FM / posix

/usr/include/boost/process/detail/posix/

/usr/include/boost/process/detail/posix

Name	Size	Mode	Actions
asio_fwd.hpp	1342	0644	edit dl rm
async_handler.hpp	1187	0644	edit dl rm
async_in.hpp	3541	0644	edit dl rm
async_out.hpp	5794	0644	edit dl rm
async_pipe.hpp	11386	0644	edit dl rm
basic_cmd.hpp	4551	0644	edit dl rm
basic_pipe.hpp	5660	0644	edit dl rm
child_handle.hpp	1432	0644	edit dl rm
close_in.hpp	1053	0644	edit dl rm
close_out.hpp	1735	0644	edit dl rm
cmd.hpp	2531	0644	edit dl rm
compare_handles.hpp	1029	0644	edit dl rm
environment.hpp	9960	0644	edit dl rm
env_init.hpp	979	0644	edit dl rm
exe.hpp	569	0644	edit dl rm
executor.hpp	15541	0644	edit dl rm
fd.hpp	2621	0644	edit dl rm
file_descriptor.hpp	1884	0644	edit dl rm
file_in.hpp	1407	0644	edit dl rm
file_out.hpp	2198	0644	edit dl rm
group_handle.hpp	2068	0644	edit dl rm
group_ref.hpp	1088	0644	edit dl rm
handler.hpp	1739	0644	edit dl rm
handles.hpp	3945	0644	edit dl rm
io_context_ref.hpp	4036	0644	edit dl rm
is_running.hpp	2304	0644	edit dl rm
null_in.hpp	1305	0644	edit dl rm
null_out.hpp	2089	0644	edit dl rm
on_exit.hpp	1001	0644	edit dl rm
pipe_in.hpp	2375	0644	edit dl rm
pipe_out.hpp	3091	0644	edit dl rm
search_path.hpp	1218	0644	edit dl rm
shell_path.hpp	878	0644	edit dl rm
sigchld_service.hpp	4102	0644	edit dl rm
signal.hpp	1898	0644	edit dl rm
start_dir.hpp	1093	0644	edit dl rm
terminate.hpp	1199	0644	edit dl rm
use_vfork.hpp	781	0644	edit dl rm
wait_for_exit.hpp	6689	0644	edit dl rm
wait_group.hpp	3423	0644	edit dl rm

Edit: /usr/include/boost/process/detail/posix/sigchld_service.hpp (4102B)

// Copyright (c) 2017 Klemens D. Morgenstern
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#ifndef BOOST_PROCESS_DETAIL_POSIX_SIGCHLD_SERVICE_HPP_
#define BOOST_PROCESS_DETAIL_POSIX_SIGCHLD_SERVICE_HPP_

#include <boost/asio/dispatch.hpp>
#include <boost/asio/post.hpp>
#include <boost/asio/signal_set.hpp>
#include <boost/asio/strand.hpp>
#include <boost/optional.hpp>
#include <signal.h>
#include <functional>
#include <sys/wait.h>

namespace boost { namespace process { namespace detail { namespace posix {

class sigchld_service : public boost::asio::detail::service_base<sigchld_service>
{
    boost::asio::strand<boost::asio::io_context::executor_type> _strand{get_io_context().get_executor()};
    boost::asio::signal_set _signal_set{get_io_context(), SIGCHLD};

std::vector<std::pair<::pid_t, std::function<void(int, std::error_code)>>> _receivers;
    inline void _handle_signal(const boost::system::error_code & ec);
public:
    sigchld_service(boost::asio::io_context & io_context)
        : boost::asio::detail::service_base<sigchld_service>(io_context)
    {
    }

template <typename SignalHandler>
    BOOST_ASIO_INITFN_RESULT_TYPE(SignalHandler,
        void (int, std::error_code))
    async_wait(::pid_t pid, SignalHandler && handler)
    {
        boost::asio::async_completion<
        SignalHandler, void(boost::system::error_code)> init{handler};

auto & h = init.completion_handler;
        boost::asio::dispatch(
                _strand,
                [this, pid, h]
                {
                    //check if the child actually is running first
                    int status;
                    auto pid_res = ::waitpid(pid, &status, WNOHANG);
                    if (pid_res < 0)
                        h(-1, get_last_error());
                    else if ((pid_res == pid) && (WIFEXITED(status) || WIFSIGNALED(status)))
                        h(status, {}); //successfully exited already
                    else //still running
                    {
                        if (_receivers.empty())
                            _signal_set.async_wait(
                                    [this](const boost::system::error_code &ec, int)
                                    {
                                        boost::asio::dispatch(_strand, [this, ec]{this->_handle_signal(ec);});
                                    });
                        _receivers.emplace_back(pid, h);
                    }
                });

return init.result.get();
    }
    void shutdown() override
    {
        _receivers.clear();
    }

void cancel()
    {
        _signal_set.cancel();
    }
    void cancel(boost::system::error_code & ec)
    {
        _signal_set.cancel(ec);
    }
};

void sigchld_service::_handle_signal(const boost::system::error_code & ec)
{
    std::error_code ec_{ec.value(), std::system_category()};

if (ec_)
    {
        for (auto & r : _receivers)
            r.second(-1, ec_);
        return;
    }

for (auto & r : _receivers) {
        int status;
        int pid = ::waitpid(r.first, &status, WNOHANG);
        if (pid < 0) {
            // error (eg: the process no longer exists)
            r.second(-1, get_last_error());
            r.first = 0; // mark for deletion
        } else if (pid == r.first) {
            r.second(status, ec_);
            r.first = 0; // mark for deletion
        }
        // otherwise the process is still around
    }

_receivers.erase(std::remove_if(_receivers.begin(), _receivers.end(),
            [](const std::pair<::pid_t, std::function<void(int, std::error_code)>> & p)
            {
                return p.first == 0;
            }),
            _receivers.end());

if (!_receivers.empty())
    {
        _signal_set.async_wait(
            [this](const boost::system::error_code & ec, int)
            {
                boost::asio::post(_strand, [this, ec]{this->_handle_signal(ec);});
            });
    }
}

}
}
}
}

#endif

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