diff options
Diffstat (limited to 'utils/utils.c')
| -rw-r--r-- | utils/utils.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/utils/utils.c b/utils/utils.c index c82bc2c74..9561521cb 100644 --- a/utils/utils.c +++ b/utils/utils.c @@ -283,6 +283,34 @@ unsigned int wallclock(void) return ((tv.tv_sec * 100) + (tv.tv_usec / 10000)); } +/* Subtract the `struct timeval' values X and Y, + storing the result in RESULT. + Return 1 if the difference is negative, otherwise 0. +*/ + +int timeval_subtract(struct timeval *result, struct timeval *x, struct timeval *y) +{ + /* Perform the carry for the later subtraction by updating y. */ + if (x->tv_usec < y->tv_usec) { + int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1; + y->tv_usec -= 1000000 * nsec; + y->tv_sec += nsec; + } + if (x->tv_usec - y->tv_usec > 1000000) { + int nsec = (x->tv_usec - y->tv_usec) / 1000000; + y->tv_usec += 1000000 * nsec; + y->tv_sec -= nsec; + } + + /* Compute the time remaining to wait. + tv_usec is certainly positive. */ + result->tv_sec = x->tv_sec - y->tv_sec; + result->tv_usec = x->tv_usec - y->tv_usec; + + /* Return 1 if result is negative. */ + return x->tv_sec < y->tv_sec; +} + #ifndef HAVE_STRCASESTR /** |