/*
** (c) 2004 Herbert Poetzl
**
** somewhat ispired by itimer_test.c
** by Olivier Poitrey
**
** V0.1 basic sleep operations
**
*/

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

#include <sys/time.h>
#include <sys/poll.h>

#define VERSION "V0.1"

enum 	_opt_type {
    	TYPE_SLEEP = 0,
	TYPE_USLEEP,
	TYPE_PAUSE,
	TYPE_POLL,
	TYPE_SELECT,
};


static	char	opt_type = TYPE_SLEEP;

static	int 	interval = 0;
static	int 	number = -1;

static  char 	*cmd_name = NULL;


#define MAX_IVAL     5
#define MIN_IVAL     1

#define TOMS(x)     ((x)*1000)
#define TOUS(x)     ((x)*1000*1000)

#define USTOS(x)    (((x)/1000)/1000)
#define USREM(x)    ((x)%(1000*1000))


#define OPTIONS "hipsuI:N:"

void 	do_nothing(int signum) { }

int	main(int argc, char *argv[])
{
        extern int optind;
        extern char *optarg;

	struct timeval start_time, end_time;
	struct sigaction action;
        char c, errflg = 0;
	int count = 0;
	long adjust;

        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"
                    "-i        use pause() and itimer\n"
                    "-p        use poll() for waiting\n"
                    "-s        use select() for waiting\n"
                    "-u        use usleep() for waiting\n"
		    "-I <arg>  interval (0 = random)\n"
                    "-N <arg>  number of runs\n",
                    cmd_name);
                exit(0);
                break;
            case 'i':
                opt_type = TYPE_PAUSE;
                break;
            case 'p':
                opt_type = TYPE_POLL;
                break;
            case 's':
                opt_type = TYPE_SELECT;
                break;
            case 'u':
                opt_type = TYPE_USLEEP;
                break;
	    case 'I':
		interval = atol(optarg);
	        break;
            case 'N':
                number = 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);
        }

	gettimeofday(&start_time, NULL);
    	for (count=100; count>0; count--)
	    gettimeofday(&end_time, NULL);

        adjust = TOUS(end_time.tv_sec - start_time.tv_sec)
	    + (end_time.tv_usec - start_time.tv_usec);
	adjust /= 100;

	action.sa_handler = do_nothing;
	action.sa_flags = 0;
	sigaction(SIGALRM, &action, NULL);

    	while (number--) {
	    struct itimerval period;
	    long secs = interval;
	    long delta, sign; 
	    
	    if (!interval)
	    	secs = (random() % (MAX_IVAL - MIN_IVAL))
		    + MIN_IVAL;
	
	    printf("%4d: [%3ld] ...", count, secs);
    	    
            period.it_interval.tv_sec = 0;
	    period.it_interval.tv_usec = 0;
	    
	    period.it_value.tv_sec = secs;
            period.it_value.tv_usec = 0;
	    
	    gettimeofday(&start_time, NULL);
	    switch (opt_type) {
	    case TYPE_SLEEP:
	    	sleep(secs);
		break;
		
	    case TYPE_USLEEP:
	    	usleep(TOUS(secs));
		break;
	    
	    case TYPE_PAUSE:
        	setitimer(ITIMER_REAL, &period, NULL);
	        pause();
		break;
		
	    case TYPE_SELECT:
	    	select(0, NULL, NULL, NULL, &period.it_value);
		break;
		
	    case TYPE_POLL:
	    	poll(NULL, 0, TOMS(secs));
		break;
	    
	    }
	    gettimeofday(&end_time, NULL);

            delta = TOUS(end_time.tv_sec - start_time.tv_sec)
	    	+ (end_time.tv_usec - start_time.tv_usec)
		- TOUS(secs) - adjust;
	    sign = (delta >= 0) ? 1 : -1;
	    delta *= sign;
		
	    printf("%4ld.%06ld s  %7.3f %%\n",
	    	sign*USTOS(delta), USREM(delta),
		(delta*100.0/TOUS(secs)));
    	    
	    count++;
	}


	exit((errflg)?1:0);
}