Linking Errors

Question

FTProtocol -24 Junior Poster in Training

15 Years Ago

Main.cpp

#include <stdio.h>
#include "CServer.cpp"

class EventReceiver:
public CServer
{
		void OnClientReceive(CServer* SVR)
		{
			char* Packet = SVR->GetReceivedBuffer();
			int packetsize = SVR->GetReceivedSize();
 
			PCLIENT_HANDLE clientthatsent = SVR->GetLatestReadClient();

			printf("\n Packet Recieved - %s", Packet);

			CLIENT_LIST_LOOP(SVR)
				if(CUR_CLIENT_SOCKETID != clientthatsent->sSocketId)
				{
					SVR->SendPacketToClient(Packet,packetsize,CUR_CLIENT);
					Sleep(250);
				}
			CLIENT_LIST_END_LOOP(SVR);
		}

		void OnClientConnection(CServer* SVR)
		{
			PCLIENT_HANDLE ConnectedClient = SVR->GetLatestConnectedClient();
			printf("\n Client  ( %s ) has connected!",ConnectedClient->szIpAddress);
		}
};

int main()
{
	CServer* Server = new CServer();
	EventReceiver* MyEvents = new EventReceiver();

	Server = MyEvents;

	Server->SetPort(555);
	Server->SetMaxClientAmmount(1000);
	Server->StartServer();
		
	while(1)
	{
		Sleep(1);
	}

	return 0;
}

CServer.cpp

#include "CServer.h"

CServer::CServer()
{
	m_CurrentReceivingClient = 0x0;
	m_CurrentAcceptingClient = 0x0;
	m_ClientListHead = 0x0;
	m_TotalClientCount = 0;
	m_ClientCount = 0;
	m_BufferSize = 0;
	m_Port = 0;
	m_MaxClient = 0;
	m_ListeningSocket = 0;
	m_isServerStarted = false;
	m_BufferReceived = (char*)malloc(4096);

	memset(m_BufferReceived,0,4096);
	WSAStartup(MAKEWORD(2,2),&m_WSAData);
}

CServer::CServer(int nPort)
{
	m_CurrentReceivingClient = 0x0;
	m_CurrentAcceptingClient = 0x0;
	m_ClientListHead = 0x0;
	m_TotalClientCount = 0;
	m_ClientCount = 0;
	m_BufferSize = 0;
	m_Port = nPort;
	m_MaxClient = 0;
	m_ListeningSocket = 0;
	m_isServerStarted = false;
	m_BufferReceived = (char*)malloc(4096);


	memset(m_BufferReceived,0,4096);
	WSAStartup(MAKEWORD(2,2),&m_WSAData);
}

CServer::~CServer()
{
	m_isServerStarted = false;
	free(m_BufferReceived);
	WSACleanup();
}

void CServer::SetPort(int nPort)
{
	m_Port = nPort;
}

bool CServer::StartServer()
{
	m_ListeningSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP); 

	m_ServerAddress.sin_family = AF_INET;
	m_ServerAddress.sin_addr.s_addr = INADDR_ANY; 
	m_ServerAddress.sin_port = htons(m_Port);

	if(bind(m_ListeningSocket, (LPSOCKADDR)&m_ServerAddress, sizeof(struct sockaddr)) == SOCKET_ERROR)
	{
		return false;
	}

	m_isServerStarted = true;

	CreateThread(NULL,0,(unsigned long (__stdcall *)(void *))StartAccepting,this,0,NULL);
	CreateThread(NULL,0,(unsigned long (__stdcall *)(void *))StartReading,this,0,NULL);
	return true;
}

void CServer::AddClient(SOCKET sSocketId,char* szIpAddress,PCLIENT_HANDLE pListHead)
{
	if (!pListHead)
	{
		m_ClientListHead = (CLIENT_HANDLE*)malloc(sizeof(CLIENT_HANDLE));
		memset(m_ClientListHead,0,sizeof(CLIENT_HANDLE));
		pListHead = m_ClientListHead;
	}

	struct CLIENT_HANDLE* MyClients = pListHead;
	while (MyClients->next != 0x0)
	{
		if(MyClients->sSocketId == sSocketId)
			return;

		MyClients = MyClients->next;
	}

	/* Set Up Client Information */
	MyClients->sSocketId = sSocketId;
	memset(MyClients->szIpAddress,0,32);
	strcpy(MyClients->szIpAddress,szIpAddress);
	MyClients->nClientNumber = m_TotalClientCount++;
	m_CurrentAcceptingClient = MyClients;
	/* End of Client Information Set Up */

	MyClients->next = (CLIENT_HANDLE*)malloc(sizeof(CLIENT_HANDLE));
	memset(MyClients->next,0x0,sizeof(CLIENT_HANDLE));
	MyClients->next->previous = MyClients;
}

void CServer::RemoveClient(SOCKET sSocketId,PCLIENT_HANDLE pListHead)
{
	struct CLIENT_HANDLE* MyClients = pListHead;
	while (MyClients->next != 0x0)
	{
		if (MyClients->sSocketId == sSocketId)
		{
			if (MyClients->previous)
			{
				if (MyClients->next)
				{
					MyClients->previous->next = MyClients->next;
					MyClients->next->previous = MyClients->previous;
				}
				else
					MyClients->previous->next = 0x0;
				
				free(MyClients);
				
			}
			else
			{

				if (MyClients->next)
				{
					m_ClientListHead = MyClients->next;
					m_ClientListHead->previous = 0x0;
					free(MyClients);
				}
				else
				{
					memset(MyClients,0x0,sizeof(CLIENT_HANDLE));
				}
			}
			break;
		}
		else
		{
			MyClients = MyClients->next;
		}
	}	
}

bool CServer::isServerStarted()
{
	return m_isServerStarted;
}

DWORD CServer::StartAccepting(void* pParam)
{
	((CServer*)pParam)->ClientAccepting();
	return 0;
}

DWORD CServer::StartReading(void* pParam)
{
	((CServer*)pParam)->ClientReading();
	return 0;
}

int CServer::GetMaxClients()
{
	return m_MaxClient;
}

int CServer::GetClientCount()
{
	return m_ClientCount;
}

void CServer::ClientAccepting()
{
	SOCKET sLatestClient = 0;
	int length = sizeof(m_ServerAddress);
	for(;;)
	{
		while ( listen( m_ListeningSocket, SOMAXCONN ) == SOCKET_ERROR );
		if(GetMaxClients() == 0)
		{
			goto accept;
		}
		else
		{
			if(GetClientCount() < GetMaxClients())
			{
				goto accept;
			}
			else
			{
				goto end;
			}
		}
accept:
			sLatestClient = accept(m_ListeningSocket,(LPSOCKADDR)&m_ServerAddress,&length);
			if(sLatestClient != SOCKET_ERROR )
			{
				AddClient(sLatestClient,inet_ntoa(m_ServerAddress.sin_addr),m_ClientListHead);
				m_ClientCount++;
				if(m_CurrentAcceptingClient)
				{
					OnClientConnection(this);
				}
				m_CurrentAcceptingClient = 0x0;
			}
end:
			sLatestClient = 0;
	}
}

void CServer::ClientReading()
{
	int timer = 0;
	static struct timeval timestruct;
	timestruct.tv_sec = 0;
	timestruct.tv_usec = 10;
	int recvsize = 0;

	while(1)
	{
		timer++;
		if(timer > 50)
		{
			Sleep(1);
			timer = 0;
		}
		PCLIENT_HANDLE MyClients = GetClientListHead();
		if(MyClients)
		{
			while(MyClients->next)
			{
				timer++;
				if(timer > 50)
				{
					Sleep(1);
					timer = 0;
				}
				if(MyClients->sSocketId)
				{
					fd_set read;
					FD_ZERO(&read);
					FD_SET(MyClients->sSocketId,&read);
					select(MyClients->sSocketId+1,&read,0x0,0x0,&timestruct);
					if(FD_ISSET(MyClients->sSocketId,&read))
					{
						memset(m_BufferReceived,0,4096);
						recvsize = recv(MyClients->sSocketId,m_BufferReceived,4096,0);
						if(recvsize > 0)
						{
							m_CurrentReceivingClient = MyClients; 
							m_BufferSize = recvsize;
							OnClientReceive(this);
						}
						else
						{
							Sleep(1);
							closesocket(MyClients->sSocketId);
							RemoveClient(MyClients->sSocketId,m_ClientListHead);
							MyClients = m_ClientListHead;
							m_ClientCount--;
						}
					}

					FD_ZERO(&read);
				}
				if(MyClients)
				{
					if(MyClients->next)
						MyClients = MyClients->next;
				}
				else
					break;
			}
		}
	}
}

PCLIENT_HANDLE CServer::GetLatestReadClient()
{
	return m_CurrentReceivingClient;
}

PCLIENT_HANDLE CServer::GetLatestConnectedClient()
{
	return m_CurrentAcceptingClient;
}

PCLIENT_HANDLE CServer::GetClientListHead()
{
	return m_ClientListHead;
}

char* CServer::GetReceivedBuffer()
{
	return m_BufferReceived;
}

int CServer::GetReceivedSize()
{
	return m_BufferSize;
}

int CServer::SetMaxClientAmmount(int nAmmount)
{
	m_MaxClient = nAmmount;
	return m_MaxClient;
}

int CServer::SendPacketToClient(char* pPacket, int nSize,PCLIENT_HANDLE pClientHandle)
{
	return send(pClientHandle->sSocketId,pPacket,nSize,0);
}

int CServer::SendPacketToAllClients(char *pPacket, int nSize)
{
	PCLIENT_HANDLE MyClients = GetClientListHead();

	while(MyClients->next)
	{
		if(MyClients->sSocketId)
		{
			send(MyClients->sSocketId,pPacket,nSize,0);
		}
		MyClients = MyClients->next;
	}

	return 1;
}

CServer.h

#ifdef WIN32
#include <windows.h>
#endif

#ifdef WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#endif

#pragma comment(lib,"ws2_32.lib")

typedef struct CLIENT_HANDLE
{
	CLIENT_HANDLE* previous;
	SOCKET sSocketId;
	int nClientNumber;
	char szIpAddress[32];
	CLIENT_HANDLE* next;
}CLIENT_HANDLE,*PCLIENT_HANDLE;

PCLIENT_HANDLE MyClients;

#define CLIENT_LIST_LOOP(a) MyClients = a->GetClientListHead(); \
	while(MyClients->next) {

#define CLIENT_LIST_END_LOOP(a) MyClients = MyClients->next; }

#define CUR_CLIENT MyClients
#define CUR_CLIENT_IP MyClients->szIpAddress
#define CUR_CLIENT_SOCKETID MyClients->sSocketId
#define CUR_CLIENT_ID MyClients->nClientNumber

class CServer
{
	// ---------------------
	// Private delcaration
private:
	PCLIENT_HANDLE m_ClientListHead;
	PCLIENT_HANDLE m_CurrentAcceptingClient;
	PCLIENT_HANDLE m_CurrentReceivingClient;
	int m_TotalClientCount;
	int m_MaxClient;
	int m_ClientCount;
	int m_BufferSize;
	char* m_BufferReceived;
	bool m_isServerStarted;

	void AddClient(SOCKET sSocketId,char* szIpAddress,PCLIENT_HANDLE pListHead);
	void RemoveClient(SOCKET sSocketId,PCLIENT_HANDLE pListHead);

	void ClientAccepting();
	static DWORD StartAccepting(void* pParam);

	void ClientReading();
	static DWORD StartReading(void* pParam);
	// ---------------------
	// Protected declaration
protected:
	SOCKADDR_IN m_ServerAddress;
	SOCKET m_ListeningSocket;
	WSADATA m_WSAData;
	int m_Port;
	// ---------------------
	// Public delcaration
public:
	CServer();
	CServer(int nPort);
	~CServer();

	void SetPort(int nPort);

	virtual void OnClientReceive(CServer*){};
	virtual void OnClientConnection(CServer*){};

	PCLIENT_HANDLE GetLatestReadClient();
	PCLIENT_HANDLE GetLatestConnectedClient();
	PCLIENT_HANDLE GetClientListHead();
	
	int SendPacketToClient(char* pPacket,int nSize,PCLIENT_HANDLE pClientHandle);
	int SendPacketToAllClients(char* pPacket,int nSize);

	bool StartServer();
	bool isServerStarted();

	char* GetReceivedBuffer();
	int GetReceivedSize();

	int SetMaxClientAmmount(int nAmmount);
	int GetClientCount();
	int GetPort();
	int GetMaxClients();

};

ERRORS:

--------------------Configuration: Chat Server - Win32 Release--------------------
Compiling...
CServer.cpp
Main.cpp
Generating Code...
Linking...
Main.obj : error LNK2005: "public: __thiscall CServer::CServer(void)" (??0CServer@@QAE@XZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: __thiscall CServer::CServer(int)" (??0CServer@@QAE@H@Z) already defined in CServer.obj
Main.obj : error LNK2005: "public: __thiscall CServer::~CServer(void)" (??1CServer@@QAE@XZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: void __thiscall CServer::SetPortA(int)" (?SetPortA@CServer@@QAEXH@Z) already defined in CServer.obj
Main.obj : error LNK2005: "public: bool __thiscall CServer::StartServer(void)" (?StartServer@CServer@@QAE_NXZ) already defined in CServer.obj
Main.obj : error LNK2005: "private: void __thiscall CServer::AddClient(unsigned int,char *,struct CLIENT_HANDLE *)" (?AddClient@CServer@@AAEXIPADPAUCLIENT_HANDLE@@@Z) already defined in CServer.obj
Main.obj : error LNK2005: "private: void __thiscall CServer::RemoveClient(unsigned int,struct CLIENT_HANDLE *)" (?RemoveClient@CServer@@AAEXIPAUCLIENT_HANDLE@@@Z) already defined in CServer.obj
Main.obj : error LNK2005: "public: bool __thiscall CServer::isServerStarted(void)" (?isServerStarted@CServer@@QAE_NXZ) already defined in CServer.obj
Main.obj : error LNK2005: "private: static unsigned long __cdecl CServer::StartAccepting(void *)" (?StartAccepting@CServer@@CAKPAX@Z) already defined in CServer.obj
Main.obj : error LNK2005: "private: static unsigned long __cdecl CServer::StartReading(void *)" (?StartReading@CServer@@CAKPAX@Z) already defined in CServer.obj
Main.obj : error LNK2005: "public: int __thiscall CServer::GetMaxClients(void)" (?GetMaxClients@CServer@@QAEHXZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: int __thiscall CServer::GetClientCount(void)" (?GetClientCount@CServer@@QAEHXZ) already defined in CServer.obj
Main.obj : error LNK2005: "private: void __thiscall CServer::ClientAccepting(void)" (?ClientAccepting@CServer@@AAEXXZ) already defined in CServer.obj
Main.obj : error LNK2005: "private: void __thiscall CServer::ClientReading(void)" (?ClientReading@CServer@@AAEXXZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: struct CLIENT_HANDLE * __thiscall CServer::GetLatestReadClient(void)" (?GetLatestReadClient@CServer@@QAEPAUCLIENT_HANDLE@@XZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: struct CLIENT_HANDLE * __thiscall CServer::GetLatestConnectedClient(void)" (?GetLatestConnectedClient@CServer@@QAEPAUCLIENT_HANDLE@@XZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: struct CLIENT_HANDLE * __thiscall CServer::GetClientListHead(void)" (?GetClientListHead@CServer@@QAEPAUCLIENT_HANDLE@@XZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: char * __thiscall CServer::GetReceivedBuffer(void)" (?GetReceivedBuffer@CServer@@QAEPADXZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: int __thiscall CServer::GetReceivedSize(void)" (?GetReceivedSize@CServer@@QAEHXZ) already defined in CServer.obj
Main.obj : error LNK2005: "public: int __thiscall CServer::SetMaxClientAmmount(int)" (?SetMaxClientAmmount@CServer@@QAEHH@Z) already defined in CServer.obj
Main.obj : error LNK2005: "public: int __thiscall CServer::SendPacketToClient(char *,int,struct CLIENT_HANDLE *)" (?SendPacketToClient@CServer@@QAEHPADHPAUCLIENT_HANDLE@@@Z) already defined in CServer.obj
Main.obj : error LNK2005: "public: int __thiscall CServer::SendPacketToAllClients(char *,int)" (?SendPacketToAllClients@CServer@@QAEHPADH@Z) already defined in CServer.obj
Main.obj : error LNK2005: "struct CLIENT_HANDLE * MyClients" (?MyClients@@3PAUCLIENT_HANDLE@@A) already defined in CServer.obj
Release/Chat Server.exe : fatal error LNK1169: one or more multiply defined symbols found
Error executing link.exe.

Chat Server.exe - 24 error(s), 0 warning(s)

c++

3 Contributors
4 Replies
112 Views
1 Day Discussion Span
Latest Post 15 Years Ago Latest Post by mahlerfive

All 4 Replies

mitrmkar 1,056 Posting Virtuoso

15 Years Ago

Don't #include "CServer.cpp" in main.cpp.
Instead #include "CServer.h" and move the CServer:: stuff from main.cpp to CServer.cpp.

Reply to this topic

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.

FTProtocol -24 Junior Poster in Training · Answer 1 · 2008-08-18T15:10:35+00:00

i dont understand you sorry?

edit:

i did that now i have

--------------------Configuration: Chat Server - Win32 Release--------------------
Compiling...
CServer.cpp
Main.cpp
Generating Code...
Linking...
Main.obj : error LNK2005: "struct CLIENT_HANDLE * Clients" (?Clients@@3PAUCLIENT_HANDLE@@A) already defined in CServer.obj
Release/Chat Server.exe : fatal error LNK1169: one or more multiply defined symbols found
Error executing link.exe.

Chat Server.exe - 2 error(s), 0 warning(s)

mitrmkar 1,056 Posting Virtuoso · Answer 2 · 2008-08-18T15:34:05+00:00

i dont understand you sorry?
edit:
i did that now i have
Linking...
Main.obj : error LNK2005: "struct CLIENT_HANDLE * Clients" (?Clients@@3PAUCLIENT_HANDLE@@A) already defined in CServer.obj
Release/Chat Server.exe : fatal error LNK1169: one or more multiply defined symbols found
Error executing link.exe.

You probably have two times the following: PCLIENT_HANDLE Clients; One in main and the other in CServer, you need to remove or rename one.

mahlerfive 23 Junior Poster in Training · Answer 3 · 2008-08-18T16:30:52+00:00

The way you've structured your headers (.h) and implementation (.cpp) files is not very good and is probably causing the problem.

Typically for a class you should always have a header file which you have header file "guards" and inside you declare the class. It should look something like this:

#ifndef _CLASSFILENAME_H_      //part of header guard
#define _CLASSFILENAME_H_     // part of header guard

// necessary includes and stuff go here

class MyClass {
   public:
      MyClass();
      void Foo();
};

#endif   // end of header guard

Then your .cpp file which contains the actual class definition should look like this:

#include "Classfilename.h"

MyClass::MyClass() {
   // do constructor stuff here
}

void MyClass::Foo() {
   // do foo stuff here
}

Then you should have a main which is completely separate from the class in main.cpp. You simply include the class file header and now you can use the class.

#include "Classfilename.h"

int main() {
   MyClass x;
   x.Foo();

   return 0;
}

Linking Errors

Recommended Answers Collapse Answers

All 4 Replies

Recommended Answers