[LTP] [PATCH 2/3] lib: implement rtctime_save and rtctime_restore function

gengcixi
2020-12-23T03:35:16Z

From: Cixi Geng <cixi.geng1@unisoc.com>

* Reading the RTC in the setup as well as timestamping with monotonic
timer
* Getting a second monotonic timestamp in the cleanup
* Setting the RTC to the value taken in setup plus the difference in
the monotonic timer timestamps

Signed-off-by: Cixi Geng <cixi.geng1@unisoc.com>
---
include/tst_wallclock.h | 4 ++++
lib/tst_wallclock.c | 42 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+)

diff --git a/include/tst_wallclock.h b/include/tst_wallclock.h
index 7d6723a7a..5103c8321 100644
--- a/include/tst_wallclock.h
+++ b/include/tst_wallclock.h
@@ -12,4 +12,8 @@ void tst_wallclock_save(void);

void tst_wallclock_restore(void);

+void tst_rtctime_save(void);
+
+void tst_rtctime_restore(void);
+
#endif /* TST_WALLCLK_H__ */
diff --git a/lib/tst_wallclock.c b/lib/tst_wallclock.c
index 282d6ada3..5be1f46d8 100644
--- a/lib/tst_wallclock.c
+++ b/lib/tst_wallclock.c
@@ -11,11 +11,14 @@
#include "tst_test.h"
#include "tst_timer.h"
#include "tst_clocks.h"
+#include "tst_rtctime.h"
#include "tst_wallclock.h"
#include "lapi/posix_clocks.h"

static struct timespec real_begin, mono_begin;

+static struct rtc_time rtc_begin;
+
static int clock_saved;

void tst_wallclock_save(void)
@@ -58,3 +61,42 @@ void tst_wallclock_restore(void)
if (tst_clock_settime(CLOCK_REALTIME, &adjust))
tst_brk(TBROK | TERRNO, "tst_clock_settime() realtime failed");
}
+
+void tst_rtctime_save(void)
+{
+ /* save initial monotonic time to restore it when needed */
+ if (tst_rtc_gettime(&rtc_begin))
+ tst_brk(TBROK | TERRNO, "tst_rtc_gettime() realtime failed");
+
+ if (tst_clock_gettime(CLOCK_MONOTONIC_RAW, &mono_begin))
+ tst_brk(TBROK | TERRNO, "tst_clock_gettime() monotonic failed");
+
+ clock_saved = 1;
+}
+
+void tst_rtctime_restore(void)
+{
+ static struct timespec mono_end, elapsed;
+ static struct timespec rtc_begin_tm, rtc_adjust;
+ static struct rtc_time rtc_restore;
+
+ if (!clock_saved)
+ return;
+
+ clock_saved = 0;
+
+ if (tst_clock_gettime(CLOCK_MONOTONIC_RAW, &mono_end))
+ tst_brk(TBROK | TERRNO, "tst_clock_gettime() monotonic failed");
+
+ elapsed = tst_timespec_diff(mono_end, mono_begin);
+
+ rtc_begin_tm.tv_sec = tst_rtc_tm_to_time(&rtc_begin);
+
+ rtc_adjust = tst_timespec_add(rtc_begin_tm, elapsed);
+
+ tst_rtc_time_to_tm(rtc_adjust.tv_sec, &rtc_restore);
+
+ /* restore realtime clock based on monotonic delta */
+ if (tst_rtc_settime(&rtc_restore))
+ tst_brk(TBROK | TERRNO, "tst_rtc_settime() realtime failed");
+}
--
2.25.1