lm1_slave.c

MPICH是MPI的重要研究,提供了一系列的接口函数,为并行计算的实现提供了编程环境.

#include "p4.h"
#include "lm.h"
    
slave()	
{
    int myid;
    char buf[100];
    int size;
    int i,j,k,n;
    int nslaves;
    int start, end;
    char *msg;
    char loc_msg[200];
    int type;
    int done;
    int from;
    int nbunches,bunchsize;
    int value;
    int msg_cnt;
    int msgs_rcvd[P4_MAXPROCS];  /* cheated and used a p4 internal def */
    
    myid = p4_get_my_id();
    nslaves = p4_num_total_ids() - 1;
    p4_get_cluster_ids(&start, &end);
    /***
      p4_dprintf("Inside slave process %d: nslaves=%d start=%d end=%d\n",
      myid, nslaves, start, end);
      ***/
    
    for (i=0; i < P4_MAXPROCS; i++)
	msgs_rcvd[i] = 0;
    
    p4_dprintfl(9,"receiving...\n");
    type = CNTL;
    from = 0;
    msg = NULL;
    p4_recv(&type, &from, &msg, &size);
    p4_dprintfl(9,"rcvd from=%d type=%d msg=%s\n",from,type,msg);
    sscanf(msg,"%d %d",&nbunches,&bunchsize);
    p4_msg_free(msg);
    msgs_rcvd[from]++;
    
    type = DATA;
    for (j=0; j < nbunches; j++)
    {
	for (i=1; i <= nslaves; i++)
	{
	    for (k=0; k < bunchsize; k++)
	    {
		if (i != myid)
		{
		    sprintf(loc_msg,"%d",j);
		    p4_dprintfl(9,"sending %d %d to %d \n",j,k,i);
		    p4_send(DATA, i, loc_msg, sizeof(loc_msg));
		}
	    }
	}
    }

    done = bunchsize * nbunches * (nslaves - 1);
    msg_cnt = 0;
    while (msg_cnt < done)
    {
	/**  p4_dprintfl(0,"receiving \n");  **/
	type = DATA;
	from = -1;
	msg = NULL;
	p4_recv(&type, &from, &msg, &size);
	value = atoi(msg);
	msg_cnt++;
	p4_msg_free(msg);
	msgs_rcvd[from]++;
	p4_dprintfl(9,"rcvd from=%d type=%d value=%d\n",from,type,value);
    }
    p4_send(DATA, 0, loc_msg, sizeof(loc_msg));
    p4_dprintf("rcvd from: %d %d %d %d %d %d %d %d \n",
	    msgs_rcvd[0], msgs_rcvd[1], msgs_rcvd[2], msgs_rcvd[3],
	    msgs_rcvd[4], msgs_rcvd[5], msgs_rcvd[6], msgs_rcvd[7]);
	
    p4_dprintfl(0,"%d exiting\n", p4_get_my_id());
}