Index/include / boost / corosio / native / detail / epoll / epoll_socket_service.hpp

include/boost/corosio/native/detail/epoll/epoll_socket_service.hpp

80.3% Lines (375/467) 94.7% Functions (36/38)
include/boost/corosio/native/detail/epoll/epoll_socket_service.hpp
Prev Index Next
Line Hits Source Code
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 301218 epoll_scheduler& scheduler() const noexcept
130 {
131 301218 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 2366 epoll_socket::register_op(
151 epoll_op& op,
152 epoll_op*& desc_slot,
153 bool& ready_flag,
154 bool& cancel_flag) noexcept
155 {
156 2366 svc_.work_started();
157
158 2366 std::lock_guard lock(desc_state_.mutex);
159 2366 bool io_done = false;
160 2366 if (ready_flag)
161 {
162 135 ready_flag = false;
163 135 op.perform_io();
164 135 io_done = (op.errn != EAGAIN && op.errn != EWOULDBLOCK);
165 135 if (!io_done)
166 135 op.errn = 0;
167 }
168
169 2366 if (cancel_flag)
170 {
171 88 cancel_flag = false;
172 88 op.cancelled.store(true, std::memory_order_relaxed);
173 }
174
175 2366 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 2278 desc_slot = &op;
183 }
184 2366 }
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 48495 epoll_op::operator()()
221 {
222 48495 stop_cb.reset();
223
224 48495 socket_impl_->svc_.scheduler().reset_inline_budget();
225
226 48495 if (cancelled.load(std::memory_order_acquire))
227 198 *ec_out = capy::error::canceled;
228 48297 else if (errn != 0)
229 ✗ *ec_out = make_err(errn);
230 48297 else if (is_read_operation() && bytes_transferred == 0)
231 ✗ *ec_out = capy::error::eof;
232 else
233 48297 *ec_out = {};
234
235 48495 *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 48495 capy::executor_ref saved_ex(ex);
243 48495 std::coroutine_handle<> saved_h(h);
244 48495 auto prevent_premature_destruction = std::move(impl_ptr);
245 48495 dispatch_coro(saved_ex, saved_h).resume();
246 48495 }
247
248 inline void
249 2172 epoll_connect_op::operator()()
250 {
251 2172 stop_cb.reset();
252
253 2172 socket_impl_->svc_.scheduler().reset_inline_budget();
254
255 2172 bool success = (errn == 0 && !cancelled.load(std::memory_order_acquire));
256
257 // Cache endpoints on successful connect
258 2172 if (success && socket_impl_)
259 {
260 // Query local endpoint via getsockname (may fail, but remote is always known)
261 2170 endpoint local_ep;
262 2170 sockaddr_in local_addr{};
263 2170 socklen_t local_len = sizeof(local_addr);
264 2170 if (::getsockname(
265 2170 fd, reinterpret_cast<sockaddr*>(&local_addr), &local_len) == 0)
266 2170 local_ep = from_sockaddr_in(local_addr);
267 // Always cache remote endpoint; local may be default if getsockname failed
268 2170 static_cast<epoll_socket*>(socket_impl_)
269 2170 ->set_endpoints(local_ep, target_endpoint);
270 }
271
272 2172 if (cancelled.load(std::memory_order_acquire))
273 ✗ *ec_out = capy::error::canceled;
274 2172 else if (errn != 0)
275 2 *ec_out = make_err(errn);
276 else
277 2170 *ec_out = {};
278
279 // Move to stack before resuming. See epoll_op::operator()() for rationale.
280 2172 capy::executor_ref saved_ex(ex);
281 2172 std::coroutine_handle<> saved_h(h);
282 2172 auto prevent_premature_destruction = std::move(impl_ptr);
283 2172 dispatch_coro(saved_ex, saved_h).resume();
284 2172 }
285
286 6568 inline epoll_socket::epoll_socket(epoll_socket_service& svc) noexcept
287 6568 : svc_(svc)
288 {
289 6568 }
290
291 6568 inline epoll_socket::~epoll_socket() = default;
292
293 inline std::coroutine_handle<>
294 2172 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 2172 auto& op = conn_;
302
303 2172 sockaddr_in addr = detail::to_sockaddr_in(ep);
304 int result =
305 2172 ::connect(fd_, reinterpret_cast<sockaddr*>(&addr), sizeof(addr));
306
307 2172 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 2172 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 2172 op.reset();
340 2172 op.h = h;
341 2172 op.ex = ex;
342 2172 op.ec_out = ec;
343 2172 op.fd = fd_;
344 2172 op.target_endpoint = ep;
345 2172 op.start(token, this);
346 2172 op.impl_ptr = shared_from_this();
347
348 2172 register_op(
349 2172 op, desc_state_.connect_op, desc_state_.write_ready,
350 2172 desc_state_.connect_cancel_pending);
351 2172 return std::noop_coroutine();
352 }
353
354 inline std::coroutine_handle<>
355 121117 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 121117 auto& op = rd_;
364 121117 op.reset();
365
366 121117 capy::mutable_buffer bufs[epoll_read_op::max_buffers];
367 121117 op.iovec_count =
368 121117 static_cast<int>(param.copy_to(bufs, epoll_read_op::max_buffers));
369
370 121117 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 242232 for (int i = 0; i < op.iovec_count; ++i)
385 {
386 121116 op.iovecs[i].iov_base = bufs[i].data();
387 121116 op.iovecs[i].iov_len = bufs[i].size();
388 }
389
390 // Speculative read
391 ssize_t n;
392 do
393 {
394 121116 n = ::readv(fd_, op.iovecs, op.iovec_count);
395 }
396 121116 while (n < 0 && errno == EINTR);
397
398 121116 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
399 {
400 120922 int err = (n < 0) ? errno : 0;
401 120922 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
402
403 120922 if (svc_.scheduler().try_consume_inline_budget())
404 {
405 96782 if (err)
406 ✗ *ec = make_err(err);
407 96782 else if (n == 0)
408 5 *ec = capy::error::eof;
409 else
410 96777 *ec = {};
411 96782 *bytes_out = bytes;
412 96782 return dispatch_coro(ex, h);
413 }
414 24140 op.h = h;
415 24140 op.ex = ex;
416 24140 op.ec_out = ec;
417 24140 op.bytes_out = bytes_out;
418 24140 op.start(token, this);
419 24140 op.impl_ptr = shared_from_this();
420 24140 op.complete(err, bytes);
421 24140 svc_.post(&op);
422 24140 return std::noop_coroutine();
423 }
424
425 // EAGAIN — register with reactor
426 194 op.h = h;
427 194 op.ex = ex;
428 194 op.ec_out = ec;
429 194 op.bytes_out = bytes_out;
430 194 op.fd = fd_;
431 194 op.start(token, this);
432 194 op.impl_ptr = shared_from_this();
433
434 194 register_op(
435 194 op, desc_state_.read_op, desc_state_.read_ready,
436 194 desc_state_.read_cancel_pending);
437 194 return std::noop_coroutine();
438 }
439
440 inline std::coroutine_handle<>
441 120924 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 120924 auto& op = wr_;
450 120924 op.reset();
451
452 120924 capy::mutable_buffer bufs[epoll_write_op::max_buffers];
453 120924 op.iovec_count =
454 120924 static_cast<int>(param.copy_to(bufs, epoll_write_op::max_buffers));
455
456 120924 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 241846 for (int i = 0; i < op.iovec_count; ++i)
470 {
471 120923 op.iovecs[i].iov_base = bufs[i].data();
472 120923 op.iovecs[i].iov_len = bufs[i].size();
473 }
474
475 // Speculative write
476 120923 msghdr msg{};
477 120923 msg.msg_iov = op.iovecs;
478 120923 msg.msg_iovlen = static_cast<std::size_t>(op.iovec_count);
479
480 ssize_t n;
481 do
482 {
483 120923 n = ::sendmsg(fd_, &msg, MSG_NOSIGNAL);
484 }
485 120923 while (n < 0 && errno == EINTR);
486
487 120923 if (n >= 0 || (errno != EAGAIN && errno != EWOULDBLOCK))
488 {
489 120923 int err = (n < 0) ? errno : 0;
490 120923 auto bytes = (n > 0) ? static_cast<std::size_t>(n) : std::size_t(0);
491
492 120923 if (svc_.scheduler().try_consume_inline_budget())
493 {
494 96764 *ec = err ? make_err(err) : std::error_code{};
495 96764 *bytes_out = bytes;
496 96764 return dispatch_coro(ex, h);
497 }
498 24159 op.h = h;
499 24159 op.ex = ex;
500 24159 op.ec_out = ec;
501 24159 op.bytes_out = bytes_out;
502 24159 op.start(token, this);
503 24159 op.impl_ptr = shared_from_this();
504 24159 op.complete(err, bytes);
505 24159 svc_.post(&op);
506 24159 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 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 19672 epoll_socket::close_socket() noexcept
756 {
757 19672 auto self = weak_from_this().lock();
758 19672 if (self)
759 {
760 19672 conn_.request_cancel();
761 19672 rd_.request_cancel();
762 19672 wr_.request_cancel();
763
764 19672 epoll_op* conn_claimed = nullptr;
765 19672 epoll_op* rd_claimed = nullptr;
766 19672 epoll_op* wr_claimed = nullptr;
767 {
768 19672 std::lock_guard lock(desc_state_.mutex);
769 19672 conn_claimed = std::exchange(desc_state_.connect_op, nullptr);
770 19672 rd_claimed = std::exchange(desc_state_.read_op, nullptr);
771 19672 wr_claimed = std::exchange(desc_state_.write_op, nullptr);
772 19672 desc_state_.read_ready = false;
773 19672 desc_state_.write_ready = false;
774 19672 desc_state_.read_cancel_pending = false;
775 19672 desc_state_.write_cancel_pending = false;
776 19672 desc_state_.connect_cancel_pending = false;
777 19672 }
778
779 19672 if (conn_claimed)
780 {
781 ✗ conn_.impl_ptr = self;
782 ✗ svc_.post(&conn_);
783 ✗ svc_.work_finished();
784 }
785 19672 if (rd_claimed)
786 {
787 1 rd_.impl_ptr = self;
788 1 svc_.post(&rd_);
789 1 svc_.work_finished();
790 }
791 19672 if (wr_claimed)
792 {
793 ✗ wr_.impl_ptr = self;
794 ✗ svc_.post(&wr_);
795 ✗ svc_.work_finished();
796 }
797
798 19672 if (desc_state_.is_enqueued_.load(std::memory_order_acquire))
799 94 desc_state_.impl_ref_ = self;
800 }
801
802 19672 if (fd_ >= 0)
803 {
804 4353 if (desc_state_.registered_events != 0)
805 4353 svc_.scheduler().deregister_descriptor(fd_);
806 4353 ::close(fd_);
807 4353 fd_ = -1;
808 }
809
810 19672 desc_state_.fd = -1;
811 19672 desc_state_.registered_events = 0;
812
813 19672 local_endpoint_ = endpoint{};
814 19672 remote_endpoint_ = endpoint{};
815 19672 }
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 6568 epoll_socket_service::construct()
845 {
846 6568 auto impl = std::make_shared<epoll_socket>(*this);
847 6568 auto* raw = impl.get();
848
849 {
850 6568 std::lock_guard lock(state_->mutex_);
851 6568 state_->socket_list_.push_back(raw);
852 6568 state_->socket_ptrs_.emplace(raw, std::move(impl));
853 6568 }
854
855 6568 return raw;
856 6568 }
857
858 inline void
859 6568 epoll_socket_service::destroy(io_object::implementation* impl)
860 {
861 6568 auto* epoll_impl = static_cast<epoll_socket*>(impl);
862 6568 epoll_impl->close_socket();
863 6568 std::lock_guard lock(state_->mutex_);
864 6568 state_->socket_list_.remove(epoll_impl);
865 6568 state_->socket_ptrs_.erase(epoll_impl);
866 6568 }
867
868 inline std::error_code
869 2183 epoll_socket_service::open_socket(tcp_socket::implementation& impl)
870 {
871 2183 auto* epoll_impl = static_cast<epoll_socket*>(&impl);
872 2183 epoll_impl->close_socket();
873
874 2183 int fd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
875 2183 if (fd < 0)
876 ✗ return make_err(errno);
877
878 2183 epoll_impl->fd_ = fd;
879
880 // Register fd with epoll (edge-triggered mode)
881 2183 epoll_impl->desc_state_.fd = fd;
882 {
883 2183 std::lock_guard lock(epoll_impl->desc_state_.mutex);
884 2183 epoll_impl->desc_state_.read_op = nullptr;
885 2183 epoll_impl->desc_state_.write_op = nullptr;
886 2183 epoll_impl->desc_state_.connect_op = nullptr;
887 2183 }
888 2183 scheduler().register_descriptor(fd, &epoll_impl->desc_state_);
889
890 2183 return {};
891 }
892
893 inline void
894 10921 epoll_socket_service::close(io_object::handle& h)
895 {
896 10921 static_cast<epoll_socket*>(h.get())->close_socket();
897 10921 }
898
899 inline void
900 48491 epoll_socket_service::post(epoll_op* op)
901 {
902 48491 state_->sched_.post(op);
903 48491 }
904
905 inline void
906 2366 epoll_socket_service::work_started() noexcept
907 {
908 2366 state_->sched_.work_started();
909 2366 }
910
911 inline void
912 190 epoll_socket_service::work_finished() noexcept
913 {
914 190 state_->sched_.work_finished();
915 190 }
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