lib/parse_opts.c

/*
 * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/NoticeExplan/
 */

/* $Id: parse_opts.c,v 1.14 2009/08/28 09:59:52 vapier Exp $ */

/**********************************************************
 *
 *    OS Testing - Silicon Graphics, Inc.
 *
 *    FUNCTION NAME	: parse_opts
 *
 *    FUNCTION TITLE	: parse standard & user options for system call tests
 *
 *    SYNOPSIS:
 *	#include "usctest.h"
 *
 *	char *parse_opts(ac, av, user_optarr, uhf)
 *	int    ac;
 *	char **av;
 *	option_t user_optarr[];
 *	void (*uhf)();
 *
 *    AUTHOR		: William Roske/Richard Logan
 *
 *    INITIAL RELEASE	: UNICOS 7.0
 *
 *    DESCRIPTION
 *	The parse_opts library routine takes that argc and argv parameters
 *	recevied by main() and an array of structures defining user options.
 *	It parses the command line setting flag and argument locations
 *      associated with the options.  It uses getopt to do the actual cmd line
 *      parsing.  uhf() is a function to print user define help
 *
 *      This module contains the functions usc_global_setup_hook and
 *      usc_test_looping, which are called by marcos defined in usctest.h.
 *
 *    RETURN VALUE
 *	parse_opts returns a pointer to an error message if an error occurs.
 *	This pointer is (char *)NULL if parsing is successful.
 *
 *#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#**/
#include "config.h"
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/time.h>
#include <stdint.h>

#if UNIT_TEST
#include <time.h>
#endif /* UNIT_TEST */

#include "test.h"
#include "ltp_priv.h"
#include "usctest.h"

#ifndef USC_COPIES
#define USC_COPIES   "USC_COPIES"
#endif

#ifndef UNIT_TEST
#define UNIT_TEST	0
#endif

#ifndef DEBUG
#define DEBUG	0
#endif

/* The timing information block. */
struct tblock tblock = { 0, ((long)-1) >> 1, 0, 0 };

#ifdef GARRETT_IS_A_PEDANTIC_BASTARD
extern pid_t spawned_program_pid;
#endif

/* Define flags and args for standard options */
int STD_FUNCTIONAL_TEST = 1,	/* flag indicating to do functional testing code */
    STD_TIMING_ON = 0,		/* flag indicating to print timing stats */
    STD_PAUSE = 0,		/* flag indicating to pause before actual start, */
    /* for contention mode */
    STD_INFINITE = 0,		/* flag indciating to loop forever */
    STD_LOOP_COUNT = 1,		/* number of iterations */
    STD_COPIES = 1,		/* number of copies */
    STD_ERRNO_LOG = 0;		/* flag indicating to do errno logging */

float STD_LOOP_DURATION = 0.0,	/* duration value in fractional seconds */
    STD_LOOP_DELAY = 0.0;	/* loop delay value in fractional seconds */

char **STD_opt_arr = NULL;	/* array of option strings */
int STD_nopts = 0,		/* number of elements in STD_opt_arr */
    STD_argind = 1;		/* argv index to next argv element */
				/* (first argument) */
				/* To getopt users, it is like optind */

/*
 * The following variables are to support system testing additions.
 */
static int STD_TP_barrier = 0;	/* flag to do barrier in TEST_PAUSE */
				/* 2 - wait_barrier(), 3 - set_barrier(), * - barrier() */
static int STD_LP_barrier = 0;	/* flag to do barrier in TEST_LOOPING */
				/* 2 - wait_barrier(), 3 - set_barrier(), * - barrier() */
static int STD_TP_shmem_sz = 0;	/* shmalloc this many words per pe in TEST_PAUSE */
static int STD_LD_shmem = 0;	/* flag to do shmem_puts and shmem_gets during delay */
static int STD_LP_shmem = 0;	/* flag to do shmem_puts and gets during TEST_LOOPING */
static int STD_LD_recfun = 0;	/* do recressive function calls in loop delay */
static int STD_LP_recfun = 0;	/* do recressive function calls in TEST_LOOPING */
static int STD_TP_sbrk = 0;	/* do sbrk in TEST_PAUSE */
static int STD_LP_sbrk = 0;	/* do sbrk in TEST_LOOPING */
static char *STD_start_break = 0;	/* original sbrk size */
static int Debug = 0;

struct std_option_t {
	char *optstr;
	char *help;
	char *flag;
	char **arg;
} std_options[] = {
	{
	"c:", "  -c n    Run n copies concurrently\n", NULL, NULL}, {
	"e", "  -e      Turn on errno logging\n", NULL, NULL}, {
	"f", "  -f      Turn off functional testing\n", NULL, NULL}, {
	"h", "  -h      Show this help screen\n", NULL, NULL}, {
	"i:", "  -i n    Execute test n times\n", NULL, NULL}, {
	"I:", "  -I x    Execute test for x seconds\n", NULL, NULL}, {
	"p", "  -p      Pause for SIGUSR1 before starting\n", NULL, NULL}, {
	"P:", "  -P x    Pause for x seconds between iterations\n", NULL, NULL},
	{
	"t", "  -t      Turn on syscall timing\n", NULL, NULL},
#ifdef UCLINUX
	{
	"C:",
		    "  -C ARG  Run the child process with arguments ARG (for internal use)\n",
		    NULL, NULL},
#endif
	{
NULL, NULL, NULL, NULL}};

void print_help(void (*user_help) ());

/*
 * Structure for usc_recressive_func argument
 */
struct usc_bigstack_t {
	char space[4096];
};

static struct usc_bigstack_t *STD_bigstack = NULL;

/*
 * Counter of errnos returned (-e option).  Indexed by errno.
 * Make the array USC_MAX_ERRNO long.  That is the first Fortran
 * Lib errno.  No syscall should return an errno that high.
 */
int STD_ERRNO_LIST[USC_MAX_ERRNO];

/* define the string length for Mesg and Mesg2 strings */
#define STRLEN 2048

static char Mesg2[STRLEN];	/* holds possible return string */
static void usc_recressive_func();

/*
 * Define bits for options that might have env variable default
 */
#define  OPT_iteration 		01
#define  OPT_nofunccheck	02
#define  OPT_duration		04
#define  OPT_delay		010
#define  OPT_copies		020

#ifdef UCLINUX
/* Allocated and used in self_exec.c: */
extern char *child_args;	/* Arguments to child when -C is used */
#endif

/**********************************************************************
 * parse_opts:
 **********************************************************************/
char *parse_opts(int ac, char **av, const option_t * user_optarr,
		 void (*uhf) ())
{
	int found;		/* flag to indicate that an option specified was */
	/* found in the user's list */
	int k;			/* scratch integer for returns and short time usage */
	float ftmp;		/* tmp float for parsing env variables */
	char *ptr;		/* used in getting env variables */
	int options = 0;	/* no options specified */
	int optstrlen, i;
	char *optionstr;
	int opt;		/* return of getopt */

	/*
	 * If not the first time this function is called, release the old STD_opt_arr
	 * vector.
	 */

#ifdef GARRETT_IS_A_PEDANTIC_BASTARD
	spawned_program_pid = getpid();
#endif

	if (STD_opt_arr != NULL) {
		free(STD_opt_arr);
		STD_opt_arr = NULL;
	}
	/* Calculate how much space we need for the option string */
	optstrlen = 0;
	for (i = 0; std_options[i].optstr; ++i)
		optstrlen += strlen(std_options[i].optstr);
	if (user_optarr)
		for (i = 0; user_optarr[i].option; ++i) {
			if (strlen(user_optarr[i].option) > 2)
				return
				    "parse_opts: ERROR - Only short options are allowed";
			optstrlen += strlen(user_optarr[i].option);
		}
	optstrlen += 1;

	/* Create the option string for getopt */
	optionstr = malloc(optstrlen);
	if (!optionstr)
		return
		    "parse_opts: ERROR - Could not allocate memory for optionstr";

	optionstr[0] = '\0';

	for (i = 0; std_options[i].optstr; ++i)
		strcat(optionstr, std_options[i].optstr);
	if (user_optarr)
		for (i = 0; user_optarr[i].option; ++i)
			/* only add the option if it wasn't there already */
			if (strchr(optionstr, user_optarr[i].option[0]) == NULL)
				strcat(optionstr, user_optarr[i].option);

#if DEBUG > 1
	printf("STD_nopts = %d\n", STD_nopts);
#endif

	/*
	 *  Loop through av parsing options.
	 */
	while ((opt = getopt(ac, av, optionstr)) > 0) {

		STD_argind = optind;
#if DEBUG > 0
		printf("parse_opts: getopt returned '%c'\n", opt);
#endif

		switch (opt) {
		case '?':	/* Unknown option */
			return "Unknown option";
			break;
		case ':':	/* Missing Arg */
			return "Missing argument";
			break;
		case 'i':	/* Iterations */
			options |= OPT_iteration;
			STD_LOOP_COUNT = atoi(optarg);
			if (STD_LOOP_COUNT == 0)
				STD_INFINITE = 1;
			break;
		case 'P':	/* Delay between iterations */
			options |= OPT_delay;
			STD_LOOP_DELAY = atof(optarg);
			break;
		case 'I':	/* Time duration */
			options |= OPT_duration;
			STD_LOOP_DURATION = atof(optarg);
			if (STD_LOOP_DURATION == 0.0)
				STD_INFINITE = 1;
			break;
		case 'c':	/* Copies */
			fprintf(stderr,
				"WARNING * WARNING * WARNING * WARNING * "
				"WARNING * WARNING * WARNING * WARNING\n\n"
				"The -c option is broken by desing. See:\n\n"
				"http://www.mail-archive.com/"
				"ltp-list@lists.sourceforge.net/msg13418.html\n"
				"\nIn short don't use it in runtest files "
				"as the option will be removed.\n\n"
				"WARNING * WARNING * WARNING * WARNING * "
				"WARNING * WARNING * WARNING * WARNING\n\n");
			options |= OPT_copies;
			STD_COPIES = atoi(optarg);
			break;
		case 'f':	/* Functional testing */
			STD_FUNCTIONAL_TEST = 0;
			break;
		case 'p':	/* Pause for SIGUSR1 */
			STD_PAUSE = 1;
			break;
		case 't':	/* syscall timing */
			STD_TIMING_ON = 1;
			break;
		case 'e':	/* errno loggin */
			STD_ERRNO_LOG = 1;
			break;
		case 'h':	/* Help */
			print_help(uhf);
			exit(0);
			break;
#ifdef UCLINUX
		case 'C':	/* Run child */
			child_args = optarg;
			break;
#endif
		default:

			/* Check all the user specified options */
			found = 0;
			for (i = 0; user_optarr[i].option; ++i) {

				if (opt == user_optarr[i].option[0]) {
					/* Yup, This is a user option, set the flag and look for argument */
					if (user_optarr[i].flag) {
						*user_optarr[i].flag = 1;
					}
					found++;

					/* save the argument at the user's location */
					if (user_optarr[i].
					    option[strlen(user_optarr[i].option)
						   - 1] == ':') {
						*user_optarr[i].arg = optarg;
					}
					break;	/* option found - break out of the for loop */
				}
			}
			/* This condition "should never happen".  SO CHECK FOR IT!!!! */
			if (!found) {
				sprintf(Mesg2,
					"parse_opts: ERROR - option:\"%c\" NOT FOUND... INTERNAL "
					"ERROR", opt);
				return (Mesg2);
			}
		}

	}			/* end of while */
	free(optionstr);

	STD_argind = optind;

	/*
	 * Turn on debug
	 */
	if (getenv("USC_DEBUG") != NULL) {
		Debug = 1;
		printf("env USC_DEBUG is defined, turning on debug\n");
	}
	if (getenv("USC_VERBOSE") != NULL) {
		Debug = 1;
		printf("env USC_VERBOSE is defined, turning on debug\n");
	}

	/*
	 * If the USC_ITERATION_ENV environmental variable is set to
	 * a number, use that number as iteration count (same as -c option).
	 * The -c option with arg will be used even if this env var is set.
	 */
	if (!(options & OPT_iteration)
	    && (ptr = getenv(USC_ITERATION_ENV)) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1) {
			if (k == 0) {	/* if arg is 0, set infinite loop flag */
				STD_INFINITE = 1;
				if (Debug)
					printf
					    ("Using env %s, set STD_INFINITE to 1\n",
					     USC_ITERATION_ENV);
			} else {	/* else, set the loop count to the arguement */
				STD_LOOP_COUNT = k;
				if (Debug)
					printf
					    ("Using env %s, set STD_LOOP_COUNT to %d\n",
					     USC_ITERATION_ENV, k);
			}
		}
	}

	/*
	 * If the USC_NO_FUNC_CHECK environmental variable is set, we'll
	 * unset the STD_FUNCTIONAL_TEST variable.
	 */
	if (!(options & OPT_nofunccheck) &&
	    getenv(USC_NO_FUNC_CHECK) != NULL) {
		STD_FUNCTIONAL_TEST = 0;	/* Turn off functional testing */
		if (Debug)
			printf("Using env %s, set STD_FUNCTIONAL_TEST to 0\n",
			       USC_NO_FUNC_CHECK);
	}

	/*
	 * If the USC_LOOP_WALLTIME environmental variable is set,
	 * use that number as duration (same as -I option).
	 * The -I option with arg will be used even if this env var is set.
	 */

	if (!(options & OPT_duration) &&
	    (ptr = getenv(USC_LOOP_WALLTIME)) != NULL) {
		if (sscanf(ptr, "%f", &ftmp) == 1 && ftmp >= 0.0) {
			STD_LOOP_DURATION = ftmp;
			if (Debug)
				printf
				    ("Using env %s, set STD_LOOP_DURATION to %f\n",
				     USC_LOOP_WALLTIME, ftmp);
			if (STD_LOOP_DURATION == 0.0) {	/* if arg is 0, set infinite loop flag */
				STD_INFINITE = 1;
				if (Debug)
					printf
					    ("Using env %s, set STD_INFINITE to 1\n",
					     USC_LOOP_WALLTIME);
			}
		}
	}
	if (!(options & OPT_duration) && (ptr = getenv("USC_DURATION")) != NULL) {
		if (sscanf(ptr, "%f", &ftmp) == 1 && ftmp >= 0.0) {
			STD_LOOP_DURATION = ftmp;
			if (Debug)
				printf
				    ("Using env USC_DURATION, set STD_LOOP_DURATION to %f\n",
				     ftmp);
			if (STD_LOOP_DURATION == 0.0) {	/* if arg is 0, set infinite loop flag */
				STD_INFINITE = 1;
				if (Debug)
					printf
					    ("Using env USC_DURATION, set STD_INFINITE to 1\n");
			}
		}
	}
	/*
	 * If the USC_LOOP_DELAY environmental variable is set,
	 * use that number as delay in factional seconds (same as -P option).
	 * The -P option with arg will be used even if this env var is set.
	 */
	if (!(options & OPT_delay) && (ptr = getenv(USC_LOOP_DELAY)) != NULL) {
		if (sscanf(ptr, "%f", &ftmp) == 1 && ftmp >= 0.0) {
			STD_LOOP_DELAY = ftmp;
			if (Debug)
				printf
				    ("Using env %s, set STD_LOOP_DELAY = %f\n",
				     USC_LOOP_DELAY, ftmp);
		}
	}

	/*
	 * If the USC_COPIES environmental variable is set,
	 * use that number as copies (same as -c option).
	 * The -c option with arg will be used even if this env var is set.
	 */
	if (!(options & OPT_copies) && (ptr = getenv(USC_COPIES)) != NULL) {
		if (sscanf(ptr, "%d", &STD_COPIES) == 1 && STD_COPIES >= 0) {
			if (Debug)
				printf("Using env %s, set STD_COPIES = %d\n",
				       USC_COPIES, STD_COPIES);
		}
	}

	/*
	 * The following are special system testing envs to turn on special
	 * hooks in the code.
	 */
	if ((ptr = getenv("USC_TP_BARRIER")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0)
			STD_TP_barrier = k;
		else
			STD_TP_barrier = 1;
		if (Debug)
			printf
			    ("using env USC_TP_BARRIER, Set STD_TP_barrier to %d\n",
			     STD_TP_barrier);
	}

	if ((ptr = getenv("USC_LP_BARRIER")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0)
			STD_LP_barrier = k;
		else
			STD_LP_barrier = 1;
		if (Debug)
			printf
			    ("using env USC_LP_BARRIER, Set STD_LP_barrier to %d\n",
			     STD_LP_barrier);
	}

	if ((ptr = getenv("USC_TP_SHMEM")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0) {
			STD_TP_shmem_sz = k;
			if (Debug)
				printf
				    ("Using env USC_TP_SHMEM, Set STD_TP_shmem_sz to %d\n",
				     STD_TP_shmem_sz);
		}
	}

	if ((ptr = getenv("USC_LP_SHMEM")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0) {
			STD_LP_shmem = k;
			if (Debug)
				printf
				    ("Using env USC_LP_SHMEM, Set STD_LP_shmem to %d\n",
				     STD_LP_shmem);
		}
	}

	if ((ptr = getenv("USC_LD_SHMEM")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0) {
			STD_LD_shmem = k;
			if (Debug)
				printf
				    ("Using env USC_LD_SHMEM, Set STD_LD_shmem to %d\n",
				     STD_LD_shmem);
		}
	}

	if ((ptr = getenv("USC_TP_SBRK")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0) {
			STD_TP_sbrk = k;
			if (Debug)
				printf
				    ("Using env USC_TP_SBRK, Set STD_TP_sbrk to %d\n",
				     STD_TP_sbrk);
		}
	}
#if !defined(UCLINUX)
	if ((ptr = getenv("USC_LP_SBRK")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0) {
			STD_LP_sbrk = k;
			if (Debug)
				printf
				    ("Using env USC_LP_SBRK, Set STD_LP_sbrk to %d\n",
				     STD_LP_sbrk);
		}
	}
#endif /* if !defined(UCLINUX) */

	if ((ptr = getenv("USC_LP_RECFUN")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0) {
			STD_LP_recfun = k;
			if (STD_bigstack != NULL)
				STD_bigstack =
				    malloc(sizeof(struct usc_bigstack_t));
			if (Debug)
				printf
				    ("Using env USC_LP_RECFUN, Set STD_LP_recfun to %d\n",
				     STD_LP_recfun);
		}
	}

	if ((ptr = getenv("USC_LD_RECFUN")) != NULL) {
		if (sscanf(ptr, "%i", &k) == 1 && k >= 0) {
			STD_LD_recfun = k;
			if (STD_bigstack != NULL)
				STD_bigstack =
				    malloc(sizeof(struct usc_bigstack_t));
			if (Debug)
				printf
				    ("Using env USC_LD_RECFUN, Set STD_LD_recfun to %d\n",
				     STD_LD_recfun);
		}
	}
#if UNIT_TEST
	printf("The following variables after option and env parsing:\n");
	printf("STD_FUNCTIONAL_TEST = %d\n", STD_FUNCTIONAL_TEST);
	printf("STD_LOOP_DURATION   = %f\n", STD_LOOP_DURATION);
	printf("STD_LOOP_DELAY      = %f\n", STD_LOOP_DELAY);
	printf("STD_COPIES          = %d\n", STD_COPIES);
	printf("STD_LOOP_COUNT      = %d\n", STD_LOOP_COUNT);
	printf("STD_INFINITE        = %d\n", STD_INFINITE);
	printf("STD_TIMING_ON       = %d\n", STD_TIMING_ON);
	printf("STD_ERRNO_LOG       = %d\n", STD_ERRNO_LOG);
	printf("STD_PAUSE           = %d\n", STD_PAUSE);
#endif

	return ((char *)NULL);

}				/* end of parse_opts */

/*********************************************************************
 * print_help() - print help message and user help message
 *********************************************************************/
void print_help(void (*user_help) ())
{
	STD_opts_help();

	if (user_help)
		user_help();
}

/*********************************************************************
 * STD_opts_help() - return a help string for the STD_OPTIONS.
 *********************************************************************/
void STD_opts_help(void)
{
	int i;

	for (i = 0; std_options[i].optstr; ++i) {
		if (std_options[i].help)
			printf("%s", std_options[i].help);
	}
}

/*
 * routine to goto when we get the SIGUSR1 for STD_PAUSE
 */
void STD_go()
{
	return;
}

/***********************************************************************
 * This function will do desired end of global setup test
 * hooks.
 * Currently it will only do a pause waiting for sigusr1 if
 * STD_PAUSE is set.
 *
 ***********************************************************************/
int usc_global_setup_hook(void)
{
#ifndef UCLINUX
	int cnt;
	/* temp variable to store old signal action to be restored after pause */
	int (*_TMP_FUNC) (void);

	/*
	 * Fork STD_COPIES-1 copies.
	 */
	for (cnt = 1; cnt < STD_COPIES; cnt++) {
		switch (fork()) {
		case -1:
			fprintf(stderr, "%s: fork failed: %d - %s\n",
				__FILE__, errno, strerror(errno));
			break;
		case 0:	/* child */
			cnt = STD_COPIES;	/* to stop the forking */
			break;

		default:	/* parent */
			break;
		}
	}

	/*
	 * pause waiting for sigusr1.
	 */
	if (STD_PAUSE) {
		_TMP_FUNC = (int (*)())signal(SIGUSR1, STD_go);
		pause();
		signal(SIGUSR1, (void (*)())_TMP_FUNC);
	}
#if !defined(UCLINUX)

	if (STD_TP_sbrk || STD_LP_sbrk) {
		STD_start_break = sbrk(0);	/* get original sbreak size */
	}

	if (STD_TP_sbrk) {
		sbrk(STD_TP_sbrk);
		if (Debug)
			printf("after sbrk(%d)\n", STD_TP_sbrk);
	}
#endif /* if !defined(UCLINUX) */
#endif
	return 0;
}

#define USECS_PER_SEC	1000000	/* microseconds per second */

/***********************************************************************
 * Returns current time in microseconds since 1970.
 ***********************************************************************/
static uint64_t get_current_time(void)
{
	struct timeval curtime;

	gettimeofday(&curtime, NULL);

	return (((uint64_t) curtime.tv_sec) * USECS_PER_SEC) + curtime.tv_usec;
}

/***********************************************************************
 *
 * This function will determine if test should continue iterating
 * If the STD_INFINITE flag is set, return 1.
 * If the STD_LOOP_COUNT variable is set, compare it against
 * the counter.
 * If the STD_LOOP_DURATION variable is set, compare current time against
 * calculated stop_time.
 * This function will return 1 until all desired looping methods
 * have been met.
 *
 * counter integer is supplied by the user program.
 ***********************************************************************/
int usc_test_looping(int counter)
{
	static int first_time = 1;
	static uint64_t stop_time = 0;
	static uint64_t delay;
	uint64_t ct, end;
	int keepgoing = 0;

	/*
	 * If this is the first iteration and we are looping for
	 * duration of STD_LOOP_DURATION seconds (fractional) or
	 * doing loop delays, get the clocks per second.
	 */
	if (first_time) {
		first_time = 0;

		/*
		 * If looping for duration, calculate stop time in
		 * clocks.
		 */
		if (STD_LOOP_DURATION) {
			stop_time =
			    (uint64_t) (USECS_PER_SEC * STD_LOOP_DURATION)
			    + get_current_time();
		}

		/*
		 * If doing delay each iteration, calcuate the number
		 * of clocks for each delay.
		 */
		if (STD_LOOP_DELAY)
			delay = USECS_PER_SEC * STD_LOOP_DELAY;
	}

	/*
	 * if delay each iteration, loop for delay clocks.
	 * This will not be done on first iteration.
	 * The delay will happen before determining if
	 * there will be another iteration.
	 */
	else if (STD_LOOP_DELAY) {
		ct = get_current_time();
		end = ct + delay;
		while (ct < end) {
			/*
			 * The following are special test hooks in the delay loop.
			 */
			if (STD_LD_recfun) {
				if (Debug)
					printf
					    ("calling usc_recressive_func(0, %d, *STD_bigstack)\n",
					     STD_LD_recfun);
				usc_recressive_func(0, STD_LD_recfun,
						    *STD_bigstack);
			}

			ct = get_current_time();
		}
	}

	if (STD_INFINITE)
		keepgoing++;

	if (STD_LOOP_COUNT && counter < STD_LOOP_COUNT)
		keepgoing++;

	if (STD_LOOP_DURATION != 0.0 && get_current_time() < stop_time)
		keepgoing++;

	if (keepgoing == 0)
		return 0;

	/*
	 * The following code allows special system testing hooks.
	 */

	if (STD_LP_recfun) {
		if (Debug)
			printf
			    ("calling usc_recressive_func(0, %d, *STD_bigstack)\n",
			     STD_LP_recfun);
		usc_recressive_func(0, STD_LP_recfun, *STD_bigstack);
	}
#if !defined(UCLINUX)
	if (STD_LP_sbrk) {
		if (Debug)
			printf("about to do sbrk(%d)\n", STD_LP_sbrk);
		sbrk(STD_LP_sbrk);
	}
#endif

	if (keepgoing)
		return 1;
	else
		return 0;	/* done - stop iterating */
}

/*
 * This function recressively calls itself max times.
 */
static void usc_recressive_func(int cnt, int max, struct usc_bigstack_t bstack)
{
	if (cnt < max)
		usc_recressive_func(cnt + 1, max, bstack);

}

#if UNIT_TEST
/******************************************************************************
 * UNIT TEST CODE
 * UNIT TEST CODE
 *
 * this following code is provide so that unit testing can
 * be done fairly easily.
 ******************************************************************************/

int Help = 0;
int Help2 = 0;
char *ptr;

/*
 * Code from usctest.h that not part of this file since we are the library.
 */

struct usc_errno_t TEST_VALID_ENO[USC_MAX_ERRNO];

long TEST_RETURN;
int TEST_ERRNO;

/* for test specific parse_opts options */
option_t Options[] = {
	{"help", &Help2, NULL},	/* -help option */
	{"h", &Help, NULL},	/* -h option */

#if INVALID_TEST_CASES
	{"missingflag", NULL, &ptr},	/* error */
	{"missingarg:", &Help, NULL},	/* error */
#endif /* INVALID_TEST_CASES */

	{NULL, NULL, NULL}
};

int main(int argc, char **argv)
{
	int lc;
	char *msg;
	struct timeval t;
	int cnt;

	if ((msg = parse_opts(argc, argv, Options, NULL)) != NULL) {
		printf("ERROR: %s\n", msg);
		exit(1);
	}

	TEST_PAUSE;

	for (lc = 0; TEST_LOOPING(lc); lc++) {

		TEST(gettimeofday(&t, NULL));
		printf("iter=%d: sec:%d, usec:%6.6d %s", lc + 1, t.tv_sec,
		       t.tv_usec, ctime(&t.tv_sec));
	}

	TEST_CLEANUP;

	exit(0);
}

#endif /* UNIT_TEST */