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//          Kokkos: Node API and Parallel Node Kernels
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#ifndef KOKKOS_DEFAULTNODE_HPP
#define KOKKOS_DEFAULTNODE_HPP

#include "Kokkos_ConfigDefs.hpp"
#include "Kokkos_NodeAPIConfigDefs.hpp"
#include "KokkosClassic_DefaultNode_config.h"
#include "KokkosCompat_ClassicNodeAPI_Wrapper.hpp"
#include "Teuchos_ParameterList.hpp"
#include "Teuchos_RCP.hpp"

namespace KokkosClassic {

namespace Details {
  /// \fn getNode
  /// \brief Create and return a Kokkos Node instance.
  /// \tparam NodeType The Kokkos Node type.
  ///
  /// \warning This function is <i>not</i> safe to be called by
  ///   multiple threads simultaneously.  The first call to this
  ///   function must be serialized.  Also, RCP is not currently
  ///   thread safe.
  ///
  /// \param params [in/out] On input: Any parameters that the Kokkos
  ///   Node accepts.  On output, the list may be modified to include
  ///   missing parameters and their default values.  If params is
  ///   null, default parameters will be used.
  ///
  /// Every Kokkos Node's constructor takes a Teuchos::ParameterList.
  /// We presume that for every Kokkos Node, if that list of
  /// parameters is empty, then the Node will use default parameters.
  /// This is true for all the Node types implemented in Kokkos.
  template<class NodeType>
  Teuchos::RCP<NodeType>
  getNode (const Teuchos::RCP<Teuchos::ParameterList>& params = Teuchos::null) {
    static Teuchos::RCP<NodeType> theNode;
    if (theNode.is_null ()) {
      if (params.is_null ()) {
        Teuchos::ParameterList defaultParams;
        theNode = Teuchos::rcp (new NodeType (defaultParams));
      } else {
        theNode = Teuchos::rcp (new NodeType (*params));
      }
    }
    return theNode;
  }

} // namespace Details

  /** \brief Class to specify %Kokkos default node type and instantiate the default node.
      \ingroup kokkos_node_api
    */
  class DefaultNode {
  public:
#if defined(HAVE_TPETRA_DEFAULTNODE_CUDAWRAPPERNODE)
    typedef ::Kokkos::Compat::KokkosCudaWrapperNode DefaultNodeType;
#elif defined(HAVE_TPETRA_DEFAULTNODE_OPENMPWRAPPERNODE)
    typedef ::Kokkos::Compat::KokkosOpenMPWrapperNode DefaultNodeType;
#elif defined(HAVE_TPETRA_DEFAULTNODE_THREADSWRAPPERNODE)
    typedef ::Kokkos::Compat::KokkosThreadsWrapperNode DefaultNodeType;
#elif defined(HAVE_TPETRA_DEFAULTNODE_SERIALWRAPPERNODE)
    typedef ::Kokkos::Compat::KokkosSerialWrapperNode DefaultNodeType;
#else
#    error "No default Kokkos Node type specified.  Please set the CMake option Tpetra_DefaultNode to a valid Node type."
#endif

    //! \brief Return a pointer to the default node.
    static Teuchos::RCP<DefaultNodeType> getDefaultNode();
  };

} // namespace KokkosClassic

#endif // KOKKOS_DEFAULTNODE_HPP

