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authorDenys Vlasenko <vda.linux@googlemail.com>2010-01-06 22:43:39 +0100
committerDenys Vlasenko <vda.linux@googlemail.com>2010-01-06 22:43:39 +0100
commit5e3b14069e3fe25ec2595124e6e0103c7be4f813 (patch)
treed818305a88168d4aff500e2dc9a5fb590763375a
parent695fa51c80047eb25cc82e6e1630b4545a6bc0b6 (diff)
downloadbusybox-5e3b14069e3fe25ec2595124e6e0103c7be4f813.tar.gz
hwclock: make it report system/rtc clock difference
function old new delta rtc_tm2time - 89 +89 read_rtc 23 86 +63 rtc_read_tm - 49 +49 hwclock_main 428 466 +38 rtcwake_main 453 477 +24 rtc_read_time 142 - -142 ------------------------------------------------------------------------------ (add/remove: 2/1 grow/shrink: 3/0 up/down: 263/-142) Total: 121 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--include/rtc_.h8
-rw-r--r--libbb/rtc.c18
-rw-r--r--util-linux/hwclock.c44
-rw-r--r--util-linux/rtcwake.c7
4 files changed, 53 insertions, 24 deletions
diff --git a/include/rtc_.h b/include/rtc_.h
index 74bb695a0..2b4ae778d 100644
--- a/include/rtc_.h
+++ b/include/rtc_.h
@@ -11,9 +11,11 @@
PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
-extern int rtc_adjtime_is_utc(void) FAST_FUNC;
-extern int rtc_xopen(const char **default_rtc, int flags) FAST_FUNC;
-extern time_t rtc_read_time(int fd, int utc) FAST_FUNC;
+int rtc_adjtime_is_utc(void) FAST_FUNC;
+int rtc_xopen(const char **default_rtc, int flags) FAST_FUNC;
+void rtc_read_tm(struct tm *tm, int fd) FAST_FUNC;
+time_t rtc_tm2time(struct tm *tm, int utc) FAST_FUNC;
+
/*
* Everything below this point has been copied from linux/rtc.h
diff --git a/libbb/rtc.c b/libbb/rtc.c
index 2f38b8a7e..9807e1cf9 100644
--- a/libbb/rtc.c
+++ b/libbb/rtc.c
@@ -59,15 +59,17 @@ int FAST_FUNC rtc_xopen(const char **default_rtc, int flags)
return xopen(*default_rtc, flags);
}
-time_t FAST_FUNC rtc_read_time(int fd, int utc)
+void FAST_FUNC rtc_read_tm(struct tm *tm, int fd)
{
- struct tm tm;
- char *oldtz = 0;
- time_t t = 0;
+ memset(tm, 0, sizeof(*tm));
+ xioctl(fd, RTC_RD_TIME, tm);
+ tm->tm_isdst = -1; /* "not known" */
+}
- memset(&tm, 0, sizeof(struct tm));
- xioctl(fd, RTC_RD_TIME, &tm);
- tm.tm_isdst = -1; /* not known */
+time_t FAST_FUNC rtc_tm2time(struct tm *tm, int utc)
+{
+ char *oldtz = oldtz; /* for compiler */
+ time_t t;
if (utc) {
oldtz = getenv("TZ");
@@ -75,7 +77,7 @@ time_t FAST_FUNC rtc_read_time(int fd, int utc)
tzset();
}
- t = mktime(&tm);
+ t = mktime(tm);
if (utc) {
unsetenv("TZ");
diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c
index 08e5bd701..606721e2c 100644
--- a/util-linux/hwclock.c
+++ b/util-linux/hwclock.c
@@ -20,34 +20,54 @@
static const char *rtcname;
-static time_t read_rtc(int utc)
+static time_t read_rtc(struct timeval *sys_tv, int utc)
{
- time_t ret;
+ struct tm tm;
int fd;
+ int before;
fd = rtc_xopen(&rtcname, O_RDONLY);
- ret = rtc_read_time(fd, utc);
+
+ rtc_read_tm(&tm, fd);
+ before = tm.tm_sec;
+ while (1) {
+ rtc_read_tm(&tm, fd);
+ gettimeofday(sys_tv, NULL);
+ if (before != tm.tm_sec)
+ break;
+ }
+
if (ENABLE_FEATURE_CLEAN_UP)
close(fd);
- return ret;
+ return rtc_tm2time(&tm, utc);
}
static void show_clock(int utc)
{
- //struct tm *ptm;
+ struct timeval sys_tv;
time_t t;
+ long diff;
char *cp;
- t = read_rtc(utc);
- //ptm = localtime(&t); /* Sets 'tzname[]' */
+ t = read_rtc(&sys_tv, utc);
cp = ctime(&t);
strchrnul(cp, '\n')[0] = '\0';
//printf("%s 0.000000 seconds %s\n", cp, utc ? "" : (ptm->tm_isdst ? tzname[1] : tzname[0]));
- /* 0.000000 stand for unimplemented difference between RTC and system clock */
- printf("%s 0.000000 seconds\n", cp);
+ diff = sys_tv.tv_sec - t;
+ if (diff < 0 /*&& tv.tv_usec != 0*/) {
+ /* Why? */
+ /* diff >= 0 is ok: diff < 0, can't just use tv.tv_usec: */
+ /* 45.520820 43.520820 */
+ /* - 44.000000 - 45.000000 */
+ /* = 0.520820 = -1.479180, not -2.520820! */
+ diff++;
+ /* should be 1000000 - tv.tv_usec, but then we must check tv.tv_usec != 0 */
+ sys_tv.tv_usec = 999999 - sys_tv.tv_usec;
+ }
+ printf("%s %ld.%06lu seconds\n", cp, diff, (unsigned long)sys_tv.tv_usec);
}
static void to_sys_clock(int utc)
@@ -58,7 +78,7 @@ static void to_sys_clock(int utc)
tz.tz_minuteswest = timezone/60 - 60*daylight;
tz.tz_dsttime = 0;
- tv.tv_sec = read_rtc(utc);
+ tv.tv_sec = read_rtc(NULL, utc);
tv.tv_usec = 0;
if (settimeofday(&tv, &tz))
bb_perror_msg_and_die("settimeofday() failed");
@@ -79,15 +99,15 @@ static void from_sys_clock(int utc)
gettimeofday(&tv, NULL);
+ t = tv.tv_sec;
rem_usec = 1000000 - tv.tv_usec;
if (rem_usec < 1024) {
/* Less than 1ms to next second. Good enough */
small_rem:
- tv.tv_sec++;
+ t++;
}
/* Prepare tm */
- t = tv.tv_sec;
if (utc)
gmtime_r(&t, &tm); /* may read /etc/xxx (it takes time) */
else
diff --git a/util-linux/rtcwake.c b/util-linux/rtcwake.c
index 049f699f5..64c3e7ed7 100644
--- a/util-linux/rtcwake.c
+++ b/util-linux/rtcwake.c
@@ -160,7 +160,12 @@ int rtcwake_main(int argc UNUSED_PARAM, char **argv)
/* relative or absolute alarm time, normalized to time_t */
sys_time = time(NULL);
- rtc_time = rtc_read_time(fd, utc);
+ {
+ struct tm tm;
+ rtc_read_tm(&tm, fd);
+ rtc_time = rtc_tm2time(&tm, utc);
+ }
+
if (alarm_time) {
if (alarm_time < sys_time)