1 /* -*- Mode: C; c-basic-offset:4 ; -*- */
2 /*
3 * (C) 2001 by Argonne National Laboratory.
4 * See COPYRIGHT in top-level directory.
5 */
6
7 #include "mpi.h"
8 #include <stdio.h>
9 #include <string.h>
10
11 #define BUFLEN 512
12
main(int argc,char * argv[])13 int main(int argc, char *argv[])
14 {
15 int myid, numprocs, next, namelen;
16 char buffer[BUFLEN], processor_name[MPI_MAX_PROCESSOR_NAME];
17 MPI_Status status;
18
19 MPI_Init(&argc,&argv);
20 MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
21 MPI_Comm_rank(MPI_COMM_WORLD,&myid);
22 MPI_Get_processor_name(processor_name,&namelen);
23
24 fprintf(stderr,"Process %d on %s\n", myid, processor_name);
25 fprintf(stderr,"Process %d of %d\n", myid, numprocs);
26 strcpy(buffer,"hello there");
27 if (myid == numprocs-1)
28 next = 0;
29 else
30 next = myid+1;
31
32 if (myid == 0)
33 {
34 printf("%d sending '%s' \n",myid,buffer);fflush(stdout);
35 MPI_Send(buffer, strlen(buffer)+1, MPI_CHAR, next, 99, MPI_COMM_WORLD);
36 printf("%d receiving \n",myid);fflush(stdout);
37 MPI_Recv(buffer, BUFLEN, MPI_CHAR, MPI_ANY_SOURCE, 99, MPI_COMM_WORLD,
38 &status);
39 printf("%d received '%s' \n",myid,buffer);fflush(stdout);
40 /* mpdprintf(001,"%d receiving \n",myid); */
41 }
42 else
43 {
44 printf("%d receiving \n",myid);fflush(stdout);
45 MPI_Recv(buffer, BUFLEN, MPI_CHAR, MPI_ANY_SOURCE, 99, MPI_COMM_WORLD,
46 &status);
47 printf("%d received '%s' \n",myid,buffer);fflush(stdout);
48 /* mpdprintf(001,"%d receiving \n",myid); */
49 MPI_Send(buffer, strlen(buffer)+1, MPI_CHAR, next, 99, MPI_COMM_WORLD);
50 printf("%d sent '%s' \n",myid,buffer);fflush(stdout);
51 }
52 MPI_Barrier(MPI_COMM_WORLD);
53 MPI_Finalize();
54 return (0);
55 }
56