grppi-execution.tex

\subsection{Controlling execution}

\begin{frame}[t]{Execution types}
\begin{itemize}
  \item Execution model is encapsulated in execution types.
    \begin{itemize}
      \item Always provided as first argument to patterns.
    \end{itemize}

  \vfill
  \item Current concrete execution types:
    \begin{itemize}
      \item \textmark{Sequential}: \cppid{sequential\_execution}.
      \item \textmark{ISO C++ Threads}: \cppid{parallel\_execution\_native}.
      \item \textmark{OpenMP}: \cppid{parallel\_execution\_omp}.
      \item \textmark{Intel TBB}: \cppid{parallel\_execution\_tbb}.
      \item \textmark{FastFlow}: \cppid{parallel\_execution\_ff}.
    \end{itemize}

  \vfill
  \item Run-time polymorphic wrapper through type erasure:
    \begin{itemize}
      \item \cppid{dynamic\_execution}.
    \end{itemize}
\end{itemize}
\end{frame}

\begin{frame}[t,fragile]{Execution model properties}
\begin{itemize}
  \item Some execution types allow finer configurtion.
    \begin{itemize}
      \item Example: Concurrency degree.
    \end{itemize}

  \vfill\pause
  \item Interface:
\begin{lstlisting}[basicstyle=\small]
ex.set_concurrency_degree(4);
int n = ex.concurrency_degree();
\end{lstlisting}

  \vfill\pause
  \item \textenum{Default values}:
    \begin{itemize}
      \item \textmark{Sequential} $\Rightarrow$ \cppid{1}.
      \item \textmark{Native} $\Rightarrow$ \cppid{std::thread::hardware\_concurrency()}.
      \item \textmark{OpenMP} $\Rightarrow$ \cppid{omp\_get\_num\_threads()}.
    \end{itemize}

\end{itemize}
\end{frame}