Index/include / boost / corosio / native / detail / epoll / epoll_socket_service.hpp

include/boost/corosio/native/detail/epoll/epoll_socket_service.hpp

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include/boost/corosio/native/detail/epoll/epoll_socket_service.hpp
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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_EPOLL_EPOLL_SOCKET_SERVICE_HPP
11 #define BOOST_COROSIO_NATIVE_DETAIL_EPOLL_EPOLL_SOCKET_SERVICE_HPP
12
13 #include <boost/corosio/detail/platform.hpp>
14
15 #if BOOST_COROSIO_HAS_EPOLL
16
17 #include <boost/corosio/detail/config.hpp>
18 #include <boost/capy/ex/execution_context.hpp>
19 #include <boost/corosio/detail/socket_service.hpp>
20
21 #include <boost/corosio/native/detail/epoll/epoll_socket.hpp>
22 #include <boost/corosio/native/detail/epoll/epoll_scheduler.hpp>
23
24 #include <boost/corosio/detail/endpoint_convert.hpp>
25 #include <boost/corosio/detail/make_err.hpp>
26 #include <boost/corosio/detail/dispatch_coro.hpp>
27 #include <boost/corosio/detail/except.hpp>
28 #include <boost/capy/buffers.hpp>
29
30 #include <coroutine>
31 #include <mutex>
32 #include <unordered_map>
33 #include <utility>
34
35 #include <errno.h>
36 #include <netinet/in.h>
37 #include <netinet/tcp.h>
38 #include <sys/epoll.h>
39 #include <sys/socket.h>
40 #include <unistd.h>
41
42 /*
43 epoll Socket Implementation
44 ===========================
45
46 Each I/O operation follows the same pattern:
47 1. Try the syscall immediately (non-blocking socket)
48 2. If it succeeds or fails with a real error, post to completion queue
49 3. If EAGAIN/EWOULDBLOCK, register with epoll and wait
50
51 This "try first" approach avoids unnecessary epoll round-trips for
52 operations that can complete immediately (common for small reads/writes
53 on fast local connections).
54
55 One-Shot Registration
56 ---------------------
57 We use one-shot epoll registration: each operation registers, waits for
58 one event, then unregisters. This simplifies the state machine since we
59 don't need to track whether an fd is currently registered or handle
60 re-arming. The tradeoff is slightly more epoll_ctl calls, but the
61 simplicity is worth it.
62
63 Cancellation
64 ------------
65 See op.hpp for the completion/cancellation race handling via the
66 `registered` atomic. cancel() must complete pending operations (post
67 them with cancelled flag) so coroutines waiting on them can resume.
68 close_socket() calls cancel() first to ensure this.
69
70 Impl Lifetime with shared_ptr
71 -----------------------------
72 Socket impls use enable_shared_from_this. The service owns impls via
73 shared_ptr maps (socket_ptrs_) keyed by raw pointer for O(1) lookup and
74 removal. When a user calls close(), we call cancel() which posts pending
75 ops to the scheduler.
76
77 CRITICAL: The posted ops must keep the impl alive until they complete.
78 Otherwise the scheduler would process a freed op (use-after-free). The
79 cancel() method captures shared_from_this() into op.impl_ptr before
80 posting. When the op completes, impl_ptr is cleared, allowing the impl
81 to be destroyed if no other references exist.
82
83 Service Ownership
84 -----------------
85 epoll_socket_service owns all socket impls. destroy_impl() removes the
86 shared_ptr from the map, but the impl may survive if ops still hold
87 impl_ptr refs. shutdown() closes all sockets and clears the map; any
88 in-flight ops will complete and release their refs.
89 */
90
91 namespace boost::corosio::detail {
92
93 /** State for epoll socket service. */
94 class epoll_socket_state
95 {
96 public:
97 205 explicit epoll_socket_state(epoll_scheduler& sched) noexcept : sched_(sched)
98 {
99 205 }
100
101 epoll_scheduler& sched_;
102 std::mutex mutex_;
103 intrusive_list<epoll_socket> socket_list_;
104 std::unordered_map<epoll_socket*, std::shared_ptr<epoll_socket>>
105 socket_ptrs_;
106 };
107
108 /** epoll socket service implementation.
109
110 Inherits from socket_service to enable runtime polymorphism.
111 Uses key_type = socket_service for service lookup.
112 */
113 class BOOST_COROSIO_DECL epoll_socket_service final : public socket_service
114 {
115 public:
116 explicit epoll_socket_service(capy::execution_context& ctx);
117 ~epoll_socket_service() override;
118
119 epoll_socket_service(epoll_socket_service const&) = delete;
120 epoll_socket_service& operator=(epoll_socket_service const&) = delete;
121
122 void shutdown() override;
123
124 io_object::implementation* construct() override;
125 void destroy(io_object::implementation*) override;
126 void close(io_object::handle&) override;
127 std::error_code open_socket(tcp_socket::implementation& impl) override;
128
129 342791 epoll_scheduler& scheduler() const noexcept
130 {
131 342791 return state_->sched_;
132 }
133 void post(epoll_op* op);
134 void work_started() noexcept;
135 void work_finished() noexcept;
136
137 private:
138 std::unique_ptr<epoll_socket_state> state_;
139 };
140
141 //--------------------------------------------------------------------------
142 //
143 // Implementation
144 //
145 //--------------------------------------------------------------------------
146
147 // Register an op with the reactor, handling cached edge events.
148 // Called under the EAGAIN/EINPROGRESS path when speculative I/O failed.
149 inline void
150 4780 epoll_socket::register_op(
151 epoll_op& op,
152 epoll_op*& desc_slot,
153 bool& ready_flag,
154 bool& cancel_flag) noexcept
155 {
156 4780 svc_.work_started();
157
158 4780 std::lock_guard lock(desc_state_.mutex);
159 4780 bool io_done = false;
160 4780 if (ready_flag)
161 {
162 140 ready_flag = false;
163 140 op.perform_io();
164 140 io_done = (op.errn != EAGAIN && op.errn != EWOULDBLOCK);
165 140 if (!io_done)
166 140 op.errn = 0;
167 }
168
169 4780 if (cancel_flag)
170 {
171 93 cancel_flag = false;
172 93 op.cancelled.store(true, std::memory_order_relaxed);
173 }
174
175 4780 if (io_done || op.cancelled.load(std::memory_order_acquire))
176 {
177 93 svc_.post(&op);
178 93 svc_.work_finished();
179 }
180 else
181 {
182 4687 desc_slot = &op;
183 }
184 4780 }
185
186 inline void
187 104 epoll_op::canceller::operator()() const noexcept
188 {
189 104 op->cancel();
190 104 }
191
192 inline void
193 ✗ epoll_connect_op::cancel() noexcept
194 {
195 ✗ if (socket_impl_)
196 ✗ socket_impl_->cancel_single_op(*this);
197 else
198 ✗ request_cancel();
199 ✗ }
200
201 inline void
202 98 epoll_read_op::cancel() noexcept
203 {
204 98 if (socket_impl_)
205 98 socket_impl_->cancel_single_op(*this);
206 else
207 ✗ request_cancel();
208 98 }
209
210 inline void
211 ✗ epoll_write_op::cancel() noexcept
212 {
213 ✗ if (socket_impl_)
214 ✗ socket_impl_->cancel_single_op(*this);
215 else
216 ✗ request_cancel();
217 ✗ }
218
219 inline void
220 53417 epoll_op::operator()()
221 {
222 53417 stop_cb.reset();
223
224 53417 socket_impl_->svc_.scheduler().reset_inline_budget();
225
226 53417 if (cancelled.load(std::memory_order_acquire))
227 203 *ec_out = capy::error::canceled;
228 53214 else if (errn != 0)
229 ✗ *ec_out = make_err(errn);
230 53214 else if (is_read_operation() && bytes_transferred == 0)
231 ✗ *ec_out = capy::error::eof;
232 else
233 53214 *ec_out = {};
234
235 53417 *bytes_out = bytes_transferred;
236
237 // Move to stack before resuming coroutine. The coroutine might close
238 // the socket, releasing the last wrapper ref. If impl_ptr were the
239 // last ref and we destroyed it while still in operator(), we'd have
240 // use-after-free. Moving to local ensures destruction happens at
241 // function exit, after all member accesses are complete.
242 53417 capy::executor_ref saved_ex(ex);
243 53417 std::coroutine_handle<> saved_h(h);
244 53417 auto prevent_premature_destruction = std::move(impl_ptr);
245 53417 dispatch_coro(saved_ex, saved_h).resume();
246 53417 }
247
248 inline void
249 4581 epoll_connect_op::operator()()
250 {
251 4581 stop_cb.reset();
252
253 4581 socket_impl_->svc_.scheduler().reset_inline_budget();
254
255 4581 bool success = (errn == 0 && !cancelled.load(std::memory_order_acquire));
256
257 // Cache endpoints on successful connect
258 4581 if (success && socket_impl_)
259 {
260 // Query local endpoint via getsockname (may fail, but remote is always known)
261 4580 endpoint local_ep;
262 4580 sockaddr_in local_addr{};
263 4580 socklen_t local_len = sizeof(local_addr);
264 4580 if (::getsockname(
265 4580 fd, reinterpret_cast<sockaddr*>(&local_addr), &local_len) == 0)
266 4580 local_ep = from_sockaddr_in(local_addr);
267 // Always cache remote endpoint; local may be default if getsockname failed
268 4580 static_cast<epoll_socket*>(socket_impl_)
269 4580 ->set_endpoints(local_ep, target_endpoint);
270 }
271
272 4581 if (cancelled.load(std::memory_order_acquire))
273 ✗ *ec_out = capy::error::canceled;
274 4581 else if (errn != 0)
275 1 *ec_out = make_err(errn);
276 else
277 4580 *ec_out = {};
278
279 // Move to stack before resuming. See epoll_op::operator()() for rationale.
280 4581 capy::executor_ref saved_ex(ex);
281 4581 std::coroutine_handle<> saved_h(h);
282 4581 auto prevent_premature_destruction = std::move(impl_ptr);
283 4581 dispatch_coro(saved_ex, saved_h).resume();
284 4581 }
285
286 13797 inline epoll_socket::epoll_socket(epoll_socket_service& svc) noexcept
287 13797 : svc_(svc)
288 {
289 13797 }
290
291 13797 inline epoll_socket::~epoll_socket() = default;
292
293 inline std::coroutine_handle<>
294 4581 epoll_socket::connect(
295 std::coroutine_handle<> h,
296 capy::executor_ref ex,
297 endpoint ep,
298 std::stop_token token,
299 std::error_code* ec)
300 {
301 4581 auto& op = conn_;
302
303 4581 sockaddr_in addr = detail::to_sockaddr_in(ep);
304 int result =
305 4581 ::connect(fd_, reinterpret_cast<sockaddr*>(&addr), sizeof(addr));
306
307 4581 if (result == 0)
308 {
309 ✗ sockaddr_in local_addr{};
310 ✗ socklen_t local_len = sizeof(local_addr);
311 ✗ if (::getsockname(
312 ✗ fd_, reinterpret_cast<sockaddr*>(&local_addr), &local_len) == 0)
313 ✗ local_endpoint_ = detail::from_sockaddr_in(local_addr);
314 ✗ remote_endpoint_ = ep;
315 }
316
317 4581 if (result == 0 || errno != EINPROGRESS)
318 {
319 ✗ int err = (result < 0) ? errno : 0;
320 ✗ if (svc_.scheduler().try_consume_inline_budget())
321 {
322 ✗ *ec = err ? make_err(err) : std::error_code{};
323 ✗ return dispatch_coro(ex, h);
324 }
325 ✗ op.reset();
326 ✗ op.h = h;
327 ✗ op.ex = ex;
328 ✗ op.ec_out = ec;
329 ✗ op.fd = fd_;
330 ✗ op.target_endpoint = ep;
331 ✗ op.start(token, this);
332 ✗ op.impl_ptr = shared_from_this();
333 ✗ op.complete(err, 0);
334 ✗ svc_.post(&op);
335 ✗ return std::noop_coroutine();
336 }
337
338 // EINPROGRESS — register with reactor
339 4581 op.reset();
340 4581 op.h = h;
341 4581 op.ex = ex;
342 4581 op.ec_out = ec;
343 4581 op.fd = fd_;
344 4581 op.target_endpoint = ep;
345 4581 op.start(token, this);
346 4581 op.impl_ptr = shared_from_this();
347
348 4581 register_op(
349 4581 op, desc_state_.connect_op, desc_state_.write_ready,
350 4581 desc_state_.connect_cancel_pending);
351 4581 return std::noop_coroutine();
352 }
353
354 inline std::coroutine_handle<>
355 133424 epoll_socket::read_some(
356 std::coroutine_handle<> h,
357 capy::executor_ref ex,
358 io_buffer_param param,
359 std::stop_token token,
360 std::error_code* ec,
361 std::size_t* bytes_out)
362 {
363 133424 auto& op = rd_;
364 133424 op.reset();
365
366 133424 capy::mutable_buffer bufs[epoll_read_op::max_buffers];
367 133424 op.iovec_count =
368 133424 static_cast<int>(param.copy_to(bufs, epoll_read_op::max_buffers));
369
370 133424 if (op.iovec_count == 0 || (op.iovec_count == 1 && bufs[0].size() == 0))
371 {
372 1 op.empty_buffer_read = true;
373 1 op.h = h;
374 1 op.ex = ex;
375 1 op.ec_out = ec;
376 1 op.bytes_out = bytes_out;
377 1 op.start(token, this);
378 1 op.impl_ptr = shared_from_this();
379 1 op.complete(0, 0);
380 1 svc_.post(&op);
381 1 return std::noop_coroutine();
382 }
383
384 266846 for (int i = 0; i < op.iovec_count; ++i)
385 {
386 133423 op.iovecs[i].iov_base = bufs[i].data();
387 133423 op.iovecs[i].iov_len = bufs[i].size();
388 }
389
390 // Speculative read
391 ssize_t n;
392 do
393 {
394 133423 n = ::readv(fd_, op.iovecs, op.iovec_count);
395 }
396 133423 while (n < 0 && errno == EINTR);
397
398 133423 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
399 {
400 133224 int err = (n < 0) ? errno : 0;
401 133224 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
402
403 133224 if (svc_.scheduler().try_consume_inline_budget())
404 {
405 106625 if (err)
406 ✗ *ec = make_err(err);
407 106625 else if (n == 0)
408 5 *ec = capy::error::eof;
409 else
410 106620 *ec = {};
411 106625 *bytes_out = bytes;
412 106625 return dispatch_coro(ex, h);
413 }
414 26599 op.h = h;
415 26599 op.ex = ex;
416 26599 op.ec_out = ec;
417 26599 op.bytes_out = bytes_out;
418 26599 op.start(token, this);
419 26599 op.impl_ptr = shared_from_this();
420 26599 op.complete(err, bytes);
421 26599 svc_.post(&op);
422 26599 return std::noop_coroutine();
423 }
424
425 // EAGAIN — register with reactor
426 199 op.h = h;
427 199 op.ex = ex;
428 199 op.ec_out = ec;
429 199 op.bytes_out = bytes_out;
430 199 op.fd = fd_;
431 199 op.start(token, this);
432 199 op.impl_ptr = shared_from_this();
433
434 199 register_op(
435 199 op, desc_state_.read_op, desc_state_.read_ready,
436 199 desc_state_.read_cancel_pending);
437 199 return std::noop_coroutine();
438 }
439
440 inline std::coroutine_handle<>
441 133226 epoll_socket::write_some(
442 std::coroutine_handle<> h,
443 capy::executor_ref ex,
444 io_buffer_param param,
445 std::stop_token token,
446 std::error_code* ec,
447 std::size_t* bytes_out)
448 {
449 133226 auto& op = wr_;
450 133226 op.reset();
451
452 133226 capy::mutable_buffer bufs[epoll_write_op::max_buffers];
453 133226 op.iovec_count =
454 133226 static_cast<int>(param.copy_to(bufs, epoll_write_op::max_buffers));
455
456 133226 if (op.iovec_count == 0 || (op.iovec_count == 1 && bufs[0].size() == 0))
457 {
458 1 op.h = h;
459 1 op.ex = ex;
460 1 op.ec_out = ec;
461 1 op.bytes_out = bytes_out;
462 1 op.start(token, this);
463 1 op.impl_ptr = shared_from_this();
464 1 op.complete(0, 0);
465 1 svc_.post(&op);
466 1 return std::noop_coroutine();
467 }
468
469 266450 for (int i = 0; i < op.iovec_count; ++i)
470 {
471 133225 op.iovecs[i].iov_base = bufs[i].data();
472 133225 op.iovecs[i].iov_len = bufs[i].size();
473 }
474
475 // Speculative write
476 133225 msghdr msg{};
477 133225 msg.msg_iov = op.iovecs;
478 133225 msg.msg_iovlen = static_cast<std::size_t>(op.iovec_count);
479
480 ssize_t n;
481 do
482 {
483 133225 n = ::sendmsg(fd_, &msg, MSG_NOSIGNAL);
484 }
485 133225 while (n < 0 && errno == EINTR);
486
487 133225 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
488 {
489 133225 int err = (n < 0) ? errno : 0;
490 133225 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
491
492 133225 if (svc_.scheduler().try_consume_inline_budget())
493 {
494 106608 *ec = err ? make_err(err) : std::error_code{};
495 106608 *bytes_out = bytes;
496 106608 return dispatch_coro(ex, h);
497 }
498 26617 op.h = h;
499 26617 op.ex = ex;
500 26617 op.ec_out = ec;
501 26617 op.bytes_out = bytes_out;
502 26617 op.start(token, this);
503 26617 op.impl_ptr = shared_from_this();
504 26617 op.complete(err, bytes);
505 26617 svc_.post(&op);
506 26617 return std::noop_coroutine();
507 }
508
509 // EAGAIN — register with reactor
510 ✗ op.h = h;
511 ✗ op.ex = ex;
512 ✗ op.ec_out = ec;
513 ✗ op.bytes_out = bytes_out;
514 ✗ op.fd = fd_;
515 ✗ op.start(token, this);
516 ✗ op.impl_ptr = shared_from_this();
517
518 ✗ register_op(
519 ✗ op, desc_state_.write_op, desc_state_.write_ready,
520 ✗ desc_state_.write_cancel_pending);
521 ✗ return std::noop_coroutine();
522 }
523
524 inline std::error_code
525 3 epoll_socket::shutdown(tcp_socket::shutdown_type what) noexcept
526 {
527 int how;
528 3 switch (what)
529 {
530 1 case tcp_socket::shutdown_receive:
531 1 how = SHUT_RD;
532 1 break;
533 1 case tcp_socket::shutdown_send:
534 1 how = SHUT_WR;
535 1 break;
536 1 case tcp_socket::shutdown_both:
537 1 how = SHUT_RDWR;
538 1 break;
539 ✗ default:
540 ✗ return make_err(EINVAL);
541 }
542 3 if (::shutdown(fd_, how) != 0)
543 ✗ return make_err(errno);
544 3 return {};
545 }
546
547 inline std::error_code
548 5 epoll_socket::set_no_delay(bool value) noexcept
549 {
550 5 int flag = value ? 1 : 0;
551 5 if (::setsockopt(fd_, IPPROTO_TCP, TCP_NODELAY, &flag, sizeof(flag)) != 0)
552 ✗ return make_err(errno);
553 5 return {};
554 }
555
556 inline bool
557 5 epoll_socket::no_delay(std::error_code& ec) const noexcept
558 {
559 5 int flag = 0;
560 5 socklen_t len = sizeof(flag);
561 5 if (::getsockopt(fd_, IPPROTO_TCP, TCP_NODELAY, &flag, &len) != 0)
562 {
563 ✗ ec = make_err(errno);
564 ✗ return false;
565 }
566 5 ec = {};
567 5 return flag != 0;
568 }
569
570 inline std::error_code
571 4 epoll_socket::set_keep_alive(bool value) noexcept
572 {
573 4 int flag = value ? 1 : 0;
574 4 if (::setsockopt(fd_, SOL_SOCKET, SO_KEEPALIVE, &flag, sizeof(flag)) != 0)
575 ✗ return make_err(errno);
576 4 return {};
577 }
578
579 inline bool
580 4 epoll_socket::keep_alive(std::error_code& ec) const noexcept
581 {
582 4 int flag = 0;
583 4 socklen_t len = sizeof(flag);
584 4 if (::getsockopt(fd_, SOL_SOCKET, SO_KEEPALIVE, &flag, &len) != 0)
585 {
586 ✗ ec = make_err(errno);
587 ✗ return false;
588 }
589 4 ec = {};
590 4 return flag != 0;
591 }
592
593 inline std::error_code
594 1 epoll_socket::set_receive_buffer_size(int size) noexcept
595 {
596 1 if (::setsockopt(fd_, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size)) != 0)
597 ✗ return make_err(errno);
598 1 return {};
599 }
600
601 inline int
602 3 epoll_socket::receive_buffer_size(std::error_code& ec) const noexcept
603 {
604 3 int size = 0;
605 3 socklen_t len = sizeof(size);
606 3 if (::getsockopt(fd_, SOL_SOCKET, SO_RCVBUF, &size, &len) != 0)
607 {
608 ✗ ec = make_err(errno);
609 ✗ return 0;
610 }
611 3 ec = {};
612 3 return size;
613 }
614
615 inline std::error_code
616 1 epoll_socket::set_send_buffer_size(int size) noexcept
617 {
618 1 if (::setsockopt(fd_, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size)) != 0)
619 ✗ return make_err(errno);
620 1 return {};
621 }
622
623 inline int
624 3 epoll_socket::send_buffer_size(std::error_code& ec) const noexcept
625 {
626 3 int size = 0;
627 3 socklen_t len = sizeof(size);
628 3 if (::getsockopt(fd_, SOL_SOCKET, SO_SNDBUF, &size, &len) != 0)
629 {
630 ✗ ec = make_err(errno);
631 ✗ return 0;
632 }
633 3 ec = {};
634 3 return size;
635 }
636
637 inline std::error_code
638 10 epoll_socket::set_linger(bool enabled, int timeout) noexcept
639 {
640 10 if (timeout < 0)
641 1 return make_err(EINVAL);
642 struct ::linger lg;
643 9 lg.l_onoff = enabled ? 1 : 0;
644 9 lg.l_linger = timeout;
645 9 if (::setsockopt(fd_, SOL_SOCKET, SO_LINGER, &lg, sizeof(lg)) != 0)
646 ✗ return make_err(errno);
647 9 return {};
648 }
649
650 inline tcp_socket::linger_options
651 3 epoll_socket::linger(std::error_code& ec) const noexcept
652 {
653 3 struct ::linger lg{};
654 3 socklen_t len = sizeof(lg);
655 3 if (::getsockopt(fd_, SOL_SOCKET, SO_LINGER, &lg, &len) != 0)
656 {
657 ✗ ec = make_err(errno);
658 ✗ return {};
659 }
660 3 ec = {};
661 3 return {.enabled = lg.l_onoff != 0, .timeout = lg.l_linger};
662 }
663
664 inline void
665 183 epoll_socket::cancel() noexcept
666 {
667 183 auto self = weak_from_this().lock();
668 183 if (!self)
669 ✗ return;
670
671 183 conn_.request_cancel();
672 183 rd_.request_cancel();
673 183 wr_.request_cancel();
674
675 183 epoll_op* conn_claimed = nullptr;
676 183 epoll_op* rd_claimed = nullptr;
677 183 epoll_op* wr_claimed = nullptr;
678 {
679 183 std::lock_guard lock(desc_state_.mutex);
680 183 if (desc_state_.connect_op == &conn_)
681 ✗ conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
682 else
683 183 desc_state_.connect_cancel_pending = true;
684 183 if (desc_state_.read_op == &rd_)
685 3 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
686 else
687 180 desc_state_.read_cancel_pending = true;
688 183 if (desc_state_.write_op == &wr_)
689 ✗ wr_claimed = std::exchange(desc_state_.write_op, nullptr);
690 else
691 183 desc_state_.write_cancel_pending = true;
692 183 }
693
694 183 if (conn_claimed)
695 {
696 ✗ conn_.impl_ptr = self;
697 ✗ svc_.post(&conn_);
698 ✗ svc_.work_finished();
699 }
700 183 if (rd_claimed)
701 {
702 3 rd_.impl_ptr = self;
703 3 svc_.post(&rd_);
704 3 svc_.work_finished();
705 }
706 183 if (wr_claimed)
707 {
708 ✗ wr_.impl_ptr = self;
709 ✗ svc_.post(&wr_);
710 ✗ svc_.work_finished();
711 }
712 183 }
713
714 inline void
715 98 epoll_socket::cancel_single_op(epoll_op& op) noexcept
716 {
717 98 auto self = weak_from_this().lock();
718 98 if (!self)
719 ✗ return;
720
721 98 op.request_cancel();
722
723 98 epoll_op** desc_op_ptr = nullptr;
724 98 if (&op == &conn_)
725 ✗ desc_op_ptr = &desc_state_.connect_op;
726 98 else if (&op == &rd_)
727 98 desc_op_ptr = &desc_state_.read_op;
728 ✗ else if (&op == &wr_)
729 ✗ desc_op_ptr = &desc_state_.write_op;
730
731 98 if (desc_op_ptr)
732 {
733 98 epoll_op* claimed = nullptr;
734 {
735 98 std::lock_guard lock(desc_state_.mutex);
736 98 if (*desc_op_ptr == &op)
737 98 claimed = std::exchange(*desc_op_ptr, nullptr);
738 ✗ else if (&op == &conn_)
739 ✗ desc_state_.connect_cancel_pending = true;
740 ✗ else if (&op == &rd_)
741 ✗ desc_state_.read_cancel_pending = true;
742 ✗ else if (&op == &wr_)
743 ✗ desc_state_.write_cancel_pending = true;
744 98 }
745 98 if (claimed)
746 {
747 98 op.impl_ptr = self;
748 98 svc_.post(&op);
749 98 svc_.work_finished();
750 }
751 }
752 98 }
753
754 inline void
755 41358 epoll_socket::close_socket() noexcept
756 {
757 41358 auto self = weak_from_this().lock();
758 41358 if (self)
759 {
760 41358 conn_.request_cancel();
761 41358 rd_.request_cancel();
762 41358 wr_.request_cancel();
763
764 41358 epoll_op* conn_claimed = nullptr;
765 41358 epoll_op* rd_claimed = nullptr;
766 41358 epoll_op* wr_claimed = nullptr;
767 {
768 41358 std::lock_guard lock(desc_state_.mutex);
769 41358 conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
770 41358 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
771 41358 wr_claimed = std::exchange(desc_state_.write_op, nullptr);
772 41358 desc_state_.read_ready = false;
773 41358 desc_state_.write_ready = false;
774 41358 desc_state_.read_cancel_pending = false;
775 41358 desc_state_.write_cancel_pending = false;
776 41358 desc_state_.connect_cancel_pending = false;
777 41358 }
778
779 41358 if (conn_claimed)
780 {
781 ✗ conn_.impl_ptr = self;
782 ✗ svc_.post(&conn_);
783 ✗ svc_.work_finished();
784 }
785 41358 if (rd_claimed)
786 {
787 1 rd_.impl_ptr = self;
788 1 svc_.post(&rd_);
789 1 svc_.work_finished();
790 }
791 41358 if (wr_claimed)
792 {
793 ✗ wr_.impl_ptr = self;
794 ✗ svc_.post(&wr_);
795 ✗ svc_.work_finished();
796 }
797
798 41358 if (desc_state_.is_enqueued_.load(std::memory_order_acquire))
799 94 desc_state_.impl_ref_ = self;
800 }
801
802 41358 if (fd_ >= 0)
803 {
804 9172 if (desc_state_.registered_events != 0)
805 9172 svc_.scheduler().deregister_descriptor(fd_);
806 9172 ::close(fd_);
807 9172 fd_ = -1;
808 }
809
810 41358 desc_state_.fd = -1;
811 41358 desc_state_.registered_events = 0;
812
813 41358 local_endpoint_ = endpoint{};
814 41358 remote_endpoint_ = endpoint{};
815 41358 }
816
817 205 inline epoll_socket_service::epoll_socket_service(capy::execution_context& ctx)
818 205 : state_(
819 std::make_unique<epoll_socket_state>(
820 205 ctx.use_service<epoll_scheduler>()))
821 {
822 205 }
823
824 410 inline epoll_socket_service::~epoll_socket_service() {}
825
826 inline void
827 205 epoll_socket_service::shutdown()
828 {
829 205 std::lock_guard lock(state_->mutex_);
830
831 205 while (auto* impl = state_->socket_list_.pop_front())
832 ✗ impl->close_socket();
833
834 // Don't clear socket_ptrs_ here. The scheduler shuts down after us and
835 // drains completed_ops_, calling destroy() on each queued op. If we
836 // released our shared_ptrs now, an epoll_op::destroy() could free the
837 // last ref to an impl whose embedded descriptor_state is still linked
838 // in the queue — use-after-free on the next pop(). Letting ~state_
839 // release the ptrs (during service destruction, after scheduler
840 // shutdown) keeps every impl alive until all ops have been drained.
841 205 }
842
843 inline io_object::implementation*
844 13797 epoll_socket_service::construct()
845 {
846 13797 auto impl = std::make_shared<epoll_socket>(*this);
847 13797 auto* raw = impl.get();
848
849 {
850 13797 std::lock_guard lock(state_->mutex_);
851 13797 state_->socket_list_.push_back(raw);
852 13797 state_->socket_ptrs_.emplace(raw, std::move(impl));
853 13797 }
854
855 13797 return raw;
856 13797 }
857
858 inline void
859 13797 epoll_socket_service::destroy(io_object::implementation* impl)
860 {
861 13797 auto* epoll_impl = static_cast<epoll_socket*>(impl);
862 13797 epoll_impl->close_socket();
863 13797 std::lock_guard lock(state_->mutex_);
864 13797 state_->socket_list_.remove(epoll_impl);
865 13797 state_->socket_ptrs_.erase(epoll_impl);
866 13797 }
867
868 inline std::error_code
869 4592 epoll_socket_service::open_socket(tcp_socket::implementation& impl)
870 {
871 4592 auto* epoll_impl = static_cast<epoll_socket*>(&impl);
872 4592 epoll_impl->close_socket();
873
874 4592 int fd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
875 4592 if (fd < 0)
876 ✗ return make_err(errno);
877
878 4592 epoll_impl->fd_ = fd;
879
880 // Register fd with epoll (edge-triggered mode)
881 4592 epoll_impl->desc_state_.fd = fd;
882 {
883 4592 std::lock_guard lock(epoll_impl->desc_state_.mutex);
884 4592 epoll_impl->desc_state_.read_op = nullptr;
885 4592 epoll_impl->desc_state_.write_op = nullptr;
886 4592 epoll_impl->desc_state_.connect_op = nullptr;
887 4592 }
888 4592 scheduler().register_descriptor(fd, &epoll_impl->desc_state_);
889
890 4592 return {};
891 }
892
893 inline void
894 22969 epoll_socket_service::close(io_object::handle& h)
895 {
896 22969 static_cast<epoll_socket*>(h.get())->close_socket();
897 22969 }
898
899 inline void
900 53413 epoll_socket_service::post(epoll_op* op)
901 {
902 53413 state_->sched_.post(op);
903 53413 }
904
905 inline void
906 4780 epoll_socket_service::work_started() noexcept
907 {
908 4780 state_->sched_.work_started();
909 4780 }
910
911 inline void
912 195 epoll_socket_service::work_finished() noexcept
913 {
914 195 state_->sched_.work_finished();
915 195 }
916
917 } // namespace boost::corosio::detail
918
919 #endif // BOOST_COROSIO_HAS_EPOLL
920
921 #endif // BOOST_COROSIO_NATIVE_DETAIL_EPOLL_EPOLL_SOCKET_SERVICE_HPP
922