\begin{table*}
  \noindent\begin{minipage}{.45\columnwidth}
    \begin{lstlisting}[caption=code 1,frame=tlrb]{Name}
      void code()
      {
      }
    \end{lstlisting}
  \end{minipage}\hfill
  \begin{minipage}{.45\columnwidth}
    \begin{lstlisting}[caption=code 2,frame=tlrb]{Name}
      void code()
      {
      }
    \end{lstlisting}
  \end{minipage}
\end{table*}

Using table and minipage to place two lstlistings side by side covering the full page width.

Latex: two side by side lstlistings in full page

LaTeX