esp-idf/components/esp32/esp_timer.c

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12 KiB
C
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// Copyright 2017 Espressif Systems (Shanghai) PTE LTD
//
// 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 <sys/param.h>
#include "esp_types.h"
#include "esp_attr.h"
#include "esp_err.h"
#include "esp_timer.h"
#include "esp_task.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "freertos/xtensa_api.h"
#include "sdkconfig.h"
#include "esp_timer_impl.h"
#ifdef CONFIG_ESP_TIMER_PROFILING
#define WITH_PROFILING 1
#endif
#ifndef NDEBUG
// Enable built-in checks in queue.h in debug builds
#define INVARIANTS
#endif
#include "rom/queue.h"
#define TIMER_EVENT_QUEUE_SIZE 16
struct esp_timer {
uint64_t alarm;
uint64_t period;
esp_timer_cb_t callback;
void* arg;
#if WITH_PROFILING
const char* name;
size_t times_triggered;
size_t times_armed;
uint64_t total_callback_run_time;
#endif // WITH_PROFILING
LIST_ENTRY(esp_timer) list_entry;
};
static bool is_initialized();
static esp_err_t timer_insert(esp_timer_handle_t timer);
static esp_err_t timer_remove(esp_timer_handle_t timer);
static bool timer_armed(esp_timer_handle_t timer);
static void timer_list_lock();
static void timer_list_unlock();
#if WITH_PROFILING
static void timer_insert_inactive(esp_timer_handle_t timer);
static void timer_remove_inactive(esp_timer_handle_t timer);
#endif // WITH_PROFILING
static const char* TAG = "esp_timer";
// list of currently armed timers
static LIST_HEAD(esp_timer_list, esp_timer) s_timers =
LIST_HEAD_INITIALIZER(s_timers);
#if WITH_PROFILING
// list of unarmed timers, used only to be able to dump statistics about
// all the timers
static LIST_HEAD(esp_inactive_timer_list, esp_timer) s_inactive_timers =
LIST_HEAD_INITIALIZER(s_timers);
#endif
// task used to dispatch timer callbacks
static TaskHandle_t s_timer_task;
// counting semaphore used to notify the timer task from ISR
static SemaphoreHandle_t s_timer_semaphore;
// lock protecting s_timers and s_inactive_timers
static portMUX_TYPE s_timer_lock = portMUX_INITIALIZER_UNLOCKED;
esp_err_t esp_timer_create(const esp_timer_create_args_t* args,
esp_timer_handle_t* out_handle)
{
if (!is_initialized()) {
return ESP_ERR_INVALID_STATE;
}
if (args->callback == NULL) {
return ESP_ERR_INVALID_ARG;
}
esp_timer_handle_t result = (esp_timer_handle_t) calloc(1, sizeof(*result));
if (result == NULL) {
return ESP_ERR_NO_MEM;
}
result->callback = args->callback;
result->arg = args->arg;
#if WITH_PROFILING
result->name = args->name;
timer_insert_inactive(result);
#endif
*out_handle = result;
return ESP_OK;
}
esp_err_t esp_timer_start_once(esp_timer_handle_t timer, uint64_t timeout_us)
{
if (!is_initialized() || timer_armed(timer)) {
return ESP_ERR_INVALID_STATE;
}
timer->alarm = esp_timer_get_time() + timeout_us;
timer->period = 0;
#if WITH_PROFILING
timer->times_armed++;
#endif
return timer_insert(timer);
}
esp_err_t esp_timer_start_periodic(esp_timer_handle_t timer, uint64_t period_us)
{
if (!is_initialized() || timer_armed(timer)) {
return ESP_ERR_INVALID_STATE;
}
period_us = MAX(period_us, esp_timer_impl_get_min_period_us());
timer->alarm = esp_timer_get_time() + period_us;
timer->period = period_us;
#if WITH_PROFILING
timer->times_armed++;
#endif
return timer_insert(timer);
}
esp_err_t esp_timer_stop(esp_timer_handle_t timer)
{
if (!is_initialized() || !timer_armed(timer)) {
return ESP_ERR_INVALID_STATE;
}
return timer_remove(timer);
}
esp_err_t esp_timer_delete(esp_timer_handle_t timer)
{
if (timer_armed(timer)) {
return ESP_ERR_INVALID_STATE;
}
#if WITH_PROFILING
timer_remove_inactive(timer);
#endif
if (timer == NULL) {
return ESP_ERR_INVALID_ARG;
}
free(timer);
return ESP_OK;
}
static esp_err_t timer_insert(esp_timer_handle_t timer)
{
timer_list_lock();
#if WITH_PROFILING
timer_remove_inactive(timer);
#endif
esp_timer_handle_t it, last = NULL;
if (LIST_FIRST(&s_timers) == NULL) {
LIST_INSERT_HEAD(&s_timers, timer, list_entry);
} else {
LIST_FOREACH(it, &s_timers, list_entry) {
if (timer->alarm < it->alarm) {
LIST_INSERT_BEFORE(it, timer, list_entry);
break;
}
last = it;
}
if (it == NULL) {
assert(last);
LIST_INSERT_AFTER(last, timer, list_entry);
}
}
if (timer == LIST_FIRST(&s_timers)) {
esp_timer_impl_set_alarm(timer->alarm);
}
timer_list_unlock();
return ESP_OK;
}
static esp_err_t timer_remove(esp_timer_handle_t timer)
{
timer_list_lock();
LIST_REMOVE(timer, list_entry);
timer->alarm = 0;
timer->period = 0;
#if WITH_PROFILING
timer_insert_inactive(timer);
#endif
timer_list_unlock();
return ESP_OK;
}
#if WITH_PROFILING
static void timer_insert_inactive(esp_timer_handle_t timer)
{
/* May be locked or not, depending on where this is called from.
* Lock recursively.
*/
timer_list_lock();
esp_timer_handle_t head = LIST_FIRST(&s_inactive_timers);
if (head == NULL) {
LIST_INSERT_HEAD(&s_inactive_timers, timer, list_entry);
} else {
/* Insert as head element as this is the fastest thing to do.
* Removal is O(1) anyway.
*/
LIST_INSERT_BEFORE(head, timer, list_entry);
}
timer_list_unlock();
}
static void timer_remove_inactive(esp_timer_handle_t timer)
{
timer_list_lock();
LIST_REMOVE(timer, list_entry);
timer_list_unlock();
}
#endif // WITH_PROFILING
static bool timer_armed(esp_timer_handle_t timer)
{
return timer->alarm > 0;
}
static void timer_list_lock()
{
portENTER_CRITICAL(&s_timer_lock);
}
static void timer_list_unlock()
{
portEXIT_CRITICAL(&s_timer_lock);
}
static void timer_process_alarm(esp_timer_dispatch_t dispatch_method)
{
/* unused, provision to allow running callbacks from ISR */
(void) dispatch_method;
timer_list_lock();
uint64_t now = esp_timer_impl_get_time();
esp_timer_handle_t it = LIST_FIRST(&s_timers);
while (it != NULL &&
it->alarm < now) {
LIST_REMOVE(it, list_entry);
if (it->period > 0) {
it->alarm += it->period;
timer_insert(it);
} else {
it->alarm = 0;
#if WITH_PROFILING
timer_insert_inactive(it);
#endif
}
#if WITH_PROFILING
uint64_t callback_start = now;
#endif
timer_list_unlock();
(*it->callback)(it->arg);
timer_list_lock();
now = esp_timer_impl_get_time();
#if WITH_PROFILING
it->times_triggered++;
it->total_callback_run_time += now - callback_start;
#endif
it = LIST_FIRST(&s_timers);
}
esp_timer_handle_t first = LIST_FIRST(&s_timers);
if (first) {
esp_timer_impl_set_alarm(first->alarm);
}
timer_list_unlock();
}
static void timer_task(void* arg)
{
while (true){
int res = xSemaphoreTake(s_timer_semaphore, portMAX_DELAY);
assert(res == pdTRUE);
timer_process_alarm(ESP_TIMER_TASK);
}
}
static void IRAM_ATTR timer_alarm_handler(void* arg)
{
int need_yield;
if (xSemaphoreGiveFromISR(s_timer_semaphore, &need_yield) != pdPASS) {
ESP_EARLY_LOGD(TAG, "timer queue overflow");
return;
}
if (need_yield == pdTRUE) {
portYIELD_FROM_ISR();
}
}
static bool is_initialized()
{
return s_timer_task != NULL;
}
esp_err_t esp_timer_init(void)
{
if (is_initialized()) {
return ESP_ERR_INVALID_STATE;
}
s_timer_semaphore = xSemaphoreCreateCounting(TIMER_EVENT_QUEUE_SIZE, 0);
if (!s_timer_semaphore) {
return ESP_ERR_NO_MEM;
}
int ret = xTaskCreatePinnedToCore(&timer_task, "esp_timer",
ESP_TASK_TIMER_STACK, NULL, ESP_TASK_TIMER_PRIO, &s_timer_task, PRO_CPU_NUM);
if (ret != pdPASS) {
vSemaphoreDelete(s_timer_semaphore);
s_timer_semaphore = NULL;
return ESP_ERR_NO_MEM;
}
esp_err_t err = esp_timer_impl_init(&timer_alarm_handler);
if (err != ESP_OK) {
vTaskDelete(s_timer_task);
s_timer_task = NULL;
vSemaphoreDelete(s_timer_semaphore);
s_timer_semaphore = NULL;
return err;
}
return ESP_OK;
}
esp_err_t esp_timer_deinit(void)
{
if (!is_initialized()) {
return ESP_ERR_INVALID_STATE;
}
/* Check if there are any active timers */
if (!LIST_EMPTY(&s_timers)) {
return ESP_ERR_INVALID_STATE;
}
/* We can only check if there are any timers which are not deleted if
* profiling is enabled.
*/
#if WITH_PROFILING
if (!LIST_EMPTY(&s_inactive_timers)) {
return ESP_ERR_INVALID_STATE;
}
#endif
esp_timer_impl_deinit();
vTaskDelete(s_timer_task);
s_timer_task = NULL;
vSemaphoreDelete(s_timer_semaphore);
s_timer_semaphore = NULL;
return ESP_OK;
}
static void print_timer_info(esp_timer_handle_t t, char** dst, size_t* dst_size)
{
size_t cb = snprintf(*dst, *dst_size,
#if WITH_PROFILING
"%-12s %12lld %12lld %9d %9d %12lld\n",
t->name, t->period, t->alarm,
t->times_armed, t->times_triggered, t->total_callback_run_time);
/* keep this in sync with the format string, used in esp_timer_dump */
#define TIMER_INFO_LINE_LEN 78
#else
"timer@%p %12lld %12lld\n", t, t->period, t->alarm);
#define TIMER_INFO_LINE_LEN 46
#endif
*dst += cb;
*dst_size -= cb;
}
esp_err_t esp_timer_dump(FILE* stream)
{
/* Since timer lock is a critical section, we don't want to print directly
* to stdout, since that may cause a deadlock if stdout is interrupt-driven
* (via the UART driver). Allocate sufficiently large chunk of memory first,
* print to it, then dump this memory to stdout.
*/
esp_timer_handle_t it;
/* First count the number of timers */
size_t timer_count = 0;
timer_list_lock();
LIST_FOREACH(it, &s_timers, list_entry) {
++timer_count;
}
#if WITH_PROFILING
LIST_FOREACH(it, &s_inactive_timers, list_entry) {
++timer_count;
}
#endif
timer_list_unlock();
/* Allocate the memory for this number of timers. Since we have unlocked,
* we may find that there are more timers. There's no bulletproof solution
* for this (can't allocate from a critical section), but we allocate
* slightly more and the output will be truncated if that is not enough.
*/
size_t buf_size = TIMER_INFO_LINE_LEN * (timer_count + 3);
char* print_buf = calloc(1, buf_size + 1);
if (print_buf == NULL) {
return ESP_ERR_NO_MEM;
}
/* Print to the buffer */
timer_list_lock();
char* pos = print_buf;
LIST_FOREACH(it, &s_timers, list_entry) {
print_timer_info(it, &pos, &buf_size);
}
#if WITH_PROFILING
LIST_FOREACH(it, &s_inactive_timers, list_entry) {
print_timer_info(it, &pos, &buf_size);
}
#endif
timer_list_unlock();
/* Print the buffer */
fputs(print_buf, stream);
free(print_buf);
return ESP_OK;
}
int64_t IRAM_ATTR esp_timer_get_time()
{
return (int64_t) esp_timer_impl_get_time();
}