/* @TITLE "Message-passing Matrix multiply"  */
/* 
 * Message-passing matrix multiply example
 * MASTER
 *
 * David Kotz 1991
 */

#include <stdio.h>
#include "p4.h"
#include "dfk.h"
#include "broadcast.h"
#include "mpmatrix.h"

char *progname;

extern void do_one_row();

/* @SUBTITLE "main program: master" */
main(argc, argv)
	int argc;
	char **argv;
{
    int nprocs;			/* number of processes to use */
    int node;				/* our node number */
    int N;					/* the size of each square matrix */
    boolean printmatrix;		/* should we print the matrix? */
    struct problem_s prob,*message; /* problem description */
    int length;			/* size of message */

    p4_initenv(&argc, argv);

    /* Get arguments */
    progname = argv[0];

    if (argc < 2) {
	   fprintf(stderr, "usage: %s [p4opts] N [print]\n", progname);
	   exit(-1);
    }

    N = atoi(argv[1]);
    if (N < 1) {
	   fprintf(stderr, "%s: N=%d; should be > 0. (N=atoi(%s))\n", 
			 progname, N, argv[1]);
	   exit(-1);
    }

    printmatrix = (argc >= 3);

    /* GENERATE PROCESSES */
    p4_create_procgroup();
    nprocs = p4_num_total_slaves()+1;
    node = 0;				/* I am master */

    /* send problem size to all nodes */
    prob.N = N;
    prob.printmatrix = printmatrix;
    length = sizeof(prob);
    message = &prob;
    broadcast(node, nprocs, &message, &length);

    if (nprocs != N)
	 fprintf(stderr, "%s: Sorry, this program is too dumb to handle N<>P.\n", 
		    progname);
    else
	 do_one_row(nprocs, node, printmatrix, N); /* we help out with the work */
    
    p4_wait_for_end();
}