Example
The all-gather version of Example Examples using MPI_GATHER, MPI_GATHERV . Using MPI_ALLGATHER, we will gather 100 ints from every process in the group to every process.
MPI_Comm comm; int gsize,sendarray[100]; int *rbuf; ... MPI_Comm_size( comm, &gsize); rbuf = (int *)malloc(gsize*100*sizeof(int)); MPI_Allgather( sendarray, 100, MPI_INT, rbuf, 100, MPI_INT, comm);After the call, every process has the group-wide concatenation of the sets of data.