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  1. /*
  2. * libev kqueue backend
  3. *
  4. * Copyright (c) 2007,2008,2009,2010,2011,2012,2013,2016,2019 Marc Alexander Lehmann <libev@schmorp.de>
  5. * All rights reserved.
  6. *
  7. * Redistribution and use in source and binary forms, with or without modifica-
  8. * tion, are permitted provided that the following conditions are met:
  9. *
  10. * 1. Redistributions of source code must retain the above copyright notice,
  11. * this list of conditions and the following disclaimer.
  12. *
  13. * 2. Redistributions in binary form must reproduce the above copyright
  14. * notice, this list of conditions and the following disclaimer in the
  15. * documentation and/or other materials provided with the distribution.
  16. *
  17. * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  18. * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
  19. * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
  20. * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
  21. * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  22. * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  23. * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  24. * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
  25. * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  26. * OF THE POSSIBILITY OF SUCH DAMAGE.
  27. *
  28. * Alternatively, the contents of this file may be used under the terms of
  29. * the GNU General Public License ("GPL") version 2 or any later version,
  30. * in which case the provisions of the GPL are applicable instead of
  31. * the above. If you wish to allow the use of your version of this file
  32. * only under the terms of the GPL and not to allow others to use your
  33. * version of this file under the BSD license, indicate your decision
  34. * by deleting the provisions above and replace them with the notice
  35. * and other provisions required by the GPL. If you do not delete the
  36. * provisions above, a recipient may use your version of this file under
  37. * either the BSD or the GPL.
  38. */
  39. #include <sys/types.h>
  40. #include <sys/time.h>
  41. #include <sys/event.h>
  42. #include <string.h>
  43. #include <errno.h>
  44. inline_speed
  45. void
  46. kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
  47. {
  48. ++kqueue_changecnt;
  49. array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, array_needsize_noinit);
  50. EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
  51. }
  52. /* OS X at least needs this */
  53. #ifndef EV_ENABLE
  54. # define EV_ENABLE 0
  55. #endif
  56. #ifndef NOTE_EOF
  57. # define NOTE_EOF 0
  58. #endif
  59. static void
  60. kqueue_modify (EV_P_ int fd, int oev, int nev)
  61. {
  62. if (oev != nev)
  63. {
  64. if (oev & EV_READ)
  65. kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
  66. if (oev & EV_WRITE)
  67. kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
  68. }
  69. /* to detect close/reopen reliably, we have to re-add */
  70. /* event requests even when oev == nev */
  71. if (nev & EV_READ)
  72. kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD | EV_ENABLE, NOTE_EOF);
  73. if (nev & EV_WRITE)
  74. kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD | EV_ENABLE, NOTE_EOF);
  75. }
  76. static void
  77. kqueue_poll (EV_P_ ev_tstamp timeout)
  78. {
  79. int res, i;
  80. struct timespec ts;
  81. /* need to resize so there is enough space for errors */
  82. if (kqueue_changecnt > kqueue_eventmax)
  83. {
  84. ev_free (kqueue_events);
  85. kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_changecnt);
  86. kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
  87. }
  88. EV_RELEASE_CB;
  89. EV_TS_SET (ts, timeout);
  90. res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
  91. EV_ACQUIRE_CB;
  92. kqueue_changecnt = 0;
  93. if (ecb_expect_false (res < 0))
  94. {
  95. if (errno != EINTR)
  96. ev_syserr ("(libev) kqueue kevent");
  97. return;
  98. }
  99. for (i = 0; i < res; ++i)
  100. {
  101. int fd = kqueue_events [i].ident;
  102. if (ecb_expect_false (kqueue_events [i].flags & EV_ERROR))
  103. {
  104. int err = kqueue_events [i].data;
  105. /* we are only interested in errors for fds that we are interested in :) */
  106. if (anfds [fd].events)
  107. {
  108. if (err == ENOENT) /* resubmit changes on ENOENT */
  109. kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
  110. else if (err == EBADF) /* on EBADF, we re-check the fd */
  111. {
  112. if (fd_valid (fd))
  113. kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
  114. else
  115. {
  116. assert (("libev: kqueue found invalid fd", 0));
  117. fd_kill (EV_A_ fd);
  118. }
  119. }
  120. else /* on all other errors, we error out on the fd */
  121. {
  122. assert (("libev: kqueue found invalid fd", 0));
  123. fd_kill (EV_A_ fd);
  124. }
  125. }
  126. }
  127. else
  128. fd_event (
  129. EV_A_
  130. fd,
  131. kqueue_events [i].filter == EVFILT_READ ? EV_READ
  132. : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
  133. : 0
  134. );
  135. }
  136. if (ecb_expect_false (res == kqueue_eventmax))
  137. {
  138. ev_free (kqueue_events);
  139. kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
  140. kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
  141. }
  142. }
  143. inline_size
  144. int
  145. kqueue_init (EV_P_ int flags)
  146. {
  147. /* initialize the kernel queue */
  148. kqueue_fd_pid = getpid ();
  149. if ((backend_fd = kqueue ()) < 0)
  150. return 0;
  151. fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
  152. backend_mintime = EV_TS_CONST (1e-9); /* apparently, they did the right thing in freebsd */
  153. backend_modify = kqueue_modify;
  154. backend_poll = kqueue_poll;
  155. kqueue_eventmax = 64; /* initial number of events receivable per poll */
  156. kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
  157. kqueue_changes = 0;
  158. kqueue_changemax = 0;
  159. kqueue_changecnt = 0;
  160. return EVBACKEND_KQUEUE;
  161. }
  162. inline_size
  163. void
  164. kqueue_destroy (EV_P)
  165. {
  166. ev_free (kqueue_events);
  167. ev_free (kqueue_changes);
  168. }
  169. inline_size
  170. void
  171. kqueue_fork (EV_P)
  172. {
  173. /* some BSD kernels don't just destroy the kqueue itself,
  174. * but also close the fd, which isn't documented, and
  175. * impossible to support properly.
  176. * we remember the pid of the kqueue call and only close
  177. * the fd if the pid is still the same.
  178. * this leaks fds on sane kernels, but BSD interfaces are
  179. * notoriously buggy and rarely get fixed.
  180. */
  181. pid_t newpid = getpid ();
  182. if (newpid == kqueue_fd_pid)
  183. close (backend_fd);
  184. kqueue_fd_pid = newpid;
  185. while ((backend_fd = kqueue ()) < 0)
  186. ev_syserr ("(libev) kqueue");
  187. fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
  188. /* re-register interest in fds */
  189. fd_rearm_all (EV_A);
  190. }
  191. /* sys/event.h defines EV_ERROR */
  192. #undef EV_ERROR