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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 313281 epoll_scheduler& scheduler() const noexcept
130 {
131 313281 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 4860 epoll_socket::register_op(
151 epoll_op& op,
152 epoll_op*& desc_slot,
153 bool& ready_flag,
154 bool& cancel_flag) noexcept
155 {
156 4860 svc_.work_started();
157
158 4860 std::lock_guard lock(desc_state_.mutex);
159 4860 bool io_done = false;
160 4860 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 4860 if (cancel_flag)
170 {
171 95 cancel_flag = false;
172 95 op.cancelled.store(true, std::memory_order_relaxed);
173 }
174
175 4860 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 4765 desc_slot = &op;
183 }
184 4860 }
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 48433 epoll_op::operator()()
221 {
222 48433 stop_cb.reset();
223
224 48433 socket_impl_->svc_.scheduler().reset_inline_budget();
225
226 48433 if (cancelled.load(std::memory_order_acquire))
227 205 *ec_out = capy::error::canceled;
228 48228 else if (errn != 0)
229 ✗ *ec_out = make_err(errn);
230 48228 else if (is_read_operation() && bytes_transferred == 0)
231 ✗ *ec_out = capy::error::eof;
232 else
233 48228 *ec_out = {};
234
235 48433 *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 48433 capy::executor_ref saved_ex(ex);
243 48433 std::coroutine_handle<> saved_h(h);
244 48433 auto prevent_premature_destruction = std::move(impl_ptr);
245 48433 dispatch_coro(saved_ex, saved_h).resume();
246 48433 }
247
248 inline void
249 4659 epoll_connect_op::operator()()
250 {
251 4659 stop_cb.reset();
252
253 4659 socket_impl_->svc_.scheduler().reset_inline_budget();
254
255 4659 bool success = (errn == 0 && !cancelled.load(std::memory_order_acquire));
256
257 // Cache endpoints on successful connect
258 4659 if (success && socket_impl_)
259 {
260 // Query local endpoint via getsockname (may fail, but remote is always known)
261 4658 endpoint local_ep;
262 4658 sockaddr_in local_addr{};
263 4658 socklen_t local_len = sizeof(local_addr);
264 4658 if (::getsockname(
265 4658 fd, reinterpret_cast<sockaddr*>(&local_addr), &local_len) == 0)
266 4658 local_ep = from_sockaddr_in(local_addr);
267 // Always cache remote endpoint; local may be default if getsockname failed
268 4658 static_cast<epoll_socket*>(socket_impl_)
269 4658 ->set_endpoints(local_ep, target_endpoint);
270 }
271
272 4659 if (cancelled.load(std::memory_order_acquire))
273 ✗ *ec_out = capy::error::canceled;
274 4659 else if (errn != 0)
275 1 *ec_out = make_err(errn);
276 else
277 4658 *ec_out = {};
278
279 // Move to stack before resuming. See epoll_op::operator()() for rationale.
280 4659 capy::executor_ref saved_ex(ex);
281 4659 std::coroutine_handle<> saved_h(h);
282 4659 auto prevent_premature_destruction = std::move(impl_ptr);
283 4659 dispatch_coro(saved_ex, saved_h).resume();
284 4659 }
285
286 14031 inline epoll_socket::epoll_socket(epoll_socket_service& svc) noexcept
287 14031 : svc_(svc)
288 {
289 14031 }
290
291 14031 inline epoll_socket::~epoll_socket() = default;
292
293 inline std::coroutine_handle<>
294 4659 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 4659 auto& op = conn_;
302
303 4659 sockaddr_in addr = detail::to_sockaddr_in(ep);
304 int result =
305 4659 ::connect(fd_, reinterpret_cast<sockaddr*>(&addr), sizeof(addr));
306
307 4659 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 4659 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 4659 op.reset();
340 4659 op.h = h;
341 4659 op.ex = ex;
342 4659 op.ec_out = ec;
343 4659 op.fd = fd_;
344 4659 op.target_endpoint = ep;
345 4659 op.start(token, this);
346 4659 op.impl_ptr = shared_from_this();
347
348 4659 register_op(
349 4659 op, desc_state_.connect_op, desc_state_.write_ready,
350 4659 desc_state_.connect_cancel_pending);
351 4659 return std::noop_coroutine();
352 }
353
354 inline std::coroutine_handle<>
355 120968 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 120968 auto& op = rd_;
364 120968 op.reset();
365
366 120968 capy::mutable_buffer bufs[epoll_read_op::max_buffers];
367 120968 op.iovec_count =
368 120968 static_cast<int>(param.copy_to(bufs, epoll_read_op::max_buffers));
369
370 120968 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 241934 for (int i = 0; i < op.iovec_count; ++i)
385 {
386 120967 op.iovecs[i].iov_base = bufs[i].data();
387 120967 op.iovecs[i].iov_len = bufs[i].size();
388 }
389
390 // Speculative read
391 ssize_t n;
392 do
393 {
394 120967 n = ::readv(fd_, op.iovecs, op.iovec_count);
395 }
396 120967 while (n < 0 && errno == EINTR);
397
398 120967 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
399 {
400 120766 int err = (n < 0) ? errno : 0;
401 120766 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
402
403 120766 if (svc_.scheduler().try_consume_inline_budget())
404 {
405 96661 if (err)
406 ✗ *ec = make_err(err);
407 96661 else if (n == 0)
408 5 *ec = capy::error::eof;
409 else
410 96656 *ec = {};
411 96661 *bytes_out = bytes;
412 96661 return dispatch_coro(ex, h);
413 }
414 24105 op.h = h;
415 24105 op.ex = ex;
416 24105 op.ec_out = ec;
417 24105 op.bytes_out = bytes_out;
418 24105 op.start(token, this);
419 24105 op.impl_ptr = shared_from_this();
420 24105 op.complete(err, bytes);
421 24105 svc_.post(&op);
422 24105 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 120768 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 120768 auto& op = wr_;
450 120768 op.reset();
451
452 120768 capy::mutable_buffer bufs[epoll_write_op::max_buffers];
453 120768 op.iovec_count =
454 120768 static_cast<int>(param.copy_to(bufs, epoll_write_op::max_buffers));
455
456 120768 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 241534 for (int i = 0; i < op.iovec_count; ++i)
470 {
471 120767 op.iovecs[i].iov_base = bufs[i].data();
472 120767 op.iovecs[i].iov_len = bufs[i].size();
473 }
474
475 // Speculative write
476 120767 msghdr msg{};
477 120767 msg.msg_iov = op.iovecs;
478 120767 msg.msg_iovlen = static_cast<std::size_t>(op.iovec_count);
479
480 ssize_t n;
481 do
482 {
483 120767 n = ::sendmsg(fd_, &msg, MSG_NOSIGNAL);
484 }
485 120767 while (n < 0 && errno == EINTR);
486
487 120767 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
488 {
489 120767 int err = (n < 0) ? errno : 0;
490 120767 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
491
492 120767 if (svc_.scheduler().try_consume_inline_budget())
493 {
494 96642 *ec = err ? make_err(err) : std::error_code{};
495 96642 *bytes_out = bytes;
496 96642 return dispatch_coro(ex, h);
497 }
498 24125 op.h = h;
499 24125 op.ex = ex;
500 24125 op.ec_out = ec;
501 24125 op.bytes_out = bytes_out;
502 24125 op.start(token, this);
503 24125 op.impl_ptr = shared_from_this();
504 24125 op.complete(err, bytes);
505 24125 svc_.post(&op);
506 24125 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 42060 epoll_socket::close_socket() noexcept
756 {
757 42060 auto self = weak_from_this().lock();
758 42060 if (self)
759 {
760 42060 conn_.request_cancel();
761 42060 rd_.request_cancel();
762 42060 wr_.request_cancel();
763
764 42060 epoll_op* conn_claimed = nullptr;
765 42060 epoll_op* rd_claimed = nullptr;
766 42060 epoll_op* wr_claimed = nullptr;
767 {
768 42060 std::lock_guard lock(desc_state_.mutex);
769 42060 conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
770 42060 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
771 42060 wr_claimed = std::exchange(desc_state_.write_op, nullptr);
772 42060 desc_state_.read_ready = false;
773 42060 desc_state_.write_ready = false;
774 42060 desc_state_.read_cancel_pending = false;
775 42060 desc_state_.write_cancel_pending = false;
776 42060 desc_state_.connect_cancel_pending = false;
777 42060 }
778
779 42060 if (conn_claimed)
780 {
781 ✗ conn_.impl_ptr = self;
782 ✗ svc_.post(&conn_);
783 ✗ svc_.work_finished();
784 }
785 42060 if (rd_claimed)
786 {
787 1 rd_.impl_ptr = self;
788 1 svc_.post(&rd_);
789 1 svc_.work_finished();
790 }
791 42060 if (wr_claimed)
792 {
793 ✗ wr_.impl_ptr = self;
794 ✗ svc_.post(&wr_);
795 ✗ svc_.work_finished();
796 }
797
798 42060 if (desc_state_.is_enqueued_.load(std::memory_order_acquire))
799 94 desc_state_.impl_ref_ = self;
800 }
801
802 42060 if (fd_ >= 0)
803 {
804 9328 if (desc_state_.registered_events != 0)
805 9328 svc_.scheduler().deregister_descriptor(fd_);
806 9328 ::close(fd_);
807 9328 fd_ = -1;
808 }
809
810 42060 desc_state_.fd = -1;
811 42060 desc_state_.registered_events = 0;
812
813 42060 local_endpoint_ = endpoint{};
814 42060 remote_endpoint_ = endpoint{};
815 42060 }
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 14031 epoll_socket_service::construct()
845 {
846 14031 auto impl = std::make_shared<epoll_socket>(*this);
847 14031 auto* raw = impl.get();
848
849 {
850 14031 std::lock_guard lock(state_->mutex_);
851 14031 state_->socket_list_.push_back(raw);
852 14031 state_->socket_ptrs_.emplace(raw, std::move(impl));
853 14031 }
854
855 14031 return raw;
856 14031 }
857
858 inline void
859 14031 epoll_socket_service::destroy(io_object::implementation* impl)
860 {
861 14031 auto* epoll_impl = static_cast<epoll_socket*>(impl);
862 14031 epoll_impl->close_socket();
863 14031 std::lock_guard lock(state_->mutex_);
864 14031 state_->socket_list_.remove(epoll_impl);
865 14031 state_->socket_ptrs_.erase(epoll_impl);
866 14031 }
867
868 inline std::error_code
869 4670 epoll_socket_service::open_socket(tcp_socket::implementation& impl)
870 {
871 4670 auto* epoll_impl = static_cast<epoll_socket*>(&impl);
872 4670 epoll_impl->close_socket();
873
874 4670 int fd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
875 4670 if (fd < 0)
876 ✗ return make_err(errno);
877
878 4670 epoll_impl->fd_ = fd;
879
880 // Register fd with epoll (edge-triggered mode)
881 4670 epoll_impl->desc_state_.fd = fd;
882 {
883 4670 std::lock_guard lock(epoll_impl->desc_state_.mutex);
884 4670 epoll_impl->desc_state_.read_op = nullptr;
885 4670 epoll_impl->desc_state_.write_op = nullptr;
886 4670 epoll_impl->desc_state_.connect_op = nullptr;
887 4670 }
888 4670 scheduler().register_descriptor(fd, &epoll_impl->desc_state_);
889
890 4670 return {};
891 }
892
893 inline void
894 23359 epoll_socket_service::close(io_object::handle& h)
895 {
896 23359 static_cast<epoll_socket*>(h.get())->close_socket();
897 23359 }
898
899 inline void
900 48429 epoll_socket_service::post(epoll_op* op)
901 {
902 48429 state_->sched_.post(op);
903 48429 }
904
905 inline void
906 4860 epoll_socket_service::work_started() noexcept
907 {
908 4860 state_->sched_.work_started();
909 4860 }
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