select() always blocks non-blocking socket

Hi,

I have simple app which sends NNTP commands like LIST or GROUP to a news server and attempts to read the server's response. My problem is, that select() will always wait for the entire timeout period event though I created a non-blocking socket. If I specify a small timeout value, select() will frequently return without any data, if I supply a large value like 5 or 10 sec, it will always wait for exactly that amount of time! Isn't the timeout parameter supposed to be a maximum value? Here is the code that does it (error checking and other code ommitted for brevity). Any idea what I'm doing wrong?

Thanks in advance, Olaf

m_Socket = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
connect( m_Socket, ( sockaddr* )&saServer, sizeof( saServer ) );
u_long ulIoctlBlock = 1;
ioctlsocket( m_Socket, FIONBIO, &ulIoctlBlock ); // <-- Create non-blocking socket
fd_set fdRead;
FD_ZERO( &fdRead );
FD_SET( m_Socket, &fdRead );
timeval tvTimeout;
tvTimeout.tv_sec = 5; // <-- Maximum (?) timeout value
tvTimeout.tv_usec = 0;
for ( int cbBytes = 0, nRet = SOCKET_ERROR; ; )
{
nRet = select( 1, &fdRead, NULL, NULL, &tvTimeout ); <-- Will always wait for the entire timeout period!
if ( nRet == SOCKET_ERROR )
{
break;
}
if ( nRet == 0 )
{
continue;
}
if ( ( cbBytes = recv( m_Socket, chBuffer, ulBufferSize, 0 ) ) <= 0 ) // <-- May reach this line without having read any data if timeout period is zero or too short
{
break;
}
}

.

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