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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 359355 epoll_scheduler& scheduler() const noexcept
130 {
131 359355 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 4935 epoll_socket::register_op(
151 epoll_op& op,
152 epoll_op*& desc_slot,
153 bool& ready_flag,
154 bool& cancel_flag) noexcept
155 {
156 4935 svc_.work_started();
157
158 4935 std::lock_guard lock(desc_state_.mutex);
159 4935 bool io_done = false;
160 4935 if (ready_flag)
161 {
162 142 ready_flag = false;
163 142 op.perform_io();
164 142 io_done = (op.errn != EAGAIN && op.errn != EWOULDBLOCK);
165 142 if (!io_done)
166 142 op.errn = 0;
167 }
168
169 4935 if (cancel_flag)
170 {
171 95 cancel_flag = false;
172 95 op.cancelled.store(true, std::memory_order_relaxed);
173 }
174
175 4935 if (io_done || op.cancelled.load(std::memory_order_acquire))
176 {
177 95 svc_.post(&op);
178 95 svc_.work_finished();
179 }
180 else
181 {
182 4840 desc_slot = &op;
183 }
184 4935 }
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 56050 epoll_op::operator()()
221 {
222 56050 stop_cb.reset();
223
224 56050 socket_impl_->svc_.scheduler().reset_inline_budget();
225
226 56050 if (cancelled.load(std::memory_order_acquire))
227 205 *ec_out = capy::error::canceled;
228 55845 else if (errn != 0)
229 ✗ *ec_out = make_err(errn);
230 55845 else if (is_read_operation() && bytes_transferred == 0)
231 ✗ *ec_out = capy::error::eof;
232 else
233 55845 *ec_out = {};
234
235 56050 *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 56050 capy::executor_ref saved_ex(ex);
243 56050 std::coroutine_handle<> saved_h(h);
244 56050 auto prevent_premature_destruction = std::move(impl_ptr);
245 56050 dispatch_coro(saved_ex, saved_h).resume();
246 56050 }
247
248 inline void
249 4734 epoll_connect_op::operator()()
250 {
251 4734 stop_cb.reset();
252
253 4734 socket_impl_->svc_.scheduler().reset_inline_budget();
254
255 4734 bool success = (errn == 0 && !cancelled.load(std::memory_order_acquire));
256
257 // Cache endpoints on successful connect
258 4734 if (success && socket_impl_)
259 {
260 // Query local endpoint via getsockname (may fail, but remote is always known)
261 4732 endpoint local_ep;
262 4732 sockaddr_in local_addr{};
263 4732 socklen_t local_len = sizeof(local_addr);
264 4732 if (::getsockname(
265 4732 fd, reinterpret_cast<sockaddr*>(&local_addr), &local_len) == 0)
266 4732 local_ep = from_sockaddr_in(local_addr);
267 // Always cache remote endpoint; local may be default if getsockname failed
268 4732 static_cast<epoll_socket*>(socket_impl_)
269 4732 ->set_endpoints(local_ep, target_endpoint);
270 }
271
272 4734 if (cancelled.load(std::memory_order_acquire))
273 ✗ *ec_out = capy::error::canceled;
274 4734 else if (errn != 0)
275 2 *ec_out = make_err(errn);
276 else
277 4732 *ec_out = {};
278
279 // Move to stack before resuming. See epoll_op::operator()() for rationale.
280 4734 capy::executor_ref saved_ex(ex);
281 4734 std::coroutine_handle<> saved_h(h);
282 4734 auto prevent_premature_destruction = std::move(impl_ptr);
283 4734 dispatch_coro(saved_ex, saved_h).resume();
284 4734 }
285
286 14254 inline epoll_socket::epoll_socket(epoll_socket_service& svc) noexcept
287 14254 : svc_(svc)
288 {
289 14254 }
290
291 14254 inline epoll_socket::~epoll_socket() = default;
292
293 inline std::coroutine_handle<>
294 4734 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 4734 auto& op = conn_;
302
303 4734 sockaddr_in addr = detail::to_sockaddr_in(ep);
304 int result =
305 4734 ::connect(fd_, reinterpret_cast<sockaddr*>(&addr), sizeof(addr));
306
307 4734 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 4734 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 4734 op.reset();
340 4734 op.h = h;
341 4734 op.ex = ex;
342 4734 op.ec_out = ec;
343 4734 op.fd = fd_;
344 4734 op.target_endpoint = ep;
345 4734 op.start(token, this);
346 4734 op.impl_ptr = shared_from_this();
347
348 4734 register_op(
349 4734 op, desc_state_.connect_op, desc_state_.write_ready,
350 4734 desc_state_.connect_cancel_pending);
351 4734 return std::noop_coroutine();
352 }
353
354 inline std::coroutine_handle<>
355 140010 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 140010 auto& op = rd_;
364 140010 op.reset();
365
366 140010 capy::mutable_buffer bufs[epoll_read_op::max_buffers];
367 140010 op.iovec_count =
368 140010 static_cast<int>(param.copy_to(bufs, epoll_read_op::max_buffers));
369
370 140010 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 280018 for (int i = 0; i < op.iovec_count; ++i)
385 {
386 140009 op.iovecs[i].iov_base = bufs[i].data();
387 140009 op.iovecs[i].iov_len = bufs[i].size();
388 }
389
390 // Speculative read
391 ssize_t n;
392 do
393 {
394 140009 n = ::readv(fd_, op.iovecs, op.iovec_count);
395 }
396 140009 while (n < 0 && errno == EINTR);
397
398 140009 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
399 {
400 139808 int err = (n < 0) ? errno : 0;
401 139808 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
402
403 139808 if (svc_.scheduler().try_consume_inline_budget())
404 {
405 111894 if (err)
406 ✗ *ec = make_err(err);
407 111894 else if (n == 0)
408 5 *ec = capy::error::eof;
409 else
410 111889 *ec = {};
411 111894 *bytes_out = bytes;
412 111894 return dispatch_coro(ex, h);
413 }
414 27914 op.h = h;
415 27914 op.ex = ex;
416 27914 op.ec_out = ec;
417 27914 op.bytes_out = bytes_out;
418 27914 op.start(token, this);
419 27914 op.impl_ptr = shared_from_this();
420 27914 op.complete(err, bytes);
421 27914 svc_.post(&op);
422 27914 return std::noop_coroutine();
423 }
424
425 // EAGAIN — register with reactor
426 201 op.h = h;
427 201 op.ex = ex;
428 201 op.ec_out = ec;
429 201 op.bytes_out = bytes_out;
430 201 op.fd = fd_;
431 201 op.start(token, this);
432 201 op.impl_ptr = shared_from_this();
433
434 201 register_op(
435 201 op, desc_state_.read_op, desc_state_.read_ready,
436 201 desc_state_.read_cancel_pending);
437 201 return std::noop_coroutine();
438 }
439
440 inline std::coroutine_handle<>
441 139810 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 139810 auto& op = wr_;
450 139810 op.reset();
451
452 139810 capy::mutable_buffer bufs[epoll_write_op::max_buffers];
453 139810 op.iovec_count =
454 139810 static_cast<int>(param.copy_to(bufs, epoll_write_op::max_buffers));
455
456 139810 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 279618 for (int i = 0; i < op.iovec_count; ++i)
470 {
471 139809 op.iovecs[i].iov_base = bufs[i].data();
472 139809 op.iovecs[i].iov_len = bufs[i].size();
473 }
474
475 // Speculative write
476 139809 msghdr msg{};
477 139809 msg.msg_iov = op.iovecs;
478 139809 msg.msg_iovlen = static_cast<std::size_t>(op.iovec_count);
479
480 ssize_t n;
481 do
482 {
483 139809 n = ::sendmsg(fd_, &msg, MSG_NOSIGNAL);
484 }
485 139809 while (n < 0 && errno == EINTR);
486
487 139809 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
488 {
489 139809 int err = (n < 0) ? errno : 0;
490 139809 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
491
492 139809 if (svc_.scheduler().try_consume_inline_budget())
493 {
494 111876 *ec = err ? make_err(err) : std::error_code{};
495 111876 *bytes_out = bytes;
496 111876 return dispatch_coro(ex, h);
497 }
498 27933 op.h = h;
499 27933 op.ex = ex;
500 27933 op.ec_out = ec;
501 27933 op.bytes_out = bytes_out;
502 27933 op.start(token, this);
503 27933 op.impl_ptr = shared_from_this();
504 27933 op.complete(err, bytes);
505 27933 svc_.post(&op);
506 27933 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
665 187 epoll_socket::cancel() noexcept
666 {
667 187 auto self = weak_from_this().lock();
668 187 if (!self)
669 ✗ return;
670
671 187 conn_.request_cancel();
672 187 rd_.request_cancel();
673 187 wr_.request_cancel();
674
675 187 epoll_op* conn_claimed = nullptr;
676 187 epoll_op* rd_claimed = nullptr;
677 187 epoll_op* wr_claimed = nullptr;
678 {
679 187 std::lock_guard lock(desc_state_.mutex);
680 187 if (desc_state_.connect_op == &conn_)
681 ✗ conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
682 else
683 187 desc_state_.connect_cancel_pending = true;
684 187 if (desc_state_.read_op == &rd_)
685 3 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
686 else
687 184 desc_state_.read_cancel_pending = true;
688 187 if (desc_state_.write_op == &wr_)
689 ✗ wr_claimed = std::exchange(desc_state_.write_op, nullptr);
690 else
691 187 desc_state_.write_cancel_pending = true;
692 187 }
693
694 187 if (conn_claimed)
695 {
696 ✗ conn_.impl_ptr = self;
697 ✗ svc_.post(&conn_);
698 ✗ svc_.work_finished();
699 }
700 187 if (rd_claimed)
701 {
702 3 rd_.impl_ptr = self;
703 3 svc_.post(&rd_);
704 3 svc_.work_finished();
705 }
706 187 if (wr_claimed)
707 {
708 ✗ wr_.impl_ptr = self;
709 ✗ svc_.post(&wr_);
710 ✗ svc_.work_finished();
711 }
712 187 }
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 42730 epoll_socket::close_socket() noexcept
756 {
757 42730 auto self = weak_from_this().lock();
758 42730 if (self)
759 {
760 42730 conn_.request_cancel();
761 42730 rd_.request_cancel();
762 42730 wr_.request_cancel();
763
764 42730 epoll_op* conn_claimed = nullptr;
765 42730 epoll_op* rd_claimed = nullptr;
766 42730 epoll_op* wr_claimed = nullptr;
767 {
768 42730 std::lock_guard lock(desc_state_.mutex);
769 42730 conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
770 42730 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
771 42730 wr_claimed = std::exchange(desc_state_.write_op, nullptr);
772 42730 desc_state_.read_ready = false;
773 42730 desc_state_.write_ready = false;
774 42730 desc_state_.read_cancel_pending = false;
775 42730 desc_state_.write_cancel_pending = false;
776 42730 desc_state_.connect_cancel_pending = false;
777 42730 }
778
779 42730 if (conn_claimed)
780 {
781 ✗ conn_.impl_ptr = self;
782 ✗ svc_.post(&conn_);
783 ✗ svc_.work_finished();
784 }
785 42730 if (rd_claimed)
786 {
787 1 rd_.impl_ptr = self;
788 1 svc_.post(&rd_);
789 1 svc_.work_finished();
790 }
791 42730 if (wr_claimed)
792 {
793 ✗ wr_.impl_ptr = self;
794 ✗ svc_.post(&wr_);
795 ✗ svc_.work_finished();
796 }
797
798 42730 if (desc_state_.is_enqueued_.load(std::memory_order_acquire))
799 94 desc_state_.impl_ref_ = self;
800 }
801
802 42730 if (fd_ >= 0)
803 {
804 9477 if (desc_state_.registered_events != 0)
805 9477 svc_.scheduler().deregister_descriptor(fd_);
806 9477 ::close(fd_);
807 9477 fd_ = -1;
808 }
809
810 42730 desc_state_.fd = -1;
811 42730 desc_state_.registered_events = 0;
812
813 42730 local_endpoint_ = endpoint{};
814 42730 remote_endpoint_ = endpoint{};
815 42730 }
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 14254 epoll_socket_service::construct()
845 {
846 14254 auto impl = std::make_shared<epoll_socket>(*this);
847 14254 auto* raw = impl.get();
848
849 {
850 14254 std::lock_guard lock(state_->mutex_);
851 14254 state_->socket_list_.push_back(raw);
852 14254 state_->socket_ptrs_.emplace(raw, std::move(impl));
853 14254 }
854
855 14254 return raw;
856 14254 }
857
858 inline void
859 14254 epoll_socket_service::destroy(io_object::implementation* impl)
860 {
861 14254 auto* epoll_impl = static_cast<epoll_socket*>(impl);
862 14254 epoll_impl->close_socket();
863 14254 std::lock_guard lock(state_->mutex_);
864 14254 state_->socket_list_.remove(epoll_impl);
865 14254 state_->socket_ptrs_.erase(epoll_impl);
866 14254 }
867
868 inline std::error_code
869 4745 epoll_socket_service::open_socket(tcp_socket::implementation& impl)
870 {
871 4745 auto* epoll_impl = static_cast<epoll_socket*>(&impl);
872 4745 epoll_impl->close_socket();
873
874 4745 int fd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
875 4745 if (fd < 0)
876 ✗ return make_err(errno);
877
878 4745 epoll_impl->fd_ = fd;
879
880 // Register fd with epoll (edge-triggered mode)
881 4745 epoll_impl->desc_state_.fd = fd;
882 {
883 4745 std::lock_guard lock(epoll_impl->desc_state_.mutex);
884 4745 epoll_impl->desc_state_.read_op = nullptr;
885 4745 epoll_impl->desc_state_.write_op = nullptr;
886 4745 epoll_impl->desc_state_.connect_op = nullptr;
887 4745 }
888 4745 scheduler().register_descriptor(fd, &epoll_impl->desc_state_);
889
890 4745 return {};
891 }
892
893 inline void
894 23731 epoll_socket_service::close(io_object::handle& h)
895 {
896 23731 static_cast<epoll_socket*>(h.get())->close_socket();
897 23731 }
898
899 inline void
900 56046 epoll_socket_service::post(epoll_op* op)
901 {
902 56046 state_->sched_.post(op);
903 56046 }
904
905 inline void
906 4935 epoll_socket_service::work_started() noexcept
907 {
908 4935 state_->sched_.work_started();
909 4935 }
910
911 inline void
912 197 epoll_socket_service::work_finished() noexcept
913 {
914 197 state_->sched_.work_finished();
915 197 }
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