Changes between Version 9 and Version 10 of mpich/point_to_point/demo1

Timestamp:

Jun 25, 2008, 5:11:30 PM (17 years ago)

Author:

wade

Comment:

--

mpich/point_to_point/demo1

@@ -1 +1 @@
 = Source code =
 {{{
-/*
- * 每個 node 將訊息傳送給 node 0，由，node 0 統一印出
- */
+/* Program:
+ *   每個 node 將自己的 id 印出，並且將所有的參與運動的 node 總數也印出
+ *   ，顯示出自己的主機名稱。
+ * History:
+ *   2008-04-09 BETA
+ *   2008-06-25 增加顯示主機名稱功能
+*/
 
 #include <stdio.h>
 #include <mpi.h>
-#include <string.h>
+main (int argc, char **argv)
+{
+  int rank, size, len;
+  char name[MPI_MAX_PROCESSOR_NAME];
+  MPI_Init(&argc, &argv);
+  int myid, numprocs;
 
-main(int argc, char **argv)
-{
-  int myrank, i, numprocs;
-  char message[20];
-  MPI_Status status;
-  MPI_Init(&argc, &argv);
-  MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
-  MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
-  if(myrank == 0)
-  {
-    printf("I am %d \n", myrank);
-    for(i = 1; i < (numprocs); i++)
-    {
-      MPI_Recv(message, 20, MPI_CHAR, i, 99, MPI_COMM_WORLD, &status);
-      printf(" I GOT %s \n", message);
-    }
-    printf("\n");
-  }
-  if(myrank != 0)
-  {
-    sprintf(message, "i am %d", myrank);
-    MPI_Send(message, 20, MPI_CHAR, 0, 99, MPI_COMM_WORLD);
-    printf("I am %d \n", myrank);
-    printf("I send '%s\n\n ", message);
-  }
+  /* 取得 node 總數 */
+  MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
+
+  /* 取得本身 node id / rank  */
+  MPI_Comm_rank(MPI_COMM_WORLD,&myid);
+
+  /* 取得本身 host name  */
+  MPI_Get_processor_name(name, &len);
+  printf("This is machine %d of %d  name = %s\n", myid, numprocs, name);
   MPI_Finalize();
 }