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 352903 epoll_scheduler& scheduler() const noexcept
130 {
131 352903 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 4880 epoll_socket::register_op(
151 epoll_op& op,
152 epoll_op*& desc_slot,
153 bool& ready_flag,
154 bool& cancel_flag) noexcept
155 {
156 4880 svc_.work_started();
157
158 4880 std::lock_guard lock(desc_state_.mutex);
159 4880 bool io_done = false;
160 4880 if (ready_flag)
161 {
162 141 ready_flag = false;
163 141 op.perform_io();
164 141 io_done = (op.errn != EAGAIN && op.errn != EWOULDBLOCK);
165 141 if (!io_done)
166 141 op.errn = 0;
167 }
168
169 4880 if (cancel_flag)
170 {
171 94 cancel_flag = false;
172 94 op.cancelled.store(true, std::memory_order_relaxed);
173 }
174
175 4880 if (io_done || op.cancelled.load(std::memory_order_acquire))
176 {
177 94 svc_.post(&op);
178 94 svc_.work_finished();
179 }
180 else
181 {
182 4786 desc_slot = &op;
183 }
184 4880 }
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 55020 epoll_op::operator()()
221 {
222 55020 stop_cb.reset();
223
224 55020 socket_impl_->svc_.scheduler().reset_inline_budget();
225
226 55020 if (cancelled.load(std::memory_order_acquire))
227 204 *ec_out = capy::error::canceled;
228 54816 else if (errn != 0)
229 ✗ *ec_out = make_err(errn);
230 54816 else if (is_read_operation() && bytes_transferred == 0)
231 ✗ *ec_out = capy::error::eof;
232 else
233 54816 *ec_out = {};
234
235 55020 *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 55020 capy::executor_ref saved_ex(ex);
243 55020 std::coroutine_handle<> saved_h(h);
244 55020 auto prevent_premature_destruction = std::move(impl_ptr);
245 55020 dispatch_coro(saved_ex, saved_h).resume();
246 55020 }
247
248 inline void
249 4680 epoll_connect_op::operator()()
250 {
251 4680 stop_cb.reset();
252
253 4680 socket_impl_->svc_.scheduler().reset_inline_budget();
254
255 4680 bool success = (errn == 0 && !cancelled.load(std::memory_order_acquire));
256
257 // Cache endpoints on successful connect
258 4680 if (success && socket_impl_)
259 {
260 // Query local endpoint via getsockname (may fail, but remote is always known)
261 4679 endpoint local_ep;
262 4679 sockaddr_in local_addr{};
263 4679 socklen_t local_len = sizeof(local_addr);
264 4679 if (::getsockname(
265 4679 fd, reinterpret_cast<sockaddr*>(&local_addr), &local_len) == 0)
266 4679 local_ep = from_sockaddr_in(local_addr);
267 // Always cache remote endpoint; local may be default if getsockname failed
268 4679 static_cast<epoll_socket*>(socket_impl_)
269 4679 ->set_endpoints(local_ep, target_endpoint);
270 }
271
272 4680 if (cancelled.load(std::memory_order_acquire))
273 ✗ *ec_out = capy::error::canceled;
274 4680 else if (errn != 0)
275 1 *ec_out = make_err(errn);
276 else
277 4679 *ec_out = {};
278
279 // Move to stack before resuming. See epoll_op::operator()() for rationale.
280 4680 capy::executor_ref saved_ex(ex);
281 4680 std::coroutine_handle<> saved_h(h);
282 4680 auto prevent_premature_destruction = std::move(impl_ptr);
283 4680 dispatch_coro(saved_ex, saved_h).resume();
284 4680 }
285
286 14094 inline epoll_socket::epoll_socket(epoll_socket_service& svc) noexcept
287 14094 : svc_(svc)
288 {
289 14094 }
290
291 14094 inline epoll_socket::~epoll_socket() = default;
292
293 inline std::coroutine_handle<>
294 4680 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 4680 auto& op = conn_;
302
303 4680 sockaddr_in addr = detail::to_sockaddr_in(ep);
304 int result =
305 4680 ::connect(fd_, reinterpret_cast<sockaddr*>(&addr), sizeof(addr));
306
307 4680 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 4680 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 4680 op.reset();
340 4680 op.h = h;
341 4680 op.ex = ex;
342 4680 op.ec_out = ec;
343 4680 op.fd = fd_;
344 4680 op.target_endpoint = ep;
345 4680 op.start(token, this);
346 4680 op.impl_ptr = shared_from_this();
347
348 4680 register_op(
349 4680 op, desc_state_.connect_op, desc_state_.write_ready,
350 4680 desc_state_.connect_cancel_pending);
351 4680 return std::noop_coroutine();
352 }
353
354 inline std::coroutine_handle<>
355 137432 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 137432 auto& op = rd_;
364 137432 op.reset();
365
366 137432 capy::mutable_buffer bufs[epoll_read_op::max_buffers];
367 137432 op.iovec_count =
368 137432 static_cast<int>(param.copy_to(bufs, epoll_read_op::max_buffers));
369
370 137432 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 274862 for (int i = 0; i < op.iovec_count; ++i)
385 {
386 137431 op.iovecs[i].iov_base = bufs[i].data();
387 137431 op.iovecs[i].iov_len = bufs[i].size();
388 }
389
390 // Speculative read
391 ssize_t n;
392 do
393 {
394 137431 n = ::readv(fd_, op.iovecs, op.iovec_count);
395 }
396 137431 while (n < 0 && errno == EINTR);
397
398 137431 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
399 {
400 137231 int err = (n < 0) ? errno : 0;
401 137231 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
402
403 137231 if (svc_.scheduler().try_consume_inline_budget())
404 {
405 109831 if (err)
406 ✗ *ec = make_err(err);
407 109831 else if (n == 0)
408 5 *ec = capy::error::eof;
409 else
410 109826 *ec = {};
411 109831 *bytes_out = bytes;
412 109831 return dispatch_coro(ex, h);
413 }
414 27400 op.h = h;
415 27400 op.ex = ex;
416 27400 op.ec_out = ec;
417 27400 op.bytes_out = bytes_out;
418 27400 op.start(token, this);
419 27400 op.impl_ptr = shared_from_this();
420 27400 op.complete(err, bytes);
421 27400 svc_.post(&op);
422 27400 return std::noop_coroutine();
423 }
424
425 // EAGAIN — register with reactor
426 200 op.h = h;
427 200 op.ex = ex;
428 200 op.ec_out = ec;
429 200 op.bytes_out = bytes_out;
430 200 op.fd = fd_;
431 200 op.start(token, this);
432 200 op.impl_ptr = shared_from_this();
433
434 200 register_op(
435 200 op, desc_state_.read_op, desc_state_.read_ready,
436 200 desc_state_.read_cancel_pending);
437 200 return std::noop_coroutine();
438 }
439
440 inline std::coroutine_handle<>
441 137233 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 137233 auto& op = wr_;
450 137233 op.reset();
451
452 137233 capy::mutable_buffer bufs[epoll_write_op::max_buffers];
453 137233 op.iovec_count =
454 137233 static_cast<int>(param.copy_to(bufs, epoll_write_op::max_buffers));
455
456 137233 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 274464 for (int i = 0; i < op.iovec_count; ++i)
470 {
471 137232 op.iovecs[i].iov_base = bufs[i].data();
472 137232 op.iovecs[i].iov_len = bufs[i].size();
473 }
474
475 // Speculative write
476 137232 msghdr msg{};
477 137232 msg.msg_iov = op.iovecs;
478 137232 msg.msg_iovlen = static_cast<std::size_t>(op.iovec_count);
479
480 ssize_t n;
481 do
482 {
483 137232 n = ::sendmsg(fd_, &msg, MSG_NOSIGNAL);
484 }
485 137232 while (n < 0 && errno == EINTR);
486
487 137232 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
488 {
489 137232 int err = (n < 0) ? errno : 0;
490 137232 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
491
492 137232 if (svc_.scheduler().try_consume_inline_budget())
493 {
494 109814 *ec = err ? make_err(err) : std::error_code{};
495 109814 *bytes_out = bytes;
496 109814 return dispatch_coro(ex, h);
497 }
498 27418 op.h = h;
499 27418 op.ex = ex;
500 27418 op.ec_out = ec;
501 27418 op.bytes_out = bytes_out;
502 27418 op.start(token, this);
503 27418 op.impl_ptr = shared_from_this();
504 27418 op.complete(err, bytes);
505 27418 svc_.post(&op);
506 27418 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
665 185 epoll_socket::cancel() noexcept
666 {
667 185 auto self = weak_from_this().lock();
668 185 if (!self)
669 ✗ return;
670
671 185 conn_.request_cancel();
672 185 rd_.request_cancel();
673 185 wr_.request_cancel();
674
675 185 epoll_op* conn_claimed = nullptr;
676 185 epoll_op* rd_claimed = nullptr;
677 185 epoll_op* wr_claimed = nullptr;
678 {
679 185 std::lock_guard lock(desc_state_.mutex);
680 185 if (desc_state_.connect_op == &conn_)
681 ✗ conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
682 else
683 185 desc_state_.connect_cancel_pending = true;
684 185 if (desc_state_.read_op == &rd_)
685 3 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
686 else
687 182 desc_state_.read_cancel_pending = true;
688 185 if (desc_state_.write_op == &wr_)
689 ✗ wr_claimed = std::exchange(desc_state_.write_op, nullptr);
690 else
691 185 desc_state_.write_cancel_pending = true;
692 185 }
693
694 185 if (conn_claimed)
695 {
696 ✗ conn_.impl_ptr = self;
697 ✗ svc_.post(&conn_);
698 ✗ svc_.work_finished();
699 }
700 185 if (rd_claimed)
701 {
702 3 rd_.impl_ptr = self;
703 3 svc_.post(&rd_);
704 3 svc_.work_finished();
705 }
706 185 if (wr_claimed)
707 {
708 ✗ wr_.impl_ptr = self;
709 ✗ svc_.post(&wr_);
710 ✗ svc_.work_finished();
711 }
712 185 }
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 42249 epoll_socket::close_socket() noexcept
756 {
757 42249 auto self = weak_from_this().lock();
758 42249 if (self)
759 {
760 42249 conn_.request_cancel();
761 42249 rd_.request_cancel();
762 42249 wr_.request_cancel();
763
764 42249 epoll_op* conn_claimed = nullptr;
765 42249 epoll_op* rd_claimed = nullptr;
766 42249 epoll_op* wr_claimed = nullptr;
767 {
768 42249 std::lock_guard lock(desc_state_.mutex);
769 42249 conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
770 42249 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
771 42249 wr_claimed = std::exchange(desc_state_.write_op, nullptr);
772 42249 desc_state_.read_ready = false;
773 42249 desc_state_.write_ready = false;
774 42249 desc_state_.read_cancel_pending = false;
775 42249 desc_state_.write_cancel_pending = false;
776 42249 desc_state_.connect_cancel_pending = false;
777 42249 }
778
779 42249 if (conn_claimed)
780 {
781 ✗ conn_.impl_ptr = self;
782 ✗ svc_.post(&conn_);
783 ✗ svc_.work_finished();
784 }
785 42249 if (rd_claimed)
786 {
787 1 rd_.impl_ptr = self;
788 1 svc_.post(&rd_);
789 1 svc_.work_finished();
790 }
791 42249 if (wr_claimed)
792 {
793 ✗ wr_.impl_ptr = self;
794 ✗ svc_.post(&wr_);
795 ✗ svc_.work_finished();
796 }
797
798 42249 if (desc_state_.is_enqueued_.load(std::memory_order_acquire))
799 94 desc_state_.impl_ref_ = self;
800 }
801
802 42249 if (fd_ >= 0)
803 {
804 9370 if (desc_state_.registered_events != 0)
805 9370 svc_.scheduler().deregister_descriptor(fd_);
806 9370 ::close(fd_);
807 9370 fd_ = -1;
808 }
809
810 42249 desc_state_.fd = -1;
811 42249 desc_state_.registered_events = 0;
812
813 42249 local_endpoint_ = endpoint{};
814 42249 remote_endpoint_ = endpoint{};
815 42249 }
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 14094 epoll_socket_service::construct()
845 {
846 14094 auto impl = std::make_shared<epoll_socket>(*this);
847 14094 auto* raw = impl.get();
848
849 {
850 14094 std::lock_guard lock(state_->mutex_);
851 14094 state_->socket_list_.push_back(raw);
852 14094 state_->socket_ptrs_.emplace(raw, std::move(impl));
853 14094 }
854
855 14094 return raw;
856 14094 }
857
858 inline void
859 14094 epoll_socket_service::destroy(io_object::implementation* impl)
860 {
861 14094 auto* epoll_impl = static_cast<epoll_socket*>(impl);
862 14094 epoll_impl->close_socket();
863 14094 std::lock_guard lock(state_->mutex_);
864 14094 state_->socket_list_.remove(epoll_impl);
865 14094 state_->socket_ptrs_.erase(epoll_impl);
866 14094 }
867
868 inline std::error_code
869 4691 epoll_socket_service::open_socket(tcp_socket::implementation& impl)
870 {
871 4691 auto* epoll_impl = static_cast<epoll_socket*>(&impl);
872 4691 epoll_impl->close_socket();
873
874 4691 int fd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
875 4691 if (fd < 0)
876 ✗ return make_err(errno);
877
878 4691 epoll_impl->fd_ = fd;
879
880 // Register fd with epoll (edge-triggered mode)
881 4691 epoll_impl->desc_state_.fd = fd;
882 {
883 4691 std::lock_guard lock(epoll_impl->desc_state_.mutex);
884 4691 epoll_impl->desc_state_.read_op = nullptr;
885 4691 epoll_impl->desc_state_.write_op = nullptr;
886 4691 epoll_impl->desc_state_.connect_op = nullptr;
887 4691 }
888 4691 scheduler().register_descriptor(fd, &epoll_impl->desc_state_);
889
890 4691 return {};
891 }
892
893 inline void
894 23464 epoll_socket_service::close(io_object::handle& h)
895 {
896 23464 static_cast<epoll_socket*>(h.get())->close_socket();
897 23464 }
898
899 inline void
900 55016 epoll_socket_service::post(epoll_op* op)
901 {
902 55016 state_->sched_.post(op);
903 55016 }
904
905 inline void
906 4880 epoll_socket_service::work_started() noexcept
907 {
908 4880 state_->sched_.work_started();
909 4880 }
910
911 inline void
912 196 epoll_socket_service::work_finished() noexcept
913 {
914 196 state_->sched_.work_finished();
915 196 }
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