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tests: timer_api: compensate for fast clocks

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A fast timer clock can advance before or after the remaining time
until an event is captured.  Verify the expected relationship between
current and remaining time holds for at least one captured current
time.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
This commit is contained in:
Peter Bigot 2020-05-21 17:08:04 -05:00 committed by Carles Cufí
parent 46e402dd6e
commit a44bc7026e
1 changed files with 14 additions and 2 deletions
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16
tests/kernel/timer/timer_api/src/main.c
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@ -578,6 +578,9 @@ void test_timeout_abs(void)
{
#ifdef CONFIG_TIMEOUT_64BIT
const u64_t exp_ms = 10000000;
u64_t cap_ticks;
u64_t rem_ticks;
u64_t cap2_ticks;
u64_t exp_ticks = k_ms_to_ticks_ceil64(exp_ms);
k_timeout_t t = K_TIMEOUT_ABS_TICKS(exp_ticks), t2;
@ -602,12 +605,21 @@ void test_timeout_abs(void)
* convention (i.e. a timer of "1 tick" will expire at "now
* plus 2 ticks", because "now plus one" will always be
* somewhat less than a tick).
*
* However, if the timer clock runs relatively fast the tick
* clock may advance before or after reading the remaining
* ticks, so we have to check that at least one case is
* satisfied.
*/
k_usleep(1); /* align to tick */
k_timer_start(&remain_timer, t, K_FOREVER);
zassert_true(k_timer_remaining_ticks(&remain_timer)
+ k_uptime_ticks() + 1 == exp_ticks, NULL);
cap_ticks = k_uptime_ticks();
rem_ticks = k_timer_remaining_ticks(&remain_timer);
cap2_ticks = k_uptime_ticks();
k_timer_stop(&remain_timer);
zassert_true((cap_ticks + rem_ticks + 1 == exp_ticks)
|| (rem_ticks + cap2_ticks + 1 == exp_ticks),
NULL);
#endif
}