int PMPI_File_open(MPI_Comm comm, const char *filename, int amode, MPI_Info info, MPI_File *fh){
if (comm == MPI_COMM_NULL)
return MPI_ERR_COMM;
int PMPI_File_open(MPI_Comm comm, const char *filename, int amode, MPI_Info info, MPI_File *fh){
if (comm == MPI_COMM_NULL)
return MPI_ERR_COMM;