#define MAXLEN 10000
-
-void main()
+
+int main(int argc, char *argv[])
{
- int out[1000000],in[1000000],i,j,k;
- int myself,tasks;
-
- MPI_Init(0,0);
- MPI_Comm_rank(MPI_COMM_WORLD,&myself);
- MPI_Comm_size(MPI_COMM_WORLD,&tasks);
- for(j=1;j<=MAXLEN;j*=10) {
- for(i=0;i<j*tasks;i++) out[i] = myself;
-
- MPI_Alltoall(out,j,MPI_INT,in,j,MPI_INT,MPI_COMM_WORLD);
-
- for(i=0;i<tasks;i++) {
- for(k=0;k<j;k++) {
- if(in[k+i*j] != i) { printf("bad answer (%d) at index %d of %d (should be %d)\n",in[k+i*j],k+i*j,j*tasks,i); break; }
- }
+#define N 1000000
+ int *out, *in, i, j, k;
+ int myself, tasks;
+
+ out = malloc(N * sizeof(int));
+ in = malloc(N * sizeof(int));
+ if ((out == NULL) || (in == NULL)) {
+ printf("Error: cannot allocate N bytes for in or out arrays\n");
+ exit(1);
+ }
+ MPI_Init(&argc, &argv);
+ MPI_Comm_rank(MPI_COMM_WORLD, &myself);
+ MPI_Comm_size(MPI_COMM_WORLD, &tasks);
+ for (j = 1; j <= MAXLEN; j *= 10) {
+ if (0 == myself) {
+ printf("* calling MPI_Alltoall with buffers of %d ints\n", j);
+ }
+ for (i = 0; i < j * tasks; i++)
+ out[i] = myself;
+
+ MPI_Alltoall(out, j, MPI_INT, in, j, MPI_INT, MPI_COMM_WORLD);
+
+ for (i = 0; i < tasks; i++) {
+ for (k = 0; k < j; k++) {
+ if (in[k + i * j] != i) {
+ printf("<%d> bad answer (%d) at index %d of %d (should be %d)\n",
+ myself, in[k + i * j], k + i * j, j * tasks, i);
+ break;
+ }
}
- }
- MPI_Barrier(MPI_COMM_WORLD);
- if(myself==0) printf("TEST COMPLETE\n");
- MPI_Finalize();
+ }
+ }
+ MPI_Barrier(MPI_COMM_WORLD);
+ if (myself == 0)
+ printf("TEST COMPLETE\n");
+ MPI_Finalize();
+ return EXIT_SUCCESS;
}
