CUDA Thrust如何使用向量将对象传输到设备

Question

我正在学习Cuda Thrust，并且我想将对象从host_vector传输到设备阵列以便在内核中使用它。

的代码如下：

#include <stdio.h> 
#include <thrust/host_vector.h> 
#include <thrust/device_vector.h> 
#include <thrust/copy.h> 
#include <cstdlib> 

#ifndef SIMULATION_H_ 
#define SIMULATION_H_ 

class Simulation { 
    public: 
    int num_layers; 
    float dz; 
    float dr; 
    int ndz; 
    int ndr; 
    int events_left; 

    __host__ __device__ Simulation(); 
    __host__ __device__ Simulation(int events_left, int num_layers, float dz, float dr, int ndz, int ndr); 
    __device__ int getNumLayers(); 
    __device__ float getDZ(); 
    __device__ float getDR(); 
    __device__ int getNDZ(); 
    __device__ int getNDR(); 
    __device__ int getEventsLeft(); 

    __device__ void setNumLayers(int num_layers); 
    __device__ void setDZ(float dz); 
    __device__ void setDR(float dr); 
    __device__ void setNDZ(int ndz); 
    __device__ void setNDR(int ndr); 
    __device__ void setEventsLeft(int events_left);  
}; 

#endif /* SIMULATION_H_ */ 

__host__ __device__ Simulation::Simulation(){} 
__host__ __device__ Simulation::Simulation(int events_left, int num_layers, float dz, float dr, int ndz, int ndr) { 
    this->events_left = events_left; 
    this->num_layers = num_layers; 
    this->dz = dz; 
    this->dr = dr; 
    this->ndz = ndz; 
    this->ndr = ndr; 
} 
__device__ int Simulation::getNumLayers() { return this->num_layers;} 
__device__ float Simulation::getDZ() { return this->dz;} 
__device__ float Simulation::getDR() { return this->dr;} 
__device__ int Simulation::getNDZ() { return this->ndz;} 
__device__ int Simulation::getNDR() { return this->ndr;} 
__device__ int Simulation::getEventsLeft() { return this->events_left;} 

__device__ void Simulation::setNumLayers(int num_layers) {this->num_layers = num_layers;} 
__device__ void Simulation::setDZ(float dz) {this->dz = dz;} 
__device__ void Simulation::setDR(float dr) {this->dr = dr;} 
__device__ void Simulation::setNDZ(int ndz) {this->ndz = ndz;} 
__device__ void Simulation::setNDR(int ndr) {this->ndr = ndr;} 
__device__ void Simulation::setEventsLeft(int events_left) {this->events_left = events_left;} 

__global__ void Foo(Simulation* sim){ 
    int i = threadIdx.x + blockIdx.x * blockDim.x; 

    printf("TH <%d>, num_layers <%d>\n", i, sim[0].num_layers); 
    printf("TH <%d>, dz   <%f>\n", i, sim[0].dz); 
    printf("TH <%d>, dr   <%f>\n", i, sim[0].dr); 
    printf("TH <%d>, ndr  <%d>\n", i, sim[0].ndr); 
    printf("TH <%d>, ndz  <%d>\n", i, sim[0].ndz); 
} 

int main(void) { 

    // Number of simulations 
    int num_simulations = 1; 

    // Simulations host vector 
    thrust::host_vector<Simulation> hv_simulations(num_simulations); 

    // Parameters for simulation one 
    float dz = 0.01; 
    float dr = 0.01; 
    int ndz = 40; 
    int ndr = 50; 
    int events_left = 1000; 
    int num_layers = 3; 

    // Create a simulation 
    Simulation sim1(events_left, num_layers, dz, dr, ndz, ndr); 

    // Add simulation one to simulations vector 
    hv_simulations.push_back(sim1); 

    // Transfer simulations to device 
    thrust::device_vector<Simulation> dv_simulations = hv_simulations; 

    // Get raw pointer to device simulations 
    Simulation* d_simulations = thrust::raw_pointer_cast(dv_simulations.data()); 

    // Call Foo kernel 
    Foo<<<1, 2>>>(d_simulations); 

    return 0; 
} 

我希望获得作为参数传递的值，而不是控制台抛出这样的：

TH <0>, num_layers <1428486120> 
TH <1>, num_layers <1428486120> 
TH <0>, dz   <0.000000> 
TH <1>, dz   <0.000000> 
TH <0>, dr   <0.000000> 
TH <1>, dr   <0.000000> 
TH <0>, ndr  <0> 
TH <1>, ndr  <0> 
TH <0>, ndz  <0> 
TH <1>, ndz  <0> 

为什么？谢谢。

Answer 1

我认为你有一个基本的vector操作错误，与CUDA或Thrust无关。

这产生长度num_simulations的向量：

thrust::host_vector<Simulation> hv_simulations(num_simulations); 

这然后追加另一元件到现有矢量的结束：

hv_simulations.push_back(sim1); 

可以通过创建一个空的载体解决这个问题：

thrust::host_vector<Simulation> hv_simulations; 

或者通过显式复制到vecto的第一个元素r：

hv_simulations[0] = sim1;