Miscellaneous
C | Fortran-2008 | Fortran-90
MPI_THREAD_SINGLE represents a thread support level. It is used as part of the MPI_Init_thread initialisation. MPI_THREAD_SINGLE is the first level; it informs MPI that the application is single threaded. Other thread support levels are, in order, MPI_THREAD_FUNNELED, MPI_THREAD_SERIALIZED and MPI_THREAD_MULTIPLE.
#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>
/**
* @brief Illustrates how to initialise the MPI environment with multithreading
* support and ask for the MPI_THREAD_SINGLE level.
* @details This application initialised MPI and asks for the
* MPI_THREAD_SINGLE thread support level. It then compares it with the
* thread support level provided by the MPI implementation.
**/
int main(int argc, char* argv[])
{
// Initilialise MPI and ask for thread support
int provided;
MPI_Init_thread(NULL, NULL, MPI_THREAD_SINGLE, &provided);
if(provided < MPI_THREAD_SINGLE)
{
printf("The threading support level is lesser than that demanded.\n");
MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);
}
else
{
printf("The threading support level corresponds to that demanded.\n");
}
// Tell MPI to shut down.
MPI_Finalize();
return EXIT_SUCCESS;
}