The problem

I am compiling a CUDA shared library that I've written, for this library, I need the capability to randomly sample stuff, therefore, as specified by the docs, I am initializing an array of curandState_t:

/**
 * @brief Sets up random number generators for each thread
 *
 * @param state pointer to the array of curandState
 * @param seed seed for the random number generator
 */
__global__ void rand_setup(curandState_t* state, unsigned long seed)
{
    /* 3D grid of 3D blocks id */
    size_t gid = getGlobalIdx_3D_3D();

    curand_init(seed, gid, 0, &state[gid]);

    printf("Initializing random number generator for thread %d");
}

The getGlobalIdx_3D_3D() call just retrieves the global ID through a bunch of tedious calculations, such as:

/**
 * @brief Get the global identifier of the thread
 *
 * thanks to: https://cs.calvin.edu/courses/cs/374/CUDA/CUDA-Thread-Indexing-Cheatsheet.pdf
 * for the snippet
 *
 * @return size_t The global index of the thread
 */
__device__ size_t getGlobalIdx_3D_3D()
{
    size_t blockId = blockIdx.x   blockIdx.y * gridDim.x
          gridDim.x * gridDim.y * blockIdx.z;
    size_t threadId = blockId * (blockDim.x * blockDim.y * blockDim.z)
          (threadIdx.z * (blockDim.x * blockDim.y))
          (threadIdx.y * blockDim.x)   threadIdx.x;
    return threadId;
}

The errors

I am getting a cascade of compilation errors (I have just completed a substantial amount of work), however, many of them seem to stem from the fact that curandState_t is not recognized as a proper type, hence I get this annoying dump:

D:\Repos\MulticoreTree\shared\libkernel.cu(325): error: attribute "__global__" does not apply here

D:\Repos\MulticoreTree\shared\libkernel.cu(325): error: incomplete type is not allowed

D:\Repos\MulticoreTree\shared\libkernel.cu(325): error: identifier "curandState_t" is undefined

D:\Repos\MulticoreTree\shared\libkernel.cu(325): error: identifier "state" is undefined

D:\Repos\MulticoreTree\shared\libkernel.cu(325): error: type name is not allowed

D:\Repos\MulticoreTree\shared\libkernel.cu(325): error: expected a ")"

D:\Repos\MulticoreTree\shared\libkernel.cu(326): error: expected a ";"

D:\Repos\MulticoreTree\shared\libkernel.cu(407): warning #12-D: parsing restarts here after previous syntax error

Looking online for documentation, there doesn't seem to be anything that tells me to import a specific header, also, I have #include <cuda_runtime.h> at the top of my file, so what could be wrong?

I personally think that the type is not being recognized, but there might also be a problem with something else in the function's signature causing it to fail compilation.

CodePudding user response：

As per the first sentence of the curand device API documentation

To use the device API, include the file curand_kernel.h in files that define kernels that use cuRAND device functions