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Diffstat (limited to 'lib/xtime.h')
-rw-r--r-- | lib/xtime.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/lib/xtime.h b/lib/xtime.h new file mode 100644 index 000000000..333f895b6 --- /dev/null +++ b/lib/xtime.h @@ -0,0 +1,87 @@ +/* xtime -- extended-resolution integer time stamps + + Copyright (C) 2005 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* Written by Paul Eggert. */ + +#ifndef XTIME_H_ +#define XTIME_H_ 1 + +/* xtime_t is a signed type used for time stamps. It is an integer + type that is a count of nanoseconds -- except for obsolescent hosts + without sufficiently-wide integers, where it is a count of + seconds. */ +#if HAVE_LONG_LONG +typedef long long int xtime_t; +# define XTIME_PRECISION 1000000000LL +#else +# include <limits.h> +typedef long int xtime_t; +# if LONG_MAX >> 31 >> 31 == 0 +# define XTIME_PRECISION 1L +# else +# define XTIME_PRECISION 1000000000L +# endif +#endif + +/* Return an extended time value that contains S seconds and NS + nanoseconds, without any overflow checking. */ +static inline xtime_t +xtime_make (xtime_t s, int ns) +{ + if (XTIME_PRECISION == 1) + return s; + else + return XTIME_PRECISION * s + ns; +} + +/* Return the number of seconds in T, which must be nonnegative. */ +static inline xtime_t +xtime_nonnegative_sec (xtime_t t) +{ + return t / XTIME_PRECISION; +} + +/* Return the number of seconds in T. */ +static inline xtime_t +xtime_sec (xtime_t t) +{ + return (XTIME_PRECISION == 1 + ? t + : t < 0 + ? (t + XTIME_PRECISION - 1) / XTIME_PRECISION - 1 + : xtime_nonnegative_sec (t)); +} + +/* Return the number of nanoseconds in T, which must be nonnegative. */ +static inline int +xtime_nonnegative_nsec (xtime_t t) +{ + return t % XTIME_PRECISION; +} + +/* Return the number of nanoseconds in T. */ +static inline int +xtime_nsec (xtime_t t) +{ + int ns = t % XTIME_PRECISION; + if (ns < 0) + ns += XTIME_PRECISION; + return ns; +} + +#endif |