Kokkos_ScratchSpace.hpp

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//   Kokkos: Manycore Performance-Portable Multidimensional Arrays
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#ifndef KOKKOS_SCRATCHSPACE_HPP
#define KOKKOS_SCRATCHSPACE_HPP

#include <stdio.h>
#include <Kokkos_Core_fwd.hpp>
#include <impl/Kokkos_Tags.hpp>

/*--------------------------------------------------------------------------*/

namespace Kokkos {

template< class ExecSpace >
class ScratchMemorySpace {
public:

  // Alignment of memory chunks returned by 'get'
  // must be a power of two
  enum { ALIGN = 8 };

private:

  mutable char * m_iter ;
  char *         m_end ;

  ScratchMemorySpace();
  ScratchMemorySpace & operator = ( const ScratchMemorySpace & );

  enum { MASK = ALIGN - 1 }; // Alignment used by View::shmem_size

public:

  typedef Impl::MemorySpaceTag              kokkos_tag ;
  typedef ScratchMemorySpace                memory_space ;
  typedef ExecSpace                         execution_space ;
  typedef typename ExecSpace::array_layout  array_layout ;

  template< typename IntType >
  KOKKOS_INLINE_FUNCTION static
  IntType align( const IntType & size )
    { return ( size + MASK ) & ~MASK ; }

  template< typename IntType >
  KOKKOS_INLINE_FUNCTION
  void * get_shmem( const IntType & size ) const
    {
      void * tmp = m_iter ;
      if ( m_end < ( m_iter += align( size ) ) ) {
        printf("ScratchMemorySpace<...>::get_shmem overflow %ld\n",long(m_end-m_iter));
        tmp = 0 ;
      }
      return tmp ;
    }

  template< typename IntType >
  KOKKOS_INLINE_FUNCTION
  ScratchMemorySpace( void * ptr , const IntType & size )
    : m_iter( (char *) ptr )
    , m_end(  m_iter + size )
    {}
};

} // namespace Kokkos

#endif /* #ifndef KOKKOS_SCRATCHSPACE_HPP */

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