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/* **************************************************************** *
* *
* APRX -- 2nd generation APRS iGate and digi with *
* minimal requirement of esoteric facilities or *
* libraries of any kind beyond UNIX system libc. *
* *
* (c) Matti Aarnio - OH2MQK, 2007-2014 *
* *
* **************************************************************** */
#include "aprx.h"
/* Bits used only in the main program.. */
#include <signal.h>
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
#endif
#ifdef HAVE_TIME_H
# include <time.h>
#endif
#include <fcntl.h>
struct timeval now; // public wall clock that can jump around
struct timeval tick; // monotonic clock
/*
* Calculate difference from now time to target time in milliseconds.
*/
int tv_timerdelta_millis(struct timeval *_now, struct timeval *_target)
{
int deltasec = _target->tv_sec - _now->tv_sec;
int deltausec = _target->tv_usec - _now->tv_usec;
while (deltausec < 0) {
deltausec += 1000000;
--deltasec;
}
return deltasec * 1000 + deltausec / 1000;
}
/*
* Add milliseconds to input parameter a returning
* the result though parameter ret.
*/
void tv_timeradd_millis(struct timeval *ret, struct timeval *a, int millis)
{
if (ret != a) {
// Copy if different pointers..
*ret = *a;
}
int usec = (int)(ret->tv_usec) + millis * 1000;
if (usec >= 1000000) {
int dsec = (usec / 1000000);
ret->tv_sec += dsec;
usec %= 1000000;
// if (debug>3) printf("tv_timeadd_millis() dsec=%d dusec=%d\n",dsec, usec);
}
ret->tv_usec = usec;
}
/*
* Add seconds to input parameter a returning
* the result though parameter ret.
*/
void tv_timeradd_seconds(struct timeval *ret, struct timeval *a, int seconds)
{
if (ret != a) {
// Copy if different pointers..
*ret = *a;
}
ret->tv_sec += seconds;
}
/*
* Comparison returning -1/0/+1 depending on ( a <=> b )
*
* This handles overflow wraparound of Y2038 issue of 32-bit UNIX time_t.
*/
int timecmp(const time_t a, const time_t b)
{
const int i = (int)(a - b);
if (i == 0) return 0;
if (i > 0) return 1;
return -1;
}
/*
* Time compare function returning -1/0/+1 depending
* which parameter presents time before the other.
* Zero means equals.
*/
int tv_timercmp(struct timeval * const a, struct timeval * const b)
{
// if (debug>3) {
// int dt_sec = a->tv_sec - b->tv_sec;
// int dt_usec = a->tv_usec - b->tv_usec;
// printf("tv_timercmp(%d.%06d <=> %d.%06d) dt=%d:%06d ret= ",
// a->tv_sec, a->tv_usec, b->tv_sec, b->tv_usec, dt_sec, dt_usec);
// }
// Time delta calculation to avoid year 2038 issue
const int dt = timecmp(a->tv_sec, b->tv_sec);
if (dt != 0) {
// if (debug>3) printf("%ds\n", dt);
return dt;
}
// tv_usec is always in range 0 .. 999 999
if (a->tv_usec < b->tv_usec) {
// if (debug>3) printf("-1u\n");
return -1;
}
if (a->tv_usec > b->tv_usec) {
// if (debug>3) printf("1u\n");
return 1;
}
// if (debug>3) printf("0\n");
return 0; // equals!
}
/*
* Compare *tv with current time value (now), and if the difference
* is more than margin seconds, then call resetfunc with resetarg.
*
* Usually resetarg == tv, but not always.
* See
*/
void tv_timerbounds(const char *timername,
struct timeval *tv,
const int margin,
void (*resetfunc)(void*),
void *resetarg)
{
// Check that system time has not jumped too far ahead/back;
// that it is within margin seconds to tv.
struct timeval nowminus;
struct timeval nowplus;
tv_timeradd_seconds(&nowminus, &tick, -margin);
// If current time MINUS margin is AFTER tv, then reset.
if (tv_timercmp(tv, &nowminus) < 0) {
if (debug)
printf("System time has gone too much forwards, Resetting timer '%s'. dt=%d margin=%d\n",
timername, (int)(tv->tv_sec - nowminus.tv_sec), margin);
resetfunc(resetarg);
}
tv_timeradd_seconds(&nowplus, &tick, margin);
// If current time PLUS margin is BEFORE tv, then reset.
if (tv_timercmp(&nowplus, tv) < 0) {
if (debug)
printf("System time has gone too much backwards, Resetting timer '%s'. dt=%d margin=%d\n",
timername, (int)(nowplus.tv_sec - tv->tv_sec), margin);
resetfunc(resetarg);
}
}
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