1/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE.
20 */
21
22#include "uv.h"
23#include "internal.h"
24
25#include <unistd.h>
26#include <assert.h>
27#include <errno.h>
28
29
30static void uv__poll_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
31  uv_poll_t* handle;
32  int pevents;
33
34  handle = container_of(w, uv_poll_t, io_watcher);
35
36  /*
37   * As documented in the kernel source fs/kernfs/file.c #780
38   * poll will return POLLERR|POLLPRI in case of sysfs
39   * polling. This does not happen in case of out-of-band
40   * TCP messages.
41   *
42   * The above is the case on (at least) FreeBSD and Linux.
43   *
44   * So to properly determine a POLLPRI or a POLLERR we need
45   * to check for both.
46   */
47  if ((events & POLLERR) && !(events & UV__POLLPRI)) {
48    uv__io_stop(loop, w, POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
49    uv__handle_stop(handle);
50    handle->poll_cb(handle, UV_EBADF, 0);
51    return;
52  }
53
54  pevents = 0;
55  if (events & POLLIN)
56    pevents |= UV_READABLE;
57  if (events & UV__POLLPRI)
58    pevents |= UV_PRIORITIZED;
59  if (events & POLLOUT)
60    pevents |= UV_WRITABLE;
61  if (events & UV__POLLRDHUP)
62    pevents |= UV_DISCONNECT;
63
64  handle->poll_cb(handle, 0, pevents);
65}
66
67
68int uv_poll_init(uv_loop_t* loop, uv_poll_t* handle, int fd) {
69  int err;
70
71  if (uv__fd_exists(loop, fd))
72    return UV_EEXIST;
73
74  err = uv__io_check_fd(loop, fd);
75  if (err)
76    return err;
77
78  /* If ioctl(FIONBIO) reports ENOTTY, try fcntl(F_GETFL) + fcntl(F_SETFL).
79   * Workaround for e.g. kqueue fds not supporting ioctls.
80   */
81  err = uv__nonblock(fd, 1);
82#if UV__NONBLOCK_IS_IOCTL
83  if (err == UV_ENOTTY)
84    err = uv__nonblock_fcntl(fd, 1);
85#endif
86
87  if (err)
88    return err;
89
90  uv__handle_init(loop, (uv_handle_t*) handle, UV_POLL);
91  uv__io_init(&handle->io_watcher, uv__poll_io, fd);
92  handle->poll_cb = NULL;
93  return 0;
94}
95
96
97int uv_poll_init_socket(uv_loop_t* loop, uv_poll_t* handle,
98    uv_os_sock_t socket) {
99  return uv_poll_init(loop, handle, socket);
100}
101
102
103static void uv__poll_stop(uv_poll_t* handle) {
104  uv__io_stop(handle->loop,
105              &handle->io_watcher,
106              POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
107  uv__handle_stop(handle);
108  uv__platform_invalidate_fd(handle->loop, handle->io_watcher.fd);
109}
110
111
112int uv_poll_stop(uv_poll_t* handle) {
113  assert(!uv__is_closing(handle));
114  uv__poll_stop(handle);
115  return 0;
116}
117
118
119int uv_poll_start(uv_poll_t* handle, int pevents, uv_poll_cb poll_cb) {
120  uv__io_t** watchers;
121  uv__io_t* w;
122  int events;
123
124  assert((pevents & ~(UV_READABLE | UV_WRITABLE | UV_DISCONNECT |
125                      UV_PRIORITIZED)) == 0);
126  assert(!uv__is_closing(handle));
127
128  watchers = handle->loop->watchers;
129  w = &handle->io_watcher;
130
131  if (uv__fd_exists(handle->loop, w->fd))
132    if (watchers[w->fd] != w)
133      return UV_EEXIST;
134
135  uv__poll_stop(handle);
136
137  if (pevents == 0)
138    return 0;
139
140  events = 0;
141  if (pevents & UV_READABLE)
142    events |= POLLIN;
143  if (pevents & UV_PRIORITIZED)
144    events |= UV__POLLPRI;
145  if (pevents & UV_WRITABLE)
146    events |= POLLOUT;
147  if (pevents & UV_DISCONNECT)
148    events |= UV__POLLRDHUP;
149
150  uv__io_start(handle->loop, &handle->io_watcher, events);
151  uv__handle_start(handle);
152  handle->poll_cb = poll_cb;
153
154  return 0;
155}
156
157
158void uv__poll_close(uv_poll_t* handle) {
159  uv__poll_stop(handle);
160}
161