Line data    Source code

       1             : /* xtime -- extended-resolution integer time stamps
       2             : 
       3             :    Copyright (C) 2005, 2006 Free Software Foundation, Inc.
       4             : 
       5             :    This program is free software: you can redistribute it and/or modify
       6             :    it under the terms of the GNU General Public License as published by
       7             :    the Free Software Foundation; either version 3 of the License, or
       8             :    (at your option) any later version.
       9             : 
      10             :    This program is distributed in the hope that it will be useful,
      11             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
      12             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      13             :    GNU General Public License for more details.
      14             : 
      15             :    You should have received a copy of the GNU General Public License
      16             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
      17             : 
      18             : /* Written by Paul Eggert.  */
      19             : 
      20             : #ifndef XTIME_H_
      21             : # define XTIME_H_ 1
      22             : 
      23             : /* xtime_t is a signed type used for time stamps.  It is an integer
      24             :    type that is a count of nanoseconds -- except for obsolescent hosts
      25             :    without sufficiently-wide integers, where it is a count of
      26             :    seconds.  */
      27             : # if HAVE_LONG_LONG_INT
      28             : typedef long long int xtime_t;
      29             : #  define XTIME_PRECISION 1000000000
      30             : # else
      31             : #  include <limits.h>
      32             : typedef long int xtime_t;
      33             : #  if LONG_MAX >> 31 >> 31 == 0
      34             : #   define XTIME_PRECISION 1
      35             : #  else
      36             : #   define XTIME_PRECISION 1000000000
      37             : #  endif
      38             : # endif
      39             : 
      40             : /* Return an extended time value that contains S seconds and NS
      41             :    nanoseconds, without any overflow checking.  */
      42             : static inline xtime_t
      43          22 : xtime_make (xtime_t s, long int ns)
      44             : {
      45             :   if (XTIME_PRECISION == 1)
      46             :     return s;
      47             :   else
      48          22 :     return XTIME_PRECISION * s + ns;
      49             : }
      50             : 
      51             : /* Return the number of seconds in T, which must be nonnegative.  */
      52             : static inline xtime_t
      53             : xtime_nonnegative_sec (xtime_t t)
      54             : {
      55             :   return t / XTIME_PRECISION;
      56             : }
      57             : 
      58             : /* Return the number of seconds in T.  */
      59             : static inline xtime_t
      60             : xtime_sec (xtime_t t)
      61             : {
      62             :   return (XTIME_PRECISION == 1
      63             :           ? t
      64             :           : t < 0
      65             :           ? (t + XTIME_PRECISION - 1) / XTIME_PRECISION - 1
      66             :           : xtime_nonnegative_sec (t));
      67             : }
      68             : 
      69             : /* Return the number of nanoseconds in T, which must be nonnegative.  */
      70             : static inline long int
      71             : xtime_nonnegative_nsec (xtime_t t)
      72             : {
      73             :   return t % XTIME_PRECISION;
      74             : }
      75             : 
      76             : /* Return the number of nanoseconds in T.  */
      77             : static inline long int
      78             : xtime_nsec (xtime_t t)
      79             : {
      80             :   long int ns = t % XTIME_PRECISION;
      81             :   if (ns < 0)
      82             :     ns += XTIME_PRECISION;
      83             :   return ns;
      84             : }
      85             : 
      86             : #endif