fork download
copy 
  1. #include <stdio.h>
  2. #include <mpi.h>
  3.  
  4. int main(int argc, char *argv[])
  5. {
  6.     const int tag = 42; /* Message tag */
  7.     int id, ntasks, source_id, dest_id, err, i;
  8.     MPI_Status status;
  9.     int msg[2]; /* Message array */
  10.  
  11.     err = MPI_Init(&argc, &argv); /* Initialize MPI */
  12.     if (err != MPI_SUCCESS) {
  13.         printf("MPI initialization failed!\n");
  14.         exit(1);
  15.     }
  16.     err = MPI_Comm_size(MPI_COMM_WORLD, &ntasks); /* Get nr of tasks */
  17.     err = MPI_Comm_rank(MPI_COMM_WORLD, &id); /* Get id of this process */
  18.     if (ntasks < 2) {
  19.         printf("You have to use at least 2 processors to run this program\n");
  20.         MPI_Finalize(); /* Quit if there is only one processor */
  21.         exit(0);
  22.     }
  23.     if (id == 0) { /* Process 0 (the receiver) does this */
  24.         for (i=1; i<ntasks; i++) {
  25.             err = MPI_Recv(msg, 2, MPI_INT, MPI_ANY_SOURCE, tag, MPI_COMM_WORLD, \
  26.                 &status); /* Receive a message */
  27.             source_id = status.MPI_SOURCE; /* Get id of sender */
  28.             printf("Received message %d %d from process %d\n", msg[0], msg[1], \
  29.                 source_id);
  30.         }
  31.     }
  32.     else { /* Processes 1 to N-1 (the senders) do this */
  33.         msg[0] = id; /* Put own identifier in the message */
  34.         msg[1] = ntasks; /* and total number of processes */
  35.         dest_id = 0; /* Destination address */
  36.         err = MPI_Send(msg, 2, MPI_INT, dest_id, tag, MPI_COMM_WORLD);
  37.     }
  38.  
  39.     err = MPI_Finalize(); /* Terminate MPI */
  40.     if (id==0) printf("Ready\n");
  41.     exit(0);
  42.     return 0;
  43. }
  44.  
Success #stdin #stdout #stderr 0.3s 40480KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Standard output is empty
stderr
copy 
Error: unexpected symbol in "int main"
Execution halted
https://ideone.com/HQXrRi
language:
R (R 3.5.2)
created:
9 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!