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

#define	MAXLOOP		80000
#define	OUR_TAG		238
#define	VLEN		8

extern	char	*strdup(__const char *__s);
static	char	*argv0;


static void sender(int dest, int n)
{
    int		i, vector[VLEN];

    if(pvm_initsend(PvmDataDefault) < 0) {
	(void)pvm_perror("pvm_initsend()");
	return;
    }
    i	= pvm_newcontext();
    (void)pvm_pkint(&i, 1, 1);
    if(pvm_send(dest, OUR_TAG) != 0) {
	(void)pvm_perror("pvm_send()");
	return;
    }

    if(pvm_setcontext(i) < 0) {
	(void)pvm_perror("pvm_setcontext()");
	return;
    }

    for(i=1 ; i<VLEN ; ++i)
	vector[i] = (1<<(i-1));

    for(i=1 ; i<=n ; ++i) {
	if(pvm_initsend(PvmDataDefault) < 0) {
	    (void)pvm_perror("pvm_initsend()");
	    return;
	}
	vector[0] = i;
	(void)pvm_pkint(vector, VLEN, 1);

	if(pvm_send(dest, OUR_TAG) != 0) {
	    (void)pvm_perror("pvm_send()");
	    return;
	}
    }

    (void)pvm_initsend(PvmDataDefault);
    vector[0] = -1;
    (void)pvm_pkint(vector, VLEN, 1);
    (void)pvm_send(dest, OUR_TAG);

    (void)pvm_initsend(PvmDataDefault);
    (void)pvm_pkstr("that's all folks");
    (void)pvm_send(dest, OUR_TAG);
}

static void receiver()
{
    int			i, m=0, values[VLEN];
    int			bufid, nbytes, msgtag, tid;
    unsigned long	sum=0;
    char		*str;

    if(pvm_recv( pvm_parent(), OUR_TAG) < 0) {
	(void)pvm_perror("pvm_recv()");
	return;
    }
    if(pvm_upkint( &i, 1, 1) < 0) {
	(void)pvm_perror("pvm_upkint()");
	return;
    }
    if(pvm_setcontext(i) < 0) {
	(void)pvm_perror("pvm_getcontext()");
	return;
    }

    for(;;) {
	if(pvm_recv( pvm_parent(), OUR_TAG) < 0) {
	    (void)pvm_perror("pvm_recv()");
	    break;
	}
	if(pvm_upkint( values, VLEN, 1) < 0) {
	    (void)pvm_perror("pvm_upkint()");
	    break;
	}
	if(values[0] < 0)
	    break;
	sum += values[0];
	++m;
    }
    (void)printf("\nreceiver got sum=%lu in %d messages\n", sum,m);

    bufid	= pvm_recv(-1, -1);
    if(bufid < 0) {
	(void)pvm_perror("pvm_recv()");
	return;
    }
    if(pvm_bufinfo(bufid, &nbytes, &msgtag, &tid) < 0) {
	(void)pvm_perror("pvm_bufinfo()");
	return;
    }
    (void)printf("another message from tid=%d tag=%d len=%d\n",
			tid, msgtag, nbytes);
    str	= malloc(nbytes);
    if(pvm_upkstr(str) < 0) {
	(void)pvm_perror("pvm_upkstr()");
	return;
    }
    (void)printf("receiver got final string \"%s\"\n", str);
    free(str);
}

int main(int argc, char **argv)
{
    argv0 = (argv0 = strrchr(argv[0],'/')) ? argv0+1 : argv[0];
    --argc; ++argv;

    switch (pvm_parent()) {
    case PvmSysErr   :				/* need to start pvmd */
	if(pvm_start_pvmd(argc, argv, 1) < 0)
	    exit(0);
	/* fall through */

    case PvmNoParent : {			/* I am the sender */
	char	*h[2], *newargs[2];
	int	i, newtid;

	h[0]	= "dropbear";
	h[1]	= NULL;
	if(pvm_addhosts(h, 1, &i) != 1)
	    (void)pvm_perror("pvm_addhosts()");

	newargs[0]	= (char *)NULL;
	if(pvm_spawn(argv0, newargs, 0, (char *)NULL, 1, &newtid) != 1) {
	    (void)pvm_perror("pvm_spawn()");
	    pvm_halt();
	}
	i	= (argc > 0 ? atoi(*argv++) : MAXLOOP);
	sender(newtid, i);
	break;
    }

    default :					/* I am the receiver */
	receiver();
	break;
    }

    (void)pvm_exit();
    return(0);
}