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/***
This file is part of avahi.
avahi is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
avahi is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with avahi; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <pthread.h>
#include <stdlib.h>
#include <assert.h>
#include "timeval.h"
int avahi_timeval_compare(const struct timeval *a, const struct timeval *b) {
assert(a);
assert(b);
if (a->tv_sec < b->tv_sec)
return -1;
if (a->tv_sec > b->tv_sec)
return 1;
if (a->tv_usec < b->tv_usec)
return -1;
if (a->tv_usec > b->tv_usec)
return 1;
return 0;
}
AvahiUsec avahi_timeval_diff(const struct timeval *a, const struct timeval *b) {
assert(a);
assert(b);
if (avahi_timeval_compare(a, b) < 0)
return - avahi_timeval_diff(b, a);
return ((AvahiUsec) a->tv_sec - b->tv_sec)*1000000 + a->tv_usec - b->tv_usec;
}
struct timeval* avahi_timeval_add(struct timeval *a, AvahiUsec usec) {
AvahiUsec u;
assert(a);
u = usec + a->tv_usec;
if (u < 0) {
a->tv_usec = (long) (1000000 + (u % 1000000));
a->tv_sec += (long) (-1 + (u / 1000000));
} else {
a->tv_usec = (long) (u % 1000000);
a->tv_sec += (long) (u / 1000000);
}
return a;
}
AvahiUsec avahi_age(const struct timeval *a) {
struct timeval now;
assert(a);
gettimeofday(&now, NULL);
return avahi_timeval_diff(&now, a);
}
struct timeval *avahi_elapse_time(struct timeval *tv, unsigned msec, unsigned jitter) {
assert(tv);
gettimeofday(tv, NULL);
if (msec)
avahi_timeval_add(tv, (AvahiUsec) msec*1000);
if (jitter) {
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static int last_rand;
static time_t timestamp = 0;
time_t now;
int r;
now = time(NULL);
pthread_mutex_lock(&mutex);
if (now >= timestamp + 10) {
timestamp = now;
last_rand = rand();
}
r = last_rand;
pthread_mutex_unlock(&mutex);
/* We use the same jitter for 10 seconds. That way our
* time events elapse in bursts which has the advantage that
* packet data can be aggregated better */
avahi_timeval_add(tv, (AvahiUsec) (jitter*1000.0*r/(RAND_MAX+1.0)));
}
return tv;
}
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