MPI send-receive-exchange example

hpc/hello-world/mpi_sendrc.c

+#include "mpi.h"
+#include <stdio.h>
+
+int main(int argc, char** argv) {
+  int size, rank, dest, source, rc, count;
+  char inmsg, outmsg='x';
+  MPI_Status Stat;
+
+  MPI_Init(&argc,&argv);
+  MPI_Comm_size(MPI_COMM_WORLD, &size);
+  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+  if (rank == 0) {
+    dest = source = 1;
+    outmsg = 'x';
+    rc = MPI_Send(&outmsg, 1, MPI_CHAR, dest, 1, MPI_COMM_WORLD);
+    rc = MPI_Recv(&inmsg, 1, MPI_CHAR, source, 1, MPI_COMM_WORLD, &Stat);
+  }
+
+  else if (rank == 1) {
+    dest = source = 0;
+    outmsg = 'y';
+    rc = MPI_Recv(&inmsg, 1, MPI_CHAR, source, 1, MPI_COMM_WORLD, &Stat);
+    rc = MPI_Send(&outmsg, 1, MPI_CHAR, dest, 1, MPI_COMM_WORLD);
+  }
+
+  printf("Rank %d: Received char %c from task %d \n", rank, inmsg, Stat.MPI_SOURCE);
+
+  MPI_Finalize();
+}