Hi I'm relatively new to creating servers, using sockets etc. I am creating a multithreaded server which allows multiple users to connect, I want to implement a method where when the client exits it should send a quit message to the server, I have been trying to do this by using CTRL_CLOSE_EVENT but can not get my head round how to use it.

here is my client code that I am trying to implement the close event on
Code:
#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#include <string>

// Need to link with Ws2_32.lib, Mswsock.lib, and Advapi32.lib
#pragma comment (lib, "Ws2_32.lib")
#pragma comment (lib, "Mswsock.lib")
#pragma comment (lib, "AdvApi32.lib")


#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT "27015"
using namespace std;

static BOOL CtrlHandler(DWORD fdwCtrlType)
{
	switch (fdwCtrlType)
	{
		// Handle the CTRL-C signal. 
	case CTRL_CLOSE_EVENT:
		Beep(600, 200);
		printf("Ctrl-Close event\n\n");
		return(TRUE);
	default:
		return FALSE;
	}
}
int __cdecl main(int argc, char **argv)
{
	WSADATA wsaData;
	DWORD fdwcontroltype = SetConsoleCtrlHandler((PHANDLER_ROUTINE)CtrlHandler, TRUE);
	
	SOCKET ConnectSocket = INVALID_SOCKET;
	struct addrinfo *result = NULL,
		*ptr = NULL,
		hints;
	char *sendbuf = "this is a test";
	char recvbuf[DEFAULT_BUFLEN];
	int iResult;
	int recvbuflen = DEFAULT_BUFLEN;

	

	// Initialize Winsock
	iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
	if (iResult != 0) {
		printf("WSAStartup failed with error: %d\n", iResult);
		return 1;
	}

	ZeroMemory(&hints, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;

	// Resolve the server address and port
	iResult = getaddrinfo("127.0.0.1", DEFAULT_PORT, &hints, &result);
	if (iResult != 0) {
		printf("getaddrinfo failed with error: %d\n", iResult);
		WSACleanup();
		return 1;
	}

	// Attempt to connect to an address until one succeeds
	for (ptr = result; ptr != NULL; ptr = ptr->ai_next) {

		// Create a SOCKET for connecting to server
		ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype,
			ptr->ai_protocol);
		if (ConnectSocket == INVALID_SOCKET) {
			printf("socket failed with error: %ld\n", WSAGetLastError());
			WSACleanup();
			return 1;
		}

		// Connect to server.
		iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
		if (iResult == SOCKET_ERROR) {
			closesocket(ConnectSocket);
			ConnectSocket = INVALID_SOCKET;
			continue;
		}
		break;
	}

	freeaddrinfo(result);

	if (ConnectSocket == INVALID_SOCKET) {
		printf("Unable to connect to server!\n");
		WSACleanup();
		return 1;
	}

	// Send an initial buffer
	iResult = send(ConnectSocket, sendbuf, (int)strlen(sendbuf), 0);
	if (iResult == SOCKET_ERROR) {
		printf("send failed with error: %d\n", WSAGetLastError());
		closesocket(ConnectSocket);
		WSACleanup();
		return 1;
	}

	printf("Bytes Sent: %ld\n", iResult);

	
	int quit = 1;
	// Send and Receive until the peer closes the connection
	do {
		
		
		iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
		
			if (iResult > 0)
				printf("Bytes received: %d\n", iResult);
			else if (iResult == 0)
				printf("Connection closed\n");
			else
				printf("recv failed with error: %d\n", WSAGetLastError());
			if (fdwcontroltype == CTRL_CLOSE_EVENT)
			{

				send(ConnectSocket, (char*)&quit, sizeof(quit), 0);

				iResult = shutdown(ConnectSocket, SD_BOTH);
				if (iResult == SOCKET_ERROR) {
					printf("shutdown failed with error: %d\n", WSAGetLastError());
					closesocket(ConnectSocket);
					WSACleanup();
					return 1;
				}
		}
	} while (iResult > 0);

	// shutdown the connection since no more data will be sent
	iResult = shutdown(ConnectSocket, SD_SEND);
	if (iResult == SOCKET_ERROR) {
		printf("shutdown failed with error: %d\n", WSAGetLastError());
		closesocket(ConnectSocket);
		WSACleanup();
		return 1;
	}
	// cleanup
	closesocket(ConnectSocket);
	WSACleanup();
	system("PAUSE");
	return 0;
}
here is my server code if you want to try and use it, you will need to remove game.h include
Code:
#undef UNICODE

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#include <mutex>
#include <iostream>
#include <string>
#include "game.h"
#include <fstream>

// Need to link with Ws2_32.lib
#pragma comment (lib, "Ws2_32.lib")
// #pragma comment (lib, "Mswsock.lib")
#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT "27015"
#define DEFAULT_IP "127.0.0.1 "
std::mutex MyMutex;
int ClientCount;
using namespace std;
std::ofstream outfile ("serverconfig.txt", std::ofstream::out | std::ofstream::app);
int callThread(SOCKET ClientSocket,int ClientCount )
{
	
	char recvbuf[DEFAULT_BUFLEN];
	
	int recvbuflen = DEFAULT_BUFLEN;
		int iResult, iSendResult;
		// Receive until the peer shuts down the connection
			
		printf("thread count: %d\n", ClientCount);
			do {
			

				iResult = recv(ClientSocket, recvbuf, recvbuflen, 0);
					if (iResult == 1)
					{
						
						cout << "Client " << ClientCount << " has left" << endl;
						closesocket(ClientSocket);
						ClientCount--;
						
					}
					if (iResult > 0) {
						
							printf("Bytes received: %d\n", iResult);
						

							
							// Echo the buffer back to the sender
							
							iSendResult = send(ClientSocket, recvbuf, iResult, 0);
						
							if (iSendResult == SOCKET_ERROR) {
								
									printf("send failed: %d\n", WSAGetLastError());
								
									closesocket(ClientSocket); 
									ClientCount--;
									return 1;
								
							}
						
							printf("Bytes sent: %d\n", iSendResult);
						
					}
				
					else if (iResult == 0)
					{
						ClientCount--;
						printf("Connection closing...\n");
					}
					else {
					
						printf("recv failed: %d\n", WSAGetLastError());
					
						closesocket(ClientSocket);
						ClientCount--;
						return 1;
					
				}
					
			} while (iResult > 0);

			
}


int __cdecl main(void)
{
	WSADATA wsaData;
	int iResult;

	SOCKET ListenSocket = INVALID_SOCKET;
	SOCKET ClientSocket = INVALID_SOCKET;

	struct addrinfo *result = NULL;
	struct addrinfo hints;

	int iSendResult;
	ClientCount = 0;
	char recvbuf[DEFAULT_BUFLEN];
	int recvbuflen = DEFAULT_BUFLEN;
	std::thread myThreads[100];
	game game1;
	string type;
	string map;
	int level;
	int max;
	int min;
	//output server details to file 
	ofstream outfile;
	outfile.open("serverconfig.txt");
	outfile << DEFAULT_IP;
	outfile << DEFAULT_PORT;
	outfile.close();
	//get start up data
	/*cout << "please choose a type: 1: Deathmatch 2: Capture the flag 3: Blood Diamond" << endl;
	cin >> type;
	cout << "Please choose a map:" << endl;
	cin >> map;
	cout << "please choose a difficulty level between 1 - 3: " << endl;
	cin >> level;
	cout << "Please choose the max number of clients: " << endl;
	cin >> max;
	cout << "Please choose the min number of clients" << endl; 
	cin >> min; */

	// Initialize Winsock
	iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
	if (iResult != 0) {
		printf("WSAStartup failed with error: %d\n", iResult);
		return 1;
	}

	ZeroMemory(&hints, sizeof(hints));
	hints.ai_family = AF_INET;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;
	hints.ai_flags = AI_PASSIVE;

	// Resolve the server address and port
	iResult = getaddrinfo(NULL, DEFAULT_PORT, &hints, &result);
	if (iResult != 0) {
		printf("getaddrinfo failed with error: %d\n", iResult);
		WSACleanup();
		return 1;
	}

	// Create a SOCKET for connecting to server
	ListenSocket = socket(result->ai_family, result->ai_socktype, result->ai_protocol);
	if (ListenSocket == INVALID_SOCKET) {
		printf("socket failed with error: %ld\n", WSAGetLastError());
		freeaddrinfo(result);
		WSACleanup();
		return 1;
	}

	// Setup the TCP listening socket
	iResult = ::bind(ListenSocket, result->ai_addr, (int)result->ai_addrlen);
	if (iResult == SOCKET_ERROR) {
		printf("bind failed with error: %d\n", WSAGetLastError());
		freeaddrinfo(result);
		closesocket(ListenSocket);
		WSACleanup();
		return 1;
	}
	
	freeaddrinfo(result);
	if (listen(ListenSocket, SOMAXCONN) == SOCKET_ERROR) {
		printf("Listen failed with error: %ld\n", WSAGetLastError());
		closesocket(ListenSocket);
		WSACleanup();
		return 1;
	}
	for (;;)
	{
		//creating a temp socket for accepting a connction
		SOCKET ClientSocket;
		// Accept a client socket
		ClientSocket = accept(ListenSocket, NULL, NULL);
		if (ClientSocket == INVALID_SOCKET) {
			printf("accept failed: %d\n", WSAGetLastError());
			closesocket(ListenSocket);
			WSACleanup();
			return 1;
		}
		else
		{

			myThreads[ClientCount] = std::thread(callThread,ClientSocket,ClientCount);
			ClientCount++;

			printf("normal count: %d\n", ClientCount);

			if (ClientCount == 1)
			{
				cout << "Waiting for another Client to connect" << endl;
			}
			/*if (ClientCount >= 2)
			{
				cout << "Game" << type << "in progress" << endl;
			}*/
			
		}
	}

	// shutdown the connection since we're done
	iResult = shutdown(ClientSocket, SD_SEND);
	if (iResult == SOCKET_ERROR) {
		printf("shutdown failed with error: %d\n", WSAGetLastError());
		closesocket(ClientSocket);
		WSACleanup();
		return 1;
	}

	// cleanup
	closesocket(ClientSocket);
	WSACleanup();
	system("PAUSE");
	return 0;
}