zephyr/kernel/timer.c

229 lines
4.8 KiB
C

/*
* Copyright (c) 1997-2016 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <debug/object_tracing_common.h>
#include <init.h>
#include <wait_q.h>
extern struct k_timer _k_timer_list_start[];
extern struct k_timer _k_timer_list_end[];
#ifdef CONFIG_OBJECT_TRACING
struct k_timer *_trace_list_k_timer;
/*
* Complete initialization of statically defined timers.
*/
static int init_timer_module(struct device *dev)
{
ARG_UNUSED(dev);
struct k_timer *timer;
for (timer = _k_timer_list_start; timer < _k_timer_list_end; timer++) {
SYS_TRACING_OBJ_INIT(k_timer, timer);
}
return 0;
}
SYS_INIT(init_timer_module, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_OBJECTS);
#endif /* CONFIG_OBJECT_TRACING */
/**
* @brief Handle expiration of a kernel timer object.
*
* @param t Timeout used by the timer.
*
* @return N/A
*/
void _timer_expiration_handler(struct _timeout *t)
{
struct k_timer *timer = CONTAINER_OF(t, struct k_timer, timeout);
struct k_thread *thread;
unsigned int key;
/*
* if the timer is periodic, start it again; don't add _TICK_ALIGN
* since we're already aligned to a tick boundary
*/
if (timer->period > 0) {
key = irq_lock();
_add_timeout(NULL, &timer->timeout, &timer->wait_q,
timer->period);
irq_unlock(key);
}
/* update timer's status */
timer->status += 1;
/* invoke timer expiry function */
if (timer->expiry_fn) {
timer->expiry_fn(timer);
}
thread = (struct k_thread *)sys_dlist_peek_head(&timer->wait_q);
if (!thread) {
return;
}
/*
* Interrupts _DO NOT_ have to be locked in this specific instance of
* calling _unpend_thread() because a) this is the only place a thread
* can be taken off this pend queue, and b) the only place a thread
* can be put on the pend queue is at thread level, which of course
* cannot interrupt the current context.
*/
_unpend_thread(thread);
key = irq_lock();
_ready_thread(thread);
irq_unlock(key);
_set_thread_return_value(thread, 0);
}
void k_timer_init(struct k_timer *timer,
void (*expiry_fn)(struct k_timer *),
void (*stop_fn)(struct k_timer *))
{
timer->expiry_fn = expiry_fn;
timer->stop_fn = stop_fn;
timer->status = 0;
sys_dlist_init(&timer->wait_q);
_init_timeout(&timer->timeout, _timer_expiration_handler);
SYS_TRACING_OBJ_INIT(k_timer, timer);
timer->user_data = NULL;
}
void k_timer_start(struct k_timer *timer, s32_t duration, s32_t period)
{
__ASSERT(duration >= 0 && period >= 0 &&
(duration != 0 || period != 0), "invalid parameters\n");
volatile s32_t period_in_ticks, duration_in_ticks;
period_in_ticks = _ms_to_ticks(period);
duration_in_ticks = _TICK_ALIGN + _ms_to_ticks(duration);
unsigned int key = irq_lock();
if (timer->timeout.delta_ticks_from_prev != _INACTIVE) {
_abort_timeout(&timer->timeout);
}
timer->period = period_in_ticks;
_add_timeout(NULL, &timer->timeout, &timer->wait_q, duration_in_ticks);
timer->status = 0;
irq_unlock(key);
}
void k_timer_stop(struct k_timer *timer)
{
int key = irq_lock();
int inactive = (_abort_timeout(&timer->timeout) == _INACTIVE);
irq_unlock(key);
if (inactive) {
return;
}
if (timer->stop_fn) {
timer->stop_fn(timer);
}
key = irq_lock();
struct k_thread *pending_thread = _unpend_first_thread(&timer->wait_q);
if (pending_thread) {
_ready_thread(pending_thread);
}
if (_is_in_isr()) {
irq_unlock(key);
} else {
_reschedule_threads(key);
}
}
u32_t k_timer_status_get(struct k_timer *timer)
{
unsigned int key = irq_lock();
u32_t result = timer->status;
timer->status = 0;
irq_unlock(key);
return result;
}
u32_t k_timer_status_sync(struct k_timer *timer)
{
__ASSERT(!_is_in_isr(), "");
unsigned int key = irq_lock();
u32_t result = timer->status;
if (result == 0) {
if (timer->timeout.delta_ticks_from_prev != _INACTIVE) {
/* wait for timer to expire or stop */
_pend_current_thread(&timer->wait_q, K_FOREVER);
_Swap(key);
/* get updated timer status */
key = irq_lock();
result = timer->status;
} else {
/* timer is already stopped */
}
} else {
/* timer has already expired at least once */
}
timer->status = 0;
irq_unlock(key);
return result;
}
s32_t _timeout_remaining_get(struct _timeout *timeout)
{
unsigned int key = irq_lock();
s32_t remaining_ticks;
if (timeout->delta_ticks_from_prev == _INACTIVE) {
remaining_ticks = 0;
} else {
/*
* compute remaining ticks by walking the timeout list
* and summing up the various tick deltas involved
*/
struct _timeout *t =
(struct _timeout *)sys_dlist_peek_head(&_timeout_q);
remaining_ticks = t->delta_ticks_from_prev;
while (t != timeout) {
t = (struct _timeout *)sys_dlist_peek_next(&_timeout_q,
&t->node);
remaining_ticks += t->delta_ticks_from_prev;
}
}
irq_unlock(key);
return __ticks_to_ms(remaining_ticks);
}