netcdf-c/nc_test4/tst_utils.c
2011-07-20 21:32:41 +00:00

36 lines
1020 B
C

/** \internal
\file
Utility functions for tests. */
#include <nc_tests.h>
#include <time.h>
#include <sys/time.h>
/** Subtract the `struct timeval' values X and Y, storing the result in
RESULT. Return 1 if the difference is negative, otherwise 0. This
function from the GNU documentation. */
int
nc4_timeval_subtract (result, x, y)
struct timeval *result, *x, *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) / MILLION + 1;
y->tv_usec -= MILLION * nsec;
y->tv_sec += nsec;
}
if (x->tv_usec - y->tv_usec > MILLION) {
int nsec = (x->tv_usec - y->tv_usec) / MILLION;
y->tv_usec += MILLION * 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;
}