correctly terminate boost::asio::ip::tcp::accept (Linux) - c++

Question

I wonder how to implement a synchronous socket accept with boost which can be terminated.
To demonstrate my problem I slightly modified the synchonous tcp echo example.
Note: the provided code seems to be working on Windows platforms but i'm having problems on a Linux machine.
Let's say the server receives a quit message and now wants to terminate an endless loop which accepts new connections.
Most tutorials etc. recommend you to run acceptor->close() in this case. But as
this post states, the results might be undefined if close() is called from another thread.
If you do so, accept() won't terminate this time but when another client tries to connect it returnes an error (on Linux!)
So my question again: how do I correctly terminate a server which is based on boost::asio which continuously synchronously accepts connections?
Here the code:
#include <cstdlib>
#include <iostream>
#include <boost/bind.hpp>
#include <boost/smart_ptr.hpp>
#include <boost/asio.hpp>
#include <boost/thread.hpp>
using boost::asio::ip::tcp;
void session(boost::shared_ptr<tcp::socket> sock, tcp::acceptor *acceptor )
{
try {
for (;;) {
char data[ 1024 ];
boost::system::error_code error;
size_t length = sock->read_some(boost::asio::buffer(data), error);
if (error == boost::asio::error::eof) { break; }
else if (error) { throw boost::system::system_error(error); }
if( std::string("quit") == data ) { // TRY TO CANCEL THE ACCEPT
acceptor->close();
break;
}
boost::asio::write(*sock, boost::asio::buffer(data, length));
}
}
catch (std::exception& e) { std::cerr << "exception in thread: " << e.what() << "\n"; }
}
void server(boost::asio::io_service& io_service, short port)
{
tcp::acceptor a( io_service, tcp::endpoint(tcp::v4(), port) );
for (;;) {
boost::shared_ptr<tcp::socket> sock(new tcp::socket(io_service));
boost::system::error_code error;
a.accept( *sock, error );
if( !error ) {
boost::thread t( boost::bind( session, sock, &a ) );
}
else {
std::cout << "acceptor canceled "<< error << std::endl;
break;
}
}
}
int main(int argc, char* argv[])
{
try{
// ..check args here...
boost::asio::io_service io_service;
server(io_service, std::atoi(argv[1]));
}
catch (std::exception& e) {std::cerr << "Exception: " << e.what() << "\n";}
return 0;
}