cudaPtr.hpp

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/** \file cudaPtr.hpp
 * \author Jared R. Males
 * \brief A wrapper for cuda device pointers
 * \ingroup cuda_files
 *
 */
 
//***********************************************************************//
// Copyright 2019,2020 Jared R. Males (jaredmales@gmail.com)
//
// This file is part of mxlib.
//
// mxlib is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// mxlib is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with mxlib.  If not, see <http://www.gnu.org/licenses/>.
//***********************************************************************//
 
#ifndef math_cudaPtr_hpp
#define math_cudaPtr_hpp
 
#include <iostream>
 
#include <cuda_runtime.h>
 
#include "templateCuda.hpp"
 
namespace mx
{
namespace cuda
{
 
/// A smart-pointer wrapper for cuda device pointers.
/**
 * \ingroup cuda
 */
template <typename T>
struct cudaPtr
{
    /// The host data type.
    // typedef typename cudaType<T>::hostType hostPtrT;
    typedef T hostPtrT;
 
    /// The device data type
    // typedef typename cudaType<T>::deviceType devicePtrT;
    typedef T devicePtrT;
 
    /// The device pointer
    devicePtrT *m_devicePtr{ nullptr };
 
    /// The allocated size
    size_t m_size{ 0 };
 
    /// Destructor, frees memory if allocated.
    ~cudaPtr();
 
    size_t size()
    {
        return m_size;
    }
 
    /// Resize the memory allocation, in 1D
    /** If no size change, this is a no-op.
     *
     * \returns 0 on success.
     * \returns a cuda error code otherwise.
     *
     * \test Scenario: scaling a vector with cublas \ref test_math_templateCublas_scal "[test doc]"
     * \test Scenario: scaling and accumulating a vector with cublas \ref test_math_templateCublas_axpy "[test doc]"
     * \test Scenario: multiplying two vectors element by element \ref test_math_templateCublas_elementwiseXxY "[test doc]"
     */
    int resize( size_t sz /**< [in] the new size */ );
 
    /// Resize the memory allocation, in 2D
    /** If no size change, this is a no-op.
     *
     * \returns 0 on success.
     * \returns a cuda error code otherwise.
     *
     */
    int resize( size_t x_sz, ///< [in] the new x size,
                size_t y_sz  ///< [in] the new y size
    );
 
    /// Resize the memory allocation, in 3D
    /** If no size change, this is a no-op.
     *
     * \returns 0 on success.
     * \returns a cuda error code otherwise.
     *
     */
    int resize( size_t x_sz, ///< [in] the new x size,
                size_t y_sz, ///< [in] the new y size,
                size_t z_sz  ///< [in] the new z size
    );
 
    /// Initialize the array bytes to 0.
    /** Just a wrapper to cudaMemset.
     *
     */
    cudaError_t initialize();
 
    /// Free the memory allocation
    /**
     * \returns 0 on success.
     * \returns a cuda error code otherwise.
     *
     */
    int free();
 
    /// Copy from the host to the device, after allocation.
    /**
     * The device pointer must be allocated.
     *
     * \returns 0 on success.
     * \returns a cuda error code otherwise.
     *
     * \test Scenario: multiplying two vectors element by element \ref test_math_templateCublas_elementwiseXxY "[test doc]"
     */
    int upload( const hostPtrT *src /**< [in] The host location */ );
 
    /// Copy from the host to the device with allocation.
    /**
     * The device pointer will be re-allocated as needed.
     *
     * \returns 0 on success.
     * \returns a cuda error code otherwise.
     *
     * \test Scenario: scaling a vector with cublas \ref test_math_templateCublas_scal "[test doc]"
     * \test Scenario: scaling and accumulating a vector with cublas \ref test_math_templateCublas_axpy "[test doc]"
     * \test Scenario: multiplying two vectors element by element \ref test_math_templateCublas_elementwiseXxY "[test doc]"
     */
    int upload( const hostPtrT *src, ///< [in] The host location
                size_t sz            ///< [in] The size of the array
    );
 
    /// Copy from the device to the host.
    /**
     *
     * \test Scenario: scaling a vector with cublas \ref test_math_templateCublas_scal "[test doc]"
     * \test Scenario: scaling and accumulating a vector with cublas \ref test_math_templateCublas_axpy "[test doc]"
     * \test Scenario: multiplying two vectors element by element \ref test_math_templateCublas_elementwiseXxY "[test doc]"
     */
    int download( hostPtrT *dest /**< [in] The host location, allocated.*/ );
 
    /// Conversion operator, accesses the device pointer for use in Cuda functions.
    /**
     * \test Scenario: scaling and accumulating a vector with cublas \ref test_math_templateCublas_axpy "[test doc]"
     * \test Scenario: multiplying two vectors element by element \ref test_math_templateCublas_elementwiseXxY "[test doc]"
     */
    typename cpp2cudaType<devicePtrT>::cudaType *operator()()
    {
        return (typename cpp2cudaType<devicePtrT>::cudaType *)m_devicePtr;
    }
 
    /// Conversion operator, accesses the device pointer for use in Cuda functions.
    /**
     *
     * \b Tests
     *     - Scaling a vector with cublas \ref test_math_templateCublas_scal "[test doc]"
     */
    const typename cpp2cudaType<devicePtrT>::cudaType *operator()() const
    {
        return (typename cpp2cudaType<devicePtrT>::cudaType *)m_devicePtr;
    }
};
 
template <typename T>
cudaPtr<T>::~cudaPtr()
{
    free();
}
 
template <typename T>
int cudaPtr<T>::resize( size_t sz )
{
    if( m_size == sz )
        return 0;
 
    m_size = sz;
 
    cudaError_t rv = cudaMalloc( (void **)&m_devicePtr, sz * sizeof( devicePtrT ) );
 
    if( rv != cudaSuccess )
    {
        std::cerr << "Error from cudaMalloc: ";
        printf( "[%s] %s\n", cudaGetErrorName( rv ), cudaGetErrorString( rv ) );
    }
 
    return 0;
}
 
template <typename T>
int cudaPtr<T>::resize( size_t x_sz, size_t y_sz )
{
    return resize( x_sz * y_sz );
}
 
template <typename T>
int cudaPtr<T>::resize( size_t x_sz, size_t y_sz, size_t z_sz )
{
    return resize( x_sz * y_sz * z_sz );
}
 
template <typename T>
cudaError_t cudaPtr<T>::initialize()
{
    return ::cudaMemset( m_devicePtr, 0, m_size * sizeof( devicePtrT ) );
}
 
template <typename T>
int cudaPtr<T>::free()
{
    if( m_devicePtr )
    {
        int rv = cudaFree( m_devicePtr );
 
        if( rv != cudaSuccess )
        {
            std::cerr << "Cuda Free Error \n";
            return rv;
        }
    }
 
    m_devicePtr = 0;
    m_size = 0;
 
    return 0;
}
 
template <typename T>
int cudaPtr<T>::upload( const hostPtrT *src )
{
    // Copy host memory to device
    int rv = cudaMemcpy( m_devicePtr, src, m_size * sizeof( devicePtrT ), cudaMemcpyHostToDevice );
 
    if( rv != cudaSuccess )
    {
        std::cerr << "Cuda Memcpy error \n";
        return rv;
    }
 
    return 0;
}
 
template <typename T>
int cudaPtr<T>::upload( const hostPtrT *src, size_t sz )
{
    int rv;
 
    rv = resize( sz );
 
    if( rv )
        return rv;
 
    return upload( src );
}
 
template <typename T>
int cudaPtr<T>::download( hostPtrT *dest )
{
    // Copy device memory to host
    int rv = cudaMemcpy( dest, m_devicePtr, m_size * sizeof( devicePtrT ), cudaMemcpyDeviceToHost );
 
    if( rv != cudaSuccess )
    {
        std::cerr << "Cuda Memcpy error \n";
        return rv;
    }
 
    return 0;
}
 
} // namespace cuda
} // namespace mx
#endif // math_cudaPtr_hpp