| Wizard1988 |
Jan 15th, 2006 4:09 PM |
sockets, problem with select()
I trying to learn how to use select() with sockets, I am having a weird problem. My code does work when i use perr() for my error checking, but when I use a method I wrote the program doesen't work. Inside an if statement I check the return value of select() for anything below zero and if the return value is below zero i display the error by calling ReportError(). Somehow select returns 1 but the body of the if statement still executes. :confused:
:
#include <iostream>
#include "winsock2.h"
using namespace std;
void ReportError(const char*,int);
int main()
{
WSADATA wsaData;
SOCKET m_socket;
SOCKET AcceptSocket;
sockaddr_in service;
sockaddr_in client;
fd_set read_fds;
fd_set SocketList;
int fdmax;
int listener;
int newfd;
FD_ZERO(&SocketList);
FD_ZERO(&read_fds);
int BytesSent;
int BytesReceived;
char SndBuffer[32] = "Server: Sending Data.";
char RecBuffer[32] = "";
if(WSAStartup(MAKEWORD(2,0), &wsaData) != NO_ERROR)
{
ReportError("WSAStartup()",WSAGetLastError());
return 1;
}
if((m_socket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
{
cout << "WSAStartup() failed\n";
return (1);
}
memset(&service, 0, sizeof(service));
service.sin_family = AF_INET;
service.sin_addr.s_addr = inet_addr("127.0.0.1");
service.sin_port = htons(1000);
if(bind(m_socket,(struct sockaddr *) &service,sizeof(service)) == SOCKET_ERROR)
{
ReportError("bind()",WSAGetLastError());
closesocket(m_socket);
return 1;
}
if(listen(m_socket,10) == SOCKET_ERROR)
{
ReportError("listen()",WSAGetLastError());
return 1;
}
FD_SET(m_socket,&SocketList);
fdmax = m_socket;
cout << "Waiting for a client to connect..." << endl;
for(;;)
{
int err;
read_fds = SocketList;
if(select(m_socket+1, &read_fds, NULL, NULL, NULL) < 0)
{
ReportError("select()",WSAGetLastError());
//perror("select()");
}
for(int x = 0; x<= fdmax; x++)
{
if(FD_ISSET(x,&read_fds))
{
if(x == m_socket)
{
int AddrSize = sizeof(client);
if(AcceptSocket = accept(m_socket,(struct sockaddr *)&client,&AddrSize) == -1)
{
ReportError("accept()",WSAGetLastError());
//perror("accept()");
}
else
{
FD_SET(AcceptSocket,&SocketList);
if(AcceptSocket > fdmax)
{
fdmax = AcceptSocket;
}
cout << "New Connection from " << inet_ntoa(client.sin_addr) << " on socket " << AcceptSocket << endl;
}
}
else
{
if((BytesReceived = recv(AcceptSocket,RecBuffer,strlen(RecBuffer),0)) <=0)
{
if(BytesReceived == 0)
{
cout << "Socket " << x << " hung up" << endl;
}
else
{
perror("recv()");
}
closesocket(AcceptSocket);
FD_CLR(AcceptSocket,&SocketList);
}
else
{
cout << "Data Received from client" << endl;
cout << RecBuffer << endl;
/*
for(int tempSock = 0; tempSock <= fdmax; tempSock++)
{
}
*/
}
}
}
}
}
WSACleanup();
system("pause");
return 0;
}
void ReportError(const char* message, int error)
{
cout << "Error occoured at " << message << endl;
cout << "Error returned: " << error << endl;
system("pause");
}
Thanks for help in advance |
