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_setup.h"
27 #include "ares.h"
28 #include "ares_private.h"
29 #include "ares_event.h"
30 #ifdef HAVE_POLL_H
31 # include <poll.h>
32 #endif
33
34 #if defined(HAVE_POLL)
35
ares_evsys_poll_init(ares_event_thread_t *e)36 static ares_bool_t ares_evsys_poll_init(ares_event_thread_t *e)
37 {
38 e->ev_signal = ares_pipeevent_create(e);
39 if (e->ev_signal == NULL) {
40 return ARES_FALSE;
41 }
42 return ARES_TRUE;
43 }
44
ares_evsys_poll_destroy(ares_event_thread_t *e)45 static void ares_evsys_poll_destroy(ares_event_thread_t *e)
46 {
47 (void)e;
48 }
49
ares_evsys_poll_event_add(ares_event_t *event)50 static ares_bool_t ares_evsys_poll_event_add(ares_event_t *event)
51 {
52 (void)event;
53 return ARES_TRUE;
54 }
55
ares_evsys_poll_event_del(ares_event_t *event)56 static void ares_evsys_poll_event_del(ares_event_t *event)
57 {
58 (void)event;
59 }
60
ares_evsys_poll_event_mod(ares_event_t *event, ares_event_flags_t new_flags)61 static void ares_evsys_poll_event_mod(ares_event_t *event,
62 ares_event_flags_t new_flags)
63 {
64 (void)event;
65 (void)new_flags;
66 }
67
ares_evsys_poll_wait(ares_event_thread_t *e, unsigned long timeout_ms)68 static size_t ares_evsys_poll_wait(ares_event_thread_t *e,
69 unsigned long timeout_ms)
70 {
71 size_t num_fds = 0;
72 ares_socket_t *fdlist = ares__htable_asvp_keys(e->ev_handles, &num_fds);
73 struct pollfd *pollfd = NULL;
74 int rv;
75 size_t cnt = 0;
76 size_t i;
77
78 if (num_fds) {
79 pollfd = ares_malloc_zero(sizeof(*pollfd) * num_fds);
80 for (i = 0; i < num_fds; i++) {
81 const ares_event_t *ev =
82 ares__htable_asvp_get_direct(e->ev_handles, fdlist[i]);
83 pollfd[i].fd = ev->fd;
84 if (ev->flags & ARES_EVENT_FLAG_READ) {
85 pollfd[i].events |= POLLIN;
86 }
87 if (ev->flags & ARES_EVENT_FLAG_WRITE) {
88 pollfd[i].events |= POLLOUT;
89 }
90 }
91 }
92 ares_free(fdlist);
93
94 rv = poll(pollfd, (nfds_t)num_fds, (timeout_ms == 0) ? -1 : (int)timeout_ms);
95 if (rv <= 0) {
96 goto done;
97 }
98
99 for (i = 0; i < num_fds; i++) {
100 ares_event_t *ev;
101 ares_event_flags_t flags = 0;
102
103 if (pollfd[i].revents == 0) {
104 continue;
105 }
106
107 cnt++;
108
109 ev = ares__htable_asvp_get_direct(e->ev_handles, pollfd[i].fd);
110 if (ev == NULL || ev->cb == NULL) {
111 continue;
112 }
113
114 if (pollfd[i].revents & (POLLERR | POLLHUP | POLLIN)) {
115 flags |= ARES_EVENT_FLAG_READ;
116 }
117
118 if (pollfd[i].revents & POLLOUT) {
119 flags |= ARES_EVENT_FLAG_WRITE;
120 }
121
122 ev->cb(e, pollfd[i].fd, ev->data, flags);
123 }
124
125 done:
126 ares_free(pollfd);
127 return cnt;
128 }
129
130 const ares_event_sys_t ares_evsys_poll = { "poll",
131 ares_evsys_poll_init,
132 ares_evsys_poll_destroy, /* NoOp */
133 ares_evsys_poll_event_add, /* NoOp */
134 ares_evsys_poll_event_del, /* NoOp */
135 ares_evsys_poll_event_mod, /* NoOp */
136 ares_evsys_poll_wait };
137
138 #endif
139