erl_time_sup.c

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    return CLOCK_RESOLUTION;
}    
/* info functions */

void 
elapsed_time_both(unsigned long *ms_user, unsigned long *ms_sys, 
		  unsigned long *ms_user_diff, unsigned long *ms_sys_diff)
{
    unsigned long prev_total_user, prev_total_sys;
    unsigned long total_user, total_sys;
    SysTimes now;

    sys_times(&now);
    total_user = (now.tms_utime * 1000) / SYS_CLK_TCK;
    total_sys = (now.tms_stime * 1000) / SYS_CLK_TCK;

    if (ms_user != NULL)
	*ms_user = total_user;
    if (ms_sys != NULL)
	*ms_sys = total_sys;

    erts_smp_mtx_lock(&erts_timeofday_mtx);
    
    prev_total_user = (t_start.tms_utime * 1000) / SYS_CLK_TCK;
    prev_total_sys = (t_start.tms_stime * 1000) / SYS_CLK_TCK;
    t_start = now;
    
    erts_smp_mtx_unlock(&erts_timeofday_mtx);

    if (ms_user_diff != NULL)
	*ms_user_diff = total_user - prev_total_user;
	  
    if (ms_sys_diff != NULL)
	*ms_sys_diff = total_sys - prev_total_sys;
}


/* wall clock routines */

void 
wall_clock_elapsed_time_both(unsigned long *ms_total, unsigned long *ms_diff)
{
    unsigned long prev_total;
    SysTimeval tv;

    erts_smp_mtx_lock(&erts_timeofday_mtx);

    get_tolerant_timeofday(&tv);

    *ms_total = 1000 * (tv.tv_sec - inittv.tv_sec) +
	(tv.tv_usec - inittv.tv_usec) / 1000;

    prev_total = 1000 * (gtv.tv_sec - inittv.tv_sec) +
	(gtv.tv_usec - inittv.tv_usec) / 1000;
    *ms_diff = *ms_total - prev_total;
    gtv = tv;

    /* must sync the machine's idea of time here */
    do_erts_deliver_time(&tv);

    erts_smp_mtx_unlock(&erts_timeofday_mtx);
}

/* get current time */
void 
get_time(int *hour, int *minute, int *second)
{
    time_t the_clock;
    struct tm *tm;
#ifdef HAVE_LOCALTIME_R
    struct tm tmbuf;
#endif
    
    the_clock = time((time_t *)0);
#ifdef HAVE_LOCALTIME_R
    localtime_r(&the_clock, (tm = &tmbuf));
#else
    tm = localtime(&the_clock);
#endif
    *hour = tm->tm_hour;
    *minute = tm->tm_min;
    *second = tm->tm_sec;
}

/* get current date */
void 
get_date(int *year, int *month, int *day)
{
    time_t the_clock;
    struct tm *tm;
#ifdef HAVE_LOCALTIME_R
    struct tm tmbuf;
#endif


    the_clock = time((time_t *)0);
#ifdef HAVE_LOCALTIME_R
    localtime_r(&the_clock, (tm = &tmbuf));
#else
    tm = localtime(&the_clock);
#endif
    *year = tm->tm_year + 1900;
    *month = tm->tm_mon +1;
    *day = tm->tm_mday;
}

/* get localtime */
void 
get_localtime(int *year, int *month, int *day, 
	      int *hour, int *minute, int *second)
{
    time_t the_clock;
    struct tm *tm;
#ifdef HAVE_LOCALTIME_R
    struct tm tmbuf;
#endif

    the_clock = time((time_t *)0);
#ifdef HAVE_LOCALTIME_R
    localtime_r(&the_clock, (tm = &tmbuf));
#else
    tm = localtime(&the_clock);
#endif
    *year = tm->tm_year + 1900;
    *month = tm->tm_mon +1;
    *day = tm->tm_mday;
    *hour = tm->tm_hour;
    *minute = tm->tm_min;
    *second = tm->tm_sec;
}


/* get universaltime */
void 
get_universaltime(int *year, int *month, int *day, 
		  int *hour, int *minute, int *second)
{
    time_t the_clock;
    struct tm *tm;
#ifdef HAVE_GMTIME_R
    struct tm tmbuf;
#endif

    the_clock = time((time_t *)0);
#ifdef HAVE_GMTIME_R
    gmtime_r(&the_clock, (tm = &tmbuf));
#else
    tm = gmtime(&the_clock);
#endif
    *year = tm->tm_year + 1900;
    *month = tm->tm_mon +1;
    *day = tm->tm_mday;
    *hour = tm->tm_hour;
    *minute = tm->tm_min;
    *second = tm->tm_sec;
}


/* days in month = 1, 2, ..., 12 */
static const int mdays[14] = {0, 31, 28, 31, 30, 31, 30,
                                 31, 31, 30, 31, 30, 31};

#define  IN_RANGE(a,x,b)  (((a) <= (x)) && ((x) <= (b)))
#define  is_leap_year(y)  (((((y) % 4) == 0) && \
                            (((y) % 100) != 0)) || \
                           (((y) % 400) == 0))

#define  BASEYEAR       1970

/*
 * gregday
 *
 * Returns the number of days since Jan 1, 1600, if year is
 * greater of equal to 1600 , and month [1-12] and day [1-31] 
 * are within range. Otherwise it returns -1.
 */
static int long gregday(int year, int month, int day)
{
  int long ndays = 0;
  int gyear, pyear, m;
  
  /* number of days in previous years */
  gyear = year - 1600;
  if (gyear > 0) {
    pyear = gyear - 1;
    ndays = (pyear/4) - (pyear/100) + (pyear/400) + pyear*365 + 366;
  }
  /* number of days in all months preceeding month */
  for (m = 1; m < month; m++)
    ndays += mdays[m];
  /* Extra day if leap year and March or later */
  if (is_leap_year(year) && (month > 2))
    ndays++;
  ndays += day - 1;
  return ndays - 135140;        /* 135140 = Jan 1, 1970 */
}



int 
local_to_univ(Sint *year, Sint *month, Sint *day, 
	      Sint *hour, Sint *minute, Sint *second, int isdst)
{
    time_t the_clock;
    struct tm *tm, t;
#ifdef HAVE_GMTIME_R
    struct tm tmbuf;
#endif
    
    if (!(IN_RANGE(BASEYEAR, *year, INT_MAX - 1) &&
          IN_RANGE(1, *month, 12) &&
          IN_RANGE(1, *day, (mdays[*month] + 
                             (*month == 2 
                              && (*year % 4 == 0) 
                              && (*year % 100 != 0 || *year % 400 == 0)))) &&
          IN_RANGE(0, *hour, 23) &&
          IN_RANGE(0, *minute, 59) &&
          IN_RANGE(0, *second, 59))) {
      return 0;
    }
    
    t.tm_year = *year - 1900;
    t.tm_mon = *month - 1;
    t.tm_mday = *day;
    t.tm_hour = *hour;
    t.tm_min = *minute;
    t.tm_sec = *second;
    t.tm_isdst = isdst;
    the_clock = mktime(&t);
#ifdef HAVE_GMTIME_R
    gmtime_r(&the_clock, (tm = &tmbuf));
#else
    tm = gmtime(&the_clock);
#endif
    *year = tm->tm_year + 1900;
    *month = tm->tm_mon +1;
    *day = tm->tm_mday;
    *hour = tm->tm_hour;
    *minute = tm->tm_min;
    *second = tm->tm_sec;
    return 1;
}

int 
univ_to_local(Sint *year, Sint *month, Sint *day, 
	      Sint *hour, Sint *minute, Sint *second)
{
    time_t the_clock;
    struct tm *tm;
#ifdef HAVE_LOCALTIME_R
    struct tm tmbuf;
#endif
    
    if (!(IN_RANGE(BASEYEAR, *year, INT_MAX - 1) &&
          IN_RANGE(1, *month, 12) &&
          IN_RANGE(1, *day, (mdays[*month] + 
                             (*month == 2 
                              && (*year % 4 == 0) 
                              && (*year % 100 != 0 || *year % 400 == 0)))) &&
          IN_RANGE(0, *hour, 23) &&
          IN_RANGE(0, *minute, 59) &&
          IN_RANGE(0, *second, 59))) {
      return 0;
    }
    
    the_clock = *second + 60 * (*minute + 60 * (*hour + 24 *
                                            gregday(*year, *month, *day)));
#ifdef HAVE_LOCALTIME_R
    localtime_r(&the_clock, (tm = &tmbuf));
#else
    tm = localtime(&the_clock);
#endif
    *year = tm->tm_year + 1900;
    *month = tm->tm_mon +1;
    *day = tm->tm_mday;
    *hour = tm->tm_hour;
    *minute = tm->tm_min;
    *second = tm->tm_sec;
    return 1;
}


/* get a timestamp */
void
get_now(Uint* megasec, Uint* sec, Uint* microsec)
{
    SysTimeval now;
    
    erts_smp_mtx_lock(&erts_timeofday_mtx);
    
    get_tolerant_timeofday(&now);
    do_erts_deliver_time(&now);

    /* Make sure time is later than last */
    if (then.tv_sec > now.tv_sec ||
	(then.tv_sec == now.tv_sec && then.tv_usec >= now.tv_usec)) {
	now = then;
	now.tv_usec++;
    }
    /* Check for carry from above + general reasonability */
    if (now.tv_usec >= 1000000) {
	now.tv_usec = 0;
	now.tv_sec++;
    }
    then = now;
    
    erts_smp_mtx_unlock(&erts_timeofday_mtx);
    
    *megasec = (Uint) (now.tv_sec / 1000000);
    *sec = (Uint) (now.tv_sec % 1000000);
    *microsec = (Uint) (now.tv_usec);
}


/* deliver elapsed *ticks* to the machine - takes a pointer
   to a struct timeval representing current time (to save
   a gettimeofday() where possible) or NULL */

#if !defined(ERTS_TIMER_THREAD)
void erts_deliver_time(void) {
    SysTimeval now;
    
    erts_smp_mtx_lock(&erts_timeofday_mtx);
    
    get_tolerant_timeofday(&now);
    do_erts_deliver_time(&now);
    
    erts_smp_mtx_unlock(&erts_timeofday_mtx);
}
#endif

/* get *real* time (not ticks) remaining until next timeout - if there
   isn't one, give a "long" time, that is guaranteed
   to not cause overflow when we report elapsed time later on */

void erts_time_remaining(SysTimeval *rem_time)
{
    int ticks;
#if !defined(ERTS_TIMER_THREAD)
    SysTimeval cur_time;
#endif
    long elapsed;

    /* next_time() returns no of ticks to next timeout or -1 if none */

    if ((ticks = next_time()) == -1) {
	/* timer queue empty */
	/* this will cause at most 100000000 ticks */
	rem_time->tv_sec = 100000;
	rem_time->tv_usec = 0;
    } else {
	/* next timeout after ticks ticks */
	ticks *= CLOCK_RESOLUTION;
	
#if defined(ERTS_TIMER_THREAD)
	elapsed = 0;
#else
	erts_smp_mtx_lock(&erts_timeofday_mtx);
	
	get_tolerant_timeofday(&cur_time);
	cur_time.tv_usec = 1000 * 
	    (cur_time.tv_usec / 1000);/* ms resolution*/
	elapsed = 1000 * (cur_time.tv_sec - last_delivered.tv_sec) +
	    (cur_time.tv_usec - last_delivered.tv_usec) / 1000;
	
	erts_smp_mtx_unlock(&erts_timeofday_mtx);
	
	if (ticks <= elapsed) { /* Ooops, better hurry */
	    rem_time->tv_sec = rem_time->tv_usec = 0;
	    return;
	}
#endif
	rem_time->tv_sec = (ticks - elapsed) / 1000;
	rem_time->tv_usec = 1000 * ((ticks - elapsed) % 1000);
    }
}

#if defined(ERTS_TIMER_THREAD)
void erts_get_timeval(SysTimeval *tv)
{
    erts_smp_mtx_lock(&erts_timeofday_mtx);
    get_tolerant_timeofday(tv);
    erts_smp_mtx_unlock(&erts_timeofday_mtx);
}
#endif

long
erts_get_time(void)
{
    SysTimeval sys_tv;
    
    erts_smp_mtx_lock(&erts_timeofday_mtx);
    
    get_tolerant_timeofday(&sys_tv);
    
    erts_smp_mtx_unlock(&erts_timeofday_mtx);
    
    return sys_tv.tv_sec;
}

#ifdef HAVE_ERTS_NOW_CPU
void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec) {
  SysCpuTime t;
  SysTimespec tp;

  sys_get_proc_cputime(t, tp);
  *microsec = (Uint)(tp.tv_nsec / 1000);
  t = (tp.tv_sec / 1000000);
  *megasec = (Uint)(t % 1000000);
  *sec = (Uint)(tp.tv_sec % 1000000);
}
#endif