diff options
Diffstat (limited to 'pk/kernel/pk_timer_core.c')
| -rw-r--r-- | pk/kernel/pk_timer_core.c | 80 |
1 files changed, 11 insertions, 69 deletions
diff --git a/pk/kernel/pk_timer_core.c b/pk/kernel/pk_timer_core.c index abc83bad..bc90a3e7 100644 --- a/pk/kernel/pk_timer_core.c +++ b/pk/kernel/pk_timer_core.c @@ -43,8 +43,8 @@ /// also be rescheduled in place. /// /// When a timeout occurs the event list is scanned from the beginning, and -/// any event that has timed out is rescheduled if necessary (periodic events) -/// and its callback is processed. Since event and callback processing take +/// any event that has timed out has its callback processed. +/// Since event and callback processing take /// time, the list is potentially scanned multiple times until there are no /// more timed-out events in the list. /// @@ -200,23 +200,14 @@ __pk_timer_handler() if (timer->timeout <= now) { - // The timer timed out. It is removed from the queue unless - // it is a peridic timer that needs to be rescheduled. We do - // rescheduling here in the critical section to correctly - // handle timers whose callbacks may cancel the timer. The - // timer is rescheduled in absolute time. + // The timer timed out. It is removed from the queue. // // The callback may be made with interrupt preemption enabled // or disabled. However to mitigate kernel interrupt latency // we go ahead and open up to interrupts after the callback if // the callback itself was not preemptible. - if (timer->period == 0) { - pk_deque_delete(timer_deque); - } else { - timer->timeout += timer->period; - tq->next_timeout = MIN(timer->timeout, tq->next_timeout); - } + pk_deque_delete(timer_deque); callback = timer->callback; if (callback) { @@ -254,22 +245,15 @@ __pk_timer_handler() } -/// Schedule a timer in absolute time. +/// Schedule a timer for an interval relative to the current time. /// /// \param timer The PkTimer to schedule. /// -/// \param timeout The timer will be scheduled to time out at this absolute -/// time. Note that if the \a timeout is less than the current time then the -/// timer will be scheduled at a minimum timeout in the future and the -/// callback will be executed in an interrupt context. -/// -/// \param period If non-0, then when the timer times out it will rescheduled -/// to time out again at the absolute time equal to the last timeout time plus -/// the \a period. By convention a \a period of 0 indicates a one-shot -/// timer that is not rescheduled. +/// \param interval The timer will be scheduled to time out at the current +/// time (pk_timebase_get()) plus this \a interval. /// /// Once created with pk_timer_create() a timer can be \e scheduled, which -/// queues the timer in the kernel time queue. It is not an error to call +/// queues the timer in the kernel time queue. It is not an error to call \c /// pk_timer_schedule() on a timer that is already scheduled in the time /// queue - the timer is simply rescheduled with the new characteristics. /// @@ -284,23 +268,19 @@ __pk_timer_handler() /// interrupt context. int -pk_timer_schedule_absolute(PkTimer *timer, - PkTimebase timeout, - PkInterval period) - +pk_timer_schedule(PkTimer *timer, + PkInterval interval) { PkMachineContext ctx; + PkTimebase timeout = pk_timebase_get() + PK_INTERVAL_SCALE(interval); pk_critical_section_enter(&ctx); if (PK_ERROR_CHECK_API) { PK_ERROR_IF(timer == 0, PK_INVALID_TIMER_AT_SCHEDULE); -// PK_ERROR_IF(__pk_kernel_context_critical_interrupt(), -// PK_ILLEGAL_CONTEXT_TIMER); } timer->timeout = timeout; - timer->period = period; __pk_timer_schedule(timer); pk_critical_section_exit(&ctx); @@ -309,44 +289,6 @@ pk_timer_schedule_absolute(PkTimer *timer, } -/// Schedule a timer for an interval relative to the current time. -/// -/// \param timer The PkTimer to schedule. -/// -/// \param interval The timer will be scheduled to time out at the current -/// time (pk_timebase_get()) plus this \a interval. -/// -/// \param period If non-0, then when the timer times out it will rescheduled -/// to time out again at the absolute time equal to the last timeout time plus -/// the \a period. By convention a \a period of 0 indicates a one-shot -/// timer that is not rescheduled. -/// -/// Once created with pk_timer_create() a timer can be \e scheduled, which -/// queues the timer in the kernel time queue. It is not an error to call \c -/// pk_timer_schedule() on a timer that is already scheduled in the time -/// queue - the timer is simply rescheduled with the new characteristics. -/// -/// Return values other than PK_OK (0) are errors; see \ref pk_errors -/// -/// \retval 0 Successful completion -/// -/// \retval -PK_INVALID_TIMER_AT_SCHEDULE A a null (0) pointer was provided as -/// the \a timer argument. -/// -/// \retval -PK_ILLEGAL_CONTEXT_TIMER The call was made from a critical -/// interrupt context. - -int -pk_timer_schedule(PkTimer *timer, - PkInterval interval, - PkInterval period) -{ - return pk_timer_schedule_absolute(timer, - pk_timebase_get() + interval, - period); -} - - /// Cancel (dequeue) a timer. /// /// \param timer The PkTimer to cancel. |
