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 302799 epoll_scheduler& scheduler() const noexcept
130 {
131 302799 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 5182 epoll_socket::register_op(
151 epoll_op& op,
152 epoll_op*& desc_slot,
153 bool& ready_flag,
154 bool& cancel_flag) noexcept
155 {
156 5182 svc_.work_started();
157
158 5182 std::lock_guard lock(desc_state_.mutex);
159 5182 bool io_done = false;
160 5182 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 5182 if (cancel_flag)
170 {
171 95 cancel_flag = false;
172 95 op.cancelled.store(true, std::memory_order_relaxed);
173 }
174
175 5182 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 5087 desc_slot = &op;
183 }
184 5182 }
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 46419 epoll_op::operator()()
221 {
222 46419 stop_cb.reset();
223
224 46419 socket_impl_->svc_.scheduler().reset_inline_budget();
225
226 46419 if (cancelled.load(std::memory_order_acquire))
227 205 *ec_out = capy::error::canceled;
228 46214 else if (errn != 0)
229 ✗ *ec_out = make_err(errn);
230 46214 else if (is_read_operation() && bytes_transferred == 0)
231 ✗ *ec_out = capy::error::eof;
232 else
233 46214 *ec_out = {};
234
235 46419 *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 46419 capy::executor_ref saved_ex(ex);
243 46419 std::coroutine_handle<> saved_h(h);
244 46419 auto prevent_premature_destruction = std::move(impl_ptr);
245 46419 dispatch_coro(saved_ex, saved_h).resume();
246 46419 }
247
248 inline void
249 4981 epoll_connect_op::operator()()
250 {
251 4981 stop_cb.reset();
252
253 4981 socket_impl_->svc_.scheduler().reset_inline_budget();
254
255 4981 bool success = (errn == 0 && !cancelled.load(std::memory_order_acquire));
256
257 // Cache endpoints on successful connect
258 4981 if (success && socket_impl_)
259 {
260 // Query local endpoint via getsockname (may fail, but remote is always known)
261 4979 endpoint local_ep;
262 4979 sockaddr_in local_addr{};
263 4979 socklen_t local_len = sizeof(local_addr);
264 4979 if (::getsockname(
265 4979 fd, reinterpret_cast<sockaddr*>(&local_addr), &local_len) == 0)
266 4979 local_ep = from_sockaddr_in(local_addr);
267 // Always cache remote endpoint; local may be default if getsockname failed
268 4979 static_cast<epoll_socket*>(socket_impl_)
269 4979 ->set_endpoints(local_ep, target_endpoint);
270 }
271
272 4981 if (cancelled.load(std::memory_order_acquire))
273 ✗ *ec_out = capy::error::canceled;
274 4981 else if (errn != 0)
275 2 *ec_out = make_err(errn);
276 else
277 4979 *ec_out = {};
278
279 // Move to stack before resuming. See epoll_op::operator()() for rationale.
280 4981 capy::executor_ref saved_ex(ex);
281 4981 std::coroutine_handle<> saved_h(h);
282 4981 auto prevent_premature_destruction = std::move(impl_ptr);
283 4981 dispatch_coro(saved_ex, saved_h).resume();
284 4981 }
285
286 14995 inline epoll_socket::epoll_socket(epoll_socket_service& svc) noexcept
287 14995 : svc_(svc)
288 {
289 14995 }
290
291 14995 inline epoll_socket::~epoll_socket() = default;
292
293 inline std::coroutine_handle<>
294 4981 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 4981 auto& op = conn_;
302
303 4981 sockaddr_in addr = detail::to_sockaddr_in(ep);
304 int result =
305 4981 ::connect(fd_, reinterpret_cast<sockaddr*>(&addr), sizeof(addr));
306
307 4981 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 4981 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 4981 op.reset();
340 4981 op.h = h;
341 4981 op.ex = ex;
342 4981 op.ec_out = ec;
343 4981 op.fd = fd_;
344 4981 op.target_endpoint = ep;
345 4981 op.start(token, this);
346 4981 op.impl_ptr = shared_from_this();
347
348 4981 register_op(
349 4981 op, desc_state_.connect_op, desc_state_.write_ready,
350 4981 desc_state_.connect_cancel_pending);
351 4981 return std::noop_coroutine();
352 }
353
354 inline std::coroutine_handle<>
355 115930 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 115930 auto& op = rd_;
364 115930 op.reset();
365
366 115930 capy::mutable_buffer bufs[epoll_read_op::max_buffers];
367 115930 op.iovec_count =
368 115930 static_cast<int>(param.copy_to(bufs, epoll_read_op::max_buffers));
369
370 115930 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 231858 for (int i = 0; i < op.iovec_count; ++i)
385 {
386 115929 op.iovecs[i].iov_base = bufs[i].data();
387 115929 op.iovecs[i].iov_len = bufs[i].size();
388 }
389
390 // Speculative read
391 ssize_t n;
392 do
393 {
394 115929 n = ::readv(fd_, op.iovecs, op.iovec_count);
395 }
396 115929 while (n < 0 && errno == EINTR);
397
398 115929 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
399 {
400 115728 int err = (n < 0) ? errno : 0;
401 115728 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
402
403 115728 if (svc_.scheduler().try_consume_inline_budget())
404 {
405 92629 if (err)
406 ✗ *ec = make_err(err);
407 92629 else if (n == 0)
408 5 *ec = capy::error::eof;
409 else
410 92624 *ec = {};
411 92629 *bytes_out = bytes;
412 92629 return dispatch_coro(ex, h);
413 }
414 23099 op.h = h;
415 23099 op.ex = ex;
416 23099 op.ec_out = ec;
417 23099 op.bytes_out = bytes_out;
418 23099 op.start(token, this);
419 23099 op.impl_ptr = shared_from_this();
420 23099 op.complete(err, bytes);
421 23099 svc_.post(&op);
422 23099 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 115730 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 115730 auto& op = wr_;
450 115730 op.reset();
451
452 115730 capy::mutable_buffer bufs[epoll_write_op::max_buffers];
453 115730 op.iovec_count =
454 115730 static_cast<int>(param.copy_to(bufs, epoll_write_op::max_buffers));
455
456 115730 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 231458 for (int i = 0; i < op.iovec_count; ++i)
470 {
471 115729 op.iovecs[i].iov_base = bufs[i].data();
472 115729 op.iovecs[i].iov_len = bufs[i].size();
473 }
474
475 // Speculative write
476 115729 msghdr msg{};
477 115729 msg.msg_iov = op.iovecs;
478 115729 msg.msg_iovlen = static_cast<std::size_t>(op.iovec_count);
479
480 ssize_t n;
481 do
482 {
483 115729 n = ::sendmsg(fd_, &msg, MSG_NOSIGNAL);
484 }
485 115729 while (n < 0 && errno == EINTR);
486
487 115729 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
488 {
489 115729 int err = (n < 0) ? errno : 0;
490 115729 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
491
492 115729 if (svc_.scheduler().try_consume_inline_budget())
493 {
494 92612 *ec = err ? make_err(err) : std::error_code{};
495 92612 *bytes_out = bytes;
496 92612 return dispatch_coro(ex, h);
497 }
498 23117 op.h = h;
499 23117 op.ex = ex;
500 23117 op.ec_out = ec;
501 23117 op.bytes_out = bytes_out;
502 23117 op.start(token, this);
503 23117 op.impl_ptr = shared_from_this();
504 23117 op.complete(err, bytes);
505 23117 svc_.post(&op);
506 23117 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 44953 epoll_socket::close_socket() noexcept
756 {
757 44953 auto self = weak_from_this().lock();
758 44953 if (self)
759 {
760 44953 conn_.request_cancel();
761 44953 rd_.request_cancel();
762 44953 wr_.request_cancel();
763
764 44953 epoll_op* conn_claimed = nullptr;
765 44953 epoll_op* rd_claimed = nullptr;
766 44953 epoll_op* wr_claimed = nullptr;
767 {
768 44953 std::lock_guard lock(desc_state_.mutex);
769 44953 conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
770 44953 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
771 44953 wr_claimed = std::exchange(desc_state_.write_op, nullptr);
772 44953 desc_state_.read_ready = false;
773 44953 desc_state_.write_ready = false;
774 44953 desc_state_.read_cancel_pending = false;
775 44953 desc_state_.write_cancel_pending = false;
776 44953 desc_state_.connect_cancel_pending = false;
777 44953 }
778
779 44953 if (conn_claimed)
780 {
781 ✗ conn_.impl_ptr = self;
782 ✗ svc_.post(&conn_);
783 ✗ svc_.work_finished();
784 }
785 44953 if (rd_claimed)
786 {
787 1 rd_.impl_ptr = self;
788 1 svc_.post(&rd_);
789 1 svc_.work_finished();
790 }
791 44953 if (wr_claimed)
792 {
793 ✗ wr_.impl_ptr = self;
794 ✗ svc_.post(&wr_);
795 ✗ svc_.work_finished();
796 }
797
798 44953 if (desc_state_.is_enqueued_.load(std::memory_order_acquire))
799 94 desc_state_.impl_ref_ = self;
800 }
801
802 44953 if (fd_ >= 0)
803 {
804 9971 if (desc_state_.registered_events != 0)
805 9971 svc_.scheduler().deregister_descriptor(fd_);
806 9971 ::close(fd_);
807 9971 fd_ = -1;
808 }
809
810 44953 desc_state_.fd = -1;
811 44953 desc_state_.registered_events = 0;
812
813 44953 local_endpoint_ = endpoint{};
814 44953 remote_endpoint_ = endpoint{};
815 44953 }
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 14995 epoll_socket_service::construct()
845 {
846 14995 auto impl = std::make_shared<epoll_socket>(*this);
847 14995 auto* raw = impl.get();
848
849 {
850 14995 std::lock_guard lock(state_->mutex_);
851 14995 state_->socket_list_.push_back(raw);
852 14995 state_->socket_ptrs_.emplace(raw, std::move(impl));
853 14995 }
854
855 14995 return raw;
856 14995 }
857
858 inline void
859 14995 epoll_socket_service::destroy(io_object::implementation* impl)
860 {
861 14995 auto* epoll_impl = static_cast<epoll_socket*>(impl);
862 14995 epoll_impl->close_socket();
863 14995 std::lock_guard lock(state_->mutex_);
864 14995 state_->socket_list_.remove(epoll_impl);
865 14995 state_->socket_ptrs_.erase(epoll_impl);
866 14995 }
867
868 inline std::error_code
869 4992 epoll_socket_service::open_socket(tcp_socket::implementation& impl)
870 {
871 4992 auto* epoll_impl = static_cast<epoll_socket*>(&impl);
872 4992 epoll_impl->close_socket();
873
874 4992 int fd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
875 4992 if (fd < 0)
876 ✗ return make_err(errno);
877
878 4992 epoll_impl->fd_ = fd;
879
880 // Register fd with epoll (edge-triggered mode)
881 4992 epoll_impl->desc_state_.fd = fd;
882 {
883 4992 std::lock_guard lock(epoll_impl->desc_state_.mutex);
884 4992 epoll_impl->desc_state_.read_op = nullptr;
885 4992 epoll_impl->desc_state_.write_op = nullptr;
886 4992 epoll_impl->desc_state_.connect_op = nullptr;
887 4992 }
888 4992 scheduler().register_descriptor(fd, &epoll_impl->desc_state_);
889
890 4992 return {};
891 }
892
893 inline void
894 24966 epoll_socket_service::close(io_object::handle& h)
895 {
896 24966 static_cast<epoll_socket*>(h.get())->close_socket();
897 24966 }
898
899 inline void
900 46415 epoll_socket_service::post(epoll_op* op)
901 {
902 46415 state_->sched_.post(op);
903 46415 }
904
905 inline void
906 5182 epoll_socket_service::work_started() noexcept
907 {
908 5182 state_->sched_.work_started();
909 5182 }
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