#include <stdio.h>
#include "cuda.h"
#include "cuda_util.h"

// CUDA utilities
// Jan Mandel, January 2009
// adapted from online sources as noted

void checkCUDAError(const char *msg)
// check for error on a previous CUDA call
// useful for kernel launch which has no return code
// or operations that can fail later after the call
// adapted from Dr Dobb's journal
{
    // block until the device has completed - added jm
    cudaThreadSynchronize();
    // check error code
    cudaError_t err = cudaGetLastError();
    if( cudaSuccess != err) 
    {
        fprintf(stderr, "Cuda error: %s: %s.\n", msg, 
                                  cudaGetErrorString( err) );
        exit(1);
    }                         
}

void cudasafe( cudaError_t err, char* str)
// adapted from FortranCUDA by NVIDA
// check return code from a CUDA routine
{
 if (err != cudaSuccess)
 {
  printf("%s failed with error code %i\n",str,err);
  exit(1);
 }
 // added jm just in case there is a delayed error
 checkCUDAError(str);
}


void cuda_device_init( int dev) {
    // adapted from FortranCUDA by NVIDA
    // initialize CUDA devide number dev  (0 if system has only one)
    int deviceCount; 
    cudasafe(cudaGetDeviceCount(&deviceCount),"cudaGetDeviceCount");
    if (deviceCount == 0) {       
        fprintf(stderr, "No devices supporting CUDA.\n");
        exit(1); 
    }           
    cudaDeviceProp deviceProp;               
    cudasafe(cudaGetDeviceProperties(&deviceProp, dev),"cudaGetDeviceProperties");
    if (deviceProp.major < 1) {                                              
        fprintf(stderr, "Device does not support CUDA.\n");     
        exit(1);                                                  
    }                                                            
    fprintf(stdout, " Device %d %s\n", dev, deviceProp.name);   

    // after all that checking finally initialize
    cudasafe(cudaSetDevice(dev),"cudaSetDevice");                    
 }

// Fortran stubs

extern "C" void cuda_device_init__( int* Dev) {
// adapted from FortranCUDA by NVIDA
// fortran callable stub to the initialization routine
    cuda_device_init( *Dev); 
}