2 // detail/impl/win_iocp_socket_service_base.ipp
3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5 // Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
11 #ifndef BOOST_ASIO_DETAIL_IMPL_WIN_IOCP_SOCKET_SERVICE_BASE_IPP
12 #define BOOST_ASIO_DETAIL_IMPL_WIN_IOCP_SOCKET_SERVICE_BASE_IPP
14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
18 #include <boost/asio/detail/config.hpp>
20 #if defined(BOOST_ASIO_HAS_IOCP)
22 #include <boost/asio/detail/win_iocp_socket_service_base.hpp>
24 #include <boost/asio/detail/push_options.hpp>
30 win_iocp_socket_service_base::win_iocp_socket_service_base(
31 execution_context& context)
33 iocp_service_(use_service<win_iocp_io_context>(context)),
42 void win_iocp_socket_service_base::base_shutdown()
44 // Close all implementations, causing all operations to complete.
45 boost::asio::detail::mutex::scoped_lock lock(mutex_);
46 base_implementation_type* impl = impl_list_;
49 close_for_destruction(*impl);
54 void win_iocp_socket_service_base::construct(
55 win_iocp_socket_service_base::base_implementation_type& impl)
57 impl.socket_ = invalid_socket;
59 impl.cancel_token_.reset();
60 #if defined(BOOST_ASIO_ENABLE_CANCELIO)
61 impl.safe_cancellation_thread_id_ = 0;
62 #endif // defined(BOOST_ASIO_ENABLE_CANCELIO)
64 // Insert implementation into linked list of all implementations.
65 boost::asio::detail::mutex::scoped_lock lock(mutex_);
66 impl.next_ = impl_list_;
69 impl_list_->prev_ = &impl;
73 void win_iocp_socket_service_base::base_move_construct(
74 win_iocp_socket_service_base::base_implementation_type& impl,
75 win_iocp_socket_service_base::base_implementation_type& other_impl)
78 impl.socket_ = other_impl.socket_;
79 other_impl.socket_ = invalid_socket;
81 impl.state_ = other_impl.state_;
82 other_impl.state_ = 0;
84 impl.cancel_token_ = other_impl.cancel_token_;
85 other_impl.cancel_token_.reset();
87 #if defined(BOOST_ASIO_ENABLE_CANCELIO)
88 impl.safe_cancellation_thread_id_ = other_impl.safe_cancellation_thread_id_;
89 other_impl.safe_cancellation_thread_id_ = 0;
90 #endif // defined(BOOST_ASIO_ENABLE_CANCELIO)
92 // Insert implementation into linked list of all implementations.
93 boost::asio::detail::mutex::scoped_lock lock(mutex_);
94 impl.next_ = impl_list_;
97 impl_list_->prev_ = &impl;
101 void win_iocp_socket_service_base::base_move_assign(
102 win_iocp_socket_service_base::base_implementation_type& impl,
103 win_iocp_socket_service_base& other_service,
104 win_iocp_socket_service_base::base_implementation_type& other_impl)
106 close_for_destruction(impl);
108 if (this != &other_service)
110 // Remove implementation from linked list of all implementations.
111 boost::asio::detail::mutex::scoped_lock lock(mutex_);
112 if (impl_list_ == &impl)
113 impl_list_ = impl.next_;
115 impl.prev_->next_ = impl.next_;
117 impl.next_->prev_= impl.prev_;
122 impl.socket_ = other_impl.socket_;
123 other_impl.socket_ = invalid_socket;
125 impl.state_ = other_impl.state_;
126 other_impl.state_ = 0;
128 impl.cancel_token_ = other_impl.cancel_token_;
129 other_impl.cancel_token_.reset();
131 #if defined(BOOST_ASIO_ENABLE_CANCELIO)
132 impl.safe_cancellation_thread_id_ = other_impl.safe_cancellation_thread_id_;
133 other_impl.safe_cancellation_thread_id_ = 0;
134 #endif // defined(BOOST_ASIO_ENABLE_CANCELIO)
136 if (this != &other_service)
138 // Insert implementation into linked list of all implementations.
139 boost::asio::detail::mutex::scoped_lock lock(other_service.mutex_);
140 impl.next_ = other_service.impl_list_;
142 if (other_service.impl_list_)
143 other_service.impl_list_->prev_ = &impl;
144 other_service.impl_list_ = &impl;
148 void win_iocp_socket_service_base::destroy(
149 win_iocp_socket_service_base::base_implementation_type& impl)
151 close_for_destruction(impl);
153 // Remove implementation from linked list of all implementations.
154 boost::asio::detail::mutex::scoped_lock lock(mutex_);
155 if (impl_list_ == &impl)
156 impl_list_ = impl.next_;
158 impl.prev_->next_ = impl.next_;
160 impl.next_->prev_= impl.prev_;
165 boost::system::error_code win_iocp_socket_service_base::close(
166 win_iocp_socket_service_base::base_implementation_type& impl,
167 boost::system::error_code& ec)
171 BOOST_ASIO_HANDLER_OPERATION((iocp_service_.context(),
172 "socket", &impl, impl.socket_, "close"));
174 // Check if the reactor was created, in which case we need to close the
175 // socket on the reactor as well to cancel any operations that might be
177 select_reactor* r = static_cast<select_reactor*>(
178 interlocked_compare_exchange_pointer(
179 reinterpret_cast<void**>(&reactor_), 0, 0));
181 r->deregister_descriptor(impl.socket_, impl.reactor_data_, true);
183 socket_ops::close(impl.socket_, impl.state_, false, ec);
186 r->cleanup_descriptor_data(impl.reactor_data_);
190 ec = boost::system::error_code();
193 impl.socket_ = invalid_socket;
195 impl.cancel_token_.reset();
196 #if defined(BOOST_ASIO_ENABLE_CANCELIO)
197 impl.safe_cancellation_thread_id_ = 0;
198 #endif // defined(BOOST_ASIO_ENABLE_CANCELIO)
203 socket_type win_iocp_socket_service_base::release(
204 win_iocp_socket_service_base::base_implementation_type& impl,
205 boost::system::error_code& ec)
208 return invalid_socket;
212 return invalid_socket;
214 nt_set_info_fn fn = get_nt_set_info();
217 ec = boost::asio::error::operation_not_supported;
218 return invalid_socket;
221 HANDLE sock_as_handle = reinterpret_cast<HANDLE>(impl.socket_);
222 ULONG_PTR iosb[2] = { 0, 0 };
223 void* info[2] = { 0, 0 };
224 if (fn(sock_as_handle, iosb, &info, sizeof(info),
225 61 /* FileReplaceCompletionInformation */))
227 ec = boost::asio::error::operation_not_supported;
228 return invalid_socket;
231 socket_type tmp = impl.socket_;
232 impl.socket_ = invalid_socket;
236 boost::system::error_code win_iocp_socket_service_base::cancel(
237 win_iocp_socket_service_base::base_implementation_type& impl,
238 boost::system::error_code& ec)
242 ec = boost::asio::error::bad_descriptor;
246 BOOST_ASIO_HANDLER_OPERATION((iocp_service_.context(),
247 "socket", &impl, impl.socket_, "cancel"));
249 if (FARPROC cancel_io_ex_ptr = ::GetProcAddress(
250 ::GetModuleHandleA("KERNEL32"), "CancelIoEx"))
252 // The version of Windows supports cancellation from any thread.
253 typedef BOOL (WINAPI* cancel_io_ex_t)(HANDLE, LPOVERLAPPED);
254 cancel_io_ex_t cancel_io_ex = reinterpret_cast<cancel_io_ex_t>(
255 reinterpret_cast<void*>(cancel_io_ex_ptr));
256 socket_type sock = impl.socket_;
257 HANDLE sock_as_handle = reinterpret_cast<HANDLE>(sock);
258 if (!cancel_io_ex(sock_as_handle, 0))
260 DWORD last_error = ::GetLastError();
261 if (last_error == ERROR_NOT_FOUND)
263 // ERROR_NOT_FOUND means that there were no operations to be
264 // cancelled. We swallow this error to match the behaviour on other
266 ec = boost::system::error_code();
270 ec = boost::system::error_code(last_error,
271 boost::asio::error::get_system_category());
276 ec = boost::system::error_code();
279 #if defined(BOOST_ASIO_ENABLE_CANCELIO)
280 else if (impl.safe_cancellation_thread_id_ == 0)
282 // No operations have been started, so there's nothing to cancel.
283 ec = boost::system::error_code();
285 else if (impl.safe_cancellation_thread_id_ == ::GetCurrentThreadId())
287 // Asynchronous operations have been started from the current thread only,
288 // so it is safe to try to cancel them using CancelIo.
289 socket_type sock = impl.socket_;
290 HANDLE sock_as_handle = reinterpret_cast<HANDLE>(sock);
291 if (!::CancelIo(sock_as_handle))
293 DWORD last_error = ::GetLastError();
294 ec = boost::system::error_code(last_error,
295 boost::asio::error::get_system_category());
299 ec = boost::system::error_code();
304 // Asynchronous operations have been started from more than one thread,
305 // so cancellation is not safe.
306 ec = boost::asio::error::operation_not_supported;
308 #else // defined(BOOST_ASIO_ENABLE_CANCELIO)
311 // Cancellation is not supported as CancelIo may not be used.
312 ec = boost::asio::error::operation_not_supported;
314 #endif // defined(BOOST_ASIO_ENABLE_CANCELIO)
316 // Cancel any operations started via the reactor.
319 select_reactor* r = static_cast<select_reactor*>(
320 interlocked_compare_exchange_pointer(
321 reinterpret_cast<void**>(&reactor_), 0, 0));
323 r->cancel_ops(impl.socket_, impl.reactor_data_);
329 boost::system::error_code win_iocp_socket_service_base::do_open(
330 win_iocp_socket_service_base::base_implementation_type& impl,
331 int family, int type, int protocol, boost::system::error_code& ec)
335 ec = boost::asio::error::already_open;
339 socket_holder sock(socket_ops::socket(family, type, protocol, ec));
340 if (sock.get() == invalid_socket)
343 HANDLE sock_as_handle = reinterpret_cast<HANDLE>(sock.get());
344 if (iocp_service_.register_handle(sock_as_handle, ec))
347 impl.socket_ = sock.release();
350 case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
351 case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
352 default: impl.state_ = 0; break;
354 impl.cancel_token_.reset(static_cast<void*>(0), socket_ops::noop_deleter());
355 ec = boost::system::error_code();
359 boost::system::error_code win_iocp_socket_service_base::do_assign(
360 win_iocp_socket_service_base::base_implementation_type& impl,
361 int type, socket_type native_socket, boost::system::error_code& ec)
365 ec = boost::asio::error::already_open;
369 HANDLE sock_as_handle = reinterpret_cast<HANDLE>(native_socket);
370 if (iocp_service_.register_handle(sock_as_handle, ec))
373 impl.socket_ = native_socket;
376 case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
377 case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
378 default: impl.state_ = 0; break;
380 impl.cancel_token_.reset(static_cast<void*>(0), socket_ops::noop_deleter());
381 ec = boost::system::error_code();
385 void win_iocp_socket_service_base::start_send_op(
386 win_iocp_socket_service_base::base_implementation_type& impl,
387 WSABUF* buffers, std::size_t buffer_count,
388 socket_base::message_flags flags, bool noop, operation* op)
390 update_cancellation_thread_id(impl);
391 iocp_service_.work_started();
394 iocp_service_.on_completion(op);
395 else if (!is_open(impl))
396 iocp_service_.on_completion(op, boost::asio::error::bad_descriptor);
399 DWORD bytes_transferred = 0;
400 int result = ::WSASend(impl.socket_, buffers,
401 static_cast<DWORD>(buffer_count), &bytes_transferred, flags, op, 0);
402 DWORD last_error = ::WSAGetLastError();
403 if (last_error == ERROR_PORT_UNREACHABLE)
404 last_error = WSAECONNREFUSED;
405 if (result != 0 && last_error != WSA_IO_PENDING)
406 iocp_service_.on_completion(op, last_error, bytes_transferred);
408 iocp_service_.on_pending(op);
412 void win_iocp_socket_service_base::start_send_to_op(
413 win_iocp_socket_service_base::base_implementation_type& impl,
414 WSABUF* buffers, std::size_t buffer_count,
415 const socket_addr_type* addr, int addrlen,
416 socket_base::message_flags flags, operation* op)
418 update_cancellation_thread_id(impl);
419 iocp_service_.work_started();
422 iocp_service_.on_completion(op, boost::asio::error::bad_descriptor);
425 DWORD bytes_transferred = 0;
426 int result = ::WSASendTo(impl.socket_, buffers,
427 static_cast<DWORD>(buffer_count),
428 &bytes_transferred, flags, addr, addrlen, op, 0);
429 DWORD last_error = ::WSAGetLastError();
430 if (last_error == ERROR_PORT_UNREACHABLE)
431 last_error = WSAECONNREFUSED;
432 if (result != 0 && last_error != WSA_IO_PENDING)
433 iocp_service_.on_completion(op, last_error, bytes_transferred);
435 iocp_service_.on_pending(op);
439 void win_iocp_socket_service_base::start_receive_op(
440 win_iocp_socket_service_base::base_implementation_type& impl,
441 WSABUF* buffers, std::size_t buffer_count,
442 socket_base::message_flags flags, bool noop, operation* op)
444 update_cancellation_thread_id(impl);
445 iocp_service_.work_started();
448 iocp_service_.on_completion(op);
449 else if (!is_open(impl))
450 iocp_service_.on_completion(op, boost::asio::error::bad_descriptor);
453 DWORD bytes_transferred = 0;
454 DWORD recv_flags = flags;
455 int result = ::WSARecv(impl.socket_, buffers,
456 static_cast<DWORD>(buffer_count),
457 &bytes_transferred, &recv_flags, op, 0);
458 DWORD last_error = ::WSAGetLastError();
459 if (last_error == ERROR_NETNAME_DELETED)
460 last_error = WSAECONNRESET;
461 else if (last_error == ERROR_PORT_UNREACHABLE)
462 last_error = WSAECONNREFUSED;
463 if (result != 0 && last_error != WSA_IO_PENDING)
464 iocp_service_.on_completion(op, last_error, bytes_transferred);
466 iocp_service_.on_pending(op);
470 int win_iocp_socket_service_base::start_null_buffers_receive_op(
471 win_iocp_socket_service_base::base_implementation_type& impl,
472 socket_base::message_flags flags, reactor_op* op, operation* iocp_op)
474 if ((impl.state_ & socket_ops::stream_oriented) != 0)
476 // For stream sockets on Windows, we may issue a 0-byte overlapped
477 // WSARecv to wait until there is data available on the socket.
478 ::WSABUF buf = { 0, 0 };
479 start_receive_op(impl, &buf, 1, flags, false, iocp_op);
484 int op_type = (flags & socket_base::message_out_of_band)
485 ? select_reactor::except_op : select_reactor::read_op;
486 start_reactor_op(impl, op_type, op);
491 void win_iocp_socket_service_base::start_receive_from_op(
492 win_iocp_socket_service_base::base_implementation_type& impl,
493 WSABUF* buffers, std::size_t buffer_count, socket_addr_type* addr,
494 socket_base::message_flags flags, int* addrlen, operation* op)
496 update_cancellation_thread_id(impl);
497 iocp_service_.work_started();
500 iocp_service_.on_completion(op, boost::asio::error::bad_descriptor);
503 DWORD bytes_transferred = 0;
504 DWORD recv_flags = flags;
505 int result = ::WSARecvFrom(impl.socket_, buffers,
506 static_cast<DWORD>(buffer_count),
507 &bytes_transferred, &recv_flags, addr, addrlen, op, 0);
508 DWORD last_error = ::WSAGetLastError();
509 if (last_error == ERROR_PORT_UNREACHABLE)
510 last_error = WSAECONNREFUSED;
511 if (result != 0 && last_error != WSA_IO_PENDING)
512 iocp_service_.on_completion(op, last_error, bytes_transferred);
514 iocp_service_.on_pending(op);
518 void win_iocp_socket_service_base::start_accept_op(
519 win_iocp_socket_service_base::base_implementation_type& impl,
520 bool peer_is_open, socket_holder& new_socket, int family, int type,
521 int protocol, void* output_buffer, DWORD address_length, operation* op)
523 update_cancellation_thread_id(impl);
524 iocp_service_.work_started();
527 iocp_service_.on_completion(op, boost::asio::error::bad_descriptor);
528 else if (peer_is_open)
529 iocp_service_.on_completion(op, boost::asio::error::already_open);
532 boost::system::error_code ec;
533 new_socket.reset(socket_ops::socket(family, type, protocol, ec));
534 if (new_socket.get() == invalid_socket)
535 iocp_service_.on_completion(op, ec);
538 DWORD bytes_read = 0;
539 BOOL result = ::AcceptEx(impl.socket_, new_socket.get(), output_buffer,
540 0, address_length, address_length, &bytes_read, op);
541 DWORD last_error = ::WSAGetLastError();
542 if (!result && last_error != WSA_IO_PENDING)
543 iocp_service_.on_completion(op, last_error);
545 iocp_service_.on_pending(op);
550 void win_iocp_socket_service_base::restart_accept_op(
551 socket_type s, socket_holder& new_socket, int family, int type,
552 int protocol, void* output_buffer, DWORD address_length,
553 long* cancel_requested, operation* op)
556 iocp_service_.work_started();
558 // Check if we were cancelled after the first AcceptEx completed.
559 if (cancel_requested)
560 if (::InterlockedExchangeAdd(cancel_requested, 0) == 1)
561 iocp_service_.on_completion(op, boost::asio::error::operation_aborted);
563 boost::system::error_code ec;
564 new_socket.reset(socket_ops::socket(family, type, protocol, ec));
565 if (new_socket.get() == invalid_socket)
566 iocp_service_.on_completion(op, ec);
569 DWORD bytes_read = 0;
570 BOOL result = ::AcceptEx(s, new_socket.get(), output_buffer,
571 0, address_length, address_length, &bytes_read, op);
572 DWORD last_error = ::WSAGetLastError();
573 if (!result && last_error != WSA_IO_PENDING)
574 iocp_service_.on_completion(op, last_error);
577 #if defined(_WIN32_WINNT) && (_WIN32_WINNT >= 0x0600)
578 if (cancel_requested)
580 if (::InterlockedExchangeAdd(cancel_requested, 0) == 1)
582 HANDLE sock_as_handle = reinterpret_cast<HANDLE>(s);
583 ::CancelIoEx(sock_as_handle, op);
586 #endif // defined(_WIN32_WINNT) && (_WIN32_WINNT >= 0x0600)
587 iocp_service_.on_pending(op);
592 void win_iocp_socket_service_base::start_reactor_op(
593 win_iocp_socket_service_base::base_implementation_type& impl,
594 int op_type, reactor_op* op)
596 select_reactor& r = get_reactor();
597 update_cancellation_thread_id(impl);
601 r.start_op(op_type, impl.socket_, impl.reactor_data_, op, false, false);
605 op->ec_ = boost::asio::error::bad_descriptor;
607 iocp_service_.post_immediate_completion(op, false);
610 int win_iocp_socket_service_base::start_connect_op(
611 win_iocp_socket_service_base::base_implementation_type& impl,
612 int family, int type, const socket_addr_type* addr, std::size_t addrlen,
613 win_iocp_socket_connect_op_base* op, operation* iocp_op)
615 // If ConnectEx is available, use that.
616 if (family == BOOST_ASIO_OS_DEF(AF_INET)
617 || family == BOOST_ASIO_OS_DEF(AF_INET6))
619 if (connect_ex_fn connect_ex = get_connect_ex(impl, type))
623 socket_addr_type base;
624 sockaddr_in4_type v4;
625 sockaddr_in6_type v6;
628 using namespace std; // For memset.
629 memset(&a, 0, sizeof(a));
630 a.base.sa_family = family;
632 socket_ops::bind(impl.socket_, &a.base,
633 family == BOOST_ASIO_OS_DEF(AF_INET)
634 ? sizeof(a.v4) : sizeof(a.v6), op->ec_);
635 if (op->ec_ && op->ec_ != boost::asio::error::invalid_argument)
637 iocp_service_.post_immediate_completion(op, false);
641 op->connect_ex_ = true;
642 update_cancellation_thread_id(impl);
643 iocp_service_.work_started();
645 BOOL result = connect_ex(impl.socket_,
646 addr, static_cast<int>(addrlen), 0, 0, 0, iocp_op);
647 DWORD last_error = ::WSAGetLastError();
648 if (!result && last_error != WSA_IO_PENDING)
649 iocp_service_.on_completion(iocp_op, last_error);
651 iocp_service_.on_pending(iocp_op);
656 // Otherwise, fall back to a reactor-based implementation.
657 select_reactor& r = get_reactor();
658 update_cancellation_thread_id(impl);
660 if ((impl.state_ & socket_ops::non_blocking) != 0
661 || socket_ops::set_internal_non_blocking(
662 impl.socket_, impl.state_, true, op->ec_))
664 if (socket_ops::connect(impl.socket_, addr, addrlen, op->ec_) != 0)
666 if (op->ec_ == boost::asio::error::in_progress
667 || op->ec_ == boost::asio::error::would_block)
669 op->ec_ = boost::system::error_code();
670 r.start_op(select_reactor::connect_op, impl.socket_,
671 impl.reactor_data_, op, false, false);
672 return select_reactor::connect_op;
677 r.post_immediate_completion(op, false);
681 void win_iocp_socket_service_base::close_for_destruction(
682 win_iocp_socket_service_base::base_implementation_type& impl)
686 BOOST_ASIO_HANDLER_OPERATION((iocp_service_.context(),
687 "socket", &impl, impl.socket_, "close"));
689 // Check if the reactor was created, in which case we need to close the
690 // socket on the reactor as well to cancel any operations that might be
692 select_reactor* r = static_cast<select_reactor*>(
693 interlocked_compare_exchange_pointer(
694 reinterpret_cast<void**>(&reactor_), 0, 0));
696 r->deregister_descriptor(impl.socket_, impl.reactor_data_, true);
698 boost::system::error_code ignored_ec;
699 socket_ops::close(impl.socket_, impl.state_, true, ignored_ec);
702 r->cleanup_descriptor_data(impl.reactor_data_);
705 impl.socket_ = invalid_socket;
707 impl.cancel_token_.reset();
708 #if defined(BOOST_ASIO_ENABLE_CANCELIO)
709 impl.safe_cancellation_thread_id_ = 0;
710 #endif // defined(BOOST_ASIO_ENABLE_CANCELIO)
713 void win_iocp_socket_service_base::update_cancellation_thread_id(
714 win_iocp_socket_service_base::base_implementation_type& impl)
716 #if defined(BOOST_ASIO_ENABLE_CANCELIO)
717 if (impl.safe_cancellation_thread_id_ == 0)
718 impl.safe_cancellation_thread_id_ = ::GetCurrentThreadId();
719 else if (impl.safe_cancellation_thread_id_ != ::GetCurrentThreadId())
720 impl.safe_cancellation_thread_id_ = ~DWORD(0);
721 #else // defined(BOOST_ASIO_ENABLE_CANCELIO)
723 #endif // defined(BOOST_ASIO_ENABLE_CANCELIO)
726 select_reactor& win_iocp_socket_service_base::get_reactor()
728 select_reactor* r = static_cast<select_reactor*>(
729 interlocked_compare_exchange_pointer(
730 reinterpret_cast<void**>(&reactor_), 0, 0));
733 r = &(use_service<select_reactor>(context_));
734 interlocked_exchange_pointer(reinterpret_cast<void**>(&reactor_), r);
739 win_iocp_socket_service_base::connect_ex_fn
740 win_iocp_socket_service_base::get_connect_ex(
741 win_iocp_socket_service_base::base_implementation_type& impl, int type)
743 #if defined(BOOST_ASIO_DISABLE_CONNECTEX)
747 #else // defined(BOOST_ASIO_DISABLE_CONNECTEX)
748 if (type != BOOST_ASIO_OS_DEF(SOCK_STREAM)
749 && type != BOOST_ASIO_OS_DEF(SOCK_SEQPACKET))
752 void* ptr = interlocked_compare_exchange_pointer(&connect_ex_, 0, 0);
755 GUID guid = { 0x25a207b9, 0xddf3, 0x4660,
756 { 0x8e, 0xe9, 0x76, 0xe5, 0x8c, 0x74, 0x06, 0x3e } };
759 if (::WSAIoctl(impl.socket_, SIO_GET_EXTENSION_FUNCTION_POINTER,
760 &guid, sizeof(guid), &ptr, sizeof(ptr), &bytes, 0, 0) != 0)
762 // Set connect_ex_ to a special value to indicate that ConnectEx is
763 // unavailable. That way we won't bother trying to look it up again.
767 interlocked_exchange_pointer(&connect_ex_, ptr);
770 return reinterpret_cast<connect_ex_fn>(ptr == this ? 0 : ptr);
771 #endif // defined(BOOST_ASIO_DISABLE_CONNECTEX)
774 win_iocp_socket_service_base::nt_set_info_fn
775 win_iocp_socket_service_base::get_nt_set_info()
777 void* ptr = interlocked_compare_exchange_pointer(&nt_set_info_, 0, 0);
780 if (HMODULE h = ::GetModuleHandleA("NTDLL.DLL"))
781 ptr = reinterpret_cast<void*>(GetProcAddress(h, "NtSetInformationFile"));
783 // On failure, set nt_set_info_ to a special value to indicate that the
784 // NtSetInformationFile function is unavailable. That way we won't bother
785 // trying to look it up again.
786 interlocked_exchange_pointer(&nt_set_info_, ptr ? ptr : this);
789 return reinterpret_cast<nt_set_info_fn>(ptr == this ? 0 : ptr);
792 void* win_iocp_socket_service_base::interlocked_compare_exchange_pointer(
793 void** dest, void* exch, void* cmp)
796 return reinterpret_cast<void*>(InterlockedCompareExchange(
797 reinterpret_cast<PLONG>(dest), reinterpret_cast<LONG>(exch),
798 reinterpret_cast<LONG>(cmp)));
800 return InterlockedCompareExchangePointer(dest, exch, cmp);
804 void* win_iocp_socket_service_base::interlocked_exchange_pointer(
805 void** dest, void* val)
808 return reinterpret_cast<void*>(InterlockedExchange(
809 reinterpret_cast<PLONG>(dest), reinterpret_cast<LONG>(val)));
811 return InterlockedExchangePointer(dest, val);
815 } // namespace detail
819 #include <boost/asio/detail/pop_options.hpp>
821 #endif // defined(BOOST_ASIO_HAS_IOCP)
823 #endif // BOOST_ASIO_DETAIL_IMPL_WIN_IOCP_SOCKET_SERVICE_BASE_IPP