Odd socket() error — returns -1, but errno=ERROR_SUCCESS

Question

I'm developing a dedicated game server on a linux machine, in C/C++ (mixed). I have the following snippet of code:

int sockfd=socket(AI_INET, SOCK_DGRAM, 0);
if(sockfd==-1)
{
    int err=errno;
    fprintf(stderr,"%s",strerror(err));
    exit(1);
}

My problem here, is that socket is returning -1 (implying a failure) and the error string is being printed, but it is "Success" (ERROR_SUCCESS).

Other notes:

• I am requesting a socket on a port >1024 (out of context, but thought I'd mention)
• I'm executing the app as the super user

Answer 1

I feel incredibly stupid. Carefully looking over my code, on my dev-computer shows:

if(sockfd==-1);
...

Answer 2

Do you have multiple threads running? They could be overwriting the errno value.

Are there any lines of code between socket() and if() that you left out? Another function call could overwrite the errno.