boost ASIO server segmentation fault - c++

Question

I created a server using Boost ASIO. It builds fine but as soon as I run it, it gives segmentation fault. Can't really figure out this behaviour.
Also, I read that this may be due to me not initialising the io_service object explicitly. If, that's the case then how do I modify this code so that I don't have to pass io_service object from outside the class.
Below is my code:
#include <iostream>
#include <string>
#include <memory>
#include <array>
#include <boost/asio.hpp>
using namespace boost::asio;
//Connection Class
class Connection : public std::enable_shared_from_this<Connection>{
ip::tcp::socket m_socket;
std::array<char, 2056> m_acceptMessage;
std::string m_acceptMessageWrapper;
std::string m_buffer;
public:
Connection(io_service& ioService): m_socket(ioService) { }
virtual ~Connection() { }
static std::shared_ptr<Connection> create(io_service& ioService){
return std::shared_ptr<Connection>(new Connection(ioService));
}
std::string& receiveMessage() {
size_t len = boost::asio::read(m_socket, boost::asio::buffer(m_acceptMessage));
m_acceptMessageWrapper = std::string(m_acceptMessage.begin(), m_acceptMessage.begin() + len);
return m_acceptMessageWrapper;
}
void sendMessage(const std::string& message) {
boost::asio::write(m_socket, boost::asio::buffer(message));
}
ip::tcp::socket& getSocket(){
return m_socket;
}
};
//Server Class
class Server {
ip::tcp::acceptor m_acceptor;
io_service m_ioService ;
public:
Server(int port):
m_acceptor(m_ioService, ip::tcp::endpoint(ip::tcp::v4(), port)){ }
virtual ~Server() { }
std::shared_ptr<Connection> createConnection(){
std::shared_ptr<Connection> newConnection = Connection::create(m_ioService);
m_acceptor.accept(newConnection->getSocket());
return newConnection;
}
void runService() {
m_ioService.run();
}
};
int main(int argc, char* argv[]) {
Server s(5000);
auto c1 = s.createConnection();
//do soething
s.runService();
return 0;
}

Answer 1

You are facing initialisation order issues. In your class Server, you have declared m_acceptor before m_ioService and using the uninitialized io_service object to construct the acceptor.
Just reorder the declarations inside the class. Surprisingly clang did not give any warning for this.
class Server {
io_service m_ioService ;
ip::tcp::acceptor m_acceptor;
public:
Server(int port):
m_acceptor(m_ioService, ip::tcp::endpoint(ip::tcp::v4(), port)){ }
virtual ~Server() { }
std::shared_ptr<Connection> createConnection(){
std::shared_ptr<Connection> newConnection = Connection::create(m_ioService);
m_acceptor.accept(newConnection->getSocket());
return newConnection;
}
void runService() {
m_ioService.run();
}
};