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Implement Helbig idea of offset calculation reducing mktime() calls

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Immediately exit if /etc/wall_cmos_clock not present
This commit is contained in:
Andrey A. Chernov 1998-04-11 21:18:55 +00:00
parent abc7a4adca
commit 84436e33cb
2 changed files with 25 additions and 25 deletions
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6
sbin/adjkerntz/adjkerntz.8
View File

@ -1,4 +1,4 @@
.\" Copyright (C) 1993-1996 by Andrey A. Chernov, Moscow, Russia.
.\" Copyright (C) 1993-1998 by Andrey A. Chernov, Moscow, Russia.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
@ -22,7 +22,7 @@
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $Id: adjkerntz.8,v 1.13 1997/02/22 14:32:08 peter Exp $
.\" $Id: adjkerntz.8,v 1.14 1998/03/19 07:44:59 charnier Exp $
.\"
.Dd April 4, 1996
.Dt ADJKERNTZ 8
@ -122,7 +122,7 @@ sleeps 30 minutes and tries again.
.Pp
This form should be invoked from root's
.Xr crontab 5
every half hour between midnight and 4am, when most modern time
every half hour between midnight and 5am, when most modern time
zone changes occur.
Warning: don't use the
.Fl s

44
sbin/adjkerntz/adjkerntz.c
View File

@ -1,5 +1,5 @@
/*
* Copyright (C) 1993-1996 by Andrey A. Chernov, Moscow, Russia.
* Copyright (C) 1993-1998 by Andrey A. Chernov, Moscow, Russia.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -23,7 +23,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: adjkerntz.c,v 1.21 1998/02/25 09:40:21 ache Exp $
* $Id: adjkerntz.c,v 1.22 1998/03/30 09:29:47 ache Exp $
*/
#ifndef lint
@ -71,14 +71,14 @@ int main(argc, argv)
int argc;
char **argv;
{
struct tm local, utc;
struct tm local;
struct timeval tv, *stv;
struct timezone tz, *stz;
int kern_offset, wall_clock, disrtcset;
size_t len;
int mib[2];
/* Avoid time_t here, can be unsigned long or worse */
long offset, utcsec, localsec, diff;
long offset, localsec, diff;
time_t initial_sec, final_sec;
int ch;
int initial_isdst = -1, final_isdst;
@ -106,6 +106,10 @@ int main(argc, argv)
}
if (init == Unknown)
usage();
if (access(_PATH_CLOCK, F_OK) != 0)
return 0;
if (init)
sleep_mode = True;
@ -161,27 +165,25 @@ recalculate:
local = *localtime(&initial_sec);
if (diff == 0)
initial_isdst = local.tm_isdst;
utc = *gmtime(&initial_sec);
local.tm_isdst = utc.tm_isdst = initial_isdst;
local.tm_isdst = initial_isdst;
/* calculate local CMOS diff from GMT */
utcsec = mktime(&utc);
localsec = mktime(&local);
if (utcsec == -1 || localsec == -1) {
if (localsec == -1) {
/*
* XXX user can only control local time, and it is
* unacceptable to fail here for init. 2:30 am in the
* middle of the nonexistent hour means 3:30 am.
*/
syslog(LOG_WARNING,
"Warning: nonexistent %s time, try to run later.",
utcsec == -1 && localsec == -1 ? "UTC time and local" :
utcsec == -1 ? "UTC" : "local");
if (!sleep_mode) {
syslog(LOG_WARNING,
"Warning: nonexistent local time, try to run later.");
syslog(LOG_WARNING, "Giving up.");
return 1;
}
syslog(LOG_WARNING,
"Warning: nonexistent local time.");
syslog(LOG_WARNING, "Will retry after %d minutes.",
REPORT_PERIOD / 60);
(void) signal(SIGTERM, SIG_DFL);
@ -189,7 +191,7 @@ recalculate:
(void) sleep(REPORT_PERIOD);
goto again;
}
offset = utcsec - localsec;
offset = -local.tm_gmtoff;
#ifdef DEBUG
fprintf(stderr, "Initial offset: %ld secs\n", offset);
#endif
@ -217,25 +219,23 @@ recalculate:
initial_isdst = final_isdst;
goto recalculate;
}
utc = *gmtime(&final_sec);
local.tm_isdst = utc.tm_isdst = final_isdst;
local.tm_isdst = final_isdst;
utcsec = mktime(&utc);
localsec = mktime(&local);
if (utcsec == -1 || localsec == -1) {
if (localsec == -1) {
bad_final:
/*
* XXX as above. The user has even less control,
* but perhaps we never get here.
*/
syslog(LOG_WARNING,
"Warning: nonexistent final %s time, try to run later.",
utcsec == -1 && localsec == -1 ? "UTC time and local" :
utcsec == -1 ? "UTC" : "local");
if (!sleep_mode) {
syslog(LOG_WARNING,
"Warning: nonexistent final local time, try to run later.");
syslog(LOG_WARNING, "Giving up.");
return 1;
}
syslog(LOG_WARNING,
"Warning: nonexistent final local time.");
syslog(LOG_WARNING, "Will retry after %d minutes.",
REPORT_PERIOD / 60);
(void) signal(SIGTERM, SIG_DFL);
@ -243,7 +243,7 @@ recalculate:
(void) sleep(REPORT_PERIOD);
goto again;
}
offset = utcsec - localsec;
offset = -local.tm_gmtoff;
#ifdef DEBUG
fprintf(stderr, "Final offset: %ld secs\n", offset);
#endif