Pointer to pointer syntax problem

Question

Lets say I have the following:

void init_gpu(cuComplex* d_hhBuff)
{   
    cutilSafeCall(cudaMalloc((void **)&d_hhBuff, memsize));
}

and I call it with something like

cuComplex *my_buff;
init_gpu(my_buff);

Well, when init_gpu returns, it is NOT pointing to the device memory that cudaMalloc allocated.

How do I modify this so that the caller of init_gpu will have my_buff pointing to the modified d_hhBuff that cudaMalloc creates?

Answer 1

The problem is that you are passing the pointer by value. Change the function header to

void init_gpu(cuComplex *& d_hhBuff)

Answer 2

Your d_hhBuf is a local copy. What you should do is pass the pointer by reference:

void init_gpu(cuComplex * & d_hhBuff)