV_LOCK(bufev); } while(0)
 194
 195         if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
 196             bufev->errorcb) {
 197                 /* The "connected" happened before any reads or writes, so
 198                    send it first. */
 199                 bufferevent_event_cb errorcb = bufev->errorcb;
 200                 void *cbarg = bufev->cbarg;
 201                 bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
 202                 UNLOCKED(errorcb(bufev, BEV_EVENT_CONNECTED, cbarg));
 203         }
 204         if (bufev_private->readcb_pending && bufev->readcb) {
 205                 bufferevent_data_cb readcb = bufev->readcb;
 206                 void *cbarg = bufev->cbarg;
 207                 bufev_private->readcb_pending = 0;
 208                 UNLOCKED(readcb(bufev, cbarg));
 209                 bufferevent_inbuf_wm_check(bufev);
 210         }
 211         if (bufev_private->writecb_pending && bufev->writecb) {
 212                 bufferevent_data_cb writecb = bufev->writecb;
 213                 void *cbarg = bufev->cbarg;
 214                 bufev_private->writecb_pending = 0;
 215                 UNLOCKED(writecb(bufev, cbarg));
 216         }
 217         if (bufev_private->eventcb_pending && bufev->errorcb) {
 218                 bufferevent_event_cb errorcb = bufev->errorcb;
 219                 void *cbarg = bufev->cbarg;
 220                 short what = bufev_private->eventcb_pending;
 221                 int err = bufev_private->errno_pending;
 222                 bufev_private->eventcb_pending = 0;
 223                 bufev_private->errno_pending = 0;
 224                 EVUTIL_SET_SOCKET_ERROR(err);
 225                 UNLOCKED(errorcb(bufev,what,cbarg));
 226         }
 227         bufferevent_decref_and_unlock_(bufev);
 228 #undef UNLOCKED
 229 }
 230
 231 #define SCHEDULE_DEFERRED(bevp)                                         \
 232         do {                                                            \
 233                 if (event_deferred_cb_schedule_(                        \
 234                             (bevp)->bev.ev_base,                        \
 235                         &(bevp)->deferred))                             \
 236                         bufferevent_incref_(&(bevp)->bev);              \
 237         } while (0)
 238
 239
 240 void
 241 bufferevent_run_readcb_(struct bufferevent *bufev, int options)
 242 {
 243         /* Requires that we hold the lock and a reference */
 244         struct bufferevent_private *p = BEV_UPCAST(bufev);
 245         if (bufev->readcb == NULL)
 246                 return;
 247         if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 248                 p->readcb_pending = 1;
 249                 SCHEDULE_DEFERRED(p);
 250         } else {
 251                 bufev->readcb(bufev, bufev->cbarg);
 252                 bufferevent_inbuf_wm_check(bufev);
 253         }
 254 }
 255
 256 void
 257 bufferevent_run_writecb_(struct bufferevent *bufev, int options)
 258 {
 259         /* Requires that we hold the lock and a reference */
 260         struct bufferevent_private *p = BEV_UPCAST(bufev);
 261         if (bufev->writecb == NULL)
 262                 return;
 263         if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 264                 p->writecb_pending = 1;
 265                 SCHEDULE_DEFERRED(p);
 266         } else {
 267                 bufev->writecb(bufev, bufev->cbarg);
 268         }
 269 }
 270
 271 #define BEV_TRIG_ALL_OPTS (                     \
 272                 BEV_TRIG_IGNORE_WATERMARKS|     \
 273                 BEV_TRIG_DEFER_CALLBACKS        \
 274         )
 275
 276 void
 277 bufferevent_trigger(struct bufferevent *bufev, short iotype, int options)
 278 {
 279         bufferevent_incref_and_lock_(bufev);
 280         bufferevent_trigger_nolock_(bufev, iotype, options&BEV_TRIG_ALL_OPTS);
 281         bufferevent_decref_and_unlock_(bufev);
 282 }
 283
 284 void
 285 bufferevent_run_eventcb_(struct bufferevent *bufev, short what, int options)
 286 {
 287         /* Requires that we hold the lock and a reference */
 288         struct bufferevent_private *p = BEV_UPCAST(bufev);
 289         if (bufev->errorcb == NULL)
 290                 return;
 291         if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 292                 p->eventcb_pending |= what;
 293                 p->errno_pending = EVUTIL_SOCKET_ERROR();
 294                 SCHEDULE_DEFERRED(p);
 295         } else {
 296                 bufev->errorcb(bufev, what, bufev->cbarg);
 297         }
 298 }
 299
 300 void
 301 bufferevent_trigger_event(struct bufferevent *bufev, short what, int options)
 302 {
 303         bufferevent_incref_and_lock_(bufev);
 304         bufferevent_run_eventcb_(bufev, what, options&BEV_TRIG_ALL_OPTS);
 305         bufferevent_decref_and_unlock_(bufev);
 306 }
 307
 308 int
 309 bufferevent_init_common_(struct bufferevent_private *bufev_private,
 310     struct event_base *base,
 311     const struct bufferevent_ops *ops,
 312     enum bufferevent_options options)
 313 {
 314         struct bufferevent *bufev = &bufev_private->bev;
 315
 316         if (!bufev->input) {
 317                 if ((bufev->input = evbuffer_new()) == NULL)
 318                         goto err;
 319         }
 320
 321         if (!bufev->output) {
 322                 if ((bufev->output = evbuffer_new()) == NULL)
 323                         goto err;
 324         }
 325
 326         bufev_private->refcnt = 1;
 327         bufev->ev_base = base;
 328
 329         /* Disable timeouts. */
 330         evutil_timerclear(&bufev->timeout_read);
 331         evutil_timerclear(&bufev->timeout_write);
 332
 333         bufev->be_ops = ops;
 334
 335         if (bufferevent_ratelim_init_(bufev_private))
 336                 goto err;
 337
 338         /*
 339          * Set to EV_WRITE so that using bufferevent_write is going to
 340          * trigger a callback.  Reading needs to be explicitly enabled
 341          * because otherwise no data will be available.
 342          */
 343         bufev->enabled = EV_WRITE;
 344
 345 #ifndef EVENT__DISABLE_THREAD_SUPPORT
 346         if (options & BEV_OPT_THREADSAFE) {
 347                 if (bufferevent_enable_locking_(bufev, NULL) < 0)
 348                         goto err;
 349         }
 350 #endif
 351         if ((options & (BEV_OPT_DEFER_CALLBACKS|BEV_OPT_UNLOCK_CALLBACKS))
 352             == BEV_OPT_UNLOCK_CALLBACKS) {
 353                 event_warnx("UNLOCK_CALLBACKS requires DEFER_CALLBACKS");
 354                 goto err;
 355         }
 356         if (options & BEV_OPT_UNLOCK_CALLBACKS)
 357                 event_deferred_cb_init_(
 358                     &bufev_private->deferred,
 359                     event_base_get_npriorities(base) / 2,
 360                     bufferevent_run_deferred_callbacks_unlocked,
 361                     bufev_private);
 362         else
 363                 event_deferred_cb_init_(
 364                     &bufev_private->deferred,
 365                     event_base_get_npriorities(base) / 2,
 366                     bufferevent_run_deferred_callbacks_locked,
 367                     bufev_private);
 368
 369         bufev_private->options = options;
 370
 371         evbuffer_set_parent_(bufev->input, bufev);
 372         evbuffer_set_parent_(bufev->output, bufev);
 373
 374         return 0;
 375
 376 err:
 377         if (bufev->input) {
 378                 evbuffer_free(bufev->input);
 379                 bufev->input = NULL;
 380         }
 381         if (bufev->output) {
 382                 evbuffer_free(bufev->output);
 383                 bufev->output = NULL;
 384         }
 385         return -1;
 386 }
 387
 388 void
 389 bufferevent_setcb(struct bufferevent *bufev,
 390     bufferevent_data_cb readcb, bufferevent_data_cb writecb,
 391     bufferevent_event_cb eventcb, void *cbarg)
 392 {
 393         BEV_LOCK(bufev);
 394
 395         bufev->readcb = readcb;
 396         bufev->writecb = writecb;
 397         bufev->errorcb = eventcb;
 398
 399         bufev->cbarg = cbarg;
 400         BEV_UNLOCK(bufev);
 401 }
 402
 403 void
 404 bufferevent_getcb(struct bufferevent *bufev,
 405     bufferevent_data_cb *readcb_ptr,
 406     bufferevent_data_cb *writecb_ptr,
 407     bufferevent_event_cb *eventcb_ptr,
 408     void **cbarg_ptr)
 409 {
 410         BEV_LOCK(bufev);
 411         if (readcb_ptr)
 412                 *readcb_ptr = bufev->readcb;
 413         if (writecb_ptr)
 414                 *writecb_ptr = bufev->writecb;
 415         if (eventcb_ptr)
 416                 *eventcb_ptr = bufev->errorcb;
 417         if (cbarg_ptr)
 418                 *cbarg_ptr = bufev->cbarg;
 419
 420         BEV_UNLOCK(bufev);
 421 }
 422
 423 struct evbuffer *
 424 bufferevent_get_input(struct bufferevent *bufev)
 425 {
 426         return bufev->input;
 427 }
 428
 429 struct evbuffer *
 430 bufferevent_get_output(struct bufferevent *bufev)
 431 {
 432         return bufev->output;
 433 }
 434
 435 struct event_base *
 436 bufferevent_get_base(struct bufferevent *bufev)
 437 {
 438         return bufev->ev_base;
 439 }
 440
 441 int
 442 bufferevent_get_priority(const struct bufferevent *bufev)
 443 {
 444         if (event_initialized(&bufev->ev_read)) {
 445                 return event_get_priority(&bufev->ev_read);
 446         } else {
 447                 return event_base_get_npriorities(bufev->ev_base) / 2;
 448         }
 449 }
 450
 451 int
 452 bufferevent_write(struct bufferevent *bufev, const void *data, size_t size)
 453 {
 454         if (evbuffer_add(bufev->output, data, size) == -1)
 455                 return (-1);
 456
 457         return 0;
 458 }
 459
 460 int
 461 bufferevent_write_buffer(struct bufferevent *bufev, struct evbuffer *buf)
 462 {
 463         if (evbuffer_add_buffer(bufev->output, buf) == -1)
 464                 return (-1);
 465
 466         return 0;
 467 }
 468
 469 size_t
 470 bufferevent_read(struct bufferevent *bufev, void *data, size_t size)
 471 {
 472         return (evbuffer_remove(bufev->input, data, size));
 473 }
 474
 475 int
 476 bufferevent_read_buffer(struct bufferevent *bufev, struct evbuffer *buf)
 477 {
 478         return (evbuffer_add_buffer(buf, bufev->input));
 479 }
 480
 481 int
 482 bufferevent_enable(struct bufferevent *bufev, short event)
 483 {
 484         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
 485         short impl_events = event;
 486         int r = 0;
 487
 488         bufferevent_incref_and_lock_(bufev);
 489         if (bufev_private->read_suspended)
 490                 impl_events &= ~EV_READ;
 491         if (bufev_private->write_suspended)
 492                 impl_events &= ~EV_WRITE;
 493
 494         bufev->enabled |= event;
 495
 496         if (impl_events && bufev->be_ops->enable(bufev, impl_events) < 0)
 497                 r = -1;
 498         if (r)
 499                 event_debug(("%s: cannot enable 0x%hx on %p", __func__, event, bufev));
 500
 501         bufferevent_decref_and_unlock_(bufev);
 502         return r;
 503 }
 504
 505 int
 506 bufferevent_set_timeouts(struct bufferevent *bufev,
 507                          const struct timeval *tv_read,
 508                          const struct timeval *tv_write)
 509 {
 510         int r = 0;
 511         BEV_LOCK(bufev);
 512         if (tv_read) {
 513                 bufev->timeout_read = *tv_read;
 514         } else {
 515                 evutil_timerclear(&bufev->timeout_read);
 516         }
 517         if (tv_write) {
 518                 bufev->timeout_write = *tv_write;
 519         } else {
 520                 evutil_timerclear(&bufev->timeout_write);
 521         }
 522
 523         if (bufev->be_ops->adj_timeouts)
 524                 r = bufev->be_ops->adj_timeouts(bufev);
 525         BEV_UNLOCK(bufev);
 526
 527         return r;
 528 }
 529
 530
 531 /* Obsolete; use bufferevent_set_timeouts */
 532 void
 533 bufferevent_settimeout(struct bufferevent *bufev,
 534                        int timeout_read, int timeout_write)
 535 {
 536         struct timeval tv_read, tv_write;
 537         struct timeval *ptv_read = NULL, *ptv_write = NULL;
 538
 539         memset(&tv_read, 0, sizeof(tv_read));
 540         memset(&tv_write, 0, sizeof(tv_write));
 541
 542         if (timeout_read) {
 543                 tv_read.tv_sec = timeout_read;
 544                 ptv_read = &tv_read;
 545         }
 546         if (timeout_write) {
 547                 tv_write.tv_sec = timeout_write;
 548                 ptv_write = &tv_write;
 549         }
 550
 551         bufferevent_set_timeouts(bufev, ptv_read, ptv_write);
 552 }
 553
 554
 555 int
 556 bufferevent_disable_hard_(struct bufferevent *bufev, short event)
 557 {
 558         int r = 0;
 559         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
 560
 561         BEV_LOCK(bufev);
 562         bufev->enabled &= ~event;
 563
 564         bufev_private->connecting = 0;
 565         if (bufev->be_ops->disable(bufev, event) < 0)
 566                 r = -1;
 567
 568         BEV_UNLOCK(bufev);
 569         return r;
 570 }
 571
 572 int
 573 bufferevent_disable(struct bufferevent *bufev, short event)
 574 {
 575         int r = 0;
 576
 577         BEV_LOCK(bufev);
 578         bufev->enabled &= ~event;
 579
 580         if (bufev->be_ops->disable(bufev, event) < 0)
 581                 r = -1;
 582         if (r)
 583                 event_debug(("%s: cannot disable 0x%hx on %p", __func__, event, bufev));
 584
 585         BEV_UNLOCK(bufev);
 586         return r;
 587 }
 588
 589 /*
 590  * Sets the water marks
 591  */
 592
 593 void
 594 bufferevent_setwatermark(struct bufferevent *bufev, short events,
 595     size_t lowmark, size_t highmark)
 596 {
 597         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
 598
 599         BEV_LOCK(bufev);
 600         if (events & EV_WRITE) {
 601                 bufev->wm_write.low = lowmark;
 602                 bufev->wm_write.high = highmark;
 603         }
 604
 605         if (events & EV_READ) {
 606                 bufev->wm_read.low = lowmark;
 607                 bufev->wm_read.high = highmark;
 608
 609                 if (highmark) {
 610                         /* There is now a new high-water mark for read.
 611                            enable the callback if needed, and see if we should
 612                            suspend/bufferevent_wm_unsuspend. */
 613
 614                         if (bufev_private->read_watermarks_cb == NULL) {
 615                                 bufev_private->read_watermarks_cb =
 616                                     evbuffer_add_cb(bufev->input,
 617                                                     bufferevent_inbuf_wm_cb,
 618                                                     bufev);
 619                         }
 620                         evbuffer_cb_set_flags(bufev->input,
 621                                       bufev_private->read_watermarks_cb,
 622                                       EVBUFFER_CB_ENABLED|EVBUFFER_CB_NODEFER);
 623
 624                         if (evbuffer_get_length(bufev->input) >= highmark)
 625                                 bufferevent_wm_suspend_read(bufev);
 626                         else if (evbuffer_get_length(bufev->input) < highmark)
 627                                 bufferevent_wm_unsuspend_read(bufev);
 628                 } else {
 629                         /* There is now no high-water mark for read. */
 630                         if (bufev_private->read_watermarks_cb)
 631                                 evbuffer_cb_clear_flags(bufev->input,
 632                                     bufev_private->read_watermarks_cb,
 633                                     EVBUFFER_CB_ENABLED);
 634                         bufferevent_wm_unsuspend_read(bufev);
 635                 }
 636         }
 637         BEV_UNLOCK(bufev);
 638 }
 639
 640 int
 641 bufferevent_getwatermark(struct bufferevent *bufev, short events,
 642     size_t *lowmark, size_t *highmark)
 643 {
 644         if (events == EV_WRITE) {
 645                 BEV_LOCK(bufev);
 646                 if (lowmark)
 647                         *lowmark = bufev->wm_write.low;
 648                 if (highmark)
 649                         *highmark = bufev->wm_write.high;
 650                 BEV_UNLOCK(bufev);
 651                 return 0;
 652         }
 653
 654         if (events == EV_READ) {
 655                 BEV_LOCK(bufev);
 656                 if (lowmark)
 657                         *lowmark = bufev->wm_read.low;
 658                 if (highmark)
 659                         *highmark = bufev->wm_read.high;
 660                 BEV_UNLOCK(bufev);
 661                 return 0;
 662         }
 663         return -1;
 664 }
 665
 666 int
 667 bufferevent_flush(struct bufferevent *bufev,
 668     short iotype,
 669     enum bufferevent_flush_mode mode)
 670 {
 671         int r = -1;
 672         BEV_LOCK(bufev);
 673         if (bufev->be_ops->flush)
 674                 r = bufev->be_ops->flush(bufev, iotype, mode);
 675         BEV_UNLOCK(bufev);
 676         return r;
 677 }
 678
 679 void
 680 bufferevent_incref_and_lock_(struct bufferevent *bufev)
 681 {
 682         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
 683         BEV_LOCK(bufev);
 684         ++bufev_private->refcnt;
 685 }
 686
 687 #if 0
 688 static void
 689 bufferevent_transfer_lock_ownership_(struct bufferevent *donor,
 690     struct bufferevent *recipient)
 691 {
 692         struct bufferevent_private *d = BEV_UPCAST(donor);
 693         struct bufferevent_private *r = BEV_UPCAST(recipient);
 694         if (d->lock != r->lock)
 695                 return;
 696         if (r->own_lock)
 697                 return;
 698         if (d->own_lock) {
 699                 d->own_lock = 0;
 700                 r->own_lock = 1;
 701         }
 702 }
 703 #endif
 704
 705 int
 706 bufferevent_decref_and_unlock_(struct bufferevent *bufev)
 707 {
 708         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
 709         int n_cbs = 0;
 710 #define MAX_CBS 16
 711         struct event_callback *cbs[MAX_CBS];
 712
 713         EVUTIL_ASSERT(bufev_private->refcnt > 0);
 714
 715         if (--bufev_private->refcnt) {
 716                 BEV_UNLOCK(bufev);
 717                 return 0;
 718         }
 719
 720         if (bufev->be_ops->unlink)
 721                 bufev->be_ops->unlink(bufev);
 722
 723         /* Okay, we're out of references. Let's finalize this once all the
 724          * callbacks are done running. */
 725         cbs[0] = &bufev->ev_read.ev_evcallback;
 726         cbs[1] = &bufev->ev_write.ev_evcallback;
 727         cbs[2] = &bufev_private->deferred;
 728         n_cbs = 3;
 729         if (bufev_private->rate_limiting) {
 730                 struct event *e = &bufev_private->rate_limiting->refill_bucket_event;
 731                 if (event_initialized(e))
 732                         cbs[n_cbs++] = &e->ev_evcallback;
 733         }
 734         n_cbs += evbuffer_get_callbacks_(bufev->input, cbs+n_cbs, MAX_CBS-n_cbs);
 735         n_cbs += evbuffer_get_callbacks_(bufev->output, cbs+n_cbs, MAX_CBS-n_cbs);
 736
 737         event_callback_finalize_many_(bufev->ev_base, n_cbs, cbs,
 738             bufferevent_finalize_cb_);
 739
 740 #undef MAX_CBS
 741         BEV_UNLOCK(bufev);
 742
 743         return 1;
 744 }
 745
 746 static void
 747 bufferevent_finalize_cb_(struct event_callback *evcb, void *arg_)
 748 {
 749         struct bufferevent *bufev = arg_;
 750         struct bufferevent *underlying;
 751         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
 752
 753         BEV_LOCK(bufev);
 754         underlying = bufferevent_get_underlying(bufev);
 755
 756         /* Clean up the shared info */
 757         if (bufev->be_ops->destruct)
 758                 bufev->be_ops->destruct(bufev);
 759
 760         /* XXX what happens if refcnt for these buffers is > 1?
 761          * The buffers can share a lock with this bufferevent object,
 762          * but the lock might be destroyed below. */
 763         /* evbuffer will free the callbacks */
 764         evbuffer_free(bufev->input);
 765         evbuffer_free(bufev->output);
 766
 767         if (bufev_private->rate_limiting) {
 768                 if (bufev_private->rate_limiting->group)
 769                         bufferevent_remove_from_rate_limit_group_internal_(bufev,0);
 770                 mm_free(bufev_private->rate_limiting);
 771                 bufev_private->rate_limiting = NULL;
 772         }
 773
 774
 775         BEV_UNLOCK(bufev);
 776
 777         if (bufev_private->own_lock)
 778                 EVTHREAD_FREE_LOCK(bufev_private->lock,
 779                     EVTHREAD_LOCKTYPE_RECURSIVE);
 780
 781         /* Free the actual allocated memory. */
 782         mm_free(((char*)bufev) - bufev->be_ops->mem_offset);
 783
 784         /* Release the reference to underlying now that we no longer need the
 785          * reference to it.  We wait this long mainly in case our lock is
 786          * shared with underlying.
 787          *
 788          * The 'destruct' function will also drop a reference to underlying
 789          * if BEV_OPT_CLOSE_ON_FREE is set.
 790          *
 791          * XXX Should we/can we just refcount evbuffer/bufferevent locks?
 792          * It would probably save us some headaches.
 793          */
 794         if (underlying)
 795                 bufferevent_decref_(underlying);
 796 }
 797
 798 int
 799 bufferevent_decref(struct bufferevent *bufev)
 800 {
 801         BEV_LOCK(bufev);
 802         return bufferevent_decref_and_unlock_(bufev);
 803 }
 804
 805 void
 806 bufferevent_free(struct bufferevent *bufev)
 807 {
 808         BEV_LOCK(bufev);
 809         bufferevent_setcb(bufev, NULL, NULL, NULL, NULL);
 810         bufferevent_cancel_all_(bufev);
 811         bufferevent_decref_and_unlock_(bufev);
 812 }
 813
 814 void
 815 bufferevent_incref(struct bufferevent *bufev)
 816 {
 817         struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
 818
 819         /* XXX: now that this function is public, we might want to
 820          * - return the count from this function
 821          * - create a new function to atomically grab the current refcount
 822          */
 823         BEV_LOCK(bufev);
 824         ++bufev_private->refcnt;
 825         BEV_UNLOCK(bufev);
 826 }
 827
 828 int
 829 bufferevent_enable_locking_(struct bufferevent *bufev, void *lock)
 830 {
 831 #ifdef EVENT__DISABLE_THREAD_SUPPORT
 832         return -1;
 833 #else
 834         struct bufferevent *underlying;
 835
 836         if (BEV_UPCAST(bufev)->lock)
 837                 return -1;
 838         underlying = bufferevent_get_underlying(bufev);
 839
 840         if (!lock && underlying && BEV_UPCAST(underlying)->lock) {
 841                 lock = BEV_UPCAST(underlying)->lock;
 842                 BEV_UPCAST(bufev)->lock = lock;
 843                 BEV_UPCAST(bufev)->own_lock = 0;
 844         } else if (!lock) {
 845                 EVTHREAD_ALLOC_LOCK(lock, EVTHREAD_LOCKTYPE_RECURSIVE);
 846                 if (!lock)
 847                         return -1;
 848                 BEV_UPCAST(bufev)->lock = lock;
 849                 BEV_UPCAST(bufev)->own_lock = 1;
 850         } else {
 851                 BEV_UPCAST(bufev)->lock = lock;
 852                 BEV_UPCAST(bufev)->own_lock = 0;
 853         }
 854         evbuffer_enable_locking(bufev->input, lock);
 855         evbuffer_enable_locking(bufev->output, lock);
 856
 857         if (underlying && !BEV_UPCAST(underlying)->lock)
 858                 bufferevent_enable_locking_(underlying, lock);
 859
 860         return 0;
 861 #endif
 862 }
 863
 864 int
 865 bufferevent_setfd(struct bufferevent *bev, evutil_socket_t fd)
 866 {
 867         union bufferevent_ctrl_data d;
 868         int res = -1;
 869         d.fd = fd;
 870         BEV_LOCK(bev);
 871         if (bev->be_ops->ctrl)
 872                 res = bev->be_ops->ctrl(bev, BEV_CTRL_SET_FD, &d);
 873         if (res)
 874                 event_debug(("%s: cannot set fd for %p to "EV_SOCK_FMT, __func__, bev, fd));
 875         BEV_UNLOCK(bev);
 876         return res;
 877 }
 878
 879 evutil_socket_t
 880 bufferevent_getfd(struct bufferevent *bev)
 881 {
 882         union bufferevent_ctrl_data d;
 883         int res = -1;
 884         d.fd = -1;
 885         BEV_LOCK(bev);
 886         if (bev->be_ops->ctrl)
 887                 res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_FD, &d);
 888         if (res)
 889                 event_debug(("%s: cannot get fd for %p", __func__, bev));
 890         BEV_UNLOCK(bev);
 891         return (res<0) ? -1 : d.fd;
 892 }
 893
 894 enum bufferevent_options
 895 bufferevent_get_options_(struct bufferevent *bev)
 896 {
 897         struct bufferevent_private *bev_p = BEV_UPCAST(bev);
 898         enum bufferevent_options options;
 899
 900         BEV_LOCK(bev);
 901         options = bev_p->options;
 902         BEV_UNLOCK(bev);
 903         return options;
 904 }
 905
 906
 907 static void
 908 bufferevent_cancel_all_(struct bufferevent *bev)
 909 {
 910         union bufferevent_ctrl_data d;
 911         memset(&d, 0, sizeof(d));
 912         BEV_LOCK(bev);
 913         if (bev->be_ops->ctrl)
 914                 bev->be_ops->ctrl(bev, BEV_CTRL_CANCEL_ALL, &d);
 915         BEV_UNLOCK(bev);
 916 }
 917
 918 short
 919 bufferevent_get_enabled(struct bufferevent *bufev)
 920 {
 921         short r;
 922         BEV_LOCK(bufev);
 923         r = bufev->enabled;
 924         BEV_UNLOCK(bufev);
 925         return r;
 926 }
 927
 928 struct bufferevent *
 929 bufferevent_get_underlying(struct bufferevent *bev)
 930 {
 931         union bufferevent_ctrl_data d;
 932         int res = -1;
 933         d.ptr = NULL;
 934         BEV_LOCK(bev);
 935         if (bev->be_ops->ctrl)
 936                 res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_UNDERLYING, &d);
 937         BEV_UNLOCK(bev);
 938         return (res<0) ? NULL : d.ptr;
 939 }
 940
 941 static void
 942 bufferevent_generic_read_timeout_cb(evutil_socket_t fd, short event, void *ctx)
 943 {
 944         struct bufferevent *bev = ctx;
 945         bufferevent_incref_and_lock_(bev);
 946         bufferevent_disable(bev, EV_READ);
 947         bufferevent_run_eventcb_(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_READING, 0);
 948         bufferevent_decref_and_unlock_(bev);
 949 }
 950 static void
 951 bufferevent_generic_write_timeout_cb(evutil_socket_t fd, short event, void *ctx)
 952 {
 953         struct bufferevent *bev = ctx;
 954         bufferevent_incref_and_lock_(bev);
 955         bufferevent_disable(bev, EV_WRITE);
 956         bufferevent_run_eventcb_(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_WRITING, 0);
 957         bufferevent_decref_and_unlock_(bev);
 958 }
 959
 960 void
 961 bufferevent_init_generic_timeout_cbs_(struct bufferevent *bev)
 962 {
 963         event_assign(&bev->ev_read, bev->ev_base, -1, EV_FINALIZE,
 964             bufferevent_generic_read_timeout_cb, bev);
 965         event_assign(&bev->ev_write, bev->ev_base, -1, EV_FINALIZE,
 966             bufferevent_generic_write_timeout_cb, bev);
 967 }
 968
 969 int
 970 bufferevent_generic_adj_timeouts_(struct bufferevent *bev)
 971 {
 972         const short enabled = bev->enabled;
 973         struct bufferevent_private *bev_p = BEV_UPCAST(bev);
 974         int r1=0, r2=0;
 975         if ((enabled & EV_READ) && !bev_p->read_suspended &&
 976             evutil_timerisset(&bev->timeout_read))
 977                 r1 = event_add(&bev->ev_read, &bev->timeout_read);
 978         else
 979                 r1 = event_del(&bev->ev_read);
 980
 981         if ((enabled & EV_WRITE) && !bev_p->write_suspended &&
 982             evutil_timerisset(&bev->timeout_write) &&
 983             evbuffer_get_length(bev->output))
 984                 r2 = event_add(&bev->ev_write, &bev->timeout_write);
 985         else
 986                 r2 = event_del(&bev->ev_write);
 987         if (r1 < 0 || r2 < 0)
 988                 return -1;
 989         return 0;
 990 }
 991
 992 int
 993 bufferevent_generic_adj_existing_timeouts_(struct bufferevent *bev)
 994 {
 995         int r = 0;
 996         if (event_pending(&bev->ev_read, EV_READ, NULL)) {
 997                 if (evutil_timerisset(&bev->timeout_read)) {
 998                             if (bufferevent_add_event_(&bev->ev_read, &bev->timeout_read) < 0)
 999                                     r = -1;
1000                 } else {
1001                         event_remove_timer(&bev->ev_read);
1002                 }
1003         }
1004         if (event_pending(&bev->ev_write, EV_WRITE, NULL)) {
1005                 if (evutil_timerisset(&bev->timeout_write)) {
1006                         if (bufferevent_add_event_(&bev->ev_write, &bev->timeout_write) < 0)
1007                                 r = -1;
1008                 } else {
1009                         event_remove_timer(&bev->ev_write);
1010                 }
1011         }
1012         return r;
1013 }
1014
1015 int
1016 bufferevent_add_event_(struct event *ev, const struct timeval *tv)
1017 {
1018         if (!evutil_timerisset(tv))
1019                 return event_add(ev, NULL);
1020         else
1021                 return event_add(ev, tv);
1022 }
1023
1024 /* For use by user programs only; internally, we should be calling
1025    either bufferevent_incref_and_lock_(), or BEV_LOCK. */
1026 void
1027 bufferevent_lock(struct bufferevent *bev)
1028 {
1029         bufferevent_incref_and_lock_(bev);
1030 }
1031
1032 void
1033 bufferevent_unlock(struct bufferevent *bev)
1034 {
1035         bufferevent_decref_and_unlock_(bev);
1036 }