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 
uv__poll_io(uv_loop_t * loop,uv__io_t * w,unsigned int events)30 static 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 
uv_poll_init(uv_loop_t * loop,uv_poll_t * handle,int fd)68 int 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 (err == UV_ENOTTY)
83     if (uv__nonblock == uv__nonblock_ioctl)
84       err = uv__nonblock_fcntl(fd, 1);
85 
86   if (err)
87     return err;
88 
89   uv__handle_init(loop, (uv_handle_t*) handle, UV_POLL);
90   uv__io_init(&handle->io_watcher, uv__poll_io, fd);
91   handle->poll_cb = NULL;
92   return 0;
93 }
94 
95 
uv_poll_init_socket(uv_loop_t * loop,uv_poll_t * handle,uv_os_sock_t socket)96 int uv_poll_init_socket(uv_loop_t* loop, uv_poll_t* handle,
97     uv_os_sock_t socket) {
98   return uv_poll_init(loop, handle, socket);
99 }
100 
101 
uv__poll_stop(uv_poll_t * handle)102 static void uv__poll_stop(uv_poll_t* handle) {
103   uv__io_stop(handle->loop,
104               &handle->io_watcher,
105               POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
106   uv__handle_stop(handle);
107   uv__platform_invalidate_fd(handle->loop, handle->io_watcher.fd);
108 }
109 
110 
uv_poll_stop(uv_poll_t * handle)111 int uv_poll_stop(uv_poll_t* handle) {
112   assert(!uv__is_closing(handle));
113   uv__poll_stop(handle);
114   return 0;
115 }
116 
117 
uv_poll_start(uv_poll_t * handle,int pevents,uv_poll_cb poll_cb)118 int uv_poll_start(uv_poll_t* handle, int pevents, uv_poll_cb poll_cb) {
119   int events;
120 
121   assert((pevents & ~(UV_READABLE | UV_WRITABLE | UV_DISCONNECT |
122                       UV_PRIORITIZED)) == 0);
123   assert(!uv__is_closing(handle));
124 
125   uv__poll_stop(handle);
126 
127   if (pevents == 0)
128     return 0;
129 
130   events = 0;
131   if (pevents & UV_READABLE)
132     events |= POLLIN;
133   if (pevents & UV_PRIORITIZED)
134     events |= UV__POLLPRI;
135   if (pevents & UV_WRITABLE)
136     events |= POLLOUT;
137   if (pevents & UV_DISCONNECT)
138     events |= UV__POLLRDHUP;
139 
140   uv__io_start(handle->loop, &handle->io_watcher, events);
141   uv__handle_start(handle);
142   handle->poll_cb = poll_cb;
143 
144   return 0;
145 }
146 
147 
uv__poll_close(uv_poll_t * handle)148 void uv__poll_close(uv_poll_t* handle) {
149   uv__poll_stop(handle);
150 }
151