Date: Thu, 22 Jun 1995 19:03:28 -0400 From: mtaylor@gateway.cybernet.com (Mark J. Taylor) To: hackers@freebsd.org Subject: brokenness in kern_time.c: timevalfix() Message-ID: <199506222303.TAA05634@gateway.cybernet.com>
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I've noticed that timevalfix() does not calculate fixes 'correctly'
(completely). I assume that it is suposed to take a given timeval structure
and 'fix' it so that tv_usec is less than one million and greater than zero,
while adjusting tv_sec appropriately.
void
timevalfix(t1)
struct timeval *t1;
{
if (t1->tv_usec < 0) { /* <------------- should be 'while'?
t1->tv_sec--;
t1->tv_usec += 1000000;
}
if (t1->tv_usec >= 1000000) { /* <------------- should be 'while'?
t1->tv_sec++;
t1->tv_usec -= 1000000;
}
}
Another way to fix it would be to do an integer division of tv_usec by 1000000
to determine how many seconds need to be added / subtracted:
int sec_cor;
sec_cor = t1->tv_usec / 1000000;
t1->tv_sec += sec_cor;
t1->tv_usec -= sec_cor * 1000000;
Also, timevalfix() is called by timevaladd() and timevalsub(), so why is it
being called in settimeofday() right after a timevaladd()? Isn't this
redundant?
These 'problems' have been in kern_time.c at least since FreeBSD 1.1.5.1.
Would someone please explain to me why not to fix timevalfix()? Does it have
to do with speed, or (possibly) other routines rely on this 'brokenness'?
-Mark Taylor
mtaylor@cybernet.com
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