AlarmServer/MailServer/Server.cpp

#include "Server.h"
#include <Logging.h>
#include <functional>
#include <sstream>
#include <sys/wait.h>


namespace MailServer {

Server::Server(asio::io_service& ioService, unsigned short port, const std::string& path, const std::string& url) :
	m_ioService(ioService),
	m_signal(ioService, SIGCHLD),
	m_acceptor(ioService, asio::ip::tcp::endpoint(asio::ip::tcp::v4(), port)),
	m_socket(ioService)
{
	m_context.path = path;
	m_context.url = url;

	StartSignalWait();
	StartAccept();
}

void Server::StartSignalWait()
{
	m_signal.async_wait(std::bind(&Server::HandleSignalWait, this));
}

void Server::HandleSignalWait()
{
	// Only the parent process should check for this signal. We can determine
	// whether we are in the parent by checking if the acceptor is still open.
	if (m_acceptor.is_open())
	{
		// Reap completed child processes so that we don't end up with zombies.
		int status = 0;
		while (waitpid(-1, &status, WNOHANG) > 0) {}

		StartSignalWait();
	}
}

void Server::StartAccept()
{
	m_connection.reset(new Connection(m_ioService, m_context));
	m_acceptor.async_accept(m_connection->Socket(), std::bind(&Server::HandleAccept, this, std::placeholders::_1));
}

void Server::HandleAccept(const asio::error_code& ec)
{
	if (!ec)
	{
		m_ioService.notify_fork(asio::io_service::fork_prepare);

		if (fork() == 0)
		{
			m_ioService.notify_fork(asio::io_service::fork_child);
			m_acceptor.close();
			m_signal.cancel();

			m_connection->Start();
		}
		else
		{
			m_ioService.notify_fork(asio::io_service::fork_parent);

			m_connection.reset();
			m_socket.close();
			StartAccept();
		}
	}
	else
	{
		std::stringstream ss;
		ss << "Server::HandleAccept() - Error" << std::endl;
		Logging::Log(Logging::Severity::Error, ss.str());

		StartAccept();
	}
}

} // namespace MailServer