1   
//
1   
//
2   
// Copyright (c) 2026 Steve Gerbino
2   
// Copyright (c) 2026 Steve Gerbino
3   
//
3   
//
4   
// Distributed under the Boost Software License, Version 1.0. (See accompanying
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)
5   
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6   
//
6   
//
7   
// Official repository: https://github.com/cppalliance/corosio
7   
// Official repository: https://github.com/cppalliance/corosio
8   
//
8   
//
9  
9  
10   
#ifndef BOOST_COROSIO_NATIVE_DETAIL_SELECT_SELECT_TCP_SERVICE_HPP
10   
#ifndef BOOST_COROSIO_NATIVE_DETAIL_SELECT_SELECT_TCP_SERVICE_HPP
11   
#define BOOST_COROSIO_NATIVE_DETAIL_SELECT_SELECT_TCP_SERVICE_HPP
11   
#define BOOST_COROSIO_NATIVE_DETAIL_SELECT_SELECT_TCP_SERVICE_HPP
12  
12  
13   
#include <boost/corosio/detail/platform.hpp>
13   
#include <boost/corosio/detail/platform.hpp>
14  
14  
15   
#if BOOST_COROSIO_HAS_SELECT
15   
#if BOOST_COROSIO_HAS_SELECT
16  
16  
17   
#include <boost/corosio/detail/config.hpp>
17   
#include <boost/corosio/detail/config.hpp>
18   
#include <boost/corosio/detail/tcp_service.hpp>
18   
#include <boost/corosio/detail/tcp_service.hpp>
19  
19  
20   
#include <boost/corosio/native/detail/select/select_tcp_socket.hpp>
20   
#include <boost/corosio/native/detail/select/select_tcp_socket.hpp>
21   
#include <boost/corosio/native/detail/select/select_scheduler.hpp>
21   
#include <boost/corosio/native/detail/select/select_scheduler.hpp>
22   
#include <boost/corosio/native/detail/reactor/reactor_socket_service.hpp>
22   
#include <boost/corosio/native/detail/reactor/reactor_socket_service.hpp>
23  
23  
24   
#include <boost/corosio/native/detail/reactor/reactor_op_complete.hpp>
24   
#include <boost/corosio/native/detail/reactor/reactor_op_complete.hpp>
25  
25  
26   
#include <coroutine>
26   
#include <coroutine>
27   
#include <mutex>
27   
#include <mutex>
28  
28  
29   
#include <errno.h>
29   
#include <errno.h>
30   
#include <fcntl.h>
30   
#include <fcntl.h>
31   
#include <netinet/in.h>
31   
#include <netinet/in.h>
32   
#include <netinet/tcp.h>
32   
#include <netinet/tcp.h>
33   
#include <sys/select.h>
33   
#include <sys/select.h>
34   
#include <sys/socket.h>
34   
#include <sys/socket.h>
35   
#include <unistd.h>
35   
#include <unistd.h>
36  
36  
37   
/*
37   
/*
38   
    Each I/O op tries the syscall speculatively; only registers with
38   
    Each I/O op tries the syscall speculatively; only registers with
39   
    the reactor on EAGAIN. Fd is registered once at open time and
39   
    the reactor on EAGAIN. Fd is registered once at open time and
40   
    stays registered until close. The reactor only marks ready_events_;
40   
    stays registered until close. The reactor only marks ready_events_;
41   
    actual I/O happens in invoke_deferred_io(). cancel() captures
41   
    actual I/O happens in invoke_deferred_io(). cancel() captures
42   
    shared_from_this() into op.impl_ptr to keep the impl alive.
42   
    shared_from_this() into op.impl_ptr to keep the impl alive.
43   
*/
43   
*/
44  
44  
45   
namespace boost::corosio::detail {
45   
namespace boost::corosio::detail {
46  
46  
47   
/** select TCP service implementation.
47   
/** select TCP service implementation.
48  
48  
49   
    Inherits from tcp_service to enable runtime polymorphism.
49   
    Inherits from tcp_service to enable runtime polymorphism.
50   
    Uses key_type = tcp_service for service lookup.
50   
    Uses key_type = tcp_service for service lookup.
51   
*/
51   
*/
52   
class BOOST_COROSIO_DECL select_tcp_service final
52   
class BOOST_COROSIO_DECL select_tcp_service final
53   
    : public reactor_socket_service<
53   
    : public reactor_socket_service<
54   
          select_tcp_service,
54   
          select_tcp_service,
55   
          tcp_service,
55   
          tcp_service,
56   
          select_scheduler,
56   
          select_scheduler,
57   
          select_tcp_socket>
57   
          select_tcp_socket>
58   
{
58   
{
59   
public:
59   
public:
60   
    explicit select_tcp_service(capy::execution_context& ctx)
60   
    explicit select_tcp_service(capy::execution_context& ctx)
61   
        : reactor_socket_service(ctx)
61   
        : reactor_socket_service(ctx)
62   
    {
62   
    {
63   
    }
63   
    }
64  
64  
65   
    std::error_code open_socket(
65   
    std::error_code open_socket(
66   
        tcp_socket::implementation& impl,
66   
        tcp_socket::implementation& impl,
67   
        int family,
67   
        int family,
68   
        int type,
68   
        int type,
69   
        int protocol) override;
69   
        int protocol) override;
70   
};
70   
};
71  
71  
72   
inline void
72   
inline void
73   
select_connect_op::cancel() noexcept
73   
select_connect_op::cancel() noexcept
74   
{
74   
{
75   
    if (socket_impl_)
75   
    if (socket_impl_)
76   
        socket_impl_->cancel_single_op(*this);
76   
        socket_impl_->cancel_single_op(*this);
77   
    else
77   
    else
78   
        request_cancel();
78   
        request_cancel();
79   
}
79   
}
80  
80  
81   
inline void
81   
inline void
82   
select_read_op::cancel() noexcept
82   
select_read_op::cancel() noexcept
83   
{
83   
{
84   
    if (socket_impl_)
84   
    if (socket_impl_)
85   
        socket_impl_->cancel_single_op(*this);
85   
        socket_impl_->cancel_single_op(*this);
86   
    else
86   
    else
87   
        request_cancel();
87   
        request_cancel();
88   
}
88   
}
89  
89  
90   
inline void
90   
inline void
91   
select_write_op::cancel() noexcept
91   
select_write_op::cancel() noexcept
92   
{
92   
{
93   
    if (socket_impl_)
93   
    if (socket_impl_)
94   
        socket_impl_->cancel_single_op(*this);
94   
        socket_impl_->cancel_single_op(*this);
95   
    else
95   
    else
96   
        request_cancel();
96   
        request_cancel();
97   
}
97   
}
98  
98  
99   
inline void
99   
inline void
100   
select_op::operator()()
100   
select_op::operator()()
101   
{
101   
{
102   
    complete_io_op(*this);
102   
    complete_io_op(*this);
103   
}
103   
}
104  
104  
105   
inline void
105   
inline void
106   
select_connect_op::operator()()
106   
select_connect_op::operator()()
107   
{
107   
{
108   
    complete_connect_op(*this);
108   
    complete_connect_op(*this);
109   
}
109   
}
110  
110  
111   
inline select_tcp_socket::select_tcp_socket(select_tcp_service& svc) noexcept
111   
inline select_tcp_socket::select_tcp_socket(select_tcp_service& svc) noexcept
112   
    : reactor_stream_socket(svc)
112   
    : reactor_stream_socket(svc)
113   
{
113   
{
114   
}
114   
}
115  
115  
116   
inline select_tcp_socket::~select_tcp_socket() = default;
116   
inline select_tcp_socket::~select_tcp_socket() = default;
117  
117  
118   
inline std::coroutine_handle<>
118   
inline std::coroutine_handle<>
119   
select_tcp_socket::connect(
119   
select_tcp_socket::connect(
120   
    std::coroutine_handle<> h,
120   
    std::coroutine_handle<> h,
121   
    capy::executor_ref ex,
121   
    capy::executor_ref ex,
122   
    endpoint ep,
122   
    endpoint ep,
123   
    std::stop_token token,
123   
    std::stop_token token,
124   
    std::error_code* ec)
124   
    std::error_code* ec)
125   
{
125   
{
126   
    auto result = do_connect(h, ex, ep, token, ec);
126   
    auto result = do_connect(h, ex, ep, token, ec);
127   
    // Rebuild fd_sets so select() watches for writability
127   
    // Rebuild fd_sets so select() watches for writability
128   
    if (result == std::noop_coroutine())
128   
    if (result == std::noop_coroutine())
129   
        svc_.scheduler().notify_reactor();
129   
        svc_.scheduler().notify_reactor();
130   
    return result;
130   
    return result;
131   
}
131   
}
132  
132  
133   
inline std::coroutine_handle<>
133   
inline std::coroutine_handle<>
134   
select_tcp_socket::read_some(
134   
select_tcp_socket::read_some(
135   
    std::coroutine_handle<> h,
135   
    std::coroutine_handle<> h,
136   
    capy::executor_ref ex,
136   
    capy::executor_ref ex,
137   
    buffer_param param,
137   
    buffer_param param,
138   
    std::stop_token token,
138   
    std::stop_token token,
139   
    std::error_code* ec,
139   
    std::error_code* ec,
140   
    std::size_t* bytes_out)
140   
    std::size_t* bytes_out)
141   
{
141   
{
142   
    return do_read_some(h, ex, param, token, ec, bytes_out);
142   
    return do_read_some(h, ex, param, token, ec, bytes_out);
143   
}
143   
}
144  
144  
145   
inline std::coroutine_handle<>
145   
inline std::coroutine_handle<>
146   
select_tcp_socket::write_some(
146   
select_tcp_socket::write_some(
147   
    std::coroutine_handle<> h,
147   
    std::coroutine_handle<> h,
148   
    capy::executor_ref ex,
148   
    capy::executor_ref ex,
149   
    buffer_param param,
149   
    buffer_param param,
150   
    std::stop_token token,
150   
    std::stop_token token,
151   
    std::error_code* ec,
151   
    std::error_code* ec,
152   
    std::size_t* bytes_out)
152   
    std::size_t* bytes_out)
153   
{
153   
{
154   
    auto result = do_write_some(h, ex, param, token, ec, bytes_out);
154   
    auto result = do_write_some(h, ex, param, token, ec, bytes_out);
155   
    // Rebuild fd_sets so select() watches for writability
155   
    // Rebuild fd_sets so select() watches for writability
156   
    if (result == std::noop_coroutine())
156   
    if (result == std::noop_coroutine())
157   
        svc_.scheduler().notify_reactor();
157   
        svc_.scheduler().notify_reactor();
158   
    return result;
158   
    return result;
159   
}
159   
}
160  
160  
161   
inline void
161   
inline void
162   
select_tcp_socket::cancel() noexcept
162   
select_tcp_socket::cancel() noexcept
163   
{
163   
{
164   
    do_cancel();
164   
    do_cancel();
165   
}
165   
}
166  
166  
167   
inline void
167   
inline void
168   
select_tcp_socket::close_socket() noexcept
168   
select_tcp_socket::close_socket() noexcept
169   
{
169   
{
170   
    do_close_socket();
170   
    do_close_socket();
171   
}
171   
}
172  
172  
173   
inline std::error_code
173   
inline std::error_code
174   
select_tcp_service::open_socket(
174   
select_tcp_service::open_socket(
175   
    tcp_socket::implementation& impl, int family, int type, int protocol)
175   
    tcp_socket::implementation& impl, int family, int type, int protocol)
176   
{
176   
{
177   
    auto* select_impl = static_cast<select_tcp_socket*>(&impl);
177   
    auto* select_impl = static_cast<select_tcp_socket*>(&impl);
178   
    select_impl->close_socket();
178   
    select_impl->close_socket();
179  
179  
180   
    int fd = ::socket(family, type, protocol);
180   
    int fd = ::socket(family, type, protocol);
181   
    if (fd < 0)
181   
    if (fd < 0)
182   
        return make_err(errno);
182   
        return make_err(errno);
183  
183  
184   
    if (family == AF_INET6)
184   
    if (family == AF_INET6)
185   
    {
185   
    {
186   
        int one = 1;
186   
        int one = 1;
187   
        ::setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
187   
        ::setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
188   
    }
188   
    }
189  
189  
190   
    int flags = ::fcntl(fd, F_GETFL, 0);
190   
    int flags = ::fcntl(fd, F_GETFL, 0);
191   
    if (flags == -1)
191   
    if (flags == -1)
192   
    {
192   
    {
193   
        int errn = errno;
193   
        int errn = errno;
194   
        ::close(fd);
194   
        ::close(fd);
195   
        return make_err(errn);
195   
        return make_err(errn);
196   
    }
196   
    }
197   
    if (::fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
197   
    if (::fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
198   
    {
198   
    {
199   
        int errn = errno;
199   
        int errn = errno;
200   
        ::close(fd);
200   
        ::close(fd);
201   
        return make_err(errn);
201   
        return make_err(errn);
202   
    }
202   
    }
203   
    if (::fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
203   
    if (::fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
204   
    {
204   
    {
205   
        int errn = errno;
205   
        int errn = errno;
206   
        ::close(fd);
206   
        ::close(fd);
207   
        return make_err(errn);
207   
        return make_err(errn);
208   
    }
208   
    }
209  
209  
210   
    if (fd >= FD_SETSIZE)
210   
    if (fd >= FD_SETSIZE)
211   
    {
211   
    {
212   
        ::close(fd);
212   
        ::close(fd);
213   
        return make_err(EMFILE);
213   
        return make_err(EMFILE);
214   
    }
214   
    }
215  
215  
216   
#ifdef SO_NOSIGPIPE
216   
#ifdef SO_NOSIGPIPE
217   
    {
217   
    {
218   
        int one = 1;
218   
        int one = 1;
219   
        ::setsockopt(fd, SOL_SOCKET, SO_NOSIGPIPE, &one, sizeof(one));
219   
        ::setsockopt(fd, SOL_SOCKET, SO_NOSIGPIPE, &one, sizeof(one));
220   
    }
220   
    }
221   
#endif
221   
#endif
222  
222  
223   
    select_impl->fd_ = fd;
223   
    select_impl->fd_ = fd;
224  
224  
225   
    select_impl->desc_state_.fd = fd;
225   
    select_impl->desc_state_.fd = fd;
226   
    {
226   
    {
227   
        std::lock_guard lock(select_impl->desc_state_.mutex);
227   
        std::lock_guard lock(select_impl->desc_state_.mutex);
228   
        select_impl->desc_state_.read_op    = nullptr;
228   
        select_impl->desc_state_.read_op    = nullptr;
229   
        select_impl->desc_state_.write_op   = nullptr;
229   
        select_impl->desc_state_.write_op   = nullptr;
230   
        select_impl->desc_state_.connect_op = nullptr;
230   
        select_impl->desc_state_.connect_op = nullptr;
231   
    }
231   
    }
232   
    scheduler().register_descriptor(fd, &select_impl->desc_state_);
232   
    scheduler().register_descriptor(fd, &select_impl->desc_state_);
233  
233  
234   
    return {};
234   
    return {};
235   
}
235   
}
236  
236  
237   
} // namespace boost::corosio::detail
237   
} // namespace boost::corosio::detail
238  
238  
239   
#endif // BOOST_COROSIO_HAS_SELECT
239   
#endif // BOOST_COROSIO_HAS_SELECT
240  
240  
241   
#endif // BOOST_COROSIO_NATIVE_DETAIL_SELECT_SELECT_TCP_SERVICE_HPP
241   
#endif // BOOST_COROSIO_NATIVE_DETAIL_SELECT_SELECT_TCP_SERVICE_HPP