[asio] The asio handle shouldnot be called

[icerlion@…]

I want to write a UDP server, which can send and receive package. The following is the demo code:

Begin of code #include "stdafx.h" #include "boost/bind.hpp" #include "boost/asio.hpp"

class UDPServer { public:

UDPServer()

:m_socket(m_io_service), m_timer(m_io_service)

{ }

virtual ~UDPServer() {

}

void Initialize(const std::string& strIP, int nPort) {

boost::system::error_code ec; boost::asio::ip::address ad = boost::asio::ip::address::from_string(strIP, ec); boost::asio::ip::udp::endpoint ep(ad, nPort); m_socket.open(ep.protocol()); m_socket.bind(ep, ec); {

TEST CODE: boost::asio::ip::udp::endpoint ep(boost::asio::ip::address::from_string("172.18.8.111", ec), 8001); m_vServerGroup.push_back(ep);

}

}

void Start() {

StartAsyncReceiveFrom(); NoticeSelfUp(); while (true) {

boost::system::error_code ec; m_io_service.poll(ec);

}

}

void SendUDPMsg(const char* pMsg, int nLen, boost::asio::ip::udp::endpoint& dest_ep) {

m_socket.async_send_to(

boost::asio::buffer(pMsg, nLen), dest_ep, boost::bind(&UDPServer::HandleSendTo, this, _1, _2, boost::ref(dest_ep)));

}

protected:

void NoticeSelfUp() {

size_t count = m_vServerGroup.size(); char* pBuff = "this is up"; for (size_t i = 0; i < count; ++i) {

SendUDPMsg(pBuff, strlen(pBuff), m_vServerGroup[i]);

} m_timer.expires_from_now(boost::posix_time::seconds(5)); m_timer.async_wait(boost::bind(&UDPServer::NoticeSelfUp, this));

}

void HandleReceiveFrom(const boost::system::error_code& ec, size_t bytes_recvd) {

if (ec) {

std::cout<<"HandleReceiveFrom error: \t"<<ec<<std::endl;

} else {

TODO

} StartAsyncReceiveFrom();

}

void HandleSendTo(const boost::system::error_code& ec, size_t bytes_sent, boost::asio::ip::udp::endpoint& ep) {

if (ec) {

std::cout<<"HandleReceiveFrom error: \t"<<ec<<"\t"<<ep<<std::endl;

} else {

TODO

}

}

void StartAsyncReceiveFrom() {

m_socket.async_receive_from(boost::asio::buffer(m_buff, max_length),

m_sender_point, boost::bind(&UDPServer::HandleReceiveFrom, this, _1, _2));

}

private:

boost::asio::io_service m_io_service; boost::asio::ip::udp::socket m_socket; boost::asio::ip::udp::endpoint m_sender_point; boost::asio::deadline_timer m_timer; std::vector<boost::asio::ip::udp::endpoint> m_vServerGroup; enum { max_length = 1024 }; char m_buff[max_length];

};

int _tmain(int argc, _TCHAR* argv[]) {

UDPServer server; server.Initialize("172.18.8.111", 8000); server.Start(); return 0;

}

End of code

What's more, localmachine IP is 172.18.8.111, the port number 8001 is not opened. After I call SendUDPMsg, the handle UDPServer::HandleReceiveFrom is called, but there is no receive operation for the socket, I just called the send function. In my opinion, the HandleReceiveFrom should not be called!

[icerlion@…]

test code for this issue

[chris_kohlhoff]

asio_error.cpp, line 85

[icerlion@…]

Replying to chris_kohlhoff:

asio_error.cpp, line 85

Thank you for your replying, but I don't understand your meaning. How should I do to fix this problem? How to set to invalid? Can you write some code?

[chris_kohlhoff]

Change line 85 from:

std::cout<<"HandleReceiveFrom error: \t"<<ec<<"\t"<<ep<<std::endl;

to:

std::cout<<"HandleSendTo error: \t"<<ec<<"\t"<<ep<<std::endl;