]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | // |
2 | // detail/impl/descriptor_ops.ipp | |
3 | // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
4 | // | |
92f5a8d4 | 5 | // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
7c673cae FG |
6 | // |
7 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | |
8 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
9 | // | |
10 | ||
11 | #ifndef BOOST_ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP | |
12 | #define BOOST_ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP | |
13 | ||
14 | #if defined(_MSC_VER) && (_MSC_VER >= 1200) | |
15 | # pragma once | |
16 | #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) | |
17 | ||
18 | #include <boost/asio/detail/config.hpp> | |
19 | #include <cerrno> | |
20 | #include <boost/asio/detail/descriptor_ops.hpp> | |
21 | #include <boost/asio/error.hpp> | |
22 | ||
23 | #if !defined(BOOST_ASIO_WINDOWS) \ | |
24 | && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \ | |
25 | && !defined(__CYGWIN__) | |
26 | ||
27 | #include <boost/asio/detail/push_options.hpp> | |
28 | ||
29 | namespace boost { | |
30 | namespace asio { | |
31 | namespace detail { | |
32 | namespace descriptor_ops { | |
33 | ||
34 | int open(const char* path, int flags, boost::system::error_code& ec) | |
35 | { | |
36 | errno = 0; | |
37 | int result = error_wrapper(::open(path, flags), ec); | |
38 | if (result >= 0) | |
39 | ec = boost::system::error_code(); | |
40 | return result; | |
41 | } | |
42 | ||
43 | int close(int d, state_type& state, boost::system::error_code& ec) | |
44 | { | |
45 | int result = 0; | |
46 | if (d != -1) | |
47 | { | |
48 | errno = 0; | |
49 | result = error_wrapper(::close(d), ec); | |
50 | ||
51 | if (result != 0 | |
52 | && (ec == boost::asio::error::would_block | |
53 | || ec == boost::asio::error::try_again)) | |
54 | { | |
55 | // According to UNIX Network Programming Vol. 1, it is possible for | |
56 | // close() to fail with EWOULDBLOCK under certain circumstances. What | |
57 | // isn't clear is the state of the descriptor after this error. The one | |
58 | // current OS where this behaviour is seen, Windows, says that the socket | |
59 | // remains open. Therefore we'll put the descriptor back into blocking | |
60 | // mode and have another attempt at closing it. | |
61 | #if defined(__SYMBIAN32__) | |
62 | int flags = ::fcntl(d, F_GETFL, 0); | |
63 | if (flags >= 0) | |
64 | ::fcntl(d, F_SETFL, flags & ~O_NONBLOCK); | |
65 | #else // defined(__SYMBIAN32__) | |
66 | ioctl_arg_type arg = 0; | |
67 | ::ioctl(d, FIONBIO, &arg); | |
68 | #endif // defined(__SYMBIAN32__) | |
69 | state &= ~non_blocking; | |
70 | ||
71 | errno = 0; | |
72 | result = error_wrapper(::close(d), ec); | |
73 | } | |
74 | } | |
75 | ||
76 | if (result == 0) | |
77 | ec = boost::system::error_code(); | |
78 | return result; | |
79 | } | |
80 | ||
81 | bool set_user_non_blocking(int d, state_type& state, | |
82 | bool value, boost::system::error_code& ec) | |
83 | { | |
84 | if (d == -1) | |
85 | { | |
86 | ec = boost::asio::error::bad_descriptor; | |
87 | return false; | |
88 | } | |
89 | ||
90 | errno = 0; | |
91 | #if defined(__SYMBIAN32__) | |
92 | int result = error_wrapper(::fcntl(d, F_GETFL, 0), ec); | |
93 | if (result >= 0) | |
94 | { | |
95 | errno = 0; | |
96 | int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK)); | |
97 | result = error_wrapper(::fcntl(d, F_SETFL, flag), ec); | |
98 | } | |
99 | #else // defined(__SYMBIAN32__) | |
100 | ioctl_arg_type arg = (value ? 1 : 0); | |
101 | int result = error_wrapper(::ioctl(d, FIONBIO, &arg), ec); | |
102 | #endif // defined(__SYMBIAN32__) | |
103 | ||
104 | if (result >= 0) | |
105 | { | |
106 | ec = boost::system::error_code(); | |
107 | if (value) | |
108 | state |= user_set_non_blocking; | |
109 | else | |
110 | { | |
111 | // Clearing the user-set non-blocking mode always overrides any | |
112 | // internally-set non-blocking flag. Any subsequent asynchronous | |
113 | // operations will need to re-enable non-blocking I/O. | |
114 | state &= ~(user_set_non_blocking | internal_non_blocking); | |
115 | } | |
116 | return true; | |
117 | } | |
118 | ||
119 | return false; | |
120 | } | |
121 | ||
122 | bool set_internal_non_blocking(int d, state_type& state, | |
123 | bool value, boost::system::error_code& ec) | |
124 | { | |
125 | if (d == -1) | |
126 | { | |
127 | ec = boost::asio::error::bad_descriptor; | |
128 | return false; | |
129 | } | |
130 | ||
131 | if (!value && (state & user_set_non_blocking)) | |
132 | { | |
133 | // It does not make sense to clear the internal non-blocking flag if the | |
134 | // user still wants non-blocking behaviour. Return an error and let the | |
135 | // caller figure out whether to update the user-set non-blocking flag. | |
136 | ec = boost::asio::error::invalid_argument; | |
137 | return false; | |
138 | } | |
139 | ||
140 | errno = 0; | |
141 | #if defined(__SYMBIAN32__) | |
142 | int result = error_wrapper(::fcntl(d, F_GETFL, 0), ec); | |
143 | if (result >= 0) | |
144 | { | |
145 | errno = 0; | |
146 | int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK)); | |
147 | result = error_wrapper(::fcntl(d, F_SETFL, flag), ec); | |
148 | } | |
149 | #else // defined(__SYMBIAN32__) | |
150 | ioctl_arg_type arg = (value ? 1 : 0); | |
151 | int result = error_wrapper(::ioctl(d, FIONBIO, &arg), ec); | |
152 | #endif // defined(__SYMBIAN32__) | |
153 | ||
154 | if (result >= 0) | |
155 | { | |
156 | ec = boost::system::error_code(); | |
157 | if (value) | |
158 | state |= internal_non_blocking; | |
159 | else | |
160 | state &= ~internal_non_blocking; | |
161 | return true; | |
162 | } | |
163 | ||
164 | return false; | |
165 | } | |
166 | ||
167 | std::size_t sync_read(int d, state_type state, buf* bufs, | |
168 | std::size_t count, bool all_empty, boost::system::error_code& ec) | |
169 | { | |
170 | if (d == -1) | |
171 | { | |
172 | ec = boost::asio::error::bad_descriptor; | |
173 | return 0; | |
174 | } | |
175 | ||
176 | // A request to read 0 bytes on a stream is a no-op. | |
177 | if (all_empty) | |
178 | { | |
179 | ec = boost::system::error_code(); | |
180 | return 0; | |
181 | } | |
182 | ||
183 | // Read some data. | |
184 | for (;;) | |
185 | { | |
186 | // Try to complete the operation without blocking. | |
187 | errno = 0; | |
188 | signed_size_type bytes = error_wrapper(::readv( | |
189 | d, bufs, static_cast<int>(count)), ec); | |
190 | ||
191 | // Check if operation succeeded. | |
192 | if (bytes > 0) | |
193 | return bytes; | |
194 | ||
195 | // Check for EOF. | |
196 | if (bytes == 0) | |
197 | { | |
198 | ec = boost::asio::error::eof; | |
199 | return 0; | |
200 | } | |
201 | ||
202 | // Operation failed. | |
203 | if ((state & user_set_non_blocking) | |
204 | || (ec != boost::asio::error::would_block | |
205 | && ec != boost::asio::error::try_again)) | |
206 | return 0; | |
207 | ||
208 | // Wait for descriptor to become ready. | |
209 | if (descriptor_ops::poll_read(d, 0, ec) < 0) | |
210 | return 0; | |
211 | } | |
212 | } | |
213 | ||
214 | bool non_blocking_read(int d, buf* bufs, std::size_t count, | |
215 | boost::system::error_code& ec, std::size_t& bytes_transferred) | |
216 | { | |
217 | for (;;) | |
218 | { | |
219 | // Read some data. | |
220 | errno = 0; | |
221 | signed_size_type bytes = error_wrapper(::readv( | |
222 | d, bufs, static_cast<int>(count)), ec); | |
223 | ||
224 | // Check for end of stream. | |
225 | if (bytes == 0) | |
226 | { | |
227 | ec = boost::asio::error::eof; | |
228 | return true; | |
229 | } | |
230 | ||
231 | // Retry operation if interrupted by signal. | |
232 | if (ec == boost::asio::error::interrupted) | |
233 | continue; | |
234 | ||
235 | // Check if we need to run the operation again. | |
236 | if (ec == boost::asio::error::would_block | |
237 | || ec == boost::asio::error::try_again) | |
238 | return false; | |
239 | ||
240 | // Operation is complete. | |
241 | if (bytes > 0) | |
242 | { | |
243 | ec = boost::system::error_code(); | |
244 | bytes_transferred = bytes; | |
245 | } | |
246 | else | |
247 | bytes_transferred = 0; | |
248 | ||
249 | return true; | |
250 | } | |
251 | } | |
252 | ||
253 | std::size_t sync_write(int d, state_type state, const buf* bufs, | |
254 | std::size_t count, bool all_empty, boost::system::error_code& ec) | |
255 | { | |
256 | if (d == -1) | |
257 | { | |
258 | ec = boost::asio::error::bad_descriptor; | |
259 | return 0; | |
260 | } | |
261 | ||
262 | // A request to write 0 bytes on a stream is a no-op. | |
263 | if (all_empty) | |
264 | { | |
265 | ec = boost::system::error_code(); | |
266 | return 0; | |
267 | } | |
268 | ||
269 | // Write some data. | |
270 | for (;;) | |
271 | { | |
272 | // Try to complete the operation without blocking. | |
273 | errno = 0; | |
274 | signed_size_type bytes = error_wrapper(::writev( | |
275 | d, bufs, static_cast<int>(count)), ec); | |
276 | ||
277 | // Check if operation succeeded. | |
278 | if (bytes > 0) | |
279 | return bytes; | |
280 | ||
281 | // Operation failed. | |
282 | if ((state & user_set_non_blocking) | |
283 | || (ec != boost::asio::error::would_block | |
284 | && ec != boost::asio::error::try_again)) | |
285 | return 0; | |
286 | ||
287 | // Wait for descriptor to become ready. | |
288 | if (descriptor_ops::poll_write(d, 0, ec) < 0) | |
289 | return 0; | |
290 | } | |
291 | } | |
292 | ||
293 | bool non_blocking_write(int d, const buf* bufs, std::size_t count, | |
294 | boost::system::error_code& ec, std::size_t& bytes_transferred) | |
295 | { | |
296 | for (;;) | |
297 | { | |
298 | // Write some data. | |
299 | errno = 0; | |
300 | signed_size_type bytes = error_wrapper(::writev( | |
301 | d, bufs, static_cast<int>(count)), ec); | |
302 | ||
303 | // Retry operation if interrupted by signal. | |
304 | if (ec == boost::asio::error::interrupted) | |
305 | continue; | |
306 | ||
307 | // Check if we need to run the operation again. | |
308 | if (ec == boost::asio::error::would_block | |
309 | || ec == boost::asio::error::try_again) | |
310 | return false; | |
311 | ||
312 | // Operation is complete. | |
313 | if (bytes >= 0) | |
314 | { | |
315 | ec = boost::system::error_code(); | |
316 | bytes_transferred = bytes; | |
317 | } | |
318 | else | |
319 | bytes_transferred = 0; | |
320 | ||
321 | return true; | |
322 | } | |
323 | } | |
324 | ||
325 | int ioctl(int d, state_type& state, long cmd, | |
326 | ioctl_arg_type* arg, boost::system::error_code& ec) | |
327 | { | |
328 | if (d == -1) | |
329 | { | |
330 | ec = boost::asio::error::bad_descriptor; | |
331 | return -1; | |
332 | } | |
333 | ||
334 | errno = 0; | |
335 | int result = error_wrapper(::ioctl(d, cmd, arg), ec); | |
336 | ||
337 | if (result >= 0) | |
338 | { | |
339 | ec = boost::system::error_code(); | |
340 | ||
341 | // When updating the non-blocking mode we always perform the ioctl syscall, | |
342 | // even if the flags would otherwise indicate that the descriptor is | |
343 | // already in the correct state. This ensures that the underlying | |
344 | // descriptor is put into the state that has been requested by the user. If | |
345 | // the ioctl syscall was successful then we need to update the flags to | |
346 | // match. | |
347 | if (cmd == static_cast<long>(FIONBIO)) | |
348 | { | |
349 | if (*arg) | |
350 | { | |
351 | state |= user_set_non_blocking; | |
352 | } | |
353 | else | |
354 | { | |
355 | // Clearing the non-blocking mode always overrides any internally-set | |
356 | // non-blocking flag. Any subsequent asynchronous operations will need | |
357 | // to re-enable non-blocking I/O. | |
358 | state &= ~(user_set_non_blocking | internal_non_blocking); | |
359 | } | |
360 | } | |
361 | } | |
362 | ||
363 | return result; | |
364 | } | |
365 | ||
366 | int fcntl(int d, int cmd, boost::system::error_code& ec) | |
367 | { | |
368 | if (d == -1) | |
369 | { | |
370 | ec = boost::asio::error::bad_descriptor; | |
371 | return -1; | |
372 | } | |
373 | ||
374 | errno = 0; | |
375 | int result = error_wrapper(::fcntl(d, cmd), ec); | |
376 | if (result != -1) | |
377 | ec = boost::system::error_code(); | |
378 | return result; | |
379 | } | |
380 | ||
381 | int fcntl(int d, int cmd, long arg, boost::system::error_code& ec) | |
382 | { | |
383 | if (d == -1) | |
384 | { | |
385 | ec = boost::asio::error::bad_descriptor; | |
386 | return -1; | |
387 | } | |
388 | ||
389 | errno = 0; | |
390 | int result = error_wrapper(::fcntl(d, cmd, arg), ec); | |
391 | if (result != -1) | |
392 | ec = boost::system::error_code(); | |
393 | return result; | |
394 | } | |
395 | ||
396 | int poll_read(int d, state_type state, boost::system::error_code& ec) | |
397 | { | |
398 | if (d == -1) | |
399 | { | |
400 | ec = boost::asio::error::bad_descriptor; | |
401 | return -1; | |
402 | } | |
403 | ||
404 | pollfd fds; | |
405 | fds.fd = d; | |
406 | fds.events = POLLIN; | |
407 | fds.revents = 0; | |
408 | int timeout = (state & user_set_non_blocking) ? 0 : -1; | |
409 | errno = 0; | |
410 | int result = error_wrapper(::poll(&fds, 1, timeout), ec); | |
411 | if (result == 0) | |
412 | ec = (state & user_set_non_blocking) | |
413 | ? boost::asio::error::would_block : boost::system::error_code(); | |
414 | else if (result > 0) | |
415 | ec = boost::system::error_code(); | |
416 | return result; | |
417 | } | |
418 | ||
419 | int poll_write(int d, state_type state, boost::system::error_code& ec) | |
420 | { | |
421 | if (d == -1) | |
422 | { | |
423 | ec = boost::asio::error::bad_descriptor; | |
424 | return -1; | |
425 | } | |
426 | ||
427 | pollfd fds; | |
428 | fds.fd = d; | |
429 | fds.events = POLLOUT; | |
430 | fds.revents = 0; | |
431 | int timeout = (state & user_set_non_blocking) ? 0 : -1; | |
432 | errno = 0; | |
433 | int result = error_wrapper(::poll(&fds, 1, timeout), ec); | |
434 | if (result == 0) | |
435 | ec = (state & user_set_non_blocking) | |
436 | ? boost::asio::error::would_block : boost::system::error_code(); | |
437 | else if (result > 0) | |
438 | ec = boost::system::error_code(); | |
439 | return result; | |
440 | } | |
441 | ||
b32b8144 FG |
442 | int poll_error(int d, state_type state, boost::system::error_code& ec) |
443 | { | |
444 | if (d == -1) | |
445 | { | |
446 | ec = boost::asio::error::bad_descriptor; | |
447 | return -1; | |
448 | } | |
449 | ||
450 | pollfd fds; | |
451 | fds.fd = d; | |
452 | fds.events = POLLPRI | POLLERR | POLLHUP; | |
453 | fds.revents = 0; | |
454 | int timeout = (state & user_set_non_blocking) ? 0 : -1; | |
455 | errno = 0; | |
456 | int result = error_wrapper(::poll(&fds, 1, timeout), ec); | |
457 | if (result == 0) | |
458 | ec = (state & user_set_non_blocking) | |
459 | ? boost::asio::error::would_block : boost::system::error_code(); | |
460 | else if (result > 0) | |
461 | ec = boost::system::error_code(); | |
462 | return result; | |
463 | } | |
464 | ||
7c673cae FG |
465 | } // namespace descriptor_ops |
466 | } // namespace detail | |
467 | } // namespace asio | |
468 | } // namespace boost | |
469 | ||
470 | #include <boost/asio/detail/pop_options.hpp> | |
471 | ||
472 | #endif // !defined(BOOST_ASIO_WINDOWS) | |
473 | // && !defined(BOOST_ASIO_WINDOWS_RUNTIME) | |
474 | // && !defined(__CYGWIN__) | |
475 | ||
476 | #endif // BOOST_ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP |