timer_process_alarm function of esp_timer holds a spinlock for the entire duration of its operation, except for the time when timer callback function is called. It is possible that when timer_process_alarm releases the spinlock, a higher priority task may run and delete the timer. Then the execution will return to timer_process_alarm, and this will either cause a crash, or undesired execution of callback after the timer has been stopped or deleted. To solve this problem, add a mutex which will prevent deletion of timers while callbacks are being dispatched.
516 lines
14 KiB
C
516 lines
14 KiB
C
// 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 <string.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);
|
|
// used to keep track of the timer when executing the callback
|
|
static esp_timer_handle_t s_timer_in_callback;
|
|
#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;
|
|
// mutex which protects timers from deletion during callback execution
|
|
static SemaphoreHandle_t s_timer_delete_mutex;
|
|
|
|
#if CONFIG_SPIRAM_USE_MALLOC
|
|
// memory for s_timer_semaphore and s_timer_delete_mutex
|
|
static StaticQueue_t s_timer_semaphore_memory;
|
|
static StaticQueue_t s_timer_delete_mutex_memory;
|
|
#endif
|
|
|
|
// lock protecting s_timers, s_inactive_timers, s_timer_in_callback
|
|
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 IRAM_ATTR 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 IRAM_ATTR 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 IRAM_ATTR 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 == NULL) {
|
|
return ESP_ERR_INVALID_ARG;
|
|
}
|
|
if (timer_armed(timer)) {
|
|
return ESP_ERR_INVALID_STATE;
|
|
}
|
|
xSemaphoreTakeRecursive(s_timer_delete_mutex, portMAX_DELAY);
|
|
#if WITH_PROFILING
|
|
if (timer == s_timer_in_callback) {
|
|
s_timer_in_callback = NULL;
|
|
}
|
|
timer_remove_inactive(timer);
|
|
#endif
|
|
free(timer);
|
|
xSemaphoreGiveRecursive(s_timer_delete_mutex);
|
|
return ESP_OK;
|
|
}
|
|
|
|
static IRAM_ATTR 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 IRAM_ATTR 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 IRAM_ATTR 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 IRAM_ATTR void timer_remove_inactive(esp_timer_handle_t timer)
|
|
{
|
|
timer_list_lock();
|
|
LIST_REMOVE(timer, list_entry);
|
|
timer_list_unlock();
|
|
}
|
|
|
|
#endif // WITH_PROFILING
|
|
|
|
static IRAM_ATTR bool timer_armed(esp_timer_handle_t timer)
|
|
{
|
|
return timer->alarm > 0;
|
|
}
|
|
|
|
static IRAM_ATTR void timer_list_lock()
|
|
{
|
|
portENTER_CRITICAL(&s_timer_lock);
|
|
}
|
|
|
|
static IRAM_ATTR 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;
|
|
|
|
xSemaphoreTakeRecursive(s_timer_delete_mutex, portMAX_DELAY);
|
|
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;
|
|
s_timer_in_callback = it;
|
|
#endif
|
|
timer_list_unlock();
|
|
(*it->callback)(it->arg);
|
|
timer_list_lock();
|
|
now = esp_timer_impl_get_time();
|
|
#if WITH_PROFILING
|
|
/* The callback might have deleted the timer.
|
|
* If this happens, esp_timer_delete will set s_timer_in_callback
|
|
* to NULL.
|
|
*/
|
|
if (s_timer_in_callback) {
|
|
s_timer_in_callback->times_triggered++;
|
|
s_timer_in_callback->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();
|
|
xSemaphoreGiveRecursive(s_timer_delete_mutex);
|
|
}
|
|
|
|
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 IRAM_ATTR bool is_initialized()
|
|
{
|
|
return s_timer_task != NULL;
|
|
}
|
|
|
|
|
|
esp_err_t esp_timer_init(void)
|
|
{
|
|
esp_err_t err;
|
|
if (is_initialized()) {
|
|
return ESP_ERR_INVALID_STATE;
|
|
}
|
|
|
|
#if CONFIG_SPIRAM_USE_MALLOC
|
|
memset(&s_timer_semaphore_memory, 0, sizeof(StaticQueue_t));
|
|
s_timer_semaphore = xSemaphoreCreateCountingStatic(TIMER_EVENT_QUEUE_SIZE, 0, &s_timer_semaphore_memory);
|
|
#else
|
|
s_timer_semaphore = xSemaphoreCreateCounting(TIMER_EVENT_QUEUE_SIZE, 0);
|
|
#endif
|
|
if (!s_timer_semaphore) {
|
|
err = ESP_ERR_NO_MEM;
|
|
goto out;
|
|
}
|
|
|
|
#if CONFIG_SPIRAM_USE_MALLOC
|
|
memset(&s_timer_delete_mutex_memory, 0, sizeof(StaticQueue_t));
|
|
s_timer_delete_mutex = xSemaphoreCreateRecursiveMutexStatic(&s_timer_delete_mutex_memory);
|
|
#else
|
|
s_timer_delete_mutex = xSemaphoreCreateRecursiveMutex();
|
|
#endif
|
|
if (!s_timer_delete_mutex) {
|
|
err = ESP_ERR_NO_MEM;
|
|
goto out;
|
|
}
|
|
|
|
|
|
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) {
|
|
err = ESP_ERR_NO_MEM;
|
|
goto out;
|
|
}
|
|
|
|
err = esp_timer_impl_init(&timer_alarm_handler);
|
|
if (err != ESP_OK) {
|
|
goto out;
|
|
}
|
|
|
|
return ESP_OK;
|
|
|
|
out:
|
|
if (s_timer_task) {
|
|
vTaskDelete(s_timer_task);
|
|
s_timer_task = NULL;
|
|
}
|
|
if (s_timer_semaphore) {
|
|
vSemaphoreDelete(s_timer_semaphore);
|
|
s_timer_semaphore = NULL;
|
|
}
|
|
if (s_timer_delete_mutex) {
|
|
vSemaphoreDelete(s_timer_delete_mutex);
|
|
s_timer_delete_mutex = NULL;
|
|
}
|
|
return ESP_ERR_NO_MEM;
|
|
}
|
|
|
|
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_next_alarm()
|
|
{
|
|
int64_t next_alarm = INT64_MAX;
|
|
timer_list_lock();
|
|
esp_timer_handle_t it = LIST_FIRST(&s_timers);
|
|
if (it) {
|
|
next_alarm = it->alarm;
|
|
}
|
|
timer_list_unlock();
|
|
return next_alarm;
|
|
}
|
|
|
|
int64_t IRAM_ATTR esp_timer_get_time()
|
|
{
|
|
return (int64_t) esp_timer_impl_get_time();
|
|
}
|