src/pulsecore/rtpoll.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as
   9   published by the Free Software Foundation; either version 2.1 of the
  10   License, or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public
  18   License along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <sys/types.h>
  28 #include <stdio.h>
  29 #include <signal.h>
  30 #include <string.h>
  31 #include <errno.h>
  32
  33 #ifdef HAVE_POLL_H
  34 #include <poll.h>
  35 #else
  36 #include <pulsecore/poll.h>
  37 #endif
  38
  39 #include <pulse/xmalloc.h>
  40 #include <pulse/timeval.h>
  41
  42 #include <pulsecore/core-error.h>
  43 #include <pulsecore/core-rtclock.h>
  44 #include <pulsecore/macro.h>
  45 #include <pulsecore/llist.h>
  46 #include <pulsecore/flist.h>
  47 #include <pulsecore/core-util.h>
  48 #include <pulsecore/winsock.h>
  49 #include <pulsecore/ratelimit.h>
  50
  51 #include "rtpoll.h"
  52
  53 /* #define DEBUG_TIMING */
  54
  55 struct pa_rtpoll {
  56     struct pollfd *pollfd, *pollfd2;
  57     unsigned n_pollfd_alloc, n_pollfd_used;
  58
  59     struct timeval next_elapse;
  60     pa_bool_t timer_enabled:1;
  61
  62     pa_bool_t scan_for_dead:1;
  63     pa_bool_t running:1;
  64     pa_bool_t rebuild_needed:1;
  65     pa_bool_t quit:1;
  66
  67 #ifdef DEBUG_TIMING
  68     pa_usec_t timestamp;
  69     pa_usec_t slept, awake;
  70 #endif
  71
  72     PA_LLIST_HEAD(pa_rtpoll_item, items);
  73 };
  74
  75 struct pa_rtpoll_item {
  76     pa_rtpoll *rtpoll;
  77     pa_bool_t dead;
  78
  79     pa_rtpoll_priority_t priority;
  80
  81     struct pollfd *pollfd;
  82     unsigned n_pollfd;
  83
  84     int (*work_cb)(pa_rtpoll_item *i);
  85     int (*before_cb)(pa_rtpoll_item *i);
  86     void (*after_cb)(pa_rtpoll_item *i);
  87     void *userdata;
  88
  89     PA_LLIST_FIELDS(pa_rtpoll_item);
  90 };
  91
  92 PA_STATIC_FLIST_DECLARE(items, 0, pa_xfree);
  93
  94 pa_rtpoll *pa_rtpoll_new(void) {
  95     pa_rtpoll *p;
  96
  97     p = pa_xnew(pa_rtpoll, 1);
  98
  99     p->n_pollfd_alloc = 32;
 100     p->pollfd = pa_xnew(struct pollfd, p->n_pollfd_alloc);
 101     p->pollfd2 = pa_xnew(struct pollfd, p->n_pollfd_alloc);
 102     p->n_pollfd_used = 0;
 103
 104     pa_zero(p->next_elapse);
 105     p->timer_enabled = FALSE;
 106
 107     p->running = FALSE;
 108     p->scan_for_dead = FALSE;
 109     p->rebuild_needed = FALSE;
 110     p->quit = FALSE;
 111
 112     PA_LLIST_HEAD_INIT(pa_rtpoll_item, p->items);
 113
 114 #ifdef DEBUG_TIMING
 115     p->timestamp = pa_rtclock_now();
 116     p->slept = p->awake = 0;
 117 #endif
 118
 119     return p;
 120 }
 121
 122 static void rtpoll_rebuild(pa_rtpoll *p) {
 123
 124     struct pollfd *e, *t;
 125     pa_rtpoll_item *i;
 126     int ra = 0;
 127
 128     pa_assert(p);
 129
 130     p->rebuild_needed = FALSE;
 131
 132     if (p->n_pollfd_used > p->n_pollfd_alloc) {
 133         /* Hmm, we have to allocate some more space */
 134         p->n_pollfd_alloc = p->n_pollfd_used * 2;
 135         p->pollfd2 = pa_xrealloc(p->pollfd2, p->n_pollfd_alloc * sizeof(struct pollfd));
 136         ra = 1;
 137     }
 138
 139     e = p->pollfd2;
 140
 141     for (i = p->items; i; i = i->next) {
 142
 143         if (i->n_pollfd > 0)  {
 144             size_t l = i->n_pollfd * sizeof(struct pollfd);
 145
 146             if (i->pollfd)
 147                 memcpy(e, i->pollfd, l);
 148             else
 149                 memset(e, 0, l);
 150
 151             i->pollfd = e;
 152         } else
 153             i->pollfd = NULL;
 154
 155         e += i->n_pollfd;
 156     }
 157
 158     pa_assert((unsigned) (e - p->pollfd2) == p->n_pollfd_used);
 159     t = p->pollfd;
 160     p->pollfd = p->pollfd2;
 161     p->pollfd2 = t;
 162
 163     if (ra)
 164         p->pollfd2 = pa_xrealloc(p->pollfd2, p->n_pollfd_alloc * sizeof(struct pollfd));
 165 }
 166
 167 static void rtpoll_item_destroy(pa_rtpoll_item *i) {
 168     pa_rtpoll *p;
 169
 170     pa_assert(i);
 171
 172     p = i->rtpoll;
 173
 174     PA_LLIST_REMOVE(pa_rtpoll_item, p->items, i);
 175
 176     p->n_pollfd_used -= i->n_pollfd;
 177
 178     if (pa_flist_push(PA_STATIC_FLIST_GET(items), i) < 0)
 179         pa_xfree(i);
 180
 181     p->rebuild_needed = TRUE;
 182 }
 183
 184 void pa_rtpoll_free(pa_rtpoll *p) {
 185     pa_assert(p);
 186
 187     while (p->items)
 188         rtpoll_item_destroy(p->items);
 189
 190     pa_xfree(p->pollfd);
 191     pa_xfree(p->pollfd2);
 192
 193     pa_xfree(p);
 194 }
 195
 196 static void reset_revents(pa_rtpoll_item *i) {
 197     struct pollfd *f;
 198     unsigned n;
 199
 200     pa_assert(i);
 201
 202     if (!(f = pa_rtpoll_item_get_pollfd(i, &n)))
 203         return;
 204
 205     for (; n > 0; n--)
 206         f[n-1].revents = 0;
 207 }
 208
 209 static void reset_all_revents(pa_rtpoll *p) {
 210     pa_rtpoll_item *i;
 211
 212     pa_assert(p);
 213
 214     for (i = p->items; i; i = i->next) {
 215
 216         if (i->dead)
 217             continue;
 218
 219         reset_revents(i);
 220     }
 221 }
 222
 223 int pa_rtpoll_run(pa_rtpoll *p, pa_bool_t wait_op) {
 224     pa_rtpoll_item *i;
 225     int r = 0;
 226     struct timeval timeout;
 227
 228     pa_assert(p);
 229     pa_assert(!p->running);
 230
 231     p->running = TRUE;
 232
 233     /* First, let's do some work */
 234     for (i = p->items; i && i->priority < PA_RTPOLL_NEVER; i = i->next) {
 235         int k;
 236
 237         if (i->dead)
 238             continue;
 239
 240         if (!i->work_cb)
 241             continue;
 242
 243         if (p->quit)
 244             goto finish;
 245
 246         if ((k = i->work_cb(i)) != 0) {
 247             if (k < 0)
 248                 r = k;
 249
 250             goto finish;
 251         }
 252     }
 253
 254     /* Now let's prepare for entering the sleep */
 255     for (i = p->items; i && i->priority < PA_RTPOLL_NEVER; i = i->next) {
 256         int k = 0;
 257
 258         if (i->dead)
 259             continue;
 260
 261         if (!i->before_cb)
 262             continue;
 263
 264         if (p->quit || (k = i->before_cb(i)) != 0) {
 265
 266             /* Hmm, this one doesn't let us enter the poll, so rewind everything */
 267
 268             for (i = i->prev; i; i = i->prev) {
 269
 270                 if (i->dead)
 271                     continue;
 272
 273                 if (!i->after_cb)
 274                     continue;
 275
 276                 i->after_cb(i);
 277             }
 278
 279             if (k < 0)
 280                 r = k;
 281
 282             goto finish;
 283         }
 284     }
 285
 286     if (p->rebuild_needed)
 287         rtpoll_rebuild(p);
 288
 289     memset(&timeout, 0, sizeof(timeout));
 290
 291     /* Calculate timeout */
 292     if (wait_op && !p->quit && p->timer_enabled) {
 293         struct timeval now;
 294         pa_rtclock_get(&now);
 295
 296         if (pa_timeval_cmp(&p->next_elapse, &now) > 0)
 297             pa_timeval_add(&timeout, pa_timeval_diff(&p->next_elapse, &now));
 298     }
 299
 300 #ifdef DEBUG_TIMING
 301     {
 302         pa_usec_t now = pa_rtclock_now();
 303         p->awake = now - p->timestamp;
 304         p->timestamp = now;
 305     }
 306 #endif
 307
 308     /* OK, now let's sleep */
 309 #ifdef HAVE_PPOLL
 310     {
 311         struct timespec ts;
 312         ts.tv_sec = timeout.tv_sec;
 313         ts.tv_nsec = timeout.tv_usec * 1000;
 314         r = ppoll(p->pollfd, p->n_pollfd_used, (!wait_op || p->quit || p->timer_enabled) ? &ts : NULL, NULL);
 315     }
 316 #else
 317         r = poll(p->pollfd, p->n_pollfd_used, (!wait_op || p->quit || p->timer_enabled) ? (int) ((timeout.tv_sec*1000) + (timeout.tv_usec / 1000)) : -1);
 318 #endif
 319
 320 #ifdef DEBUG_TIMING
 321     {
 322         pa_usec_t now = pa_rtclock_now();
 323         p->slept = now - p->timestamp;
 324         p->timestamp = now;
 325
 326         pa_log("Process time %llu ms; sleep time %llu ms",
 327                (unsigned long long) (p->awake / PA_USEC_PER_MSEC),
 328                (unsigned long long) (p->slept / PA_USEC_PER_MSEC));
 329     }
 330 #endif
 331
 332     if (r < 0) {
 333         if (errno == EAGAIN || errno == EINTR)
 334             r = 0;
 335         else
 336             pa_log_error("poll(): %s", pa_cstrerror(errno));
 337
 338         reset_all_revents(p);
 339     }
 340
 341     /* Let's tell everyone that we left the sleep */
 342     for (i = p->items; i && i->priority < PA_RTPOLL_NEVER; i = i->next) {
 343
 344         if (i->dead)
 345             continue;
 346
 347         if (!i->after_cb)
 348             continue;
 349
 350         i->after_cb(i);
 351     }
 352
 353 finish:
 354
 355     p->running = FALSE;
 356
 357     if (p->scan_for_dead) {
 358         pa_rtpoll_item *n;
 359
 360         p->scan_for_dead = FALSE;
 361
 362         for (i = p->items; i; i = n) {
 363             n = i->next;
 364
 365             if (i->dead)
 366                 rtpoll_item_destroy(i);
 367         }
 368     }
 369
 370     return r < 0 ? r : !p->quit;
 371 }
 372
 373 void pa_rtpoll_set_timer_absolute(pa_rtpoll *p, pa_usec_t usec) {
 374     pa_assert(p);
 375
 376     pa_timeval_store(&p->next_elapse, usec);
 377     p->timer_enabled = TRUE;
 378 }
 379
 380 void pa_rtpoll_set_timer_relative(pa_rtpoll *p, pa_usec_t usec) {
 381     pa_assert(p);
 382
 383     /* Scheduling a timeout for more than an hour is very very suspicious */
 384     pa_assert(usec <= PA_USEC_PER_SEC*60ULL*60ULL);
 385
 386     pa_rtclock_get(&p->next_elapse);
 387     pa_timeval_add(&p->next_elapse, usec);
 388     p->timer_enabled = TRUE;
 389 }
 390
 391 void pa_rtpoll_set_timer_disabled(pa_rtpoll *p) {
 392     pa_assert(p);
 393
 394     memset(&p->next_elapse, 0, sizeof(p->next_elapse));
 395     p->timer_enabled = FALSE;
 396 }
 397
 398 pa_rtpoll_item *pa_rtpoll_item_new(pa_rtpoll *p, pa_rtpoll_priority_t prio, unsigned n_fds) {
 399     pa_rtpoll_item *i, *j, *l = NULL;
 400
 401     pa_assert(p);
 402
 403     if (!(i = pa_flist_pop(PA_STATIC_FLIST_GET(items))))
 404         i = pa_xnew(pa_rtpoll_item, 1);
 405
 406     i->rtpoll = p;
 407     i->dead = FALSE;
 408     i->n_pollfd = n_fds;
 409     i->pollfd = NULL;
 410     i->priority = prio;
 411
 412     i->userdata = NULL;
 413     i->before_cb = NULL;
 414     i->after_cb = NULL;
 415     i->work_cb = NULL;
 416
 417     for (j = p->items; j; j = j->next) {
 418         if (prio <= j->priority)
 419             break;
 420
 421         l = j;
 422     }
 423
 424     PA_LLIST_INSERT_AFTER(pa_rtpoll_item, p->items, j ? j->prev : l, i);
 425
 426     if (n_fds > 0) {
 427         p->rebuild_needed = 1;
 428         p->n_pollfd_used += n_fds;
 429     }
 430
 431     return i;
 432 }
 433
 434 void pa_rtpoll_item_free(pa_rtpoll_item *i) {
 435     pa_assert(i);
 436
 437     if (i->rtpoll->running) {
 438         i->dead = TRUE;
 439         i->rtpoll->scan_for_dead = TRUE;
 440         return;
 441     }
 442
 443     rtpoll_item_destroy(i);
 444 }
 445
 446 struct pollfd *pa_rtpoll_item_get_pollfd(pa_rtpoll_item *i, unsigned *n_fds) {
 447     pa_assert(i);
 448
 449     if (i->n_pollfd > 0)
 450         if (i->rtpoll->rebuild_needed)
 451             rtpoll_rebuild(i->rtpoll);
 452
 453     if (n_fds)
 454         *n_fds = i->n_pollfd;
 455
 456     return i->pollfd;
 457 }
 458
 459 void pa_rtpoll_item_set_before_callback(pa_rtpoll_item *i, int (*before_cb)(pa_rtpoll_item *i)) {
 460     pa_assert(i);
 461     pa_assert(i->priority < PA_RTPOLL_NEVER);
 462
 463     i->before_cb = before_cb;
 464 }
 465
 466 void pa_rtpoll_item_set_after_callback(pa_rtpoll_item *i, void (*after_cb)(pa_rtpoll_item *i)) {
 467     pa_assert(i);
 468     pa_assert(i->priority < PA_RTPOLL_NEVER);
 469
 470     i->after_cb = after_cb;
 471 }
 472
 473 void pa_rtpoll_item_set_work_callback(pa_rtpoll_item *i, int (*work_cb)(pa_rtpoll_item *i)) {
 474     pa_assert(i);
 475     pa_assert(i->priority < PA_RTPOLL_NEVER);
 476
 477     i->work_cb = work_cb;
 478 }
 479
 480 void pa_rtpoll_item_set_userdata(pa_rtpoll_item *i, void *userdata) {
 481     pa_assert(i);
 482
 483     i->userdata = userdata;
 484 }
 485
 486 void* pa_rtpoll_item_get_userdata(pa_rtpoll_item *i) {
 487     pa_assert(i);
 488
 489     return i->userdata;
 490 }
 491
 492 static int fdsem_before(pa_rtpoll_item *i) {
 493
 494     if (pa_fdsem_before_poll(i->userdata) < 0)
 495         return 1; /* 1 means immediate restart of the loop */
 496
 497     return 0;
 498 }
 499
 500 static void fdsem_after(pa_rtpoll_item *i) {
 501     pa_assert(i);
 502
 503     pa_assert((i->pollfd[0].revents & ~POLLIN) == 0);
 504     pa_fdsem_after_poll(i->userdata);
 505 }
 506
 507 pa_rtpoll_item *pa_rtpoll_item_new_fdsem(pa_rtpoll *p, pa_rtpoll_priority_t prio, pa_fdsem *f) {
 508     pa_rtpoll_item *i;
 509     struct pollfd *pollfd;
 510
 511     pa_assert(p);
 512     pa_assert(f);
 513
 514     i = pa_rtpoll_item_new(p, prio, 1);
 515
 516     pollfd = pa_rtpoll_item_get_pollfd(i, NULL);
 517
 518     pollfd->fd = pa_fdsem_get(f);
 519     pollfd->events = POLLIN;
 520
 521     i->before_cb = fdsem_before;
 522     i->after_cb = fdsem_after;
 523     i->userdata = f;
 524
 525     return i;
 526 }
 527
 528 static int asyncmsgq_read_before(pa_rtpoll_item *i) {
 529     pa_assert(i);
 530
 531     if (pa_asyncmsgq_read_before_poll(i->userdata) < 0)
 532         return 1; /* 1 means immediate restart of the loop */
 533
 534     return 0;
 535 }
 536
 537 static void asyncmsgq_read_after(pa_rtpoll_item *i) {
 538     pa_assert(i);
 539
 540     pa_assert((i->pollfd[0].revents & ~POLLIN) == 0);
 541     pa_asyncmsgq_read_after_poll(i->userdata);
 542 }
 543
 544 static int asyncmsgq_read_work(pa_rtpoll_item *i) {
 545     pa_msgobject *object;
 546     int code;
 547     void *data;
 548     pa_memchunk chunk;
 549     int64_t offset;
 550
 551     pa_assert(i);
 552
 553     if (pa_asyncmsgq_get(i->userdata, &object, &code, &data, &offset, &chunk, 0) == 0) {
 554         int ret;
 555
 556         if (!object && code == PA_MESSAGE_SHUTDOWN) {
 557             pa_asyncmsgq_done(i->userdata, 0);
 558             pa_rtpoll_quit(i->rtpoll);
 559             return 1;
 560         }
 561
 562         ret = pa_asyncmsgq_dispatch(object, code, data, offset, &chunk);
 563         pa_asyncmsgq_done(i->userdata, ret);
 564         return 1;
 565     }
 566
 567     return 0;
 568 }
 569
 570 pa_rtpoll_item *pa_rtpoll_item_new_asyncmsgq_read(pa_rtpoll *p, pa_rtpoll_priority_t prio, pa_asyncmsgq *q) {
 571     pa_rtpoll_item *i;
 572     struct pollfd *pollfd;
 573
 574     pa_assert(p);
 575     pa_assert(q);
 576
 577     i = pa_rtpoll_item_new(p, prio, 1);
 578
 579     pollfd = pa_rtpoll_item_get_pollfd(i, NULL);
 580     pollfd->fd = pa_asyncmsgq_read_fd(q);
 581     pollfd->events = POLLIN;
 582
 583     i->before_cb = asyncmsgq_read_before;
 584     i->after_cb = asyncmsgq_read_after;
 585     i->work_cb = asyncmsgq_read_work;
 586     i->userdata = q;
 587
 588     return i;
 589 }
 590
 591 static int asyncmsgq_write_before(pa_rtpoll_item *i) {
 592     pa_assert(i);
 593
 594     pa_asyncmsgq_write_before_poll(i->userdata);
 595     return 0;
 596 }
 597
 598 static void asyncmsgq_write_after(pa_rtpoll_item *i) {
 599     pa_assert(i);
 600
 601     pa_assert((i->pollfd[0].revents & ~POLLIN) == 0);
 602     pa_asyncmsgq_write_after_poll(i->userdata);
 603 }
 604
 605 pa_rtpoll_item *pa_rtpoll_item_new_asyncmsgq_write(pa_rtpoll *p, pa_rtpoll_priority_t prio, pa_asyncmsgq *q) {
 606     pa_rtpoll_item *i;
 607     struct pollfd *pollfd;
 608
 609     pa_assert(p);
 610     pa_assert(q);
 611
 612     i = pa_rtpoll_item_new(p, prio, 1);
 613
 614     pollfd = pa_rtpoll_item_get_pollfd(i, NULL);
 615     pollfd->fd = pa_asyncmsgq_write_fd(q);
 616     pollfd->events = POLLIN;
 617
 618     i->before_cb = asyncmsgq_write_before;
 619     i->after_cb = asyncmsgq_write_after;
 620     i->work_cb = NULL;
 621     i->userdata = q;
 622
 623     return i;
 624 }
 625
 626 void pa_rtpoll_quit(pa_rtpoll *p) {
 627     pa_assert(p);
 628
 629     p->quit = TRUE;
 630 }