CAsyncSocket implementaion in C++ Console application

[Cho Cho Aung]

I've got a Visual C++ console applications that
implementing a CAsyncSocket client / server sockets. The
client socket can connect to the server and send data to
the server. The server can also send the data back to the
client but it doesn't seem to trigger the notification
events like OnReceive, OnConnect.

Is it possible that CAsyncSocket only works for window
based application?

[Thomas Mooney]

CAsyncSocket requires a message pump to function properly. A message pump
is the heart of a Windows application.

TFM3

Note: Spam-resistant e-mail address

Cho Cho Aung <cho...@itvworld.com> wrote in message
news:006101c181cc$b3a040a0$37ef2ecf@TKMSFTNGXA13...

[Joseph M. Newcomer]

I'm surprised that it could work at all. The notifications are sent by using a hidden
window to receive them and dispatch the event handlers, and a console application does not
have the message pump to make this work. Hint: whenever you think "console app" think,
instead, "dialog-based GUI app". You might also want to check out my essay on doing
dialog-based apps on my MVP Tips site.
joe

Joseph M. Newcomer [MVP]
email: newc...@flounder.com
Web: http://www3.pgh.net/~newcomer
MVP Tips: http://www3.pgh.net/~newcomer/mvp_tips.htm

[christ...@gmail.com]

I found an interesting solution of that issue.
First of all:
YES its possible to use CAsyncSocket with full features without a CWin Window.
NO its no common Console App.
And it works fine :-)

You need a CWorker Class derived from CWinApp, because CWinApp:CWinThread has the MFC-Message-Loop Run().
class CWorkerApp :public CWinApp;

Second you need your CAsync Class derived from CAsyncSocket, to override the virtual Callbacks.
class CAsync :public CAsyncSocket;

Third you must tell CWinApp tu run without a CWin-Dialog, because default it stops, if it has no Window.
AfxOleSetUserCtrl(FALSE);
Keep in mind, you have no UI to that App. You just see it under Processes in Task-Manager and you can Kill it only that way.
But the good message, you can allocate a Console Window to put your DEBUG output there.
The rest I found in MSDN dokumentation, Sample EchoServer, and "of course" in Internet :))

I post the full source afterwards. They consist of
MyEchoSocket.h
EchoServer.h
MyEchoSocket.cpp
EchoServer.cpp

// MyEchoSocket.h : header file
//

#if !defined(AFX_MYECHOSOCKET_H__166D4120_2F94_4231_AE60_7C719E3EC05C__INCLUDED_)
#define AFX_MYECHOSOCKET_H__166D4120_2F94_4231_AE60_7C719E3EC05C__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class MyEchoSocket : public CAsyncSocket
{
public:
//my Overwrites of the Callbacks of the Socket-Events, I hook on by Create
virtual void OnReceive(int nErrorCode); //FD_READ
virtual void OnSend(int nErrorCode); //FD_WRITE
virtual void OnOutOfBandData(int nErrorCode); //FD_OOB
virtual void OnAccept(int nErrorCode); //FD_ACCEPT
virtual void OnConnect(int nErrorCode); //FD_CONNECT
virtual void OnClose(int nErrorCode); //FD_CLOSE

BOOL Create(
UINT nSocketPort = 0,
int nSocketType = SOCK_STREAM,
long lEvent = FD_READ | FD_WRITE | FD_OOB | FD_ACCEPT | FD_CONNECT | FD_CLOSE,
LPCTSTR lpszSocketAddress = NULL
);

void SetParentApp(CWinApp* pParent);

MyEchoSocket();
virtual ~MyEchoSocket();

private:
CWinApp* m_pParent;
};

#endif // !defined(AFX_MYECHOSOCKET_H__166D4120_2F94_4231_AE60_7C719E3EC05C__INCLUDED_)

// EchoServer.h
//

#if !defined(AFX_ECHOSERVER_H__7AA7D190_8407_49A5_A315_FB3E228E6F80__INCLUDED_)
#define AFX_ECHOSERVER_H__7AA7D190_8407_49A5_A315_FB3E228E6F80__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#ifndef __AFXWIN_H__
#error include 'stdafx.h' before including this file for PCH
#endif

#include "resource.h" // main symbols
#include "MyEchoSocket.h"

class CEchoServerApp : public CWinApp
{
public:
void JobOnReceive();
void JobOnClose();
void JobOnAccept();

CEchoServerApp();

int m_port;
CString m_recieveddata;
CString m_status;

virtual BOOL InitInstance();
virtual int ExitInstance( );

//declare the Message-Loop ========================================
DECLARE_MESSAGE_MAP()

private:
MyEchoSocket m_sListener;
MyEchoSocket m_sConnected;
};

#endif // !defined(AFX_ECHOSERVER_H__7AA7D190_8407_49A5_A315_FB3E228E6F80__INCLUDED_)

// MyEchoSocket.cpp
//

#include "stdafx.h"
#include "EchoServer.h"
#include "MyEchoSocket.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

MyEchoSocket::MyEchoSocket()
{}

MyEchoSocket::~MyEchoSocket()
{}

void MyEchoSocket::OnAccept(int nErrorCode)
{
_cprintf_s("==> OnAccept ++++++++++++++\n");
if(nErrorCode==0)
{
reinterpret_cast<CEchoServerApp*>(m_pParent)->JobOnAccept();
}
CAsyncSocket::OnAccept(nErrorCode);
}

void MyEchoSocket::OnClose(int nErrorCode)
{
_cprintf_s("==> OnClose ++++++++++++++\n");
if(nErrorCode==0)
{
reinterpret_cast<CEchoServerApp*>(m_pParent)->JobOnClose();
}
CAsyncSocket::OnClose(nErrorCode);
}

void MyEchoSocket::OnConnect(int nErrorCode)
{
_cprintf_s("==> OnConnect ++++++++++++++\n");
CAsyncSocket::OnConnect(nErrorCode);
}

void MyEchoSocket::OnOutOfBandData(int nErrorCode)
{
CAsyncSocket::OnOutOfBandData(nErrorCode);
}

void MyEchoSocket::OnReceive(int nErrorCode)
{
_cprintf_s("==> OnReceive ++++++++++++++\n");
if(nErrorCode==0)
{
reinterpret_cast<CEchoServerApp*>(m_pParent)->JobOnReceive();
}
CAsyncSocket::OnReceive(nErrorCode);
}

void MyEchoSocket::OnSend(int nErrorCode)
{
_cprintf_s("==> OnSend ++++++++++++++\n");
CAsyncSocket::OnSend(nErrorCode);
}

BOOL MyEchoSocket::Create(UINT nSocketPort, int nSocketType, long lEvent, LPCTSTR lpszSocketAddress)
{
return CAsyncSocket::Create(nSocketPort, nSocketType, lEvent, lpszSocketAddress);
}

void MyEchoSocket::SetParentApp(CWinApp *pParent)
{
m_pParent=pParent;
}

// EchoServer.cpp
//

#include "stdafx.h"
#include "EchoServer.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

//default Message-Loop of CWinApp =====================================
BEGIN_MESSAGE_MAP(CEchoServerApp, CWinApp)
END_MESSAGE_MAP()

CEchoServerApp::CEchoServerApp()
{}

CEchoServerApp theApp;

BOOL CEchoServerApp::InitInstance()
{
//I allocate a Console for CWinApp-Output =========================
BOOL R = AllocConsole();
if (!R)
{
AfxMessageBox("No Console");
return FALSE;
}
_cprintf_s("InitInstance()\n");

//prevent CWinApp from stopping without CWnd ======================
AfxOleSetUserCtrl(FALSE);

//initialize Windows Socket =======================================
if(AfxSocketInit()==FALSE)
{
_cprintf_s("Sockets Could Not Be Initialized");
return FALSE;
}

m_sListener.SetParentApp(this);
m_sConnected.SetParentApp(this);
m_port=12345;
// m_port=0; //Listen on all Ports does not work!

//I start the Listener here ==========================================
m_sListener.Create(m_port);
if(m_sListener.Listen()==FALSE)
{
_cprintf_s("Unable to Listen on that port,please try another port");
m_sListener.Close();
return FALSE;
}
_cprintf_s("++>Server is listening...\n");

return TRUE; //to start CWinApp::Run() -the MFC Message Loop- ========
}
int CEchoServerApp::ExitInstance()
{
_cprintf_s("ExitInstance: press ENTER to close App...");
char cb[256];
size_t sRead;
errno_t err = _cgets_s(cb, 255, &sRead);

//Cleanup ============================================================
BOOL R = FreeConsole();
if (!R)
{
//error
return 1;
}
return 0;
}

void CEchoServerApp::JobOnAccept()
{
CString strIP;
UINT port;
if(m_sListener.Accept(m_sConnected))
{
m_sConnected.GetSockName(strIP,port);
m_status="Client Connected,IP :"+ strIP;
_cprintf_s("++>%s Port:%d\n", m_status, port);
}
else
{
_cprintf_s("Can not Accept Connection");
}
}
void CEchoServerApp::JobOnClose()
{
_cprintf_s("++>post WM_QUIT\n");
AfxPostQuitMessage(0); //send WM_QUIT Message
}
void CEchoServerApp::JobOnReceive()
{
char pBuf[1024];
CString strData;
int iLen;
iLen=m_sConnected.Receive(pBuf,1023);
if(iLen==SOCKET_ERROR)
{
_cprintf_s("Could not Recieve");
}
else
{
pBuf[iLen]=NULL;
strData=pBuf;
m_recieveddata.Insert(m_recieveddata.GetLength(),strData); //store in class
_cprintf_s("++>%s\n", strData);
m_sConnected.Send(pBuf,iLen); //echo
//m_sConnected.ShutDown(0);
}

}

[christ...@gmail.com]

I forgot the Includes of stdafx.h.

// stdafx.h : include file for standard system include files,
// or project specific include files that are used frequently, but
// are changed infrequently
//

#if !defined(AFX_STDAFX_H__BA0ED324_F513_410F_A554_9CD9FABD7A80__INCLUDED_)
#define AFX_STDAFX_H__BA0ED324_F513_410F_A554_9CD9FABD7A80__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#define VC_EXTRALEAN // Exclude rarely-used stuff from Windows headers

#include <conio.h>
#include <afxwin.h> // MFC core and standard components
#include <afxext.h> // MFC extensions
#include <afxdisp.h> // MFC Automation classes
#include <afxdtctl.h> // MFC support for Internet Explorer 4 Common Controls
#ifndef _AFX_NO_AFXCMN_SUPPORT
#include <afxcmn.h> // MFC support for Windows Common Controls
#endif // _AFX_NO_AFXCMN_SUPPORT
#include "afxsock.h"

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_STDAFX_H__BA0ED324_F513_410F_A554_9CD9FABD7A80__INCLUDED_)