consume_input (PGconn)

    /*
     * call-seq:
     *    conn.consume_input()
     *
     * If input is available from the server, consume it.
     * After calling +consume_input+, you can check +is_busy+
     * or *notifies* to see if the state has changed.
     */
    static VALUE
    pgconn_consume_input(self)
            VALUE self;
    {
            VALUE error;
            PGconn *conn = get_pgconn(self);
            /* returns 0 on error */
            if(PQconsumeInput(conn) == 0) {
                    error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                    rb_iv_set(error, "@connection", self);
                    rb_exc_raise(error);
            }
            return Qnil;
    }