From 5e3b14069e3fe25ec2595124e6e0103c7be4f813 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Wed, 6 Jan 2010 22:43:39 +0100 Subject: [PATCH] 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 --- include/rtc_.h | 8 +++++--- libbb/rtc.c | 18 ++++++++++-------- util-linux/hwclock.c | 44 ++++++++++++++++++++++++++++++++------------ util-linux/rtcwake.c | 7 ++++++- 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) -- 2.25.1