/*
//@HEADER
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// 
//                        Kokkos v. 2.0
//              Copyright (2014) Sandia Corporation
// 
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
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*/

#ifndef KOKKOS_OPENMP_HPP
#define KOKKOS_OPENMP_HPP

#include <Kokkos_Core_fwd.hpp>

#if defined( KOKKOS_HAVE_OPENMP ) && defined( _OPENMP )

#include <omp.h>

#include <cstddef>
#include <iosfwd>
#include <Kokkos_HostSpace.hpp>
#ifdef KOKKOS_HAVE_HBWSPACE
#include <Kokkos_HBWSpace.hpp>
#endif
#include <Kokkos_ScratchSpace.hpp>
#include <Kokkos_Parallel.hpp>
#include <Kokkos_Layout.hpp>
#include <impl/Kokkos_Tags.hpp>

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

namespace Kokkos {

/// \class OpenMP
/// \brief Kokkos device for multicore processors in the host memory space.
class OpenMP {
public:
  //------------------------------------
  //! \name Type declarations that all Kokkos devices must provide.
  //@{

  //! Tag this class as a kokkos execution space
  typedef OpenMP                execution_space ;
  #ifdef KOKKOS_HAVE_HBWSPACE
  typedef Experimental::HBWSpace memory_space ;
  #else
  typedef HostSpace             memory_space ;
  #endif
  //! This execution space preferred device_type
  typedef Kokkos::Device<execution_space,memory_space> device_type;

  typedef LayoutRight           array_layout ;
  typedef memory_space::size_type  size_type ;

  typedef ScratchMemorySpace< OpenMP > scratch_memory_space ;

  //@}
  //------------------------------------
  //! \name Functions that all Kokkos devices must implement.
  //@{

  inline static bool in_parallel() { return omp_in_parallel(); }

  /** \brief  Set the device in a "sleep" state. A noop for OpenMP.  */
  static bool sleep();

  /** \brief Wake the device from the 'sleep' state. A noop for OpenMP. */
  static bool wake();

  /** \brief Wait until all dispatched functors complete. A noop for OpenMP. */
  static void fence() {}

  /// \brief Print configuration information to the given output stream.
  static void print_configuration( std::ostream & , const bool detail = false );

  /// \brief Free any resources being consumed by the device.
  static void finalize();

  /** \brief  Initialize the device.
   *
   *  1) If the hardware locality library is enabled and OpenMP has not
   *     already bound threads then bind OpenMP threads to maximize
   *     core utilization and group for memory hierarchy locality.
   *
   *  2) Allocate a HostThread for each OpenMP thread to hold its
   *     topology and fan in/out data.
   */
  static void initialize( unsigned thread_count = 0 ,
                          unsigned use_numa_count = 0 ,
                          unsigned use_cores_per_numa = 0 );

  static int is_initialized();
  //@}
  //------------------------------------
  /** \brief  This execution space has a topological thread pool which can be queried.
   *
   *  All threads within a pool have a common memory space for which they are cache coherent.
   *    depth = 0  gives the number of threads in the whole pool.
   *    depth = 1  gives the number of threads in a NUMA region, typically sharing L3 cache.
   *    depth = 2  gives the number of threads at the finest granularity, typically sharing L1 cache.
   */
  inline static int thread_pool_size( int depth = 0 );

  /** \brief  The rank of the executing thread in this thread pool */
  KOKKOS_INLINE_FUNCTION static int thread_pool_rank();

  //------------------------------------

  inline static unsigned max_hardware_threads() { return thread_pool_size(0); }

  KOKKOS_INLINE_FUNCTION static
  unsigned hardware_thread_id() { return thread_pool_rank(); }
};

} // namespace Kokkos

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

namespace Kokkos {
namespace Impl {

template<>
struct VerifyExecutionCanAccessMemorySpace
  < Kokkos::OpenMP::memory_space
  , Kokkos::OpenMP::scratch_memory_space
  >
{
  enum { value = true };
  inline static void verify( void ) { }
  inline static void verify( const void * ) { }
};

} // namespace Impl
} // namespace Kokkos

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

#include <OpenMP/Kokkos_OpenMPexec.hpp>
#include <OpenMP/Kokkos_OpenMP_Parallel.hpp>

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

#endif /* #if defined( KOKKOS_HAVE_OPENMP ) && defined( _OPENMP ) */
#endif /* #ifndef KOKKOS_OPENMP_HPP */


