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  1. /*
  2. * libev kqueue backend
  3. *
  4. * Copyright (c) 2007,2008,2009,2010,2011,2012,2013 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. void inline_speed
  45. kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
  46. {
  47. ++kqueue_changecnt;
  48. array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2);
  49. EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
  50. }
  51. /* OS X at least needs this */
  52. #ifndef EV_ENABLE
  53. # define EV_ENABLE 0
  54. #endif
  55. #ifndef NOTE_EOF
  56. # define NOTE_EOF 0
  57. #endif
  58. static void
  59. kqueue_modify (EV_P_ int fd, int oev, int nev)
  60. {
  61. if (oev != nev)
  62. {
  63. if (oev & EV_READ)
  64. kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
  65. if (oev & EV_WRITE)
  66. kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
  67. }
  68. /* to detect close/reopen reliably, we have to re-add */
  69. /* event requests even when oev == nev */
  70. if (nev & EV_READ)
  71. kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD | EV_ENABLE, NOTE_EOF);
  72. if (nev & EV_WRITE)
  73. kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD | EV_ENABLE, NOTE_EOF);
  74. }
  75. static void
  76. kqueue_poll (EV_P_ ev_tstamp timeout)
  77. {
  78. int res, i;
  79. struct timespec ts;
  80. /* need to resize so there is enough space for errors */
  81. if (kqueue_changecnt > kqueue_eventmax)
  82. {
  83. ev_free (kqueue_events);
  84. kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_changecnt);
  85. kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
  86. }
  87. EV_RELEASE_CB;
  88. EV_TS_SET (ts, timeout);
  89. res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
  90. EV_ACQUIRE_CB;
  91. kqueue_changecnt = 0;
  92. if (expect_false (res < 0))
  93. {
  94. if (errno != EINTR)
  95. ev_syserr ("(libev) kevent");
  96. return;
  97. }
  98. for (i = 0; i < res; ++i)
  99. {
  100. int fd = kqueue_events [i].ident;
  101. if (expect_false (kqueue_events [i].flags & EV_ERROR))
  102. {
  103. int err = kqueue_events [i].data;
  104. /* we are only interested in errors for fds that we are interested in :) */
  105. if (anfds [fd].events)
  106. {
  107. if (err == ENOENT) /* resubmit changes on ENOENT */
  108. kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
  109. else if (err == EBADF) /* on EBADF, we re-check the fd */
  110. {
  111. if (fd_valid (fd))
  112. kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
  113. else
  114. fd_kill (EV_A_ fd);
  115. }
  116. else /* on all other errors, we error out on the fd */
  117. fd_kill (EV_A_ fd);
  118. }
  119. }
  120. else
  121. fd_event (
  122. EV_A_
  123. fd,
  124. kqueue_events [i].filter == EVFILT_READ ? EV_READ
  125. : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
  126. : 0
  127. );
  128. }
  129. if (expect_false (res == kqueue_eventmax))
  130. {
  131. ev_free (kqueue_events);
  132. kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
  133. kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
  134. }
  135. }
  136. int inline_size
  137. kqueue_init (EV_P_ int flags)
  138. {
  139. /* initialize the kernel queue */
  140. kqueue_fd_pid = getpid ();
  141. if ((backend_fd = kqueue ()) < 0)
  142. return 0;
  143. fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
  144. backend_mintime = 1e-9; /* apparently, they did the right thing in freebsd */
  145. backend_modify = kqueue_modify;
  146. backend_poll = kqueue_poll;
  147. kqueue_eventmax = 64; /* initial number of events receivable per poll */
  148. kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
  149. kqueue_changes = 0;
  150. kqueue_changemax = 0;
  151. kqueue_changecnt = 0;
  152. return EVBACKEND_KQUEUE;
  153. }
  154. void inline_size
  155. kqueue_destroy (EV_P)
  156. {
  157. ev_free (kqueue_events);
  158. ev_free (kqueue_changes);
  159. }
  160. void inline_size
  161. kqueue_fork (EV_P)
  162. {
  163. /* some BSD kernels don't just destroy the kqueue itself,
  164. * but also close the fd, which isn't documented, and
  165. * impossible to support properly.
  166. * we remember the pid of the kqueue call and only close
  167. * the fd if the pid is still the same.
  168. * this leaks fds on sane kernels, but BSD interfaces are
  169. * notoriously buggy and rarely get fixed.
  170. */
  171. pid_t newpid = getpid ();
  172. if (newpid == kqueue_fd_pid)
  173. close (backend_fd);
  174. kqueue_fd_pid = newpid;
  175. while ((backend_fd = kqueue ()) < 0)
  176. ev_syserr ("(libev) kqueue");
  177. fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
  178. /* re-register interest in fds */
  179. fd_rearm_all (EV_A);
  180. }
  181. /* sys/event.h defines EV_ERROR */
  182. #undef EV_ERROR