[git commit master] hwclock: fix sizeof bug (used it on pointer, not array); make --systohc exact
Denys Vlasenko
vda.linux at googlemail.com
Wed Jan 6 17:16:39 UTC 2010
commit: http://git.busybox.net/busybox/commit/?id=695fa51c80047eb25cc82e6e1630b4545a6bc0b6
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
hwclock_main 329 428 +99
rtc_adjtime_is_utc 138 134 -4
edir 365 354 -11
read_rtc 39 23 -16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/3 up/down: 99/-31) Total: 68 bytes
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
libbb/rtc.c | 4 +--
networking/tc.c | 5 +--
runit/chpst.c | 3 +-
util-linux/hwclock.c | 94 +++++++++++++++++++++++++++++++++++++-------------
4 files changed, 74 insertions(+), 32 deletions(-)
diff --git a/libbb/rtc.c b/libbb/rtc.c
index 51834f8..2f38b8a 100644
--- a/libbb/rtc.c
+++ b/libbb/rtc.c
@@ -19,7 +19,7 @@ int FAST_FUNC rtc_adjtime_is_utc(void)
FILE *f = fopen_for_read(ADJTIME_PATH);
if (f) {
- RESERVE_CONFIG_BUFFER(buffer, 128);
+ char buffer[128];
while (fgets(buffer, sizeof(buffer), f)) {
int len = strlen(buffer);
@@ -35,8 +35,6 @@ int FAST_FUNC rtc_adjtime_is_utc(void)
}
}
fclose(f);
-
- RELEASE_CONFIG_BUFFER(buffer);
}
return utc;
diff --git a/networking/tc.c b/networking/tc.c
index 3115a52..dbdba33 100644
--- a/networking/tc.c
+++ b/networking/tc.c
@@ -191,8 +191,8 @@ static int cbq_print_opt(struct rtattr *opt)
struct tc_cbq_wrropt *wrr = NULL;
struct tc_cbq_fopt *fopt = NULL;
struct tc_cbq_ovl *ovl = NULL;
- const char * const error = "CBQ: too short %s opt";
- RESERVE_CONFIG_BUFFER(buf, 64);
+ const char *const error = "CBQ: too short %s opt";
+ char buf[64];
if (opt == NULL)
goto done;
@@ -272,7 +272,6 @@ static int cbq_print_opt(struct rtattr *opt)
}
}
done:
- RELEASE_CONFIG_BUFFER(buf);
return 0;
}
diff --git a/runit/chpst.c b/runit/chpst.c
index 082d726..1a68eb7 100644
--- a/runit/chpst.c
+++ b/runit/chpst.c
@@ -104,7 +104,7 @@ static NOINLINE void edir(const char *directory_name)
xchdir(directory_name);
dir = xopendir(".");
for (;;) {
- RESERVE_CONFIG_BUFFER(buf, 256);
+ char buf[256];
char *tail;
int size;
@@ -148,7 +148,6 @@ static NOINLINE void edir(const char *directory_name)
break;
}
xsetenv(d->d_name, buf);
- RELEASE_CONFIG_BUFFER(buf);
}
closedir(dir);
if (fchdir(wdir) == -1)
diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c
index 6dff57f..08e5bd7 100644
--- a/util-linux/hwclock.c
+++ b/util-linux/hwclock.c
@@ -27,27 +27,12 @@ static time_t read_rtc(int utc)
fd = rtc_xopen(&rtcname, O_RDONLY);
ret = rtc_read_time(fd, utc);
- close(fd);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(fd);
return ret;
}
-static void write_rtc(time_t t, int utc)
-{
- struct tm tm;
- int rtc = rtc_xopen(&rtcname, O_WRONLY);
-
- if (utc)
- gmtime_r(&t, &tm);
- else
- localtime_r(&t, &tm);
- tm.tm_isdst = 0;
-
- xioctl(rtc, RTC_SET_TIME, &tm);
-
- close(rtc);
-}
-
static void show_clock(int utc)
{
//struct tm *ptm;
@@ -58,10 +43,10 @@ static void show_clock(int utc)
//ptm = localtime(&t); /* Sets 'tzname[]' */
cp = ctime(&t);
- if (cp[0])
- cp[strlen(cp) - 1] = '\0';
+ strchrnul(cp, '\n')[0] = '\0';
- //printf("%s %.6f seconds %s\n", cp, 0.0, utc ? "" : (ptm->tm_isdst ? tzname[1] : tzname[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);
}
@@ -81,12 +66,73 @@ static void to_sys_clock(int utc)
static void from_sys_clock(int utc)
{
+#define TWEAK_USEC 200
+ struct tm tm;
struct timeval tv;
+ unsigned adj = TWEAK_USEC;
+ int rtc = rtc_xopen(&rtcname, O_WRONLY);
+
+ /* Try to catch the moment when whole second is close */
+ while (1) {
+ unsigned rem_usec;
+ time_t t;
+
+ gettimeofday(&tv, NULL);
+
+ rem_usec = 1000000 - tv.tv_usec;
+ if (rem_usec < 1024) {
+ /* Less than 1ms to next second. Good enough */
+ small_rem:
+ tv.tv_sec++;
+ }
+
+ /* Prepare tm */
+ t = tv.tv_sec;
+ if (utc)
+ gmtime_r(&t, &tm); /* may read /etc/xxx (it takes time) */
+ else
+ localtime_r(&t, &tm); /* same */
+ tm.tm_isdst = 0;
+
+ /* gmtime/localtime took some time, re-get cur time */
+ gettimeofday(&tv, NULL);
+
+ if (tv.tv_sec < t /* may happen if rem_usec was < 1024 */
+ || (tv.tv_sec == t && tv.tv_usec < 1024)
+ ) {
+ /* We are not too far into next second. Good. */
+ break;
+ }
+ adj += 32; /* 2^(10-5) = 2^5 = 32 iterations max */
+ if (adj >= 1024) {
+ /* Give up trying to sync */
+ break;
+ }
+
+ /* Try to sync up by sleeping */
+ rem_usec = 1000000 - tv.tv_usec;
+ if (rem_usec < 1024) {
+ goto small_rem; /* already close, don't sleep */
+ }
+ /* Need to sleep.
+ * Note that small adj on slow processors can make us
+ * to always overshoot tv.tv_usec < 1024 check on next
+ * iteration. That's why adj is increased on each iteration.
+ * This also allows it to be reused as a loop limiter.
+ */
+ usleep(rem_usec - adj);
+ }
+
+ xioctl(rtc, RTC_SET_TIME, &tm);
+
+ /* Debug aid to find "good" TWEAK_USEC.
+ * Look for a value which makes tv_usec close to 999999 or 0.
+ * for 2.20GHz Intel Core 2: TWEAK_USEC ~= 200
+ */
+ //bb_error_msg("tv.tv_usec:%d adj:%d", (int)tv.tv_usec, adj);
- gettimeofday(&tv, NULL);
- //if (gettimeofday(&tv, NULL))
- // bb_perror_msg_and_die("gettimeofday() failed");
- write_rtc(tv.tv_sec, utc);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(rtc);
}
#define HWCLOCK_OPT_LOCALTIME 0x01
--
1.6.3.3
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