Changes between Version 6 and Version 7 of mpich/point_to_point/demo2

Timestamp:

Jun 25, 2008, 5:15:48 PM (16 years ago)

Author:

wade

Comment:

--

mpich/point_to_point/demo2

@@ -7 +7 @@
  *   2008-06-06 改變 #30 printf 位置，以了解 MPI 函式執行順序關係
  *   2008-06-12 更改顯示方法。
+ *   2008-06-17 變更變數名 myid -> myrank，增加註解
  */
 
@@ -12 +13 @@
 #include <stdio.h>
 
-int main(int argc,char *argv[])
+main(int argc,char **argv)     
 {
-  int n, myid, numprocs;
+  int n, myrank, numprocs;
   MPI_Status status;
   MPI_Init(&argc,&argv);
   MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
-  MPI_Comm_rank(MPI_COMM_WORLD,&myid);
+  MPI_Comm_rank(MPI_COMM_WORLD,&myrank);
 
   /* node 0 will send the first message */
-  if(myid==0)
+  if(myrank == 0)
   {
-    n = myid;
+    n = myrank;
     MPI_Send(&n, 1, MPI_INT, 1, 99, MPI_COMM_WORLD);
-    printf("[Ndde %d]「%d」 >> [Node %d]\n\n", myid, n, myid+1);
+    printf("[Ndde %d]「%d」 >> [Node %d]\n\n", myrank, n, myrank+1);
   }
 
   /* node 1 to node n-2 will send message to the next node */
-  if(myid>0 && myid<numprocs-1)
+  if(myrank>0 && myrank<numprocs-1)
   {
-    MPI_Recv(&n, 1, MPI_INT, myid-1, 99, MPI_COMM_WORLD, &status);
-    printf("[Node %d] << 「%d」[Node %d]\n", myid, n, status.MPI_SOURCE);
-    n = myid;
-    MPI_Send(&n, 1, MPI_INT, myid+1, 99, MPI_COMM_WORLD);
-    printf("[Ndde %d]「%d」 >> [Node %d]\n\n", myid, n, myid+1);
+    MPI_Recv(&n, 1, MPI_INT, myrank-1, 99, MPI_COMM_WORLD, &status);
+    printf("[Node %d] << 「%d」[Node %d]\n", myrank, n, status.MPI_SOURCE);
+    n = myrank;
+    MPI_Send(&n, 1, MPI_INT, myrank+1, 99, MPI_COMM_WORLD);
+    printf("[Ndde %d]「%d」 >> [Node %d]\n\n", myrank, n, myrank+1);
   }
 
   /* the final node n-1 will not send any message but receive*/
-  if(myid==numprocs-1)
+  if(myrank==numprocs-1)
   {
-    MPI_Recv(&n, 1, MPI_INT, myid-1, 99, MPI_COMM_WORLD, &status);
-    printf("[Node %d] << 「%d」[Node %d]\n", myid, n, status.MPI_SOURCE);
+    MPI_Recv(&n, 1, MPI_INT, myrank-1, 99, MPI_COMM_WORLD, &status);
+    printf("[Node %d] << 「%d」[Node %d]\n", myrank, n, status.MPI_SOURCE);
   }
   MPI_Finalize();
- return 0;
+}
 }}}
 = Result =