// Send the specified number of individuals from the current population to
// the specified task.
int
SendMigration(int toid, GAGeneticAlgorithm& ga, int count) {
int status = 0;
status = pvm_initsend(PvmDataDefault);
status = pvm_pkint(&count, 1, 1);
for(int i=0; i<count && status>=0; i++)
status = PackIndividual(ga.population().best(i));
status = pvm_send(toid, MSG_INCOMING_MIGRATION);
return status;
}
// Receive a bunch of individuals from a task. To do this, we clone the GA's
// population, stuff the immigrants into the population, trash the worst
// individuals to bring the population size back down to what it was, then
// stick the population back into the GA.
// This implementation is really inefficient, but you get the idea of how
// to do this...
int
RecvMigration(GAGeneticAlgorithm& ga) {
int status = 0;
GAPopulation pop(ga.population());
GAGenome *tmpind = ga.population().individual(0).clone();
int count = 0;
status = pvm_upkint(&count, 1, 1);
for(int i=0; i<count && status>=0; i++) {
status = UnpackIndividual(*tmpind);
pop.add(*tmpind);
}
for(int j=0; j<count; j++)
pop.destroy(); // default behavior is to destroy worst
ga.population(pop);
delete tmpind;
return status;
}