htpd: trivial simplification in random interval selection

function                                             old     new   delta
poll_interval                                         57      52      -5

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2014-02-09 15:35:04 +01:00
parent 8ed9672660
commit 3e78f6f955

View File

@ -1660,13 +1660,14 @@ retry_interval(void)
static unsigned
poll_interval(int exponent)
{
unsigned interval, r;
unsigned interval, r, mask;
exponent = G.poll_exp + exponent;
if (exponent < 0)
exponent = 0;
interval = 1 << exponent;
mask = ((interval-1) >> 4) | 1;
r = random();
interval += ((r & (interval-1)) >> 4) + ((r >> 8) & 1); /* + 1/16 of interval, max */
interval += r & mask; /* ~ random(0..1) * interval/16 */
VERB4 bb_error_msg("chose poll interval:%u (poll_exp:%d exp:%d)", interval, G.poll_exp, exponent);
return interval;
}