/* master program for bug population - bifurcation map of m*y*(1-y) */
#include <stdio.h>
#include <pvm3.h>

#define min 1				/* minimum for m */
#define max 4				/* maximum for m */
#define step 0.1			/* m range for slave */ 
#define nstep 100.0			/* number of steps for slave */
#define skip 200			/* results slave should skip */
#define count 300			/* results slave should record */

main()
{
struct pvmhostinfo *hostp;
int bufid, check, dum, i, nhost, narch, ptid, stid;
char name[64];
double buf[5], m; 

ptid = pvm_mytid();			/* get your PVM ID number */

pvm_config( &nhost, &narch, &hostp );	/* configuration of virtual machine */
gethostname(name, 64);
printf("The master process runs on %s \n", name);
printf("I found the following hosts in your virtual machine\n");
for (i = 0; i < nhost; i++)
{ 
   printf("\t%s\n", hostp[i].hi_name);
}

printf("\nStarting slaves\n");
for (i=0; i<nhost; i++)			/* start slaves on all hosts */
{
   check=pvm_spawn("mapslave", 0,PvmTaskHost,hostp[i].hi_name, 1, &stid);
   if (!check) 
   {
      printf("Couldn't start process on %s\n", hostp[i].hi_name);
      nhost--;
   } 
}

pvm_setopt(PvmRoute, PvmRouteDirect);
buf[2]=nstep;				/* some parameters we send to */
buf[3]=skip;				/* the slave so we can change */ 
buf[4]=count;				/* all parameters in here */

for(m=min; m<=max; m+=step)		/* m parameter for slaves */
{   
   printf("%f\n", m);				/* some feedback */
   bufid=pvm_recv(-1, 2);     			/* slave is ready */
   pvm_bufinfo(bufid, &dum, &dum, &stid);	/* which machine */
   buf[0]=m;					/* min and max of m */
   if((m+step)<max) buf[1]=m+step;
   else buf[1]=max;
   pvm_initsend(PvmDataDefault);		/* send parameters */
   pvm_pkdouble(buf, 5, 1);			/* to slave */
   pvm_send(stid, 1);				
}

for (i=0; i<nhost; i++)				/* wait for final results */
{   
   bufid=pvm_recv(-1, 2);			/* wait for message */
   pvm_bufinfo(bufid, &dum, &dum, &stid);	/* which machine */
   pvm_initsend(PvmDataDefault);		/* tell slave to shut down */
   pvm_send(stid, 0);
}

pvm_exit;
}