[Apples]

i'm currently writing a pseudo-chat program, and it's my first real project using sockets. my operating system / language of choice is windows/c, and i would like to be able to manage ( send() / recv() ) multiple connections at the same time. how can i do something like this? help is always appreciated. thanks

[Xing]

http://www.sockets.com/

[Apples]

alright, i think my server is able to handle multiple connections now. however, when i Ctrl+C'd out of the client, the server went bonkers with messages. can anyone tell me if what i'm doing is right?

#include <stdio.h>
#include <winsock.h>
#include <windows.h>

#define MAX_CONNECTIONS 7

typedef struct _connectionData {
	SOCKET socket;
	char charCode[2];
	char user[8],pass[8];
	int intCode;
	char message[100];
} CONNECTIONDATA, *PCONNECTIONDATA;

SOCKET establish(unsigned short portnum);
DWORD WINAPI handleConnection(LPVOID lpParam);
void checkForError(int result, char *function);

SOCKET connections[MAX_CONNECTIONS];
int sockets[MAX_CONNECTIONS];

DWORD dwThreadId[MAX_CONNECTIONS];
HANDLE hThread[MAX_CONNECTIONS];

short i = 0;
SOCKET hoster;

int main()
{
	WSADATA info;	

	if (WSAStartup(MAKEWORD(1,1), &info) != 0)
	{
		printf("Cannot initialize WinSock!");
		exit(1);
	}

	if((hoster = establish(5697)) == INVALID_SOCKET)
	{	
		printf("Cannot establish socket on port 5697!");
		exit(1);
	}

	
	int len = sizeof(struct sockaddr_in);

	PCONNECTIONDATA pConData;

	// Create MAX_CONNECTIONS worker threads.
	for( i=0; i<MAX_CONNECTIONS; i++ )
	{
		// Allocate memory for thread data.
		pConData = (PCONNECTIONDATA) HeapAlloc(GetProcessHeap(),
				HEAP_ZERO_MEMORY, sizeof(CONNECTIONDATA));

			if( pConData == NULL )
					ExitProcess(2);
	
			// Generate unique data for each thread.
			pConData->socket = accept(hoster,NULL,NULL);;

			hThread[i] = CreateThread( 
				NULL,			  // default security attributes
				0,				 // use default stack size  
				handleConnection,		// thread function 
				pConData,			 // argument to thread function 
				0,				 // use default creation flags 
				&dwThreadId[i]);   // returns the thread identifier 
 
			// Check the return value for success. 
			if (hThread[i] == NULL) 
			   ExitProcess(i);
	}
		
		// Wait until all threads have terminated.
		WaitForMultipleObjects(MAX_CONNECTIONS, hThread, TRUE, INFINITE);

	// Close all thread handles upon completion.
		for(i=0; i<MAX_CONNECTIONS; i++)
		{
			CloseHandle(hThread[i]);
		}

	WSACleanup();
	return 0;
}

SOCKET establish(unsigned short portnum)
{
	char myname[256];
	SOCKET s;
	struct sockaddr_in sa;
	struct hostent *hp;
	memset(&sa, 0, sizeof(struct sockaddr_in)); /* clear our address */
	gethostname(myname, sizeof(myname)); /* who are we? */
	hp = gethostbyname(myname); /* get our address info */
	if (hp == NULL) /* we don't exist !? */
		return(INVALID_SOCKET);
	sa.sin_family = hp->h_addrtype; /* this is our host address */
	sa.sin_port = htons(portnum); /* this is our port number */
	s = socket(AF_INET, SOCK_STREAM, 0); /* create the socket */
	if (s == INVALID_SOCKET)
		return INVALID_SOCKET;
	
	/* bind the socket to the internet address */
	if (bind(s, (struct sockaddr *)&sa, sizeof(struct sockaddr_in)) == SOCKET_ERROR)
	{
		closesocket(s);
		return(INVALID_SOCKET);
	}
	
	listen(s, MAX_CONNECTIONS); /* max # of queued connects */
	return(s);
}

DWORD WINAPI handleConnection(LPVOID lpParameter)
{	
	PCONNECTIONDATA pConData = (PCONNECTIONDATA)lpParameter;	
	int result;

	while(1)
	{
		result = recv(pConData->socket,pConData->charCode,2,0);

		checkForError(result,"recv()");
	
		int pConData->intCode = atoi(pConData->charCode);

		if(pConData->intCode == 0)
			printf("Error. Bad packet sent.");

		switch(pConData->intCode)
		{
			case 10:
				printf("Successful connection.\n");
				break;
			case 11:
				printf("Login requested.\n");
			
				result = recv(pConData->socket,pConData->user,8,0);
				checkForError(result,"recv()");	
			
				result = recv(pConData->socket,pConData->pass,8,0);
				checkForError(result,"recv()");

				printf("user:%s\npass:%s\n",pConData->user,pConData->pass);
	
				result = send(pConData->socket,"12",2,0);
				checkForError(result,"send()");

				break;
			case 14:
				printf("Account creation requested.\n");
				break;
			case 17:
				printf("User list requested.\n");
				break;
			case 19:
				printf("Text being received.\n");
				break;
		}
	}
	
	HeapFree(GetProcessHeap(), 0, pConData);

	return 0;
}

void checkForError(int result, char *function)
{
	if(result == SOCKET_ERROR)
	{
		printf("%s failed with error: %d\n",function,WSAGetLastError());
		printf("Please contact apples.\n");
	}
}

i'll post the code for the client if i have to as well.

[help-linux]

result = recv(pConData->socket,pConData->charCode,2,0);

When the client disconnecteds, Winsock lets you know by returning something from this function;

result = recv(pConData->socket,pConData->charCode,2,0);
if(result <= 0)
{
  //disconnected
  //cleanup
  return 0;
}

you want something like that