doc: remove left-over legacy event loop docs

docs/en/api-guides/event-handling.rst

@@ -1,152 +0,0 @@
-Event Handling
-==============
-
-Several ESP-IDF components use *events* to inform application about state changes, such as connection or disconnection. This document gives an overview of these event mechanisms.
-
-Wi-Fi, Ethernet, and IP Events
-------------------------------
-
-Before the introduction of :doc:`esp_event library<../api-reference/system/esp_event>`, events from Wi-Fi driver, Ethernet driver, and TCP/IP stack were dispatched using the so-called *legacy event loop*. The following sections explain each of the methods.
-
-esp_event Library Event Loop
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-esp_event library is designed to supersede the legacy event loop for the purposes of event handling in ESP-IDF. In the legacy event loop, all possible event types and event data structures had to be defined in :cpp:type:`system_event_id_t` enumeration and :cpp:type:`system_event_info_t` union, which made it impossible to send custom events to the event loop, and use the event loop for other kinds of events (e.g. Mesh). Legacy event loop also supported only one event handler function, therefore application components could not handle some of Wi-Fi or IP events themselves, and required application to forward these events from its event handler function.
-
-See :doc:`esp_event library API reference<../api-reference/system/esp_event>` for general information on using this library. Wi-Fi, Ethernet, and IP events are sent to the :ref:`default event loop <esp-event-default-loops>` provided by this library.
-
-.. _legacy-event-loop:
-
-Legacy Event Loop
-~~~~~~~~~~~~~~~~~
-
-This event loop implementation is started using :cpp:func:`esp_event_loop_init` function. Application typically supplies an *event handler*, a function with the following signature::
-
-    esp_err_t event_handler(void *ctx, system_event_t *event)
-    {
-    }
-
-Both the pointer to event handler function, and an arbitrary context pointer are passed to :cpp:func:`esp_event_loop_init`.
-
-When Wi-Fi, Ethernet, or IP stack generate an event, this event is sent to a high-priority ``event`` task via a queue. Application-provided event handler function is called in the context of this task. Event task stack size and event queue size can be adjusted using :ref:`CONFIG_ESP_SYSTEM_EVENT_TASK_STACK_SIZE` and :ref:`CONFIG_ESP_SYSTEM_EVENT_QUEUE_SIZE` options, respectively.
-
-Event handler receives a pointer to the event structure (:cpp:type:`system_event_t`) which describes current event. This structure follows a *tagged union* pattern: ``event_id`` member indicates the type of event, and ``event_info`` member is a union of description structures. Application event handler will typically use ``switch(event->event_id)`` to handle different kinds of events.
-
-If application event handler needs to relay the event to some other task, it is important to note that event pointer passed to the event handler is a pointer to temporary structure. To pass the event to another task, application has to make a copy of the entire structure.
-
-
-Event IDs and Corresponding Data Structures
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-+------------------------------------+-----------------------------------------------+
-| Event ID                           | Event data structure                          |
-| (legacy event ID)                  |                                               |
-+------------------------------------+-----------------------------------------------+
-| **Wi-Fi**                                                                          |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_WIFI_READY              | n/a                                           |
-| (SYSTEM_EVENT_WIFI_READY)          |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_SCAN_DONE               | :cpp:class:`wifi_event_sta_scan_done_t`       |
-| (SYSTEM_EVENT_SCAN_DONE)           |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_START               | n/a                                           |
-| (SYSTEM_EVENT_STA_START)           |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_STOP                | n/a                                           |
-| (SYSTEM_EVENT_STA_STOP)            |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_CONNECTED           | :cpp:class:`wifi_event_sta_connected_t`       |
-| (SYSTEM_EVENT_STA_CONNECTED)       |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_DISCONNECTED        | :cpp:class:`wifi_event_sta_disconnected_t`    |
-| (SYSTEM_EVENT_STA_DISCONNECTED)    |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_AUTHMODE_CHANGE     | :cpp:class:`wifi_event_sta_authmode_change_t` |
-| (SYSTEM_EVENT_STA_AUTHMODE_CHANGE) |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_WPS_ER_SUCCESS      | n/a                                           |
-| (SYSTEM_EVENT_STA_WPS_ER_SUCCESS)  |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_WPS_ER_FAILED       | :cpp:type:`wifi_event_sta_wps_fail_reason_t`  |
-| (SYSTEM_EVENT_STA_WPS_ER_FAILED)   |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_WPS_ER_TIMEOUT      | n/a                                           |
-| (SYSTEM_EVENT_STA_WPS_ER_TIMEOUT)  |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_STA_WPS_ER_PIN          | :cpp:class:`wifi_event_sta_wps_er_pin_t`      |
-| (SYSTEM_EVENT_STA_WPS_ER_PIN)      |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_AP_START                | n/a                                           |
-| (SYSTEM_EVENT_AP_START)            |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_AP_STOP                 | n/a                                           |
-| (SYSTEM_EVENT_AP_STOP)             |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_AP_STACONNECTED         | :cpp:class:`wifi_event_ap_staconnected_t`     |
-| (SYSTEM_EVENT_AP_STACONNECTED)     |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_AP_STADISCONNECTED      | :cpp:class:`wifi_event_ap_stadisconnected_t`  |
-| (SYSTEM_EVENT_AP_STADISCONNECTED)  |                                               |
-+------------------------------------+-----------------------------------------------+
-| WIFI_EVENT_AP_PROBEREQRECVED       | :cpp:class:`wifi_event_ap_probe_req_rx_t`     |
-| (SYSTEM_EVENT_AP_PROBEREQRECVED)   |                                               |
-+------------------------------------+-----------------------------------------------+
-| **Ethernet**                                                                       |
-+------------------------------------+-----------------------------------------------+
-| ETHERNET_EVENT_START               | n/a                                           |
-| (SYSTEM_EVENT_ETH_START)           |                                               |
-+------------------------------------+-----------------------------------------------+
-| ETHERNET_EVENT_STOP                | n/a                                           |
-| (SYSTEM_EVENT_ETH_STOP)            |                                               |
-+------------------------------------+-----------------------------------------------+
-| ETHERNET_EVENT_CONNECTED           | n/a                                           |
-| (SYSTEM_EVENT_ETH_CONNECTED)       |                                               |
-+------------------------------------+-----------------------------------------------+
-| ETHERNET_EVENT_DISCONNECTED        | n/a                                           |
-| (SYSTEM_EVENT_ETH_DISCONNECTED)    |                                               |
-+------------------------------------+-----------------------------------------------+
-| **IP**                                                                             |
-+------------------------------------+-----------------------------------------------+
-| IP_EVENT_STA_GOT_IP                | :cpp:class:`ip_event_got_ip_t`                |
-| (SYSTEM_EVENT_STA_GOT_IP)          |                                               |
-+------------------------------------+-----------------------------------------------+
-| IP_EVENT_STA_LOST_IP               | n/a                                           |
-| (SYSTEM_EVENT_STA_LOST_IP)         |                                               |
-+------------------------------------+-----------------------------------------------+
-| IP_EVENT_AP_STAIPASSIGNED          | n/a                                           |
-| (SYSTEM_EVENT_AP_STAIPASSIGNED)    |                                               |
-+------------------------------------+-----------------------------------------------+
-| IP_EVENT_GOT_IP6                   | :cpp:class:`ip_event_got_ip6_t`               |
-| (SYSTEM_EVENT_GOT_IP6)             |                                               |
-+------------------------------------+-----------------------------------------------+
-| IP_EVENT_ETH_GOT_IP                | :cpp:class:`ip_event_got_ip_t`                |
-| (SYSTEM_EVENT_ETH_GOT_IP)          |                                               |
-+------------------------------------+-----------------------------------------------+
-| IP_EVENT_ETH_LOST_IP               | n/a                                           |
-| (SYSTEM_EVENT_ETH_LOST_IP)         |                                               |
-+------------------------------------+-----------------------------------------------+
-
-.. only:: SOC_WIFI_MESH_SUPPORT
-
-    Mesh Events
-    -----------
-
-    ESP-WIFI-MESH uses a system similar to the :ref:`legacy-event-loop` to deliver events to the application. See :ref:`mesh-events` for details.
-
-
-Bluetooth Events
-----------------
-
-Various modules of the Bluetooth stack deliver events to applications via dedicated callback functions. Callback functions receive the event type (enumerated value) and event data (union of structures for each event type). The following list gives the registration API name, event enumeration type, and event parameters type.
-
-* BLE GAP: :cpp:func:`esp_ble_gap_register_callback`, :cpp:type:`esp_gap_ble_cb_event_t`, :cpp:type:`esp_ble_gap_cb_param_t`.
-* BT GAP: :cpp:func:`esp_bt_gap_register_callback`, :cpp:type:`esp_bt_gap_cb_event_t`, :cpp:type:`esp_bt_gap_cb_param_t`.
-* GATTC: :cpp:func:`esp_ble_gattc_register_callback`, :cpp:type:`esp_ble_gattc_cb_event_t`, :cpp:type:`esp_ble_gattc_cb_param_t`.
-* GATTS: :cpp:func:`esp_ble_gatts_register_callback`, :cpp:type:`esp_ble_gatts_cb_event_t`, :cpp:type:`esp_ble_gatts_cb_param_t`.
-* SPP: :cpp:func:`esp_spp_register_callback`, :cpp:type:`esp_spp_cb_event_t`, :cpp:type:`esp_spp_cb_param_t`.
-* Blufi: :cpp:func:`esp_blufi_register_callbacks`, :cpp:type:`esp_blufi_cb_event_t`, :cpp:type:`esp_blufi_cb_param_t`.
-* A2DP: :cpp:func:`esp_a2d_register_callback`, :cpp:type:`esp_a2d_cb_event_t`, :cpp:type:`esp_a2d_cb_param_t`.
-* AVRC: :cpp:func:`esp_avrc_ct_register_callback`, :cpp:type:`esp_avrc_ct_cb_event_t`, :cpp:type:`esp_avrc_ct_cb_param_t`.
-* HFP Client: :cpp:func:`esp_hf_client_register_callback`, :cpp:type:`esp_hf_client_cb_event_t`, :cpp:type:`esp_hf_client_cb_param_t`.
-* HFP AG: :cpp:func:`esp_bt_hf_register_callback`, :cpp:type:`esp_hf_cb_event_t`, :cpp:type:`esp_hf_cb_param_t`.

docs/en/api-guides/index.rst

@@ -18,7 +18,6 @@ API Guides
    error-handling
    :SOC_BLE_MESH_SUPPORTED: esp-ble-mesh/ble-mesh-index
    :SOC_WIFI_MESH_SUPPORT: esp-wifi-mesh
-   event-handling
    :SOC_SPIRAM_SUPPORTED: external-ram
    fatal-errors
    ../security/flash-encryption

docs/en/api-guides/performance/ram-usage.rst

@@ -76,7 +76,7 @@ The default stack sizes for these tasks are usually set conservatively high, to
    - :ref:`Main task that executes app_main function <app-main-task>` has stack size :ref:`CONFIG_ESP_MAIN_TASK_STACK_SIZE`.
    - :doc:`/api-reference/system/esp_timer` system task which executes callbacks has stack size :ref:`CONFIG_ESP_TIMER_TASK_STACK_SIZE`.
    - FreeRTOS Timer Task to handle FreeRTOS timer callbacks has stack size :ref:`CONFIG_FREERTOS_TIMER_TASK_STACK_DEPTH`.
-   - :doc:`/api-guides/event-handling` system task to execute callbacks for the default system event loop has stack size :ref:`CONFIG_ESP_SYSTEM_EVENT_TASK_STACK_SIZE`.
+   - :doc:`/api-reference/system/esp_event` system task to execute callbacks for the default system event loop has stack size :ref:`CONFIG_ESP_SYSTEM_EVENT_TASK_STACK_SIZE`.
    - :doc:`/api-guides/lwip` TCP/IP task has stack size :ref:`CONFIG_LWIP_TCPIP_TASK_STACK_SIZE`
    :SOC_BT_SUPPORTED: - :doc:`Bluedroid Bluetooth Host </api-reference/bluetooth/index>` have task stack sizes :ref:`CONFIG_BT_BTC_TASK_STACK_SIZE`, :ref:`CONFIG_BT_BTU_TASK_STACK_SIZE`.
    :SOC_BT_SUPPORTED: - :doc:`NimBLE Bluetooth Host </api-reference/bluetooth/nimble/index>` has task stack size :ref:`CONFIG_BT_NIMBLE_HOST_TASK_STACK_SIZE`

docs/en/api-guides/performance/speed.rst

@@ -162,7 +162,7 @@ Common priorities are:
         - :ref:`Main task that executes app_main function <app-main-task>` has minimum priority (1).
         - :doc:`/api-reference/system/esp_timer` system task to manage timer events and execute callbacks has high priority (22, ``ESP_TASK_TIMER_PRIO``)
         - FreeRTOS Timer Task to handle FreeRTOS timer callbacks is created when the scheduler initializes and has minimum task priority (1, :ref:`configurable <CONFIG_FREERTOS_TIMER_TASK_PRIORITY>`).
-        - :doc:`/api-guides/event-handling` system task to manage the default system event loop and execute callbacks has high priority (20, ``ESP_TASK_EVENT_PRIO``). This configuration is only used if the application calls :cpp:func:`esp_event_loop_create_default`, it's possible to call :cpp:func:`esp_event_loop_create` with a custom task configuration instead.
+        - :doc:`/api-reference/system/esp_event` system task to manage the default system event loop and execute callbacks has high priority (20, ``ESP_TASK_EVENT_PRIO``). This configuration is only used if the application calls :cpp:func:`esp_event_loop_create_default`, it's possible to call :cpp:func:`esp_event_loop_create` with a custom task configuration instead.
         - :doc:`/api-guides/lwip` TCP/IP task has high priority (18, ``ESP_TASK_TCPIP_PRIO``).
         :SOC_WIFI_SUPPORTED: - :doc:`Wi-Fi Driver </api-guides/wifi>` task has high priority (23).
         :SOC_WIFI_SUPPORTED: - Wi-Fi wpa_supplicant component may create dedicated tasks while the Wi-Fi Protected Setup (WPS), WPA2 EAP-TLS, Device Provisioning Protocol (DPP) or BSS Transition Management (BTM) features are in use. These tasks all have low priority (2).
@@ -179,7 +179,7 @@ Common priorities are:
         - :ref:`Main task that executes app_main function <app-main-task>` has minimum priority (1). This task is pinned to Core 0 by default (:ref:`configurable<CONFIG_ESP_MAIN_TASK_AFFINITY>`).
         - :doc:`/api-reference/system/esp_timer` system task to manage high precision timer events and execute callbacks has high priority (22, ``ESP_TASK_TIMER_PRIO``). This task is pinned to Core 0.
         - FreeRTOS Timer Task to handle FreeRTOS timer callbacks is created when the scheduler initializes and has minimum task priority (1, :ref:`configurable <CONFIG_FREERTOS_TIMER_TASK_PRIORITY>`). This task is pinned to Core 0.
-        - :doc:`/api-guides/event-handling` system task to manage the default system event loop and execute callbacks has high priority (20, ``ESP_TASK_EVENT_PRIO``) and pinned to Core 0. This configuration is only used if the application calls :cpp:func:`esp_event_loop_create_default`, it's possible to call :cpp:func:`esp_event_loop_create` with a custom task configuration instead.
+        - :doc:`/api-reference/system/esp_event` system task to manage the default system event loop and execute callbacks has high priority (20, ``ESP_TASK_EVENT_PRIO``) and pinned to Core 0. This configuration is only used if the application calls :cpp:func:`esp_event_loop_create_default`, it's possible to call :cpp:func:`esp_event_loop_create` with a custom task configuration instead.
         - :doc:`/api-guides/lwip` TCP/IP task has high priority (18, ``ESP_TASK_TCPIP_PRIO``) and is not pinned to any core (:ref:`configurable<CONFIG_LWIP_TCPIP_TASK_AFFINITY>`).
         :SOC_WIFI_SUPPORTED: - :doc:`Wi-Fi Driver </api-guides/wifi>` task has high priority (23) and is pinned to Core 0 by default (:ref:`configurable<CONFIG_ESP_WIFI_TASK_CORE_ID>`).
         :SOC_WIFI_SUPPORTED: - Wi-Fi wpa_supplicant component may create dedicated tasks while the Wi-Fi Protected Setup (WPS), WPA2 EAP-TLS, Device Provisioning Protocol (DPP) or BSS Transition Management (BTM) features are in use. These tasks all have low priority (2) and are not pinned to any core.

docs/en/api-guides/wifi.rst

@@ -59,7 +59,7 @@ Refer to `{IDF_TARGET_NAME} Wi-Fi station General Scenario`_ and `{IDF_TARGET_NA
 
 Event-Handling
 ++++++++++++++
-Generally, it is easy to write code in "sunny-day" scenarios, such as `WIFI_EVENT_STA_START`_ and `WIFI_EVENT_STA_CONNECTED`_. The hard part is to write routines in "rainy-day" scenarios, such as `WIFI_EVENT_STA_DISCONNECTED`_. Good handling of "rainy-day" scenarios is fundamental to robust Wi-Fi applications. Refer to `{IDF_TARGET_NAME} Wi-Fi Event Description`_, `{IDF_TARGET_NAME} Wi-Fi station General Scenario`_, and `{IDF_TARGET_NAME} Wi-Fi AP General Scenario`_. See also :doc:`an overview of event handling in ESP-IDF<event-handling>`.
+Generally, it is easy to write code in "sunny-day" scenarios, such as `WIFI_EVENT_STA_START`_ and `WIFI_EVENT_STA_CONNECTED`_. The hard part is to write routines in "rainy-day" scenarios, such as `WIFI_EVENT_STA_DISCONNECTED`_. Good handling of "rainy-day" scenarios is fundamental to robust Wi-Fi applications. Refer to `{IDF_TARGET_NAME} Wi-Fi Event Description`_, `{IDF_TARGET_NAME} Wi-Fi station General Scenario`_, and `{IDF_TARGET_NAME} Wi-Fi AP General Scenario`_. See also the :doc:`overview of the Event Loop Library in ESP-IDF<../api-reference/system/esp_event>`.
 
 Write Error-Recovery Routines Correctly at All Times
 ++++++++++++++++++++++++++++++++++++++++++++++++++++

docs/en/api-reference/system/esp_event.rst

@@ -4,11 +4,17 @@ Event Loop Library
 Overview
 --------
 
-The event loop library allows components to declare events to which other components can register handlers -- code which will
+The event loop library allows components to declare events to which other components can register handlers -- code which will execute when those events occur. This allows loosely coupled components to attach desired behavior to state changes of other components without application involvement. This also simplifies event processing by serializing and deferring code execution to another context.
-execute when those events occur. This allows loosely coupled components to attach desired behavior to changes in state of other components
+
-without application involvement. For instance, a high level connection handling library may subscribe to events produced
+.. only:: SOC_WIFI_SUPPORTED
-by the Wi-Fi subsystem directly and act on those events. This also simplifies event processing by serializing and deferring
+
-code execution to another context.
+    One common use case is if a high level library is using the WiFi library: it may subscribe to :ref:`events produced by the Wi-Fi subsystem <wifi-programming-model>` directly and act on those events. 
+
+.. only:: SOC_BT_SUPPORTED
+
+    .. note::
+    
+        Various modules of the Bluetooth stack deliver events to applications via dedicated callback functions instead of via the Event Loop Library.
 
 Using ``esp_event`` APIs
 ------------------------

docs/page_redirects.txt

@@ -69,6 +69,7 @@ api-guides/ulps2_instruction_set                api-reference/system/ulp_instruc
 api-guides/ulp_macros                           api-reference/system/ulp_macros
 api-guides/ulp-risc-v                           api-reference/system/ulp-risc-v
 api-guides/console                              api-reference/system/console
+api-guides/event-handling                       api-reference/system/esp_event
 
 api-reference/network/tcpip_adapter             migration-guides/tcpip-adapter
 api-reference/system/system                     api-reference/system/misc_system_api

docs/zh_CN/api-guides/event-handling.rst

@@ -1 +0,0 @@
-.. include:: ../../en/api-guides/event-handling.rst

docs/zh_CN/api-guides/index.rst

@@ -18,7 +18,6 @@ API 指南
    error-handling
    :SOC_BLE_MESH_SUPPORTED: esp-ble-mesh/ble-mesh-index
    :SOC_WIFI_MESH_SUPPORT: esp-wifi-mesh
-   event-handling
    :SOC_SPIRAM_SUPPORTED: external-ram
    fatal-errors
    ../security/flash-encryption

docs/zh_CN/api-guides/wifi.rst

@@ -1,4 +1,4 @@
-Wi-Fi 驱动程序
+Wi-Fi 驱动程序
 ==================
 
 :link_to_translation:`en:[English]`
@@ -59,7 +59,7 @@ Wi-Fi 初始化
 
 事件处理
 ++++++++++++++
-通常，在理想环境下编写代码难度并不大，如 `WIFI_EVENT_STA_START`_、`WIFI_EVENT_STA_CONNECTED`_ 中所述。难度在于如何在现实的困难环境下编写代码，如 `WIFI_EVENT_STA_DISCONNECTED`_ 中所述。能否在后者情况下完美地解决各类事件冲突，是编写一个强健的 Wi-Fi 应用程序的根本。请参阅 `{IDF_TARGET_NAME} Wi-Fi 事件描述`_, `{IDF_TARGET_NAME} Wi-Fi station 一般情况`_, `{IDF_TARGET_NAME} Wi-Fi AP 一般情况`_。另可参阅 ESP-IDF 中的 `事件处理概述 <https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/event-handling.html?highlight=event%20handling>`_。
+通常，在理想环境下编写代码难度并不大，如 `WIFI_EVENT_STA_START`_、`WIFI_EVENT_STA_CONNECTED`_ 中所述。难度在于如何在现实的困难环境下编写代码，如 `WIFI_EVENT_STA_DISCONNECTED`_ 中所述。能否在后者情况下完美地解决各类事件冲突，是编写一个强健的 Wi-Fi 应用程序的根本。请参阅 `{IDF_TARGET_NAME} Wi-Fi 事件描述`_, `{IDF_TARGET_NAME} Wi-Fi station 一般情况`_, `{IDF_TARGET_NAME} Wi-Fi AP 一般情况`_。另可参阅 ESP-IDF 中的 :doc:`事件处理概述 <../api-reference/system/esp_event>`。
 
 编写错误恢复程序
 ++++++++++++++++++++++++++++++++++++++++++++++++++++