Newer
Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
#include <mpi.h>
#include <stdio.h>
int main(int argc, char *argv[])
{
int rank, nprocs, len, n, sum;
char pname[MPI_MAX_PROCESSOR_NAME];
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD,&nprocs);
MPI_Comm_rank(MPI_COMM_WORLD,&rank);
MPI_Get_processor_name(pname,&len);
printf("Hello world! from rank %d of %d on host %s\n", rank, nprocs,pname);
MPI_Barrier(); //Work for you
if (rank==0) {
printf("Enter the number to broadcast ");
scanf("%d",&n);
}
MPI_Bcast(); //Work: broadcast n from rank 0 to all other ranks
printf("1, rank %d, n= %d\n",rank,n);
if (rank==1) {
n=5;
MPI_Send(); //Work: send n from rank to rank 2
printf("2. rank %d, n= %d\n",rank,n);
MPI_Recv(); //Work: receive n from rank 2
printf("3. rank %d, n= %d\n",rank,n);
}
if (rank==2) {
MPI_Recv(); //Work: receive n from rank 1
printf("2. rank %d, n= %d\n",rank,n);
n=15;
MPI_Send(); //Work: send n to rank 1
printf("3. rank %d, n= %d\n",rank,n);
}
//Work: insert barrier
sum=0;
MPI_Reduce(); //Work: Reduce values of n to variable sum, on rank 0.
printf("4. rank %d, n= %d\n",rank,sum);
MPI_Finalize();
return 0;
}