CUDA Thrust: An example of conversion between device_vector, device_ptr, host_vector and raw pointer

 

   1: #pragma once 

   2:  

   3: #include <cuda_runtime.h>

   4: #include <thrust/device_vector.h>

   5: #include <thrust/device_ptr.h>

   6: #include "Particle.h"

   7: #include "ParticleSystem.h"

   8: #include <vector> 

   9:  

  10: // Template structure to pass to kernel

  11: template < typename T >

  12: struct KernelArray

  13: {    

  14:     T*  _array;    

  15:     int _size;

  16: }; 

  17:  

  18: // Function to convert device_vector to structure

  19: template < typename T >

  20: KernelArray< T > vecToKernelArr( thrust::device_vector< T >& dVec )

  21: {    

  22:     KernelArray< T > kArray;    

  23:     kArray._array = thrust::raw_pointer_cast( &dVec[0] );    

  24:     kArray._size  = ( int ) dVec.size();     

  25:     return kArray;

  26: }; 

  27:  

  28: // Function to convert a KernelArray to a thrust::device_vector

  29: template <typename T>

  30: thrust::device_vector<T> kernelArrToDevVec( KernelArray<T>& kArray )

  31: {  

  32:     thrust::device_ptr<T> dev_ptr = thrust::device_pointer_cast(kArray._array);

  33:     thrust::device_vector<T> dVec(dev_ptr, dev_ptr + kArray._size);

  34:     return dVec;

  35: } 

  36:  

  37: // Function to convert a KernelArray to a thrust::device_vector

  38: template <typename T>

  39: thrust::host_vector<T> kernelArrToHostVec( KernelArray<T>& kArray )

  40: {

  41:     thrust::device_ptr<T> dev_ptr = thrust::device_pointer_cast(kArray._array);

  42:     thrust::host_vector<T> hVec(dev_ptr, dev_ptr + kArray._size);

  43:     return hVec;

  44: } 

  45:  

  46: // Function to convert a KernelArray to a thrust::device_ptr

  47: template <typename T>

  48: thrust::device_ptr<T> kernelArrToDevPtr( KernelArray<T>& kArray )

  49: {

  50:     thrust::device_ptr<T> dev_ptr = thrust::device_pointer_cast(kArray._array);

  51:     return dev_ptr;

  52: }