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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2010-01-06 22:43:39 +0100 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2010-01-06 22:43:39 +0100 |
| commit | 5e3b14069e3fe25ec2595124e6e0103c7be4f813 (patch) | |
| tree | d818305a88168d4aff500e2dc9a5fb590763375a /util-linux/hwclock.c | |
| parent | 695fa51c80047eb25cc82e6e1630b4545a6bc0b6 (diff) | |
| download | busybox-w32-5e3b14069e3fe25ec2595124e6e0103c7be4f813.tar.gz busybox-w32-5e3b14069e3fe25ec2595124e6e0103c7be4f813.tar.bz2 busybox-w32-5e3b14069e3fe25ec2595124e6e0103c7be4f813.zip | |
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>
Diffstat (limited to 'util-linux/hwclock.c')
| -rw-r--r-- | util-linux/hwclock.c | 44 |
1 files changed, 32 insertions, 12 deletions
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 @@ | |||
| 20 | 20 | ||
| 21 | static const char *rtcname; | 21 | static const char *rtcname; |
| 22 | 22 | ||
| 23 | static time_t read_rtc(int utc) | 23 | static time_t read_rtc(struct timeval *sys_tv, int utc) |
| 24 | { | 24 | { |
| 25 | time_t ret; | 25 | struct tm tm; |
| 26 | int fd; | 26 | int fd; |
| 27 | int before; | ||
| 27 | 28 | ||
| 28 | fd = rtc_xopen(&rtcname, O_RDONLY); | 29 | fd = rtc_xopen(&rtcname, O_RDONLY); |
| 29 | ret = rtc_read_time(fd, utc); | 30 | |
| 31 | rtc_read_tm(&tm, fd); | ||
| 32 | before = tm.tm_sec; | ||
| 33 | while (1) { | ||
| 34 | rtc_read_tm(&tm, fd); | ||
| 35 | gettimeofday(sys_tv, NULL); | ||
| 36 | if (before != tm.tm_sec) | ||
| 37 | break; | ||
| 38 | } | ||
| 39 | |||
| 30 | if (ENABLE_FEATURE_CLEAN_UP) | 40 | if (ENABLE_FEATURE_CLEAN_UP) |
| 31 | close(fd); | 41 | close(fd); |
| 32 | 42 | ||
| 33 | return ret; | 43 | return rtc_tm2time(&tm, utc); |
| 34 | } | 44 | } |
| 35 | 45 | ||
| 36 | static void show_clock(int utc) | 46 | static void show_clock(int utc) |
| 37 | { | 47 | { |
| 38 | //struct tm *ptm; | 48 | struct timeval sys_tv; |
| 39 | time_t t; | 49 | time_t t; |
| 50 | long diff; | ||
| 40 | char *cp; | 51 | char *cp; |
| 41 | 52 | ||
| 42 | t = read_rtc(utc); | 53 | t = read_rtc(&sys_tv, utc); |
| 43 | //ptm = localtime(&t); /* Sets 'tzname[]' */ | ||
| 44 | 54 | ||
| 45 | cp = ctime(&t); | 55 | cp = ctime(&t); |
| 46 | strchrnul(cp, '\n')[0] = '\0'; | 56 | strchrnul(cp, '\n')[0] = '\0'; |
| 47 | 57 | ||
| 48 | //printf("%s 0.000000 seconds %s\n", cp, utc ? "" : (ptm->tm_isdst ? tzname[1] : tzname[0])); | 58 | //printf("%s 0.000000 seconds %s\n", cp, utc ? "" : (ptm->tm_isdst ? tzname[1] : tzname[0])); |
| 49 | /* 0.000000 stand for unimplemented difference between RTC and system clock */ | 59 | diff = sys_tv.tv_sec - t; |
| 50 | printf("%s 0.000000 seconds\n", cp); | 60 | if (diff < 0 /*&& tv.tv_usec != 0*/) { |
| 61 | /* Why? */ | ||
| 62 | /* diff >= 0 is ok: diff < 0, can't just use tv.tv_usec: */ | ||
| 63 | /* 45.520820 43.520820 */ | ||
| 64 | /* - 44.000000 - 45.000000 */ | ||
| 65 | /* = 0.520820 = -1.479180, not -2.520820! */ | ||
| 66 | diff++; | ||
| 67 | /* should be 1000000 - tv.tv_usec, but then we must check tv.tv_usec != 0 */ | ||
| 68 | sys_tv.tv_usec = 999999 - sys_tv.tv_usec; | ||
| 69 | } | ||
| 70 | printf("%s %ld.%06lu seconds\n", cp, diff, (unsigned long)sys_tv.tv_usec); | ||
| 51 | } | 71 | } |
| 52 | 72 | ||
| 53 | static void to_sys_clock(int utc) | 73 | static void to_sys_clock(int utc) |
| @@ -58,7 +78,7 @@ static void to_sys_clock(int utc) | |||
| 58 | tz.tz_minuteswest = timezone/60 - 60*daylight; | 78 | tz.tz_minuteswest = timezone/60 - 60*daylight; |
| 59 | tz.tz_dsttime = 0; | 79 | tz.tz_dsttime = 0; |
| 60 | 80 | ||
| 61 | tv.tv_sec = read_rtc(utc); | 81 | tv.tv_sec = read_rtc(NULL, utc); |
| 62 | tv.tv_usec = 0; | 82 | tv.tv_usec = 0; |
| 63 | if (settimeofday(&tv, &tz)) | 83 | if (settimeofday(&tv, &tz)) |
| 64 | bb_perror_msg_and_die("settimeofday() failed"); | 84 | bb_perror_msg_and_die("settimeofday() failed"); |
| @@ -79,15 +99,15 @@ static void from_sys_clock(int utc) | |||
| 79 | 99 | ||
| 80 | gettimeofday(&tv, NULL); | 100 | gettimeofday(&tv, NULL); |
| 81 | 101 | ||
| 102 | t = tv.tv_sec; | ||
| 82 | rem_usec = 1000000 - tv.tv_usec; | 103 | rem_usec = 1000000 - tv.tv_usec; |
| 83 | if (rem_usec < 1024) { | 104 | if (rem_usec < 1024) { |
| 84 | /* Less than 1ms to next second. Good enough */ | 105 | /* Less than 1ms to next second. Good enough */ |
| 85 | small_rem: | 106 | small_rem: |
| 86 | tv.tv_sec++; | 107 | t++; |
| 87 | } | 108 | } |
| 88 | 109 | ||
| 89 | /* Prepare tm */ | 110 | /* Prepare tm */ |
| 90 | t = tv.tv_sec; | ||
| 91 | if (utc) | 111 | if (utc) |
| 92 | gmtime_r(&t, &tm); /* may read /etc/xxx (it takes time) */ | 112 | gmtime_r(&t, &tm); /* may read /etc/xxx (it takes time) */ |
| 93 | else | 113 | else |