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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 321202 epoll_scheduler& scheduler() const noexcept
130 {
131 321202 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 3899 epoll_socket::register_op(
151 epoll_op& op,
152 epoll_op*& desc_slot,
153 bool& ready_flag,
154 bool& cancel_flag) noexcept
155 {
156 3899 svc_.work_started();
157
158 3899 std::lock_guard lock(desc_state_.mutex);
159 3899 bool io_done = false;
160 3899 if (ready_flag)
161 {
162 134 ready_flag = false;
163 134 op.perform_io();
164 134 io_done = (op.errn != EAGAIN && op.errn != EWOULDBLOCK);
165 134 if (!io_done)
166 134 op.errn = 0;
167 }
168
169 3899 if (cancel_flag)
170 {
171 88 cancel_flag = false;
172 88 op.cancelled.store(true, std::memory_order_relaxed);
173 }
174
175 3899 if (io_done || op.cancelled.load(std::memory_order_acquire))
176 {
177 88 svc_.post(&op);
178 88 svc_.work_finished();
179 }
180 else
181 {
182 3811 desc_slot = &op;
183 }
184 3899 }
185
186 inline void
187 103 epoll_op::canceller::operator()() const noexcept
188 {
189 103 op->cancel();
190 103 }
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 97 epoll_read_op::cancel() noexcept
203 {
204 97 if (socket_impl_)
205 97 socket_impl_->cancel_single_op(*this);
206 else
207 ✗ request_cancel();
208 97 }
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 50546 epoll_op::operator()()
221 {
222 50546 stop_cb.reset();
223
224 50546 socket_impl_->svc_.scheduler().reset_inline_budget();
225
226 50546 if (cancelled.load(std::memory_order_acquire))
227 197 *ec_out = capy::error::canceled;
228 50349 else if (errn != 0)
229 ✗ *ec_out = make_err(errn);
230 50349 else if (is_read_operation() && bytes_transferred == 0)
231 ✗ *ec_out = capy::error::eof;
232 else
233 50349 *ec_out = {};
234
235 50546 *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 50546 capy::executor_ref saved_ex(ex);
243 50546 std::coroutine_handle<> saved_h(h);
244 50546 auto prevent_premature_destruction = std::move(impl_ptr);
245 50546 dispatch_coro(saved_ex, saved_h).resume();
246 50546 }
247
248 inline void
249 3706 epoll_connect_op::operator()()
250 {
251 3706 stop_cb.reset();
252
253 3706 socket_impl_->svc_.scheduler().reset_inline_budget();
254
255 3706 bool success = (errn == 0 && !cancelled.load(std::memory_order_acquire));
256
257 // Cache endpoints on successful connect
258 3706 if (success && socket_impl_)
259 {
260 // Query local endpoint via getsockname (may fail, but remote is always known)
261 3704 endpoint local_ep;
262 3704 sockaddr_in local_addr{};
263 3704 socklen_t local_len = sizeof(local_addr);
264 3704 if (::getsockname(
265 3704 fd, reinterpret_cast<sockaddr*>(&local_addr), &local_len) == 0)
266 3704 local_ep = from_sockaddr_in(local_addr);
267 // Always cache remote endpoint; local may be default if getsockname failed
268 3704 static_cast<epoll_socket*>(socket_impl_)
269 3704 ->set_endpoints(local_ep, target_endpoint);
270 }
271
272 3706 if (cancelled.load(std::memory_order_acquire))
273 ✗ *ec_out = capy::error::canceled;
274 3706 else if (errn != 0)
275 2 *ec_out = make_err(errn);
276 else
277 3704 *ec_out = {};
278
279 // Move to stack before resuming. See epoll_op::operator()() for rationale.
280 3706 capy::executor_ref saved_ex(ex);
281 3706 std::coroutine_handle<> saved_h(h);
282 3706 auto prevent_premature_destruction = std::move(impl_ptr);
283 3706 dispatch_coro(saved_ex, saved_h).resume();
284 3706 }
285
286 11170 inline epoll_socket::epoll_socket(epoll_socket_service& svc) noexcept
287 11170 : svc_(svc)
288 {
289 11170 }
290
291 11170 inline epoll_socket::~epoll_socket() = default;
292
293 inline std::coroutine_handle<>
294 3706 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 3706 auto& op = conn_;
302
303 3706 sockaddr_in addr = detail::to_sockaddr_in(ep);
304 int result =
305 3706 ::connect(fd_, reinterpret_cast<sockaddr*>(&addr), sizeof(addr));
306
307 3706 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 3706 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 3706 op.reset();
340 3706 op.h = h;
341 3706 op.ex = ex;
342 3706 op.ec_out = ec;
343 3706 op.fd = fd_;
344 3706 op.target_endpoint = ep;
345 3706 op.start(token, this);
346 3706 op.impl_ptr = shared_from_this();
347
348 3706 register_op(
349 3706 op, desc_state_.connect_op, desc_state_.write_ready,
350 3706 desc_state_.connect_cancel_pending);
351 3706 return std::noop_coroutine();
352 }
353
354 inline std::coroutine_handle<>
355 126247 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 126247 auto& op = rd_;
364 126247 op.reset();
365
366 126247 capy::mutable_buffer bufs[epoll_read_op::max_buffers];
367 126247 op.iovec_count =
368 126247 static_cast<int>(param.copy_to(bufs, epoll_read_op::max_buffers));
369
370 126247 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 252492 for (int i = 0; i < op.iovec_count; ++i)
385 {
386 126246 op.iovecs[i].iov_base = bufs[i].data();
387 126246 op.iovecs[i].iov_len = bufs[i].size();
388 }
389
390 // Speculative read
391 ssize_t n;
392 do
393 {
394 126246 n = ::readv(fd_, op.iovecs, op.iovec_count);
395 }
396 126246 while (n < 0 && errno == EINTR);
397
398 126246 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
399 {
400 126053 int err = (n < 0) ? errno : 0;
401 126053 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
402
403 126053 if (svc_.scheduler().try_consume_inline_budget())
404 {
405 100887 if (err)
406 ✗ *ec = make_err(err);
407 100887 else if (n == 0)
408 5 *ec = capy::error::eof;
409 else
410 100882 *ec = {};
411 100887 *bytes_out = bytes;
412 100887 return dispatch_coro(ex, h);
413 }
414 25166 op.h = h;
415 25166 op.ex = ex;
416 25166 op.ec_out = ec;
417 25166 op.bytes_out = bytes_out;
418 25166 op.start(token, this);
419 25166 op.impl_ptr = shared_from_this();
420 25166 op.complete(err, bytes);
421 25166 svc_.post(&op);
422 25166 return std::noop_coroutine();
423 }
424
425 // EAGAIN — register with reactor
426 193 op.h = h;
427 193 op.ex = ex;
428 193 op.ec_out = ec;
429 193 op.bytes_out = bytes_out;
430 193 op.fd = fd_;
431 193 op.start(token, this);
432 193 op.impl_ptr = shared_from_this();
433
434 193 register_op(
435 193 op, desc_state_.read_op, desc_state_.read_ready,
436 193 desc_state_.read_cancel_pending);
437 193 return std::noop_coroutine();
438 }
439
440 inline std::coroutine_handle<>
441 126056 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 126056 auto& op = wr_;
450 126056 op.reset();
451
452 126056 capy::mutable_buffer bufs[epoll_write_op::max_buffers];
453 126056 op.iovec_count =
454 126056 static_cast<int>(param.copy_to(bufs, epoll_write_op::max_buffers));
455
456 126056 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 252110 for (int i = 0; i < op.iovec_count; ++i)
470 {
471 126055 op.iovecs[i].iov_base = bufs[i].data();
472 126055 op.iovecs[i].iov_len = bufs[i].size();
473 }
474
475 // Speculative write
476 126055 msghdr msg{};
477 126055 msg.msg_iov = op.iovecs;
478 126055 msg.msg_iovlen = static_cast<std::size_t>(op.iovec_count);
479
480 ssize_t n;
481 do
482 {
483 126055 n = ::sendmsg(fd_, &msg, MSG_NOSIGNAL);
484 }
485 126055 while (n < 0 && errno == EINTR);
486
487 126055 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
488 {
489 126055 int err = (n < 0) ? errno : 0;
490 126055 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
491
492 126055 if (svc_.scheduler().try_consume_inline_budget())
493 {
494 100870 *ec = err ? make_err(err) : std::error_code{};
495 100870 *bytes_out = bytes;
496 100870 return dispatch_coro(ex, h);
497 }
498 25185 op.h = h;
499 25185 op.ex = ex;
500 25185 op.ec_out = ec;
501 25185 op.bytes_out = bytes_out;
502 25185 op.start(token, this);
503 25185 op.impl_ptr = shared_from_this();
504 25185 op.complete(err, bytes);
505 25185 svc_.post(&op);
506 25185 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
665 173 epoll_socket::cancel() noexcept
666 {
667 173 auto self = weak_from_this().lock();
668 173 if (!self)
669 ✗ return;
670
671 173 conn_.request_cancel();
672 173 rd_.request_cancel();
673 173 wr_.request_cancel();
674
675 173 epoll_op* conn_claimed = nullptr;
676 173 epoll_op* rd_claimed = nullptr;
677 173 epoll_op* wr_claimed = nullptr;
678 {
679 173 std::lock_guard lock(desc_state_.mutex);
680 173 if (desc_state_.connect_op == &conn_)
681 ✗ conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
682 else
683 173 desc_state_.connect_cancel_pending = true;
684 173 if (desc_state_.read_op == &rd_)
685 3 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
686 else
687 170 desc_state_.read_cancel_pending = true;
688 173 if (desc_state_.write_op == &wr_)
689 ✗ wr_claimed = std::exchange(desc_state_.write_op, nullptr);
690 else
691 173 desc_state_.write_cancel_pending = true;
692 173 }
693
694 173 if (conn_claimed)
695 {
696 ✗ conn_.impl_ptr = self;
697 ✗ svc_.post(&conn_);
698 ✗ svc_.work_finished();
699 }
700 173 if (rd_claimed)
701 {
702 3 rd_.impl_ptr = self;
703 3 svc_.post(&rd_);
704 3 svc_.work_finished();
705 }
706 173 if (wr_claimed)
707 {
708 ✗ wr_.impl_ptr = self;
709 ✗ svc_.post(&wr_);
710 ✗ svc_.work_finished();
711 }
712 173 }
713
714 inline void
715 97 epoll_socket::cancel_single_op(epoll_op& op) noexcept
716 {
717 97 auto self = weak_from_this().lock();
718 97 if (!self)
719 ✗ return;
720
721 97 op.request_cancel();
722
723 97 epoll_op** desc_op_ptr = nullptr;
724 97 if (&op == &conn_)
725 ✗ desc_op_ptr = &desc_state_.connect_op;
726 97 else if (&op == &rd_)
727 97 desc_op_ptr = &desc_state_.read_op;
728 ✗ else if (&op == &wr_)
729 ✗ desc_op_ptr = &desc_state_.write_op;
730
731 97 if (desc_op_ptr)
732 {
733 97 epoll_op* claimed = nullptr;
734 {
735 97 std::lock_guard lock(desc_state_.mutex);
736 97 if (*desc_op_ptr == &op)
737 97 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 97 }
745 97 if (claimed)
746 {
747 97 op.impl_ptr = self;
748 97 svc_.post(&op);
749 97 svc_.work_finished();
750 }
751 }
752 97 }
753
754 inline void
755 33478 epoll_socket::close_socket() noexcept
756 {
757 33478 auto self = weak_from_this().lock();
758 33478 if (self)
759 {
760 33478 conn_.request_cancel();
761 33478 rd_.request_cancel();
762 33478 wr_.request_cancel();
763
764 33478 epoll_op* conn_claimed = nullptr;
765 33478 epoll_op* rd_claimed = nullptr;
766 33478 epoll_op* wr_claimed = nullptr;
767 {
768 33478 std::lock_guard lock(desc_state_.mutex);
769 33478 conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
770 33478 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
771 33478 wr_claimed = std::exchange(desc_state_.write_op, nullptr);
772 33478 desc_state_.read_ready = false;
773 33478 desc_state_.write_ready = false;
774 33478 desc_state_.read_cancel_pending = false;
775 33478 desc_state_.write_cancel_pending = false;
776 33478 desc_state_.connect_cancel_pending = false;
777 33478 }
778
779 33478 if (conn_claimed)
780 {
781 ✗ conn_.impl_ptr = self;
782 ✗ svc_.post(&conn_);
783 ✗ svc_.work_finished();
784 }
785 33478 if (rd_claimed)
786 {
787 1 rd_.impl_ptr = self;
788 1 svc_.post(&rd_);
789 1 svc_.work_finished();
790 }
791 33478 if (wr_claimed)
792 {
793 ✗ wr_.impl_ptr = self;
794 ✗ svc_.post(&wr_);
795 ✗ svc_.work_finished();
796 }
797
798 33478 if (desc_state_.is_enqueued_.load(std::memory_order_acquire))
799 94 desc_state_.impl_ref_ = self;
800 }
801
802 33478 if (fd_ >= 0)
803 {
804 7421 if (desc_state_.registered_events != 0)
805 7421 svc_.scheduler().deregister_descriptor(fd_);
806 7421 ::close(fd_);
807 7421 fd_ = -1;
808 }
809
810 33478 desc_state_.fd = -1;
811 33478 desc_state_.registered_events = 0;
812
813 33478 local_endpoint_ = endpoint{};
814 33478 remote_endpoint_ = endpoint{};
815 33478 }
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 11170 epoll_socket_service::construct()
845 {
846 11170 auto impl = std::make_shared<epoll_socket>(*this);
847 11170 auto* raw = impl.get();
848
849 {
850 11170 std::lock_guard lock(state_->mutex_);
851 11170 state_->socket_list_.push_back(raw);
852 11170 state_->socket_ptrs_.emplace(raw, std::move(impl));
853 11170 }
854
855 11170 return raw;
856 11170 }
857
858 inline void
859 11170 epoll_socket_service::destroy(io_object::implementation* impl)
860 {
861 11170 auto* epoll_impl = static_cast<epoll_socket*>(impl);
862 11170 epoll_impl->close_socket();
863 11170 std::lock_guard lock(state_->mutex_);
864 11170 state_->socket_list_.remove(epoll_impl);
865 11170 state_->socket_ptrs_.erase(epoll_impl);
866 11170 }
867
868 inline std::error_code
869 3717 epoll_socket_service::open_socket(tcp_socket::implementation& impl)
870 {
871 3717 auto* epoll_impl = static_cast<epoll_socket*>(&impl);
872 3717 epoll_impl->close_socket();
873
874 3717 int fd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
875 3717 if (fd < 0)
876 ✗ return make_err(errno);
877
878 3717 epoll_impl->fd_ = fd;
879
880 // Register fd with epoll (edge-triggered mode)
881 3717 epoll_impl->desc_state_.fd = fd;
882 {
883 3717 std::lock_guard lock(epoll_impl->desc_state_.mutex);
884 3717 epoll_impl->desc_state_.read_op = nullptr;
885 3717 epoll_impl->desc_state_.write_op = nullptr;
886 3717 epoll_impl->desc_state_.connect_op = nullptr;
887 3717 }
888 3717 scheduler().register_descriptor(fd, &epoll_impl->desc_state_);
889
890 3717 return {};
891 }
892
893 inline void
894 18591 epoll_socket_service::close(io_object::handle& h)
895 {
896 18591 static_cast<epoll_socket*>(h.get())->close_socket();
897 18591 }
898
899 inline void
900 50542 epoll_socket_service::post(epoll_op* op)
901 {
902 50542 state_->sched_.post(op);
903 50542 }
904
905 inline void
906 3899 epoll_socket_service::work_started() noexcept
907 {
908 3899 state_->sched_.work_started();
909 3899 }
910
911 inline void
912 189 epoll_socket_service::work_finished() noexcept
913 {
914 189 state_->sched_.work_finished();
915 189 }
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