clock: Add clock_delay2abstick.

This commit added a macro function clock_delay2abstick to calculate the
absolute tick after the delay.

Signed-off-by: ouyangxiangzhen <ouyangxiangzhen@xiaomi.com>

include/nuttx/clock.h

@@ -384,6 +384,28 @@ EXTERN volatile clock_t g_system_ticks;
 #define clock_time2nsec(ts) \
   ((uint64_t)(ts)->tv_sec * NSEC_PER_SEC + (uint64_t)(ts)->tv_nsec)
 
+/* Calculate delay+1, forcing the delay into a range that we can handle.
+ *
+ * NOTE that one is added to the delay.  This is correct and must not be
+ * changed:  The contract for the use wdog_start is that the wdog will
+ * delay FOR AT LEAST as long as requested, but may delay longer due to
+ * variety of factors.  The wdog logic has no knowledge of the the phase
+ * of the system timer when it is started:  The next timer interrupt may
+ * occur immediately or may be delayed for almost a full cycle. In order
+ * to meet the contract requirement, the requested time is also always
+ * incremented by one so that the delay is always at least as long as
+ * requested.
+ *
+ * E.g. delay+1 can prevent the insufficient sleep time if we are
+ * currently near the boundary to the next tick.
+ * | current_tick | current_tick + 1 | current_tick + 2 | .... |
+ * |           ^ Here we get the current tick
+ * In this case we delay 1 tick, timer will be triggered at
+ * current_tick + 1, which is not enough for at least 1 tick.
+ */
+
+#define clock_delay2abstick(delay) (clock_systime_ticks() + (delay) + 1)
+
 /****************************************************************************
  * Name:  clock_timespec_add
  *

sched/semaphore/sem_tickwait.c

@@ -150,7 +150,7 @@ out:
 
 int nxsem_tickwait_uninterruptible(FAR sem_t *sem, uint32_t delay)
 {
-  clock_t end = clock_systime_ticks() + delay + 1;
+  clock_t end = clock_delay2abstick(delay);
   int ret;
 
   for (; ; )

sched/signal/sig_timedwait.c

@@ -304,15 +304,7 @@ int nxsig_clockwait(int clockid, int flags,
 
       if ((flags & TIMER_ABSTIME) == 0)
         {
-          /* delay+1 is to prevent the insufficient sleep time if we are
+          expect = clock_delay2abstick(clock_time2ticks(rqtp));
-           * currently near the boundary to the next tick.
-           * | current_tick | current_tick + 1 | current_tick + 2 | .... |
-           * |           ^ Here we get the current tick
-           * In this case we delay 1 tick, timer will be triggered at
-           * current_tick + 1, which is not enough for at least 1 tick.
-           */
-
-          expect = clock_systime_ticks() + clock_time2ticks(rqtp) + 1;
           wd_start_abstick(&rtcb->waitdog, expect,
                            nxsig_timeout, (uintptr_t)rtcb);
         }

sched/timer/timer_settime.c

@@ -316,9 +316,7 @@ int timer_settime(timer_t timerid, int flags,
     {
       /* Calculate a delay corresponding to the absolute time in 'value' */
 
-      clock_abstime2ticks(timer->pt_clock, &value->it_value,
+      clock_abstime2ticks(timer->pt_clock, &value->it_value, &delay);
-                          &timer->pt_expected);
-      timer->pt_expected += clock_systime_ticks();
     }
   else
     {
@@ -328,18 +326,9 @@ int timer_settime(timer_t timerid, int flags,
        */
 
       delay = clock_time2ticks(&value->it_value);
-      timer->pt_expected = clock_systime_ticks() + delay;
     }
 
-  /* This is to prevent the insufficient sleep time if we are
+  timer->pt_expected = clock_delay2abstick(delay);
-   * currently near the boundary to the next tick.
-   * | current_tick | current_tick + 1 | current_tick + 2 | .... |
-   * |           ^ Here we get the current tick
-   * In this case we delay 1 tick, timer will be triggered at
-   * current_tick + 1, which is not enough for at least 1 tick.
-   */
-
-  timer->pt_expected += 1;
 
   /* Then start the watchdog */
 

sched/wdog/wd_start.c

@@ -416,23 +416,7 @@ int wd_start(FAR struct wdog_s *wdog, sclock_t delay,
       return -EINVAL;
     }
 
-  /* Calculate delay+1, forcing the delay into a range that we can handle.
+  return wd_start_abstick(wdog, clock_delay2abstick(delay), wdentry, arg);
-   *
-   * NOTE that one is added to the delay.  This is correct and must not be
-   * changed:  The contract for the use wdog_start is that the wdog will
-   * delay FOR AT LEAST as long as requested, but may delay longer due to
-   * variety of factors.  The wdog logic has no knowledge of the the phase
-   * of the system timer when it is started:  The next timer interrupt may
-   * occur immediately or may be delayed for almost a full cycle. In order
-   * to meet the contract requirement, the requested time is also always
-   * incremented by one so that the delay is always at least as long as
-   * requested.
-   *
-   * There is extensive documentation about this time issue elsewhere.
-   */
-
-  return wd_start_abstick(wdog, clock_systime_ticks() + delay + 1,
-                          wdentry, arg);
 }
 
 /****************************************************************************

sched/wqueue/kwork_queue.c

@@ -88,15 +88,7 @@ int work_queue_period_wq(FAR struct kwork_wqueue_s *wqueue,
       return -EINVAL;
     }
 
-  /* delay+1 is to prevent the insufficient sleep time if we are
+  expected = clock_delay2abstick(delay);
-   * currently near the boundary to the next tick.
-   * | current_tick | current_tick + 1 | current_tick + 2 | .... |
-   * |           ^ Here we get the current tick
-   * In this case we delay 1 tick, timer will be triggered at
-   * current_tick + 1, which is not enough for at least 1 tick.
-   */
-
-  expected = clock_systime_ticks() + delay + 1;
 
   /* Interrupts are disabled so that this logic can be called from with
    * task logic or from interrupt handling logic.