/*
** (c) 2003-2006 Herbert Poetzl
**
** V0.1 basic cpu hogging
** V0.2 multi threaded
**
*/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <pthread.h>

#define VERSION "V0.1"

static	int 	number = 0;
static	int 	seconds = 0;
static  char 	*cmd_name = NULL;


/* do some CPU hogging */

void *do_hog(void *arg) 
{
  	int i;
	unsigned long long v1,v2,v3;

	while (1) {
		v1 = 42;
		v2 = v3 = -1;
		for (i=0; i<1000; i++) {
			v1 += i;
			v2 = v1*i + v3;
			v3 = v1 ^ v2;
		}
	}
}


#define OPTIONS "hn:s:"

int	main(int argc, char *argv[])
{
        extern int optind;
        extern char *optarg;
	pthread_t *threads;
	pthread_attr_t pthread_custom_attr;
	int i,c,errflg = 0;

        cmd_name = argv[0];
        while ((c = getopt(argc, argv, OPTIONS)) != EOF) {
            switch (c) {
            case 'h':
                fprintf(stderr,
                    "This is %s " VERSION "\n"
                    "options are:\n"
                    "-h        print this help message\n"
 		    "-n <arg>  number of threads\n"
 		    "-s <arg>  seconds to sleep\n"
                    ,cmd_name);
                exit(0);
                break;
            case 'n':
                number = atol(optarg);
                break;
            case 's':
                seconds = atol(optarg);
                break;
            case '?':
            default:
                errflg++;
                break;
            }
        }
        if (errflg) {
            fprintf(stderr, 
                "Usage: %s -" OPTIONS "\n"
                "%s -h for help.\n",
                cmd_name, cmd_name);
            exit(2);
        }

	threads=(pthread_t *)malloc(number * sizeof(*threads));
	pthread_attr_init(&pthread_custom_attr);

	for (i=0; i<number; i++) {
		int ret = pthread_create(&threads[i], 
		    &pthread_custom_attr, do_hog, NULL);
    	    	if (ret)
		    perror("pthread_create");
    	}

    	if (seconds)
	    sleep(seconds);
	else 
	    do_hog(NULL);
	exit((errflg)?1:0);
}