ares_event_poll.c (4170B)
1 /* MIT License 2 * 3 * Copyright (c) 2024 Brad House 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a copy 6 * of this software and associated documentation files (the "Software"), to deal 7 * in the Software without restriction, including without limitation the rights 8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 * copies of the Software, and to permit persons to whom the Software is 10 * furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice (including the next 13 * paragraph) shall be included in all copies or substantial portions of the 14 * Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 22 * SOFTWARE. 23 * 24 * SPDX-License-Identifier: MIT 25 */ 26 #include "ares_private.h" 27 #include "ares_event.h" 28 29 #if defined(HAVE_POLL) && defined(CARES_THREADS) 30 31 #ifdef HAVE_POLL_H 32 # include <poll.h> 33 #endif 34 35 static ares_bool_t ares_evsys_poll_init(ares_event_thread_t *e) 36 { 37 e->ev_signal = ares_pipeevent_create(e); 38 if (e->ev_signal == NULL) { 39 return ARES_FALSE; /* LCOV_EXCL_LINE: UntestablePath */ 40 } 41 return ARES_TRUE; 42 } 43 44 static void ares_evsys_poll_destroy(ares_event_thread_t *e) 45 { 46 (void)e; 47 } 48 49 static ares_bool_t ares_evsys_poll_event_add(ares_event_t *event) 50 { 51 (void)event; 52 return ARES_TRUE; 53 } 54 55 static void ares_evsys_poll_event_del(ares_event_t *event) 56 { 57 (void)event; 58 } 59 60 static void ares_evsys_poll_event_mod(ares_event_t *event, 61 ares_event_flags_t new_flags) 62 { 63 (void)event; 64 (void)new_flags; 65 } 66 67 static size_t ares_evsys_poll_wait(ares_event_thread_t *e, 68 unsigned long timeout_ms) 69 { 70 size_t num_fds = 0; 71 ares_socket_t *fdlist = ares_htable_asvp_keys(e->ev_sock_handles, &num_fds); 72 struct pollfd *pollfd = NULL; 73 int rv; 74 size_t cnt = 0; 75 size_t i; 76 77 if (fdlist != NULL && num_fds) { 78 pollfd = ares_malloc_zero(sizeof(*pollfd) * num_fds); 79 if (pollfd == NULL) { 80 goto done; /* LCOV_EXCL_LINE: OutOfMemory */ 81 } 82 for (i = 0; i < num_fds; i++) { 83 const ares_event_t *ev = 84 ares_htable_asvp_get_direct(e->ev_sock_handles, fdlist[i]); 85 pollfd[i].fd = ev->fd; 86 if (ev->flags & ARES_EVENT_FLAG_READ) { 87 pollfd[i].events |= POLLIN; 88 } 89 if (ev->flags & ARES_EVENT_FLAG_WRITE) { 90 pollfd[i].events |= POLLOUT; 91 } 92 } 93 } 94 ares_free(fdlist); 95 96 rv = poll(pollfd, (nfds_t)num_fds, (timeout_ms == 0) ? -1 : (int)timeout_ms); 97 if (rv <= 0) { 98 goto done; 99 } 100 101 for (i = 0; pollfd != NULL && i < num_fds; i++) { 102 ares_event_t *ev; 103 ares_event_flags_t flags = 0; 104 105 if (pollfd[i].revents == 0) { 106 continue; 107 } 108 109 cnt++; 110 111 ev = ares_htable_asvp_get_direct(e->ev_sock_handles, pollfd[i].fd); 112 if (ev == NULL || ev->cb == NULL) { 113 continue; /* LCOV_EXCL_LINE: DefensiveCoding */ 114 } 115 116 if (pollfd[i].revents & (POLLERR | POLLHUP | POLLIN)) { 117 flags |= ARES_EVENT_FLAG_READ; 118 } 119 120 if (pollfd[i].revents & POLLOUT) { 121 flags |= ARES_EVENT_FLAG_WRITE; 122 } 123 124 ev->cb(e, pollfd[i].fd, ev->data, flags); 125 } 126 127 done: 128 ares_free(pollfd); 129 return cnt; 130 } 131 132 const ares_event_sys_t ares_evsys_poll = { "poll", 133 ares_evsys_poll_init, 134 ares_evsys_poll_destroy, /* NoOp */ 135 ares_evsys_poll_event_add, /* NoOp */ 136 ares_evsys_poll_event_del, /* NoOp */ 137 ares_evsys_poll_event_mod, /* NoOp */ 138 ares_evsys_poll_wait }; 139 140 #endif