从构造函数中本地声明的device_vector使用device_vector :: data（）方法初始化结构内部的指针是否安全？

Question

I have coded some functors that initialize a member pointer in this way:

struct A
{
    A() {
        thust::device_vector<int> d_vect(3);
        d_vect[0]=1;
        d_vect[1]=2;
        d_vect[2]=3;

        pointer = thrust::raw_pointer_cast(d_vect.data());
    }

    __host__ __device__ void operator() {
        //code using pointer
    };

    int* pointer;

};

The functor coded in this way run without any apparent problem, so I wounder what happens to the data stored in d_vect . Reading the documentation I have the impression this data should be destroyed when the d_vect goes out of the scope, so I would expect the data point by pointer should get erased, but it is not. Please could some one clarify this thing to me?

Answer 1

Your understanding is correct: thrust::device_vector is a managed container and frees all allocated storage when it goes out of scope.

Now de-allocation merely updates bookkeeping information about which memory blocks are free to use, it doesn't explicitly overwrite those blocks with say zeros (for performance reasons). You have to do that manually if that's the behavior you wish.