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lammps/lib/kokkos/core/src/Cuda/Kokkos_Cuda_UniqueToken.hpp
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Kokkos_Cuda_UniqueToken.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_UNIQUE_TOKEN_HPP
#define KOKKOS_CUDA_UNIQUE_TOKEN_HPP
#include <Kokkos_Macros.hpp>
#ifdef KOKKOS_ENABLE_CUDA
#include <Kokkos_CudaSpace.hpp>
#include <Kokkos_UniqueToken.hpp>
#include <impl/Kokkos_SharedAlloc.hpp>
#include <impl/Kokkos_ConcurrentBitset.hpp>
namespace Kokkos { namespace Experimental {
// both global and instance Unique Tokens are implemented in the same way
template<>
class UniqueToken< Cuda, UniqueTokenScope::Global >
{
private:
uint32_t volatile * m_buffer ;
uint32_t m_count ;
public:
using execution_space = Cuda;
explicit
UniqueToken( execution_space const& );
KOKKOS_INLINE_FUNCTION
UniqueToken() : m_buffer(0), m_count(0) {}
KOKKOS_INLINE_FUNCTION
UniqueToken( const UniqueToken & ) = default;
KOKKOS_INLINE_FUNCTION
UniqueToken( UniqueToken && ) = default;
KOKKOS_INLINE_FUNCTION
UniqueToken & operator=( const UniqueToken & ) = default ;
KOKKOS_INLINE_FUNCTION
UniqueToken & operator=( UniqueToken && ) = default ;
/// \brief upper bound for acquired values, i.e. 0 <= value < size()
KOKKOS_INLINE_FUNCTION
int32_t size() const noexcept { return m_count ; }
/// \brief acquire value such that 0 <= value < size()
KOKKOS_INLINE_FUNCTION
int32_t acquire() const
{
const Kokkos::pair<int,int> result =
Kokkos::Impl::concurrent_bitset::
acquire_bounded( m_buffer
, m_count
, Kokkos::Impl::clock_tic() % m_count
);
if ( result.first < 0 ) {
Kokkos::abort("UniqueToken<Cuda> failure to release tokens, no tokens available" );
}
return result.first;
}
/// \brief release an acquired value
KOKKOS_INLINE_FUNCTION
void release( int32_t i ) const noexcept
{
Kokkos::Impl::concurrent_bitset::release( m_buffer, i );
}
};
template<>
class UniqueToken< Cuda, UniqueTokenScope::Instance >
: public UniqueToken< Cuda, UniqueTokenScope::Global >
{
public:
explicit
UniqueToken( execution_space const& arg )
: UniqueToken< Cuda, UniqueTokenScope::Global >( arg ) {}
};
}} // namespace Kokkos::Experimental
#endif // KOKKOS_ENABLE_CUDA
#endif // KOKKOS_CUDA_UNIQUE_TOKEN_HPP
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