1 /* 2 * libev poll fd activity backend 3 * 4 * Copyright (c) 2007,2008,2009,2010,2011 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 40 #include <poll.h> 41 42 void inline_size 43 pollidx_init (int *base, int count) 44 { 45 /* consider using memset (.., -1, ...), which is practically guaranteed 46 * to work on all systems implementing poll */ 47 while (count--) 48 *base++ = -1; 49 } 50 51 static void 52 poll_modify (EV_P_ int fd, int oev, int nev) 53 { 54 int idx; 55 56 if (oev == nev) 57 return; 58 59 array_needsize (int, pollidxs, pollidxmax, fd + 1, pollidx_init); 60 61 idx = pollidxs [fd]; 62 63 if (idx < 0) /* need to allocate a new pollfd */ 64 { 65 pollidxs [fd] = idx = pollcnt++; 66 array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2); 67 polls [idx].fd = fd; 68 } 69 70 assert (polls [idx].fd == fd); 71 72 if (nev) 73 polls [idx].events = 74 (nev & EV_READ ? POLLIN : 0) 75 | (nev & EV_WRITE ? POLLOUT : 0); 76 else /* remove pollfd */ 77 { 78 pollidxs [fd] = -1; 79 80 if (expect_true (idx < --pollcnt)) 81 { 82 polls [idx] = polls [pollcnt]; 83 pollidxs [polls [idx].fd] = idx; 84 } 85 } 86 } 87 88 static void 89 poll_poll (EV_P_ ev_tstamp timeout) 90 { 91 struct pollfd *p; 92 int res; 93 94 EV_RELEASE_CB; 95 res = poll (polls, pollcnt, timeout * 1e3); 96 EV_ACQUIRE_CB; 97 98 if (expect_false (res < 0)) 99 { 100 if (errno == EBADF) 101 fd_ebadf (EV_A); 102 else if (errno == ENOMEM && !syserr_cb) 103 fd_enomem (EV_A); 104 else if (errno != EINTR) 105 ev_syserr ("(libev) poll"); 106 } 107 else 108 for (p = polls; res; ++p) 109 { 110 assert (("libev: poll() returned illegal result, broken BSD kernel?", p < polls + pollcnt)); 111 112 if (expect_false (p->revents)) /* this expect is debatable */ 113 { 114 --res; 115 116 if (expect_false (p->revents & POLLNVAL)) 117 fd_kill (EV_A_ p->fd); 118 else 119 fd_event ( 120 EV_A_ 121 p->fd, 122 (p->revents & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0) 123 | (p->revents & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0) 124 ); 125 } 126 } 127 } 128 129 int inline_size 130 poll_init (EV_P_ int flags) 131 { 132 backend_mintime = 1e-3; 133 backend_modify = poll_modify; 134 backend_poll = poll_poll; 135 136 pollidxs = 0; pollidxmax = 0; 137 polls = 0; pollmax = 0; pollcnt = 0; 138 139 return EVBACKEND_POLL; 140 } 141 142 void inline_size 143 poll_destroy (EV_P) 144 { 145 ev_free (pollidxs); 146 ev_free (polls); 147 } 148 149