1 /* 2 * libev kqueue backend 3 * 4 * Copyright (c) 2007,2008,2009,2010 Marc Alexander Lehmann <[email protected]> 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 40 #include <sys/types.h> 41 #include <sys/time.h> 42 #include <sys/event.h> 43 #include <string.h> 44 #include <errno.h> 45 46 void inline_speed 47 kqueue_change (EV_P_ int fd, int filter, int flags, int fflags) 48 { 49 ++kqueue_changecnt; 50 array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2); 51 52 EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0); 53 } 54 55 /* OS X at least needs this */ 56 #ifndef EV_ENABLE 57 # define EV_ENABLE 0 58 #endif 59 #ifndef NOTE_EOF 60 # define NOTE_EOF 0 61 #endif 62 63 static void 64 kqueue_modify (EV_P_ int fd, int oev, int nev) 65 { 66 if (oev != nev) 67 { 68 if (oev & EV_READ) 69 kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0); 70 71 if (oev & EV_WRITE) 72 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0); 73 } 74 75 /* to detect close/reopen reliably, we have to re-add */ 76 /* event requests even when oev == nev */ 77 78 if (nev & EV_READ) 79 kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD | EV_ENABLE, NOTE_EOF); 80 81 if (nev & EV_WRITE) 82 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD | EV_ENABLE, NOTE_EOF); 83 } 84 85 static void 86 kqueue_poll (EV_P_ ev_tstamp timeout) 87 { 88 int res, i; 89 struct timespec ts; 90 91 /* need to resize so there is enough space for errors */ 92 if (kqueue_changecnt > kqueue_eventmax) 93 { 94 ev_free (kqueue_events); 95 kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_changecnt); 96 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax); 97 } 98 99 EV_RELEASE_CB; 100 EV_TS_SET (ts, timeout); 101 res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts); 102 EV_ACQUIRE_CB; 103 kqueue_changecnt = 0; 104 105 if (expect_false (res < 0)) 106 { 107 if (errno != EINTR) 108 ev_syserr ("(libev) kevent"); 109 110 return; 111 } 112 113 for (i = 0; i < res; ++i) 114 { 115 int fd = kqueue_events [i].ident; 116 117 if (expect_false (kqueue_events [i].flags & EV_ERROR)) 118 { 119 int err = kqueue_events [i].data; 120 121 /* we are only interested in errors for fds that we are interested in :) */ 122 if (anfds [fd].events) 123 { 124 if (err == ENOENT) /* resubmit changes on ENOENT */ 125 kqueue_modify (EV_A_ fd, 0, anfds [fd].events); 126 else if (err == EBADF) /* on EBADF, we re-check the fd */ 127 { 128 if (fd_valid (fd)) 129 kqueue_modify (EV_A_ fd, 0, anfds [fd].events); 130 else 131 fd_kill (EV_A_ fd); 132 } 133 else /* on all other errors, we error out on the fd */ 134 fd_kill (EV_A_ fd); 135 } 136 } 137 else 138 fd_event ( 139 EV_A_ 140 fd, 141 kqueue_events [i].filter == EVFILT_READ ? EV_READ 142 : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE 143 : 0 144 ); 145 } 146 147 if (expect_false (res == kqueue_eventmax)) 148 { 149 ev_free (kqueue_events); 150 kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1); 151 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax); 152 } 153 } 154 155 int inline_size 156 kqueue_init (EV_P_ int flags) 157 { 158 /* Initialize the kernel queue */ 159 if ((backend_fd = kqueue ()) < 0) 160 return 0; 161 162 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */ 163 164 backend_fudge = 0.; 165 backend_modify = kqueue_modify; 166 backend_poll = kqueue_poll; 167 168 kqueue_eventmax = 64; /* initial number of events receivable per poll */ 169 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax); 170 171 kqueue_changes = 0; 172 kqueue_changemax = 0; 173 kqueue_changecnt = 0; 174 175 return EVBACKEND_KQUEUE; 176 } 177 178 void inline_size 179 kqueue_destroy (EV_P) 180 { 181 ev_free (kqueue_events); 182 ev_free (kqueue_changes); 183 } 184 185 void inline_size 186 kqueue_fork (EV_P) 187 { 188 close (backend_fd); 189 190 while ((backend_fd = kqueue ()) < 0) 191 ev_syserr ("(libev) kqueue"); 192 193 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); 194 195 /* re-register interest in fds */ 196 fd_rearm_all (EV_A); 197 } 198 199