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lammps/lib/kokkos/core/src/Kokkos_Cuda.hpp
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Kokkos_Cuda.hpp
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/*
//@HEADER
// ************************************************************************
//
// Kokkos v. 2.0
// Copyright (2014) Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact H. Carter Edwards (hcedwar@sandia.gov)
//
// ************************************************************************
//@HEADER
*/
#ifndef KOKKOS_CUDA_HPP
#define KOKKOS_CUDA_HPP
#include <Kokkos_Macros.hpp>
#if defined( KOKKOS_ENABLE_CUDA )
#include <Kokkos_Core_fwd.hpp>
#include <iosfwd>
#include <vector>
#include <Kokkos_CudaSpace.hpp>
#include <Kokkos_Parallel.hpp>
#include <Kokkos_TaskScheduler.hpp>
#include <Kokkos_Layout.hpp>
#include <Kokkos_ScratchSpace.hpp>
#include <Kokkos_MemoryTraits.hpp>
#include <impl/Kokkos_Tags.hpp>
/*--------------------------------------------------------------------------*/
namespace Kokkos {
namespace Impl {
class CudaExec ;
} // namespace Impl
} // namespace Kokkos
/*--------------------------------------------------------------------------*/
namespace Kokkos {
/// \class Cuda
/// \brief Kokkos Execution Space that uses CUDA to run on GPUs.
///
/// An "execution space" represents a parallel execution model. It tells Kokkos
/// how to parallelize the execution of kernels in a parallel_for or
/// parallel_reduce. For example, the Threads execution space uses Pthreads or
/// C++11 threads on a CPU, the OpenMP execution space uses the OpenMP language
/// extensions, and the Serial execution space executes "parallel" kernels
/// sequentially. The Cuda execution space uses NVIDIA's CUDA programming
/// model to execute kernels in parallel on GPUs.
class Cuda {
public:
//! \name Type declarations that all Kokkos execution spaces must provide.
//@{
//! Tag this class as a kokkos execution space
typedef Cuda execution_space ;
#if defined( KOKKOS_ENABLE_CUDA_UVM )
//! This execution space's preferred memory space.
typedef CudaUVMSpace memory_space ;
#else
//! This execution space's preferred memory space.
typedef CudaSpace memory_space ;
#endif
//! This execution space preferred device_type
typedef Kokkos::Device<execution_space,memory_space> device_type;
//! The size_type best suited for this execution space.
typedef memory_space::size_type size_type ;
//! This execution space's preferred array layout.
typedef LayoutLeft array_layout ;
//!
typedef ScratchMemorySpace< Cuda > scratch_memory_space ;
//@}
//--------------------------------------------------
//! \name Functions that all Kokkos devices must implement.
//@{
/// \brief True if and only if this method is being called in a
/// thread-parallel function.
KOKKOS_INLINE_FUNCTION static int in_parallel() {
#if defined( __CUDA_ARCH__ )
return true;
#else
return false;
#endif
}
/** \brief Set the device in a "sleep" state.
*
* This function sets the device in a "sleep" state in which it is
* not ready for work. This may consume less resources than if the
* device were in an "awake" state, but it may also take time to
* bring the device from a sleep state to be ready for work.
*
* \return True if the device is in the "sleep" state, else false if
* the device is actively working and could not enter the "sleep"
* state.
*/
static bool sleep();
/// \brief Wake the device from the 'sleep' state so it is ready for work.
///
/// \return True if the device is in the "ready" state, else "false"
/// if the device is actively working (which also means that it's
/// awake).
static bool wake();
/// \brief Wait until all dispatched functors complete.
///
/// The parallel_for or parallel_reduce dispatch of a functor may
/// return asynchronously, before the functor completes. This
/// method does not return until all dispatched functors on this
/// device have completed.
static void fence();
//! Free any resources being consumed by the device.
static void finalize();
//! Has been initialized
static int is_initialized();
/** \brief Return the maximum amount of concurrency. */
static int concurrency();
//! Print configuration information to the given output stream.
static void print_configuration( std::ostream & , const bool detail = false );
//@}
//--------------------------------------------------
//! \name Cuda space instances
~Cuda() {}
Cuda();
explicit Cuda( const int instance_id );
Cuda( Cuda && ) = default ;
Cuda( const Cuda & ) = default ;
Cuda & operator = ( Cuda && ) = default ;
Cuda & operator = ( const Cuda & ) = default ;
//--------------------------------------------------------------------------
//! \name Device-specific functions
//@{
struct SelectDevice {
int cuda_device_id ;
SelectDevice() : cuda_device_id(0) {}
explicit SelectDevice( int id ) : cuda_device_id( id ) {}
};
//! Initialize, telling the CUDA run-time library which device to use.
static void initialize( const SelectDevice = SelectDevice()
, const size_t num_instances = 1 );
/// \brief Cuda device architecture of the selected device.
///
/// This matches the __CUDA_ARCH__ specification.
static size_type device_arch();
//! Query device count.
static size_type detect_device_count();
/** \brief Detect the available devices and their architecture
* as defined by the __CUDA_ARCH__ specification.
*/
static std::vector<unsigned> detect_device_arch();
cudaStream_t cuda_stream() const { return m_stream ; }
int cuda_device() const { return m_device ; }
//@}
//--------------------------------------------------------------------------
static const char* name();
private:
cudaStream_t m_stream ;
int m_device ;
};
} // namespace Kokkos
/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/
namespace Kokkos {
namespace Impl {
template<>
struct MemorySpaceAccess
< Kokkos::CudaSpace
, Kokkos::Cuda::scratch_memory_space
>
{
enum { assignable = false };
enum { accessible = true };
enum { deepcopy = false };
};
#if defined( KOKKOS_ENABLE_CUDA_UVM )
// If forcing use of UVM everywhere
// then must assume that CudaUVMSpace
// can be a stand-in for CudaSpace.
// This will fail when a strange host-side execution space
// that defines CudaUVMSpace as its preferredmemory space.
template<>
struct MemorySpaceAccess
< Kokkos::CudaUVMSpace
, Kokkos::Cuda::scratch_memory_space
>
{
enum { assignable = false };
enum { accessible = true };
enum { deepcopy = false };
};
#endif
template<>
struct VerifyExecutionCanAccessMemorySpace
< Kokkos::CudaSpace
, Kokkos::Cuda::scratch_memory_space
>
{
enum { value = true };
KOKKOS_INLINE_FUNCTION static void verify( void ) { }
KOKKOS_INLINE_FUNCTION static void verify( const void * ) { }
};
template<>
struct VerifyExecutionCanAccessMemorySpace
< Kokkos::HostSpace
, Kokkos::Cuda::scratch_memory_space
>
{
enum { value = false };
inline static void verify( void ) { CudaSpace::access_error(); }
inline static void verify( const void * p ) { CudaSpace::access_error(p); }
};
} // namespace Impl
} // namespace Kokkos
/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/
#include <Cuda/Kokkos_CudaExec.hpp>
#include <Cuda/Kokkos_Cuda_View.hpp>
#include <Cuda/Kokkos_Cuda_Team.hpp>
#include <Cuda/Kokkos_Cuda_Parallel.hpp>
#include <Cuda/Kokkos_Cuda_Task.hpp>
#include <KokkosExp_MDRangePolicy.hpp>
//----------------------------------------------------------------------------
#endif /* #if defined( KOKKOS_ENABLE_CUDA ) */
#endif /* #ifndef KOKKOS_CUDA_HPP */
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