BOOST ASIO - How to write console server
I have to write asynchronous TCP Sever. TCP Server have to be managed by console (for eg: remove client, show list of all connected client, etcc..)
The problem is: How can I attach (or write) console, which can calls above functionalities. This console have to be a client? Should I run this console client as a sepearate thread?
I have read a lot of tutorials and I couldn`t find a solution to my problem.
ServerTCP code
class ServerTCP
{
public:
ServerTCP(boost::asio::io_service& A_ioService, unsigned short A_uPortNumber = 13)
: m_tcpAcceptor(A_ioService, tcp::endpoint(tcp::v4(), A_uPortNumber)), m_ioService (A_ioService)
{
start();
}
private:
void start()
{
ClientSessionPtr spClient(new ClientSession(m_tcpAcceptor.io_service(), m_connectedClients));
m_tcpAcceptor.async_accept(spClient->getSocket(),
开发者_开发问答 boost::bind(&ServerTCP::handleAccept, this, spClient,
boost::asio::placeholders::error));
}
void handleAccept(ClientSessionPtr A_spNewClient, const boost::system::error_code& A_nError)
{
if ( !A_nError )
{
A_spNewClient->start();
start();
}
}
boost::asio::io_service& m_ioService;
tcp::acceptor m_tcpAcceptor;
Clients m_connectedClients;
};
Main function:
try
{
boost::asio::io_service ioService;
ServerTCP server(ioService);
ioService.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
Hello Sam. Thanks for reply. Could you be so kind and show me a some piece of code or some links to examples involve with this problem ? Propably, I don`t understand correctly "... single threaded server ..."
In Fact in "console" where I want to manage server operations, I need smt like below:
main()
cout << "Options: q - close server, s - show clients";
while(1)
{
char key = _getch();
switch( key )
{
case 'q':
closeServer();
break
case 's':
showClients();
break
}
}
The problem is: How can I attach (or write) console, which can calls above functionalities. This console have to be a client? Should I run this console client as a sepearate thread?
You don't need a separate thread, use a posix::stream_descriptor
and assign STDIN_FILENO
to it. Use async_read
and handle the requests in the read handlers.
#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <boost/enable_shared_from_this.hpp>
#include <boost/shared_ptr.hpp>
#include <iostream>
using namespace boost::asio;
class Input : public boost::enable_shared_from_this<Input>
{
public:
typedef boost::shared_ptr<Input> Ptr;
public:
static void create(
io_service& io_service
)
{
Ptr input(
new Input( io_service )
);
input->read();
}
private:
explicit Input(
io_service& io_service
) :
_input( io_service )
{
_input.assign( STDIN_FILENO );
}
void read()
{
async_read(
_input,
boost::asio::buffer( &_command, sizeof(_command) ),
boost::bind(
&Input::read_handler,
shared_from_this(),
placeholders::error,
placeholders::bytes_transferred
)
);
}
void read_handler(
const boost::system::error_code& error,
size_t bytes_transferred
)
{
if ( error ) {
std::cerr << "read error: " << boost::system::system_error(error).what() << std::endl;
return;
}
if ( _command != '\n' ) {
std::cout << "command: " << _command << std::endl;
}
this->read();
}
private:
posix::stream_descriptor _input;
char _command;
};
int
main()
{
io_service io_service;
Input::create( io_service );
io_service.run();
}
If I understand the OP correctly, he/she wants to run an async TCP server that is controlled via a console i.e console is used as user interface. In that case you don't need a separate client application to query the server for connected clients, etc.:
- You need to spawn a thread that somehow calls the io_service::run method. Currently you are calling this from main. Since your server will probably be scoped in main, you need do something like pass a ref to the server to the new thread. The io_service could e.g be a member of the server class (unless your application has other requirements in which case pass both the server and the io_service to the new thread).
- add the corresponding methods such as showClients, closeServer, etc. to your server class
- make sure that these calls which are triggered via the console are thread-safe
- in your closeServer method you could for instance call io_service::stop which would result in the server ending.
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