这是我关于 Stack Overflow 的第一个问题，这是一个很长的问题。 tl;dr 版本是:我如何使用 thrust::device_vector如果我希望它存储不同类型的对象 DerivedClass1 , DerivedClass2等，同时？

我想利用 CUDA Thrust 的多态性。我正在编译 -arch=sm_30 GPU(GeForce GTX 670)。

让我们看看下面的问题:假设镇上有 80 个家庭。其中60人为已婚夫妇，20人为单亲家庭。因此，每个家庭都有不同数量的成员。现在是人口普查时间，家庭必须说明 parent 的年龄和他们有多少 child 。因此，Family 的数组对象由政府 build ，即thrust::device_vector familiesInTown(80) , 这样的家庭信息 familiesInTown[0]ĐẾNfamiliesInTown[59]对应已婚夫妇，其余(familiesInTown[60] ĐẾN familiesInTown[79])为单亲家庭。

#include 
#include 
#include 

class Family
{
protected:
  unsigned int numParents;
  unsigned int numChildren;
công cộng:
  __host__ __device__ Family() {};
  __host__ __device__ Family(const unsigned int& nPars, const unsigned int& nChil) : numParents(nPars), numChildren(nChil) {};
  __host__ __device__ virtual ~Family() {};

  __host__ __device__ unsigned int showNumOfParents() {return numParents;}
  __host__ __device__ unsigned int showNumOfChildren() {return numChildren;}
};

class SingleParent : public Family
{
protected:
  unsigned int ageOfParent;
công cộng:
  __host__ __device__ SingleParent() {};
  __host__ __device__ SingleParent(const unsigned int& nChil, const unsigned int& age) : Family(1, nChil), ageOfParent(age) {};

  __host__ __device__ unsigned int showAgeOfParent() {return ageOfParent;}
};

class MarriedCouple : public Family
{
protected:
  unsigned int ageOfParent1;
  unsigned int ageOfParent2;
công cộng:
  __host__ __device__ MarriedCouple() {};
  __host__ __device__ MarriedCouple(const unsigned int& nChil, const unsigned int& age1, const unsigned int& age2) : Family(2, nChil), ageOfParent1(age1), ageOfParent2(age2) {};

  __host__ __device__ unsigned int showAgeOfParent1() {return ageOfParent1;}
  __host__ __device__ unsigned int showAgeOfParent2() {return ageOfParent2;}
};

struct initSlicedCouples : public thrust::unary_function
{
  __device__ MarriedCouple operator()(const unsigned int& idx) const
  // I use a thrust::counting_iterator to get idx
  {
    return MarriedCouple(idx % 3, 20 + idx, 19 + idx); 
    // Couple 0: Ages 20 and 19, no children
    // Couple 1: Ages 21 and 20, 1 child
    // Couple 2: Ages 22 and 21, 2 children
    // Couple 3: Ages 23 and 22, no children
    // etc
  }
};

struct initSlicedSingles : public thrust::unary_function
{
  __device__ SingleParent operator()(const unsigned int& idx) const
  {
    return SingleParent(idx % 3, 25 + idx);
  }
};

int chính()
{
  unsigned int Num_couples = 60;
  unsigned int Num_single_parents = 20;

  thrust::device_vector familiesInTown(Num_couples + Num_single_parents);
  // Families [0] to [59] are couples. Families [60] to [79] are single-parent households.
  thrust::transform(thrust::counting_iterator(0),
                    thrust::counting_iterator(Num_couples),
                    familiesInTown.begin(),
                    initSlicedCouples());
  thrust::transform(thrust::counting_iterator(Num_couples),
                    thrust::counting_iterator(Num_couples + Num_single_parents),
                    familiesInTown.begin() + Num_couples,
                    initSlicedSingles());
  trả về 0;
}

struct initCouples : public thrust::unary_function
{
  __device__ MarriedCouple* operator()(const unsigned int& idx) const
  {
    return new MarriedCouple(idx % 3, 20 + idx, 19 + idx); // Memory issues?
  }
};
struct initSingles : public thrust::unary_function
{
  __device__ SingleParent* operator()(const unsigned int& idx) const
  {
    return new SingleParent(idx % 3, 25 + idx);
  }
};

int chính()
{
  unsigned int Num_couples = 60;
  unsigned int Num_single_parents = 20;

  thrust::device_vector familiesInTown(Num_couples + Num_single_parents);
  // Families [0] to [59] are couples. Families [60] to [79] are single-parent households.
  thrust::transform(thrust::counting_iterator(0),
                    thrust::counting_iterator(Num_couples),
                    familiesInTown.begin(),
                    initCouples()); 
  thrust::transform(thrust::counting_iterator(Num_couples),
                    thrust::counting_iterator(Num_couples + Num_single_parents),
                    familiesInTown.begin() + Num_couples,
                    initSingles());

  Family A = *(familiesInTown[2]); // Compiles, but object slicing takes place (in theory)
  std::cout << A.showNumOfParents() << "\n"; // Segmentation fault
 trả về 0;
}

Family *pA = familiesInTown[2];
MarriedCouple *pB = dynamic_cast(pA);

  std::cout << "Ages " << (pB -> showAgeOfParent1()) << ", " << (pB -> showAgeOfParent2()) << "\n";

  MarriedCouple B = *pB;
  std::cout << "Ages " << B.showAgeOfParent1() << ", " << B.showAgeOfParent2() << "\n";

1 Câu trả lời

我不会试图回答这个问题的所有内容，它太大了。话虽如此，以下是对您发布的代码的一些观察，可能会有所帮助:

关于cuda - CUDA/CUDA Thrust 中的多态性和派生类，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22988244/