pvmfitness.c

比较完整的遗传算法的源代码

#include <stdlib.h>
#include <pvm3.h>

#include "petrol.h"
#include "utils.h"

static int started = FALSE;

static int                 nhosts;
static struct pvmhostinfo *hinfo;
static int                *children;

static void SendAllMessage(int *hosts, int nhosts, int message);
static void SendMessage(int tid, int message);
static int  GetMessage(int *tid);
static void SendIndividuals(Population *p, int tid, int n, int howmany);
static void GetIndividualsFitness(Population *p);

void PVMFitness(Settings *s, Population *p) {
  int n, keepgoing, workcount, tid;

  if (!started) {
    /* Start by getting the configuration of the current PVM environment */
    if (pvm_config(&nhosts, NULL, &hinfo) == PvmSysErr) {
      pvmerror("PVMFitness");
    }

    if (!(children = (int *)malloc(sizeof(int) * nhosts))) {
      syserror("PVMFitness");
    }
  
    /* For each host, spawn a new petrolslave */
    for (n = 0; n < nhosts; n++) {
      if (pvm_spawn("petrolslave", NULL, PvmTaskHost, (hinfo + n)->hi_name, 1,
		    &children[n]) != 1) {
	pvmerror("PVMFitness");
      }
    }
    
    started = TRUE;
  }

  /* Notify all the slaves about available work */
  SendAllMessage(children, nhosts, PETROL_WORK);

  n = 0; keepgoing = TRUE; workcount = 0;
  while (keepgoing) {

    switch(GetMessage(&tid)) {
      
    case PETROL_WORK_REQUEST:
      {
	int howmany;

	/* Send work out to the slave */
	if (n + s->packetSize >= p->popSize)
	  howmany = p->popSize - n;
	else
	  howmany = s->packetSize;

	SendIndividuals(p, tid, n, howmany);
	n += howmany;
	workcount++;
      }
      break;

    case PETROL_WORK_DONE:

      /* Update fitness values */
      GetIndividualsFitness(p);
      workcount--;

      /* Send more work out if any */
      if (n < p->popSize)
	SendMessage(tid, PETROL_WORK);

      break;

    default:
      error("PVMFitness", "Unkown message received");

    }

    if (n == p->popSize && workcount == 0)
      keepgoing = FALSE;
  }
 
}

void PVMFitnessExit(void) {
  int n;

  for (n = 0; n < nhosts; n++) {
    pvm_kill(children[n]);
  }

  started = FALSE;
  pvm_exit();
}
  
void SendAllMessage(int *hosts, int nhosts, int message) {
  if (pvm_initsend(PvmDataDefault) < 0) {
    pvmerror("SendAllMessage");
  }
  if (pvm_mcast(hosts, nhosts, message) < 0) {
    pvmerror("SendAllMessage");
  }
}

void SendMessage(int tid, int message) {
  if (pvm_initsend(PvmDataDefault) < 0) {
    pvmerror("SendAllMessage");
  }
  if (pvm_send(tid, message) < 0) {
    pvmerror("SendAllMessage");
  }
}

int GetMessage(int *tid) {
  int message, buf;

  if ((buf = pvm_recv(-1, -1)) < 0) {
    pvmerror("GetMessage");
  }
  if (pvm_bufinfo(buf, NULL, &message, tid) < 0) {
    pvmerror("GetMessage");
  }

  return message;
}

void SendIndividuals(Population *p, int tid, int n, int howmany) {
  int         x;
  Individual *i; 

  if (pvm_initsend(PvmDataDefault) < 0) {
    pvmerror("SendIndividuals");
  }

  /* First send the location of this packet (so we know where
     to put it when the slave is done */
  x = n;
  if (pvm_pkint(&x, 1, 1)) {
    pvmerror("SendIndividuals");
  }

  /* Next send how many individuals to be evaluated */
  x = howmany;
  if (pvm_pkint(&x, 1, 1)) {
    pvmerror("SendIndividuals");
  }

  /* Finally, loop through all the Individuals and send them */
  for (x = 0; x < howmany; x++) {
    i = p->pop + n + x;

    /* Pack the chromosome length for the Individual */
    if (pvm_pkint(&(i->chromLen), 1, 1) < 0) {
      pvmerror("SendIndividuals");
    }
    /* Pack the chromosome for the Individual */
    if (pvm_pkint(i->chrom, i->chromLen, 1) < 0) {
      pvmerror("SendIndividuals");
    }
  }

  /* Send the bundle out */
  if (pvm_send(tid, PETROL_WORK_INDIVIDUALS) < 0) {
    pvmerror("SendIndividuals");
  }

}

void GetIndividualsFitness(Population *p) {
  int         location, howmany, n;
  Individual *i;

  /* First, get the starting location of the first Individual */
  if (pvm_upkint(&location, 1, 1)) {
    pvmerror("GetIndividualsFitness");
  }

  /* Get how many Individuals' fitnesses are packed in this message */
  if (pvm_upkint(&howmany, 1, 1)) {
    pvmerror("GetIndividualsFitness");
  }
  
  /* Cycle through and save the fitness in each Individual */
  for (n = 0; n < howmany; n++) {
    i = p->pop + location + n;

    if (pvm_upkdouble(&(i->fitness), 1, 1)) {
      pvmerror("GetIndividualsFitness");
    }
  }

}