cqs.txt

来自「这里是一个PVM的例子」· 文本 代码 · 共 77 行

 /*spmd.c*/

 #define NPROC 8

 #include <stdio.h>
 #include <sys/types.h>
 #include "pvm3.h"

 main()
{
int mytid; /* my task id */
 int tids[NPROC]; /* array of task id */
 int me; /* my process number */
 int i;

 /* enroll in pvm */
mytid = pvm_mytid();

 /* Join a group and if I am the first instance */
 /* i.e. me=0 spawn more copies of myself */

 me = pvm_joingroup( "foo" );
 printf("me = %d mytid = %d\n",me,mytid);

 if( me == 0 )
 pvm_spawn("spmd", (char**)0, 0, "", NPROC-1, &tids[1]);

 /* Wait for everyone to startup before proceeding. */
 pvm_freezegroup("foo", NPROC);
 pvm_barrier( "foo", NPROC );
 /*--------------------------------------------------------------------------*/

 dowork( me, NPROC );

 /* program finished leave group and exit pvm */
 pvm_lvgroup( "foo" );
 pvm_exit();
 exit(1);
}

/* Simple example passes a token around a ring */

 dowork( me, nproc )
 int me;
 int nproc;
 {
 int token;
 int src, dest;
 int count = 1;
 int stride = 1;
 int msgtag = 4;

 /* Determine neighbors in the ring */
src = pvm_gettid("foo", me - 1);
 dest= pvm_gettid("foo", me + 1);
 if( me == 0 ) src = pvm_gettid("foo", NPROC-1);
 if( me == NPROC-1 ) dest = pvm_gettid("foo", 0);

 if( me == 0 )
 {
 token = dest;
 pvm_initsend( PvmDataDefault );
 pvm_pkint( &token, count, stride );
 pvm_send( dest, msgtag );
 pvm_recv( src, msgtag );
 printf("token ring done\n");
 }
 else
 {
 pvm_recv( src, msgtag );
 pvm_upkint( &token, count, stride );
 pvm_initsend( PvmDataDefault );
 pvm_pkint( &token, count, stride );
 pvm_send( dest, msgtag );
 }
 }