esp_task_wdt.h

// Copyright 2015-2016 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.

#pragma once

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_err.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
  * @brief  Initialize the Task Watchdog Timer (TWDT)
  *
  * This function configures and initializes the TWDT. If the TWDT is already
  * initialized when this function is called, this function will update the
  * TWDT's timeout period and panic configurations instead. After initializing
  * the TWDT, any task can elect to be watched by the TWDT by subscribing to it
  * using esp_task_wdt_add().
  *
  * @param[in]  timeout     Timeout period of TWDT in seconds
  * @param[in]  panic       Flag that controls whether the panic handler will be
  *                         executed when the TWDT times out
  *
  * @return
  *     - ESP_OK: Initialization was successful
  *     - ESP_ERR_NO_MEM: Initialization failed due to lack of memory
  *
  * @note   esp_task_wdt_init() must only be called after the scheduler
  *         started
  */
esp_err_t esp_task_wdt_init(uint32_t timeout, bool panic);

/**
 * @brief   Deinitialize the Task Watchdog Timer (TWDT)
 *
 * This function will deinitialize the TWDT. Calling this function whilst tasks
 * are still subscribed to the TWDT, or when the TWDT is already deinitialized,
 * will result in an error code being returned.
 *
 * @return
 *      - ESP_OK: TWDT successfully deinitialized
 *      - ESP_ERR_INVALID_STATE: Error, tasks are still subscribed to the TWDT
 *      - ESP_ERR_NOT_FOUND: Error, TWDT has already been deinitialized
 */
esp_err_t esp_task_wdt_deinit(void);

/**
  * @brief  Subscribe a task to the Task Watchdog Timer (TWDT)
  *
  * This function subscribes a task to the TWDT. Each subscribed task must
  * periodically call esp_task_wdt_reset() to prevent the TWDT from elapsing its
  * timeout period. Failure to do so will result in a TWDT timeout. If the task
  * being subscribed is one of the Idle Tasks, this function will automatically
  * enable esp_task_wdt_reset() to called from the Idle Hook of the Idle Task.
  * Calling this function whilst the TWDT is uninitialized or attempting to
  * subscribe an already subscribed task will result in an error code being
  * returned.
  *
  * @param[in]  handle  Handle of the task. Input NULL to subscribe the current
  *                     running task to the TWDT
  *
  * @return
  *     - ESP_OK: Successfully subscribed the task to the TWDT
  *     - ESP_ERR_INVALID_ARG: Error, the task is already subscribed
  *     - ESP_ERR_NO_MEM: Error, could not subscribe the task due to lack of
  *                       memory
  *     - ESP_ERR_INVALID_STATE: Error, the TWDT has not been initialized yet
  */
esp_err_t esp_task_wdt_add(TaskHandle_t handle);

/**
  * @brief  Reset the Task Watchdog Timer (TWDT) on behalf of the currently
  *         running task
  *
  * This function will reset the TWDT on behalf of the currently running task.
  * Each subscribed task must periodically call this function to prevent the
  * TWDT from timing out. If one or more subscribed tasks fail to reset the
  * TWDT on their own behalf, a TWDT timeout will occur. If the IDLE tasks have
  * been subscribed to the TWDT, they will automatically call this function from
  * their idle hooks. Calling this function from a task that has not subscribed
  * to the TWDT, or when the TWDT is uninitialized will result in an error code
  * being returned.
  *
  * @return
  *     - ESP_OK: Successfully reset the TWDT on behalf of the currently
  *               running task
  *     - ESP_ERR_NOT_FOUND: Error, the current running task has not subscribed
  *                          to the TWDT
  *     - ESP_ERR_INVALID_STATE: Error, the TWDT has not been initialized yet
  */
esp_err_t esp_task_wdt_reset(void);

/**
  * @brief  Unsubscribes a task from the Task Watchdog Timer (TWDT)
  *
  * This function will unsubscribe a task from the TWDT. After being
  * unsubscribed, the task should no longer call esp_task_wdt_reset(). If the
  * task is an IDLE task, this function will automatically disable the calling
  * of esp_task_wdt_reset() from the Idle Hook. Calling this function whilst the
  * TWDT is uninitialized or attempting to unsubscribe an already unsubscribed
  * task from the TWDT will result in an error code being returned.
  *
  * @param[in]  handle  Handle of the task. Input NULL to unsubscribe the
  *                     current running task.
  *
  * @return
  *     - ESP_OK: Successfully unsubscribed the task from the TWDT
  *     - ESP_ERR_INVALID_ARG: Error, the task is already unsubscribed
  *     - ESP_ERR_INVALID_STATE: Error, the TWDT has not been initialized yet
  */
esp_err_t esp_task_wdt_delete(TaskHandle_t handle);

/**
  * @brief   Query whether a task is subscribed to the Task Watchdog Timer (TWDT)
  *
  * This function will query whether a task is currently subscribed to the TWDT,
  * or whether the TWDT is initialized.
  *
  * @param[in]  handle  Handle of the task. Input NULL to query the current
  *                     running task.
  *
  * @return:
  *     - ESP_OK: The task is currently subscribed to the TWDT
  *     - ESP_ERR_NOT_FOUND: The task is currently not subscribed to the TWDT
  *     - ESP_ERR_INVALID_STATE: The TWDT is not initialized, therefore no tasks
  *                              can be subscribed
  */
esp_err_t esp_task_wdt_status(TaskHandle_t handle);


#ifdef __cplusplus
}
#endif