extern "C" {
#include <stdio.h>
    __global__ void twice(strct LoopCounter* loopCounter, int prefix ,int* array) {
         int index = blockIdx.x * blockDim.x + threadIdx.x;
        printf("array %p, blockIdx.x = %d, blockDim.x = %d, threadIdx.x = %d\n");
         int i = 0;
         while (i < prefix) {
              array[i+index*prefix] = array[i+index*prefix]*2;
         }
    }
}