diff options
Diffstat (limited to 'lib/timespec.h')
| -rw-r--r-- | lib/timespec.h | 41 |
1 files changed, 3 insertions, 38 deletions
diff --git a/lib/timespec.h b/lib/timespec.h index 02684ce6eac..dc999f944b2 100644 --- a/lib/timespec.h +++ b/lib/timespec.h @@ -34,7 +34,6 @@ extern "C" { #endif #include "arg-nonnull.h" -#include "verify.h" /* Inverse resolution of timespec timestamps (in units per second), and log base 10 of the inverse resolution. */ @@ -59,46 +58,12 @@ make_timespec (time_t s, long int ns) return r; } -/* Return negative, zero, positive if A < B, A == B, A > B, respectively. - - For each timestamp T, this code assumes that either: - - * T.tv_nsec is in the range 0..999999999; or - * T.tv_sec corresponds to a valid leap second on a host that supports - leap seconds, and T.tv_nsec is in the range 1000000000..1999999999; or - * T.tv_sec is the minimum time_t value and T.tv_nsec is -1; or - T.tv_sec is the maximum time_t value and T.tv_nsec is 2000000000. - This allows for special struct timespec values that are less or - greater than all possible valid timestamps. - - In all these cases, it is safe to subtract two tv_nsec values and - convert the result to integer without worrying about overflow on - any platform of interest to the GNU project, since all such - platforms have 32-bit int or wider. - - Replacing "a.tv_nsec - b.tv_nsec" with something like - "a.tv_nsec < b.tv_nsec ? -1 : a.tv_nsec > b.tv_nsec" would cause - this function to work in some cases where the above assumption is - violated, but not in all cases (e.g., a.tv_sec==1, a.tv_nsec==-2, - b.tv_sec==0, b.tv_nsec==999999999) and is arguably not worth the - extra instructions. Using a subtraction has the advantage of - detecting some invalid cases on platforms that detect integer - overflow. */ +/* Return negative, zero, positive if A < B, A == B, A > B, respectively. */ _GL_TIMESPEC_INLINE int _GL_ATTRIBUTE_PURE timespec_cmp (struct timespec a, struct timespec b) { - if (a.tv_sec < b.tv_sec) - return -1; - if (a.tv_sec > b.tv_sec) - return 1; - - /* Pacify gcc -Wstrict-overflow (bleeding-edge circa 2017-10-02). See: - https://lists.gnu.org/r/bug-gnulib/2017-10/msg00006.html */ - assume (-1 <= a.tv_nsec && a.tv_nsec <= 2 * TIMESPEC_HZ); - assume (-1 <= b.tv_nsec && b.tv_nsec <= 2 * TIMESPEC_HZ); - - return a.tv_nsec - b.tv_nsec; + return 2 * _GL_CMP (a.tv_sec, b.tv_sec) + _GL_CMP (a.tv_nsec, b.tv_nsec); } /* Return -1, 0, 1, depending on the sign of A. A.tv_nsec must be @@ -106,7 +71,7 @@ timespec_cmp (struct timespec a, struct timespec b) _GL_TIMESPEC_INLINE int _GL_ATTRIBUTE_PURE timespec_sign (struct timespec a) { - return a.tv_sec < 0 ? -1 : a.tv_sec || a.tv_nsec; + return _GL_CMP (a.tv_sec, 0) + (!a.tv_sec & !!a.tv_nsec); } struct timespec timespec_add (struct timespec, struct timespec) |