zephyr/kernel/nanokernel/nano_timer.c

160 lines
3.6 KiB
C

/* nano_timer.c - timer for nanokernel-only systems */
/*
* Copyright (c) 1997-2014 Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <nano_private.h>
struct nano_timer *_nano_timer_list;
void nano_timer_init(struct nano_timer *timer, void *data)
{
nano_lifo_init(&timer->lifo);
timer->userData = data;
DEBUG_TRACING_OBJ_INIT(struct nano_timer *, timer, _track_list_nano_timer);
}
FUNC_ALIAS(_timer_start, nano_isr_timer_start, void);
FUNC_ALIAS(_timer_start, nano_fiber_timer_start, void);
FUNC_ALIAS(_timer_start, nano_task_timer_start, void);
FUNC_ALIAS(_timer_start, nano_timer_start, void);
/**
*
* @brief Start a nanokernel timer (generic implementation)
*
* This function starts a previously initialized nanokernel timer object.
* The timer will expire in <ticks> system clock ticks.
*
* @return N/A
*/
void _timer_start(struct nano_timer *timer, /* timer to start */
int ticks /* number of system ticks
* before expiry
*/
)
{
unsigned int imask;
struct nano_timer *cur;
struct nano_timer *prev = NULL;
timer->ticks = ticks;
imask = irq_lock();
cur = _nano_timer_list;
while (cur && (timer->ticks > cur->ticks)) {
timer->ticks -= cur->ticks;
prev = cur;
cur = cur->link;
}
timer->link = cur;
if (cur != NULL)
cur->ticks -= timer->ticks;
if (prev != NULL)
prev->link = timer;
else
_nano_timer_list = timer;
irq_unlock(imask);
}
/**
* @brief Stop a nanokernel timer (generic implementation)
*
* This function stops a previously started nanokernel timer object.
* @param timer Timer to stop
* @return N/A
*/
static void _timer_stop(struct nano_timer *timer)
{
unsigned int imask;
struct nano_timer *cur;
struct nano_timer *prev = NULL;
imask = irq_lock();
cur = _nano_timer_list;
/* find prev */
while (cur && cur != timer) {
prev = cur;
cur = cur->link;
}
/* if found it, remove it */
if (cur) {
/* if it was first */
if (prev == NULL) {
_nano_timer_list = timer->link;
/* if not last */
if (_nano_timer_list)
_nano_timer_list->ticks += timer->ticks;
} else {
prev->link = timer->link;
/* if not last */
if (prev->link)
prev->link->ticks += timer->ticks;
}
}
/* now the timer can't expire since it is removed from the list */
irq_unlock(imask);
}
FUNC_ALIAS(_timer_stop_non_preemptible, nano_isr_timer_stop, void);
FUNC_ALIAS(_timer_stop_non_preemptible, nano_fiber_timer_stop, void);
void _timer_stop_non_preemptible(struct nano_timer *timer)
{
extern void _lifo_put_non_preemptible(struct nano_lifo *lifo, void *data);
_timer_stop(timer);
/* if there was a waiter, kick it */
if (timer->lifo.wait_q.head) {
_lifo_put_non_preemptible(&timer->lifo, (void *)0);
}
}
void nano_task_timer_stop(struct nano_timer *timer)
{
_timer_stop(timer);
/* if there was a waiter, kick it */
if (timer->lifo.wait_q.head) {
nano_task_lifo_put(&timer->lifo, (void *)0);
}
}
void nano_timer_stop(struct nano_timer *timer)
{
static void (*func[3])(struct nano_timer *) = {
nano_isr_timer_stop,
nano_fiber_timer_stop,
nano_task_timer_stop,
};
func[sys_execution_context_type_get()](timer);
}