Winsock IO 模型 - 选择模型

#define FD_SETSIZE 8888 /* 可以自己定义可以连接的客户端个数 */
#include <winsock2.h>
#include <stdio.h>
#pragma comment(lib,"kernel32.lib")
#pragma comment(lib,"user32.lib")
#pragma comment(linker, "/SUBSYSTEM:windows")
#pragma comment(linker, "/ENTRY:main")
#define PORT	5150
#define MSGSIZE 1024
#pragma comment(lib, "ws2_32.lib")
int	g_iTotalConn = 0;
SOCKET	g_CliSocketArr[FD_SETSIZE];
DWORD WINAPI WorkerThread( LPVOID lpParameter );


/* Define an example conditional function that depends on the pQos field */
int CALLBACK ConditionAcceptFunc( LPWSABUF lpCallerId, LPWSABUF lpCallerData, LPQOS pQos, LPQOS lpGQOS, LPWSABUF lpCalleeId, LPWSABUF lpCalleeData, GROUP FAR * g, DWORD_PTR dwCallbackData )
{
/* 当前连接数要小才可以 */
	if ( pQos != NULL && g_iTotalConn < FD_SETSIZE )
	{
		RtlZeroMemory( pQos, sizeof(QOS) );
		/* 可以连接 */
		return(CF_ACCEPT);
	} else return(CF_REJECT);
}


int main()
{
	WSADATA					wsaData;
	SOCKET					sListen, sClient; SOCKADDR_IN local, client;
	int					iaddrSize = sizeof(SOCKADDR_IN);
	DWORD					dwThreadId;
	Initialize Windows socket library	WSAStartup( 0x0202, &wsaData );
	Create listening socket			sListen = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
	Bind local.sin_addr.S_un.		S_addr	= htonl( INADDR_ANY );
	local.sin_family	= AF_INET;
	local.sin_port		= htons( PORT );
	bind( sListen, (struct sockaddr *) &local, sizeof(SOCKADDR_IN) );
	Listen listen( sListen, 3 );
	printf( "Listening.../n" );
	Create worker thread CreateThread( NULL, 0, WorkerThread, NULL, 0, &dwThreadId );
	while ( TRUE )
	{
		Accept a connection sClient = accept( sListen, (struct sockaddr *) &client, &iaddrSize );
		/* WSAAccept 不会用... */
		sClient = WSAAccept( sListen, (struct sockaddr *) &client, &iaddrSize, ConditionAcceptFunc, NULL );
		printf( "Accepted client:%s:%d/n", inet_ntoa( client.sin_addr ), ntohs( client.sin_port ) );
		/* Add socket to g_CliSocketArr */
		g_CliSocketArr[g_iTotalConn++] = sClient;
	}
	closesocket( sListen );
	WSACleanup();
	return(0);
}


DWORD WINAPI WorkerThread( LPVOID lpParam )
{
	int		i;
	fd_set		fdread;
	int		ret;
	struct timeval	tv = { 1, 0 };
	char		szMessage[MSGSIZE];
	while ( TRUE )
	{
		FD_ZERO( &fdread );
		for ( i = 0; i < g_iTotalConn; i++ )
		{
			FD_SET( g_CliSocketArr[i], &fdread );
		}
		/* We only care read event */
		ret = select( 0, &fdread, NULL, NULL, &tv ); if ( ret == 0 )
		{
			/* Time expired */
			continue;
		}
		if ( g_iTotalConn == 0 )

		{
/* 没有客户连接 */
			Sleep( 1 );
/* 貌似这种情况必须延迟一下或者处理下别的 不然 cpu100% */
			continue;
		}
		for ( i = 0; i < g_iTotalConn; i++ )
		{
			if ( FD_ISSET( g_CliSocketArr[i], &fdread ) )
			{
				/* A read event happened on g_CliSocketArr[i] */
				ret = recv( g_CliSocketArr[i], szMessage, MSGSIZE, 0 );
				if ( ret == 0 || (ret == SOCKET_ERROR && WSAGetLastError() == WSAECONNRESET) )
				{
					/* Client socket closed */
					printf( "Client socket %d closed./n", g_CliSocketArr[i] );
					closesocket( g_CliSocketArr[i] );
					if ( i < g_iTotalConn - 1 )
					{
						g_CliSocketArr[i--] = g_CliSocketArr[--g_iTotalConn];
					} else { g_iTotalConn--; }
				} else {
					/* We received a message from client */
					szMessage[ret] = '/0';
					SOCKET		s	= g_CliSocketArr[i];
					SOCKADDR_IN	sa	= { 0 };
					int		nsaLen	= sizeof(SOCKADDR_IN);
					char		*szIp	= NULL; int nPort = 0;
					if ( getpeername( s, (struct sockaddr *) &sa, &nsaLen ) == 0 )
					{
						szIp = inet_ntoa( sa.sin_addr ); nPort = htons( sa.sin_port );
					}
					printf( "RecvDatFrom s:%d %s:%d dat:%s/r/n", s, szIp, nPort, szMessage );
					send( g_CliSocketArr[i], szMessage, strlen( szMessage ), 0 );
				}
			}
		}
	}
	return(0);
}