4 * Licensed under GPLv2, see file LICENSE in this source tree.
10 #if ENABLE_FEATURE_HWCLOCK_ADJTIME_FHS
11 # define ADJTIME_PATH "/var/lib/hwclock/adjtime"
13 # define ADJTIME_PATH "/etc/adjtime"
16 int FAST_FUNC rtc_adjtime_is_utc(void)
19 FILE *f = fopen_for_read(ADJTIME_PATH);
24 while (fgets(buffer, sizeof(buffer), f)) {
25 if (is_prefixed_with(buffer, "UTC")) {
36 /* rtc opens are exclusive.
37 * Try to run two "hwclock -w" at the same time to see it.
38 * Users wouldn't expect that to fail merely because /dev/rtc
39 * was momentarily busy, let's try a bit harder on errno == EBUSY.
41 static int open_loop_on_busy(const char *name, int flags)
45 * Tested with two parallel "hwclock -w" loops.
46 * With try = 10, no failures with 2x1000000 loop iterations.
51 rtc = open(name, flags);
56 /* EBUSY. Last try, exit on error instead of returning -1 */
57 return xopen(name, flags);
63 int FAST_FUNC rtc_xopen(const char **default_rtc, int flags)
73 name = ""; /*else: we have rtc name, don't try other names */
76 rtc = open_loop_on_busy(*default_rtc, flags);
80 return xopen(*default_rtc, flags);
83 name += strlen(name) + 1;
87 void FAST_FUNC rtc_read_tm(struct tm *ptm, int fd)
89 memset(ptm, 0, sizeof(*ptm));
90 xioctl(fd, RTC_RD_TIME, ptm);
91 ptm->tm_isdst = -1; /* "not known" */
94 time_t FAST_FUNC rtc_tm2time(struct tm *ptm, int utc)
96 char *oldtz = oldtz; /* for compiler */
100 oldtz = getenv("TZ");
101 putenv((char*)"TZ=UTC0");