vtk-m/vtkm/exec/AtomicArray.h
2016-03-09 14:29:59 -05:00

79 lines
2.6 KiB
C++

//============================================================================
// Copyright (c) Kitware, Inc.
// All rights reserved.
// See LICENSE.txt for details.
// This software is distributed WITHOUT ANY WARRANTY; without even
// the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
// PURPOSE. See the above copyright notice for more information.
//
// Copyright 2015 Sandia Corporation.
// Copyright 2015 UT-Battelle, LLC.
// Copyright 2015 Los Alamos National Security.
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
// Laboratory (LANL), the U.S. Government retains certain rights in
// this software.
//============================================================================
#ifndef vtk_m_exec_AtomicArray_h
#define vtk_m_exec_AtomicArray_h
#include <vtkm/cont/DeviceAdapter.h>
#include <vtkm/cont/ArrayHandle.h>
#include <vtkm/exec/ExecutionObjectBase.h>
namespace vtkm {
namespace exec {
/// A class that can be used to atomically operate on an array of values
/// safely across multiple instances of the same worklet. This is useful when
/// you have an algorithm that needs to accumulate values in parallel, but writing
/// out a value per worklet might be memory prohibitive.
///
/// To construct an AtomicArray you will need to pass in an vtkm::cont::ArrayHandle
/// that is used as the underlying storage for the AtomicArray
///
/// Supported Operations: add / compare and swap (CAS)
///
/// Supported Types: 32 / 64 bit signed integers
///
///
template<typename T, typename DeviceAdapterTag>
class AtomicArray : public vtkm::exec::ExecutionObjectBase
{
public:
template<typename StorageType>
VTKM_CONT_EXPORT
AtomicArray(vtkm::cont::ArrayHandle<T, StorageType> handle):
AtomicImplementation( handle )
{
}
VTKM_EXEC_EXPORT
T Add(vtkm::Id index, const T& value) const
{
return this->AtomicImplementation.Add(index,value);
}
//
// Compare and Swap is an atomic exchange operation. If the value at
// the index is equal to oldValue, then newValue is written to the index.
// The operation was successful if return value is eqaul to oldValue
//
VTKM_EXEC_EXPORT
T CompareAndSwap(vtkm::Id index, const T& newValue, const T& oldValue) const
{
return this->AtomicImplementation.CompareAndSwap(index,newValue, oldValue);
}
private:
vtkm::cont::DeviceAdapterAtomicArrayImplementation<T,DeviceAdapterTag>
AtomicImplementation;
};
}
} // namespace vtkm::exec
#endif //vtk_m_exec_AtomicArray_h