29 lines
847 B
C
29 lines
847 B
C
/* Subtract the `struct timeval' values X and Y,
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storing the result in RESULT.
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Return 1 if the difference is negative, otherwise 0. */
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int
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timeval_subtract (result, x, y)
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struct timeval *result, *x, *y;
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{
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/* Perform the carry for the later subtraction by updating @var{y}. */
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if (x->tv_usec < y->tv_usec) {
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int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1;
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y->tv_usec -= 1000000 * nsec;
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y->tv_sec += nsec;
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}
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if (x->tv_usec - y->tv_usec > 1000000) {
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int nsec = (x->tv_usec - y->tv_usec) / 1000000;
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y->tv_usec += 1000000 * nsec;
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y->tv_sec -= nsec;
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}
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/* Compute the time remaining to wait.
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@code{tv_usec} is certainly positive. */
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result->tv_sec = x->tv_sec - y->tv_sec;
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result->tv_usec = x->tv_usec - y->tv_usec;
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/* Return 1 if result is negative. */
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return x->tv_sec < y->tv_sec;
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}
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