ndk-busybox/libbb/rtc.c
Denys Vlasenko 8dff01d06a libbb: introduce and use is_prefixed_with()
function                                             old     new   delta
is_prefixed_with                                       -      18     +18
complete_username                                     78      77      -1
man_main                                             737     735      -2
fsck_device                                          429     427      -2
unpack_ar_archive                                     80      76      -4
strip_unsafe_prefix                                  105     101      -4
singlemount                                         1054    1050      -4
rtc_adjtime_is_utc                                    90      86      -4
resolve_mount_spec                                    88      84      -4
parse_one_line                                      1029    1025      -4
parse_conf                                          1460    1456      -4
may_wakeup                                            83      79      -4
loadkmap_main                                        219     215      -4
get_irqs_from_stat                                   103      99      -4
get_header_cpio                                      913     909      -4
findfs_main                                           79      75      -4
fbsplash_main                                       1230    1226      -4
load_crontab                                         776     771      -5
expand_vars_to_list                                 1151    1146      -5
date_main                                            881     876      -5
skip_dev_pfx                                          30      24      -6
make_device                                         2199    2193      -6
complete_cmd_dir_file                                773     767      -6
run_applet_and_exit                                  715     708      -7
uudecode_main                                        321     313      -8
pwdx_main                                            197     189      -8
execute                                              568     560      -8
i2cdetect_main                                      1186    1176     -10
procps_scan                                         1242    1230     -12
procps_read_smaps                                   1017    1005     -12
process_module                                       746     734     -12
patch_main                                          1903    1891     -12
nfsmount                                            3572    3560     -12
stack_machine                                        126     112     -14
process_timer_stats                                  449     435     -14
match_fstype                                         111      97     -14
do_ipaddr                                           1344    1330     -14
open_list_and_close                                  359     343     -16
get_header_tar                                      1795    1779     -16
prepend_new_eth_table                                340     323     -17
fsck_main                                           1811    1794     -17
find_iface_state                                      56      38     -18
dnsd_main                                           1321    1303     -18
base_device                                          179     158     -21
find_keyword                                         104      82     -22
handle_incoming_and_exit                            2785    2762     -23
parse_and_put_prompt                                 774     746     -28
modinfo                                              347     317     -30
find_action                                          204     171     -33
update_passwd                                       1470    1436     -34
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/49 up/down: 18/-540)         Total: -522 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-03-12 17:48:34 +01:00

116 lines
2.1 KiB
C

/*
* Common RTC functions
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
#include "libbb.h"
#include "rtc_.h"
#if ENABLE_FEATURE_HWCLOCK_ADJTIME_FHS
# define ADJTIME_PATH "/var/lib/hwclock/adjtime"
#else
# define ADJTIME_PATH "/etc/adjtime"
#endif
int FAST_FUNC rtc_adjtime_is_utc(void)
{
int utc = 0;
FILE *f = fopen_for_read(ADJTIME_PATH);
if (f) {
char buffer[128];
while (fgets(buffer, sizeof(buffer), f)) {
if (is_prefixed_with(buffer, "UTC")) {
utc = 1;
break;
}
}
fclose(f);
}
return utc;
}
/* rtc opens are exclusive.
* Try to run two "hwclock -w" at the same time to see it.
* Users wouldn't expect that to fail merely because /dev/rtc
* was momentarily busy, let's try a bit harder on errno == EBUSY.
*/
static int open_loop_on_busy(const char *name, int flags)
{
int rtc;
/*
* Tested with two parallel "hwclock -w" loops.
* With try = 10, no failures with 2x1000000 loop iterations.
*/
int try = 1000 / 20;
again:
errno = 0;
rtc = open(name, flags);
if (errno == EBUSY) {
usleep(20 * 1000);
if (--try != 0)
goto again;
/* EBUSY. Last try, exit on error instead of returning -1 */
return xopen(name, flags);
}
return rtc;
}
/* Never fails */
int FAST_FUNC rtc_xopen(const char **default_rtc, int flags)
{
int rtc;
const char *name =
"/dev/rtc""\0"
"/dev/rtc0""\0"
"/dev/misc/rtc""\0";
if (!*default_rtc)
goto try_name;
name = ""; /*else: we have rtc name, don't try other names */
for (;;) {
rtc = open_loop_on_busy(*default_rtc, flags);
if (rtc >= 0)
return rtc;
if (!name[0])
return xopen(*default_rtc, flags);
try_name:
*default_rtc = name;
name += strlen(name) + 1;
}
}
void FAST_FUNC rtc_read_tm(struct tm *ptm, int fd)
{
memset(ptm, 0, sizeof(*ptm));
xioctl(fd, RTC_RD_TIME, ptm);
ptm->tm_isdst = -1; /* "not known" */
}
time_t FAST_FUNC rtc_tm2time(struct tm *ptm, int utc)
{
char *oldtz = oldtz; /* for compiler */
time_t t;
if (utc) {
oldtz = getenv("TZ");
putenv((char*)"TZ=UTC0");
tzset();
}
t = mktime(ptm);
if (utc) {
unsetenv("TZ");
if (oldtz)
putenv(oldtz - 3);
tzset();
}
return t;
}