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Question 6: You develop a parallel application that will be deployed on a Windows HPC Server 2008 cluster.You write the following code segment. (Line numbers are included for reference only.)
01 int rank;
02 MPI_Comm_rank(MPI_COMM_WORLD, &rank);
03 // declaration of variable hostName
04 // code to execute
05
06 std::cout << "hostname of rank " << rank;
07 std::cout << ": " << hostName << "\n";
You need to ensure that a variable named hostName contains the name of the cluster node that the code
runs on.
Which code segment should you add at line 05?
A. char *hostName = getenv("MPI_HOSTNAME");
B. char hostName[MPI_MAX_PROCESSOR_NAME];
int resultlen;
MPI_Get_processor_name(&resultlen, hostName);
C. char hostName[MPI_MAX_NAME_STRING];
int resultlen;
MPI_Comm_get_name(MPI_COMM_WORLD, hostName, &resultlen);
D. char hostName[256];
int resultlen = sizeof(hostName);
if (rank == 0)
{
gethostname(hostName, resultlen);
}
Correct Answer: B
