problem with mysql_real_connect and mysql_close

Hi
mysql_real_connect open a socket connection to the database.
But who closes this connection and when
Is this done by mysql_close() or do I have to explicitly close the
connection?

   171     if(!mysql_real_connect(conn, server, username, password,
database, 0, NULL, 0))
   172     {
   173         mysql_close(conn);
   174         free(*server_addr);
   175         printf("%s: Error in connection!!....1\n", __func__);
   176         printf("%s: %s\n", __func__, mysql_error(conn));
   177         return ERROR;
   178     }



  263     mysql_close(conn);
The error i get is cannot create UNIX socket. The application runs for
sometime and when I check the proc file system, I see 1024 fd's.

Please let me know if i need to do something in addition to the above.

Thanks
Mikhail.