TLA Line data Source code
1 : //
2 : // Copyright (c) 2026 Steve Gerbino
3 : //
4 : // Distributed under the Boost Software License, Version 1.0. (See accompanying
5 : // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 : //
7 : // Official repository: https://github.com/cppalliance/corosio
8 : //
9 :
10 : #ifndef BOOST_COROSIO_NATIVE_DETAIL_REACTOR_REACTOR_STREAM_SOCKET_HPP
11 : #define BOOST_COROSIO_NATIVE_DETAIL_REACTOR_REACTOR_STREAM_SOCKET_HPP
12 :
13 : #include <boost/corosio/tcp_socket.hpp>
14 : #include <boost/corosio/shutdown_type.hpp>
15 : #include <boost/corosio/wait_type.hpp>
16 : #include <boost/corosio/native/detail/reactor/reactor_basic_socket.hpp>
17 : #include <boost/corosio/native/detail/reactor/reactor_descriptor_state.hpp>
18 : #include <boost/corosio/detail/dispatch_coro.hpp>
19 : #include <boost/capy/buffers.hpp>
20 :
21 : #include <coroutine>
22 :
23 : #include <errno.h>
24 : #include <sys/socket.h>
25 : #include <sys/uio.h>
26 :
27 : namespace boost::corosio::detail {
28 :
29 : /** CRTP base for reactor-backed stream socket implementations.
30 :
31 : Inherits shared data members and cancel/close/register logic
32 : from reactor_basic_socket. Adds the stream-specific remote
33 : endpoint, shutdown, and I/O dispatch (connect, read, write, wait).
34 :
35 : @tparam Derived The concrete socket type (CRTP).
36 : @tparam Service The backend's socket service type.
37 : @tparam ConnOp The backend's connect op type.
38 : @tparam ReadOp The backend's read op type.
39 : @tparam WriteOp The backend's write op type.
40 : @tparam WaitOp The backend's wait op type.
41 : @tparam DescState The backend's descriptor_state type.
42 : @tparam ImplBase The public vtable base
43 : (tcp_socket::implementation or
44 : local_stream_socket::implementation).
45 : @tparam Endpoint The endpoint type (endpoint or local_endpoint).
46 : */
47 : template<
48 : class Derived,
49 : class Service,
50 : class ConnOp,
51 : class ReadOp,
52 : class WriteOp,
53 : class WaitOp,
54 : class DescState,
55 : class ImplBase = tcp_socket::implementation,
56 : class Endpoint = endpoint>
57 : class reactor_stream_socket
58 : : public reactor_basic_socket<
59 : Derived,
60 : ImplBase,
61 : Service,
62 : DescState,
63 : Endpoint>
64 : {
65 : using base_type = reactor_basic_socket<
66 : Derived,
67 : ImplBase,
68 : Service,
69 : DescState,
70 : Endpoint>;
71 : using self_type = reactor_stream_socket<
72 : Derived, Service, ConnOp, ReadOp, WriteOp, WaitOp,
73 : DescState, ImplBase, Endpoint>;
74 : friend base_type;
75 : friend Derived;
76 :
77 : protected:
78 : // NOLINTNEXTLINE(bugprone-crtp-constructor-accessibility)
79 HIT 20259 : explicit reactor_stream_socket(Service& svc) noexcept : base_type(svc) {}
80 :
81 : protected:
82 : Endpoint remote_endpoint_;
83 :
84 : public:
85 : /// Pending connect operation slot.
86 : ConnOp conn_;
87 :
88 : /// Pending read operation slot.
89 : ReadOp rd_;
90 :
91 : /// Pending write operation slot.
92 : WriteOp wr_;
93 :
94 : /// Pending wait-for-read operation slot.
95 : WaitOp wait_rd_;
96 :
97 : /// Pending wait-for-write operation slot.
98 : WaitOp wait_wr_;
99 :
100 : /// Pending wait-for-error operation slot.
101 : WaitOp wait_er_;
102 :
103 20259 : ~reactor_stream_socket() override = default;
104 :
105 : /// Return the cached remote endpoint.
106 62 : Endpoint remote_endpoint() const noexcept override
107 : {
108 62 : return remote_endpoint_;
109 : }
110 :
111 : // --- Virtual method overrides (satisfy ImplBase pure virtuals) ---
112 :
113 6616 : std::coroutine_handle<> connect(
114 : std::coroutine_handle<> h,
115 : capy::executor_ref ex,
116 : Endpoint ep,
117 : std::stop_token token,
118 : std::error_code* ec) override
119 : {
120 6616 : return do_connect(h, ex, ep, token, ec);
121 : }
122 :
123 214835 : std::coroutine_handle<> read_some(
124 : std::coroutine_handle<> h,
125 : capy::executor_ref ex,
126 : buffer_param param,
127 : std::stop_token token,
128 : std::error_code* ec,
129 : std::size_t* bytes_out) override
130 : {
131 214835 : return do_read_some(h, ex, param, token, ec, bytes_out);
132 : }
133 :
134 214143 : std::coroutine_handle<> write_some(
135 : std::coroutine_handle<> h,
136 : capy::executor_ref ex,
137 : buffer_param param,
138 : std::stop_token token,
139 : std::error_code* ec,
140 : std::size_t* bytes_out) override
141 : {
142 214143 : return do_write_some(h, ex, param, token, ec, bytes_out);
143 : }
144 :
145 92 : std::coroutine_handle<> wait(
146 : std::coroutine_handle<> h,
147 : capy::executor_ref ex,
148 : wait_type w,
149 : std::stop_token token,
150 : std::error_code* ec) override
151 : {
152 92 : return do_wait(h, ex, w, token, ec);
153 : }
154 :
155 : std::error_code
156 25 : shutdown(corosio::shutdown_type what) noexcept override
157 : {
158 25 : return do_shutdown(static_cast<int>(what));
159 : }
160 :
161 219 : void cancel() noexcept override
162 : {
163 219 : this->do_cancel();
164 219 : }
165 :
166 : // --- End virtual overrides ---
167 :
168 : /// Close the socket (non-virtual, called by the service).
169 : void close_socket() noexcept
170 : {
171 : this->do_close_socket();
172 : }
173 :
174 : /** Shut down part or all of the full-duplex connection.
175 :
176 : @param what 0 = receive, 1 = send, 2 = both.
177 : */
178 25 : std::error_code do_shutdown(int what) noexcept
179 : {
180 : int how;
181 25 : switch (what)
182 : {
183 4 : case 0: // shutdown_receive
184 4 : how = SHUT_RD;
185 4 : break;
186 17 : case 1: // shutdown_send
187 17 : how = SHUT_WR;
188 17 : break;
189 4 : case 2: // shutdown_both
190 4 : how = SHUT_RDWR;
191 4 : break;
192 MIS 0 : default:
193 0 : return make_err(EINVAL);
194 : }
195 HIT 25 : if (::shutdown(this->fd_, how) != 0)
196 2 : return make_err(errno);
197 23 : return {};
198 : }
199 :
200 : /// Cache local and remote endpoints.
201 13273 : void set_endpoints(Endpoint local, Endpoint remote) noexcept
202 : {
203 13273 : this->local_endpoint_ = std::move(local);
204 13273 : remote_endpoint_ = std::move(remote);
205 13273 : }
206 :
207 : /** Shared connect dispatch.
208 :
209 : Tries the connect syscall speculatively. On synchronous
210 : completion, returns via inline budget or posts through queue.
211 : On EINPROGRESS, registers with the reactor.
212 : */
213 : std::coroutine_handle<> do_connect(
214 : std::coroutine_handle<>,
215 : capy::executor_ref,
216 : Endpoint const&,
217 : std::stop_token const&,
218 : std::error_code*);
219 :
220 : /** Shared scatter-read dispatch.
221 :
222 : Tries readv() speculatively. On success or hard error,
223 : returns via inline budget or posts through queue.
224 : On EAGAIN, registers with the reactor.
225 : */
226 : std::coroutine_handle<> do_read_some(
227 : std::coroutine_handle<>,
228 : capy::executor_ref,
229 : buffer_param,
230 : std::stop_token const&,
231 : std::error_code*,
232 : std::size_t*);
233 :
234 : /** Shared gather-write dispatch.
235 :
236 : Tries the write via WriteOp::write_policy speculatively.
237 : On success or hard error, returns via inline budget or
238 : posts through queue. On EAGAIN, registers with the reactor.
239 : */
240 : std::coroutine_handle<> do_write_some(
241 : std::coroutine_handle<>,
242 : capy::executor_ref,
243 : buffer_param,
244 : std::stop_token const&,
245 : std::error_code*,
246 : std::size_t*);
247 :
248 : /** Shared readiness-wait dispatch.
249 :
250 : Every wait type probes the descriptor with a zero-timeout
251 : `poll()` and completes at once if the condition already
252 : holds; otherwise the op re-probes under the descriptor mutex
253 : and parks, completing when a reactor event arrives and a
254 : fresh probe confirms the condition. A write wait therefore
255 : completes only while a non-blocking write can make progress.
256 : */
257 : std::coroutine_handle<> do_wait(
258 : std::coroutine_handle<>,
259 : capy::executor_ref,
260 : wait_type,
261 : std::stop_token const&,
262 : std::error_code*);
263 :
264 : /** Close the socket and cancel pending operations.
265 :
266 : Extends the base do_close_socket() to also reset
267 : the remote endpoint.
268 : */
269 60784 : void do_close_socket() noexcept
270 : {
271 60784 : base_type::do_close_socket();
272 60784 : remote_endpoint_ = Endpoint{};
273 60784 : }
274 :
275 : /// Release ownership of the descriptor and drop the cached peer.
276 8 : native_handle_type do_release_socket() noexcept
277 : {
278 8 : auto fd = base_type::do_release_socket();
279 8 : remote_endpoint_ = Endpoint{};
280 8 : return fd;
281 : }
282 :
283 : private:
284 : // CRTP callbacks for reactor_basic_socket cancel/close
285 :
286 : template<class Op>
287 235 : reactor_op_base** op_to_desc_slot(Op& op) noexcept
288 : {
289 235 : if (&op == static_cast<void*>(&conn_))
290 5 : return &this->desc_state_.connect_op;
291 230 : if (&op == static_cast<void*>(&rd_))
292 211 : return &this->desc_state_.read_op;
293 19 : if (&op == static_cast<void*>(&wr_))
294 4 : return &this->desc_state_.write_op;
295 15 : if (&op == static_cast<void*>(&wait_rd_))
296 11 : return &this->desc_state_.wait_read_op;
297 4 : if (&op == static_cast<void*>(&wait_wr_))
298 2 : return &this->desc_state_.wait_write_op;
299 2 : if (&op == static_cast<void*>(&wait_er_))
300 2 : return &this->desc_state_.wait_error_op;
301 MIS 0 : return nullptr;
302 : }
303 :
304 :
305 : template<class Fn>
306 HIT 61011 : void for_each_op(Fn fn) noexcept
307 : {
308 61011 : fn(conn_);
309 61011 : fn(rd_);
310 61011 : fn(wr_);
311 61011 : fn(wait_rd_);
312 61011 : fn(wait_wr_);
313 61011 : fn(wait_er_);
314 61011 : }
315 :
316 : template<class Fn>
317 61011 : void for_each_desc_entry(Fn fn) noexcept
318 : {
319 61011 : fn(conn_, this->desc_state_.connect_op);
320 61011 : fn(rd_, this->desc_state_.read_op);
321 61011 : fn(wr_, this->desc_state_.write_op);
322 61011 : fn(wait_rd_, this->desc_state_.wait_read_op);
323 61011 : fn(wait_wr_, this->desc_state_.wait_write_op);
324 61011 : fn(wait_er_, this->desc_state_.wait_error_op);
325 61011 : }
326 : };
327 :
328 : template<
329 : class Derived,
330 : class Service,
331 : class ConnOp,
332 : class ReadOp,
333 : class WriteOp,
334 : class WaitOp,
335 : class DescState,
336 : class ImplBase,
337 : class Endpoint>
338 : std::coroutine_handle<>
339 6616 : reactor_stream_socket<Derived, Service, ConnOp, ReadOp, WriteOp, WaitOp, DescState, ImplBase, Endpoint>::
340 : do_connect(
341 : std::coroutine_handle<> h,
342 : capy::executor_ref ex,
343 : Endpoint const& ep,
344 : std::stop_token const& token,
345 : std::error_code* ec)
346 : {
347 6616 : auto& op = conn_;
348 :
349 6616 : sockaddr_storage storage{};
350 6616 : socklen_t addrlen = to_sockaddr(ep, socket_family(this->fd_), storage);
351 : int result =
352 6616 : ::connect(this->fd_, reinterpret_cast<sockaddr*>(&storage), addrlen);
353 :
354 6616 : if (result == 0)
355 : {
356 31 : sockaddr_storage local_storage{};
357 31 : socklen_t local_len = sizeof(local_storage);
358 31 : if (::getsockname(
359 : this->fd_, reinterpret_cast<sockaddr*>(&local_storage),
360 31 : &local_len) == 0)
361 MIS 0 : this->local_endpoint_ =
362 HIT 31 : from_sockaddr_as(local_storage, local_len, Endpoint{});
363 31 : remote_endpoint_ = ep;
364 : }
365 :
366 6616 : if (result == 0 || errno != EINPROGRESS)
367 : {
368 43 : int err = (result < 0) ? errno : 0;
369 43 : if (this->svc_.scheduler().try_consume_inline_budget())
370 : {
371 4 : *ec = err ? make_err(err) : std::error_code{};
372 4 : op.cont.h = h;
373 4 : return dispatch_coro(ex, op.cont);
374 : }
375 39 : op.reset();
376 39 : op.h = h;
377 39 : op.ex = ex;
378 39 : op.ec_out = ec;
379 39 : op.fd = this->fd_;
380 39 : op.target_endpoint = ep;
381 39 : op.start(token, static_cast<Derived*>(this));
382 39 : op.impl_ptr = this->shared_from_this();
383 39 : op.complete(err, 0);
384 39 : this->svc_.post(&op);
385 39 : return std::noop_coroutine();
386 : }
387 :
388 : // EINPROGRESS — register with reactor
389 6573 : op.reset();
390 6573 : op.h = h;
391 6573 : op.ex = ex;
392 6573 : op.ec_out = ec;
393 6573 : op.fd = this->fd_;
394 6573 : op.target_endpoint = ep;
395 6573 : op.start(token, static_cast<Derived*>(this));
396 6573 : op.impl_ptr = this->shared_from_this();
397 :
398 6573 : this->register_op(
399 6573 : op, this->desc_state_.connect_op, this->desc_state_.write_ready, true);
400 6573 : return std::noop_coroutine();
401 : }
402 :
403 : template<
404 : class Derived,
405 : class Service,
406 : class ConnOp,
407 : class ReadOp,
408 : class WriteOp,
409 : class WaitOp,
410 : class DescState,
411 : class ImplBase,
412 : class Endpoint>
413 : std::coroutine_handle<>
414 214835 : reactor_stream_socket<Derived, Service, ConnOp, ReadOp, WriteOp, WaitOp, DescState, ImplBase, Endpoint>::
415 : do_read_some(
416 : std::coroutine_handle<> h,
417 : capy::executor_ref ex,
418 : buffer_param param,
419 : std::stop_token const& token,
420 : std::error_code* ec,
421 : std::size_t* bytes_out)
422 : {
423 214835 : auto& op = rd_;
424 214835 : op.reset();
425 :
426 : // Closed-object contract: complete with bad_file_descriptor without
427 : // touching the kernel or the unregistered descriptor state.
428 214835 : if (this->fd_ < 0)
429 : {
430 8 : op.h = h;
431 8 : op.ex = ex;
432 8 : op.ec_out = ec;
433 8 : op.bytes_out = bytes_out;
434 8 : op.start(token, static_cast<Derived*>(this));
435 8 : op.impl_ptr = this->shared_from_this();
436 8 : op.complete(EBADF, 0);
437 8 : this->svc_.post(&op);
438 8 : return std::noop_coroutine();
439 : }
440 :
441 214827 : capy::mutable_buffer bufs[ReadOp::max_buffers];
442 214827 : op.iovec_count = static_cast<int>(param.copy_to(bufs, ReadOp::max_buffers));
443 :
444 214827 : if (op.iovec_count == 0 || (op.iovec_count == 1 && bufs[0].size() == 0))
445 : {
446 4 : op.empty_buffer_read = true;
447 4 : op.h = h;
448 4 : op.ex = ex;
449 4 : op.ec_out = ec;
450 4 : op.bytes_out = bytes_out;
451 4 : op.start(token, static_cast<Derived*>(this));
452 4 : op.impl_ptr = this->shared_from_this();
453 4 : op.complete(0, 0);
454 4 : this->svc_.post(&op);
455 4 : return std::noop_coroutine();
456 : }
457 :
458 429664 : for (int i = 0; i < op.iovec_count; ++i)
459 : {
460 214841 : op.iovecs[i].iov_base = bufs[i].data();
461 214841 : op.iovecs[i].iov_len = bufs[i].size();
462 : }
463 :
464 : // Speculative read; for the single-buffer case use recv() so the
465 : // kernel skips the readv iov_iter setup.
466 : ssize_t n;
467 214823 : if (op.iovec_count == 1)
468 : {
469 : do
470 : {
471 214811 : n = ::recv(this->fd_, bufs[0].data(), bufs[0].size(), 0);
472 : }
473 214811 : while (n < 0 && errno == EINTR);
474 : }
475 : else
476 : {
477 : do
478 : {
479 16 : n = ::readv(this->fd_, op.iovecs, op.iovec_count);
480 : }
481 16 : while (n < 0 && errno == EINTR);
482 : }
483 :
484 214823 : if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
485 : {
486 214048 : int err = (n < 0) ? errno : 0;
487 214048 : auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
488 :
489 214048 : if (this->svc_.scheduler().try_consume_inline_budget())
490 : {
491 171272 : if (err)
492 4 : *ec = make_err(err);
493 171268 : else if (n == 0)
494 15 : *ec = capy::error::eof;
495 : else
496 171253 : *ec = {};
497 171272 : *bytes_out = bytes;
498 171272 : op.cont.h = h;
499 171272 : return dispatch_coro(ex, op.cont);
500 : }
501 42776 : op.h = h;
502 42776 : op.ex = ex;
503 42776 : op.ec_out = ec;
504 42776 : op.bytes_out = bytes_out;
505 42776 : op.start(token, static_cast<Derived*>(this));
506 42776 : op.impl_ptr = this->shared_from_this();
507 42776 : op.complete(err, bytes);
508 42776 : this->svc_.post(&op);
509 42776 : return std::noop_coroutine();
510 : }
511 :
512 : // EAGAIN — register with reactor
513 775 : op.h = h;
514 775 : op.ex = ex;
515 775 : op.ec_out = ec;
516 775 : op.bytes_out = bytes_out;
517 775 : op.fd = this->fd_;
518 775 : op.start(token, static_cast<Derived*>(this));
519 775 : op.impl_ptr = this->shared_from_this();
520 :
521 775 : this->register_op(
522 775 : op, this->desc_state_.read_op, this->desc_state_.read_ready);
523 775 : return std::noop_coroutine();
524 : }
525 :
526 : template<
527 : class Derived,
528 : class Service,
529 : class ConnOp,
530 : class ReadOp,
531 : class WriteOp,
532 : class WaitOp,
533 : class DescState,
534 : class ImplBase,
535 : class Endpoint>
536 : std::coroutine_handle<>
537 214143 : reactor_stream_socket<Derived, Service, ConnOp, ReadOp, WriteOp, WaitOp, DescState, ImplBase, Endpoint>::
538 : do_write_some(
539 : std::coroutine_handle<> h,
540 : capy::executor_ref ex,
541 : buffer_param param,
542 : std::stop_token const& token,
543 : std::error_code* ec,
544 : std::size_t* bytes_out)
545 : {
546 214143 : auto& op = wr_;
547 214143 : op.reset();
548 :
549 : // Closed-object contract: complete with bad_file_descriptor without
550 : // touching the kernel or the unregistered descriptor state.
551 214143 : if (this->fd_ < 0)
552 : {
553 8 : op.h = h;
554 8 : op.ex = ex;
555 8 : op.ec_out = ec;
556 8 : op.bytes_out = bytes_out;
557 8 : op.start(token, static_cast<Derived*>(this));
558 8 : op.impl_ptr = this->shared_from_this();
559 8 : op.complete(EBADF, 0);
560 8 : this->svc_.post(&op);
561 8 : return std::noop_coroutine();
562 : }
563 :
564 214135 : capy::mutable_buffer bufs[WriteOp::max_buffers];
565 214135 : op.iovec_count =
566 214135 : static_cast<int>(param.copy_to(bufs, WriteOp::max_buffers));
567 :
568 214135 : if (op.iovec_count == 0 || (op.iovec_count == 1 && bufs[0].size() == 0))
569 : {
570 4 : op.h = h;
571 4 : op.ex = ex;
572 4 : op.ec_out = ec;
573 4 : op.bytes_out = bytes_out;
574 4 : op.start(token, static_cast<Derived*>(this));
575 4 : op.impl_ptr = this->shared_from_this();
576 4 : op.complete(0, 0);
577 4 : this->svc_.post(&op);
578 4 : return std::noop_coroutine();
579 : }
580 :
581 428278 : for (int i = 0; i < op.iovec_count; ++i)
582 : {
583 214147 : op.iovecs[i].iov_base = bufs[i].data();
584 214147 : op.iovecs[i].iov_len = bufs[i].size();
585 : }
586 :
587 : // Speculative write; the single-buffer case dispatches to a
588 : // backend-specific fast path so the kernel skips msghdr/iov_iter
589 : // setup (and so each backend can pick the right SIGPIPE strategy).
590 : ssize_t n;
591 214131 : if (op.iovec_count == 1)
592 : {
593 428238 : n = WriteOp::write_policy::write_one(
594 214119 : this->fd_, bufs[0].data(), bufs[0].size());
595 : }
596 : else
597 : {
598 12 : n = WriteOp::write_policy::write(
599 12 : this->fd_, op.iovecs, op.iovec_count);
600 : }
601 :
602 214131 : if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
603 : {
604 213991 : int err = (n < 0) ? errno : 0;
605 213991 : auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
606 :
607 213991 : if (this->svc_.scheduler().try_consume_inline_budget())
608 : {
609 171144 : *ec = err ? make_err(err) : std::error_code{};
610 171144 : *bytes_out = bytes;
611 171144 : op.cont.h = h;
612 171144 : return dispatch_coro(ex, op.cont);
613 : }
614 42847 : op.h = h;
615 42847 : op.ex = ex;
616 42847 : op.ec_out = ec;
617 42847 : op.bytes_out = bytes_out;
618 42847 : op.start(token, static_cast<Derived*>(this));
619 42847 : op.impl_ptr = this->shared_from_this();
620 42847 : op.complete(err, bytes);
621 42847 : this->svc_.post(&op);
622 42847 : return std::noop_coroutine();
623 : }
624 :
625 : // EAGAIN — register with reactor
626 140 : op.h = h;
627 140 : op.ex = ex;
628 140 : op.ec_out = ec;
629 140 : op.bytes_out = bytes_out;
630 140 : op.fd = this->fd_;
631 140 : op.start(token, static_cast<Derived*>(this));
632 140 : op.impl_ptr = this->shared_from_this();
633 :
634 140 : this->register_op(
635 140 : op, this->desc_state_.write_op, this->desc_state_.write_ready, true);
636 140 : return std::noop_coroutine();
637 : }
638 :
639 : template<
640 : class Derived,
641 : class Service,
642 : class ConnOp,
643 : class ReadOp,
644 : class WriteOp,
645 : class WaitOp,
646 : class DescState,
647 : class ImplBase,
648 : class Endpoint>
649 : std::coroutine_handle<>
650 92 : reactor_stream_socket<Derived, Service, ConnOp, ReadOp, WriteOp, WaitOp, DescState, ImplBase, Endpoint>::
651 : do_wait(
652 : std::coroutine_handle<> h,
653 : capy::executor_ref ex,
654 : wait_type w,
655 : std::stop_token const& token,
656 : std::error_code* ec)
657 : {
658 : // Pick refs up-front to avoid duplicating the register_op call.
659 : WaitOp* op_ptr;
660 : reactor_op_base** desc_slot_ptr;
661 : std::uint32_t event;
662 :
663 92 : if (w == wait_type::read)
664 : {
665 51 : op_ptr = &wait_rd_;
666 51 : desc_slot_ptr = &this->desc_state_.wait_read_op;
667 51 : event = reactor_event_read;
668 : }
669 41 : else if (w == wait_type::write)
670 : {
671 23 : op_ptr = &wait_wr_;
672 23 : desc_slot_ptr = &this->desc_state_.wait_write_op;
673 23 : event = reactor_event_write;
674 : }
675 : else // wait_type::error
676 : {
677 18 : op_ptr = &wait_er_;
678 18 : desc_slot_ptr = &this->desc_state_.wait_error_op;
679 18 : event = reactor_event_error;
680 : }
681 :
682 92 : auto& op = *op_ptr;
683 :
684 : // Speculative probe, mirroring the speculative read: an
685 : // edge-triggered reactor cannot report a condition that already
686 : // holds, so a wait initiated on an already-ready socket would
687 : // otherwise park forever.
688 92 : int perr = 0;
689 92 : if (WaitOp::probe(this->fd_, event, perr))
690 : {
691 30 : if (this->svc_.scheduler().try_consume_inline_budget())
692 : {
693 4 : *ec = perr ? make_err(perr) : std::error_code{};
694 4 : op.cont.h = h;
695 4 : return dispatch_coro(ex, op.cont);
696 : }
697 26 : op.reset();
698 26 : op.wait_event = event;
699 26 : op.h = h;
700 26 : op.ex = ex;
701 26 : op.ec_out = ec;
702 26 : op.fd = this->fd_;
703 26 : op.start(token, static_cast<Derived*>(this));
704 26 : op.impl_ptr = this->shared_from_this();
705 26 : op.complete(perr, 0);
706 26 : this->svc_.post(&op);
707 26 : return std::noop_coroutine();
708 : }
709 :
710 62 : op.reset();
711 62 : op.wait_event = event;
712 62 : op.h = h;
713 62 : op.ex = ex;
714 62 : op.ec_out = ec;
715 62 : op.fd = this->fd_;
716 62 : op.start(token, static_cast<Derived*>(this));
717 62 : op.impl_ptr = this->shared_from_this();
718 :
719 : // Force register_op's ready path so the wait op re-probes under
720 : // the descriptor mutex before parking. An edge consumed between
721 : // the speculative probe above and the park (a concurrent short
722 : // read, or an error event dispatched to an empty slot) would
723 : // otherwise leave the wait parked on a ready socket.
724 62 : bool force_probe = true;
725 62 : this->register_op(op, *desc_slot_ptr, force_probe,
726 : event == reactor_event_write);
727 62 : return std::noop_coroutine();
728 : }
729 :
730 : } // namespace boost::corosio::detail
731 :
732 : #endif // BOOST_COROSIO_NATIVE_DETAIL_REACTOR_REACTOR_STREAM_SOCKET_HPP
|
