thirdparty/util-linux
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hwclock: don't open /dev/rtc repeatedly

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Signed-off-by: Karel Zak <kzak@redhat.com>
This commit is contained in:
Karel Zak 2008-08-18 14:08:57 +02:00
parent d92026e4c2
commit 27f9db17bd
1 changed files with 29 additions and 21 deletions
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50
hwclock/rtc.c
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@ -92,6 +92,15 @@ struct linux_rtc_time {
/* default or user defined dev (by hwclock --rtc=<path>) */
char *rtc_dev_name;
static int rtc_dev_fd = -1;
static void
close_rtc(void) {
if (rtc_dev_fd != -1)
close(rtc_dev_fd);
rtc_dev_fd = -1;
}
static int
open_rtc(void) {
char *fls[] = {
@ -106,20 +115,28 @@ open_rtc(void) {
};
char **p;
if (rtc_dev_fd != -1)
return rtc_dev_fd;
/* --rtc option has been given */
if (rtc_dev_name)
return open(rtc_dev_name, O_RDONLY);
rtc_dev_fd = open(rtc_dev_name, O_RDONLY);
else {
for (p=fls; *p; ++p) {
rtc_dev_fd = open(*p, O_RDONLY);
for (p=fls; *p; ++p) {
int fd = open(*p, O_RDONLY);
if (fd < 0 && (errno == ENOENT || errno == ENODEV))
continue;
rtc_dev_name = *p;
return fd;
if (rtc_dev_fd < 0 && (errno == ENOENT || errno == ENODEV))
continue;
rtc_dev_name = *p;
break;
}
if (rtc_dev_fd < 0)
rtc_dev_name = *fls; /* default for error messages */
}
rtc_dev_name = *fls; /* default */
return -1;
if (rtc_dev_fd != 1)
atexit(close_rtc);
return rtc_dev_fd;
}
static int
@ -219,7 +236,7 @@ synchronize_to_clock_tick_rtc(void) {
int rtc_fd; /* File descriptor of /dev/rtc */
int ret;
rtc_fd = open(rtc_dev_name, O_RDONLY);
rtc_fd = open_rtc();
if (rtc_fd == -1) {
outsyserr(_("open() of %s failed"), rtc_dev_name);
ret = 1;
@ -287,7 +304,6 @@ int ret;
"failed unexpectedly"), rtc_dev_name);
ret = 1;
}
close(rtc_fd);
}
return ret;
}
@ -302,7 +318,6 @@ read_hardware_clock_rtc(struct tm *tm) {
/* Read the RTC time/date, return answer via tm */
rc = do_rtc_read_ioctl(rtc_fd, tm);
close(rtc_fd);
return rc;
}
@ -350,7 +365,6 @@ set_hardware_clock_rtc(const struct tm *new_broken_time) {
if (debug)
printf(_("ioctl(%s) was successful.\n"), ioctlname);
close(rtc_fd);
return 0;
}
@ -372,10 +386,8 @@ static struct clock_ops rtc = {
struct clock_ops *
probe_for_rtc_clock(){
int rtc_fd = open_rtc();
if (rtc_fd >= 0) {
close(rtc_fd);
if (rtc_fd >= 0)
return &rtc;
}
if (debug)
outsyserr(_("Open of %s failed"), rtc_dev_name);
return NULL;
@ -408,7 +420,6 @@ get_epoch_rtc(unsigned long *epoch_p, int silent) {
if (ioctl(rtc_fd, RTC_EPOCH_READ, epoch_p) == -1) {
if (!silent)
outsyserr(_("ioctl(RTC_EPOCH_READ) to %s failed"), rtc_dev_name);
close(rtc_fd);
return 1;
}
@ -416,7 +427,6 @@ get_epoch_rtc(unsigned long *epoch_p, int silent) {
printf(_("we have read epoch %ld from %s "
"with RTC_EPOCH_READ ioctl.\n"), *epoch_p, rtc_dev_name);
close(rtc_fd);
return 0;
}
@ -460,10 +470,8 @@ set_epoch_rtc(unsigned long epoch) {
"does not have the RTC_EPOCH_SET ioctl.\n"), rtc_dev_name);
else
outsyserr(_("ioctl(RTC_EPOCH_SET) to %s failed"), rtc_dev_name);
close(rtc_fd);
return 1;
}
close(rtc_fd);
return 0;
}