ESP32-默认事件循环

默认的事件循环是一个事件循环的系统应用发布和处理事件（例如，Wi-Fi无线事件）。

基于ESP-IDF4.1

  1 #include "esp_log.h"
  2 #include "freertos/FreeRTOS.h"
  3 #include "freertos/task.h"
  4 #include "event_source.h"
  5
  6 static const char* TAG = "default_event_loop";
  7
  8 static char* get_id_string(esp_event_base_t base, int32_t id) {
  9     char* event = "";
 10     if (base == TIMER_EVENTS) {
 11         switch(id) {
 12             case TIMER_EVENT_STARTED:
 13             event = "TIMER_EVENT_STARTED";
 14             break;
 15             case TIMER_EVENT_EXPIRY:
 16             event = "TIMER_EVENT_EXPIRY";
 17             break;
 18             case TIMER_EVENT_STOPPED:
 19             event = "TIMER_EVENT_STOPPED";
 20             break;
 21         }
 22     } else {
 23         event = "TASK_ITERATION_EVENT";
 24     }
 25     return event;
 26 }
 27
 28 //事件源周期定时器相关的定义
 29 ESP_EVENT_DEFINE_BASE(TIMER_EVENTS);
 30
 31 esp_timer_handle_t TIMER;
 32
 33 //计时器周期过期时执行回调，将计时器到期事件发布到默认事件循环
 34 static void timer_callback(void* arg)
 35 {
 36     ESP_LOGI(TAG, "%s:%s: posting to default loop", TIMER_EVENTS, get_id_string(TIMER_EVENTS, TIMER_EVENT_EXPIRY));
 37     ESP_ERROR_CHECK(esp_event_post(TIMER_EVENTS, TIMER_EVENT_EXPIRY, NULL, 0, portMAX_DELAY));
 38 }
 39
 40 // 当计时器启动事件被循环执行时，执行的处理程序
 41 static void timer_started_handler(void* handler_args, esp_event_base_t base, int32_t id, void* event_data)
 42 {
 43     ESP_LOGI(TAG, "%s:%s: timer_started_handler", base, get_id_string(base, id));
 44 }
 45
 46 //当计时器到期时间被循环执行时，执行的处理程序。处理程序跟踪计时器过期次数，当达到设置的过期次数，处理程序停止计时器并发送计时器停止事件
 47 static void timer_expiry_handler(void* handler_args, esp_event_base_t base, int32_t id, void* event_data)
 48 {
 49     static int count = 0;
 50     count++;
 51
 52     if (count >= TIMER_EXPIRIES_COUNT) {
 53         // 停止计时器
 54         ESP_ERROR_CHECK(esp_timer_stop(TIMER));
 55         ESP_LOGI(TAG, "%s:%s: posting to default loop", base, get_id_string(base, TIMER_EVENT_STOPPED));
 56
 57         //发送计时器停止事件
 58         ESP_ERROR_CHECK(esp_event_post(TIMER_EVENTS, TIMER_EVENT_STOPPED, NULL, 0, portMAX_DELAY));
 59     }
 60
 61     ESP_LOGI(TAG, "%s:%s: timer_expiry_handler, executed %d out of %d times", base, get_id_string(base, id), count, TIMER_EXPIRIES_COUNT);
 62 }
 63
 64 //任何计时器事件(启动/到期/停止)被循环执行时，执行的处理程序
 65 static void timer_any_handler(void* handler_args, esp_event_base_t base, int32_t id, void* event_data)
 66 {
 67     ESP_LOGI(TAG, "%s:%s: timer_any_handler", base, get_id_string(base, id));
 68 }
 69
 70 //计时器停止事件被循环执行时，执行的处理程序。由于计时器已经停止，可以安全的删除它。
 71 static void timer_stopped_handler(void* handler_args, esp_event_base_t base, int32_t id, void* event_data)
 72 {
 73     ESP_LOGI(TAG, "%s:%s: timer_stopped_handler", base, get_id_string(base, id));
 74
 75     // 删除计时器
 76     esp_timer_delete(TIMER);
 77
 78     ESP_LOGI(TAG, "%s:%s: deleted timer event source", base, get_id_string(base, id));
 79 }
 80
 81 //事件源任务相关的定义
 82 ESP_EVENT_DEFINE_BASE(TASK_EVENTS);
 83
 84 //任务迭代处理
 85 static void task_iteration_handler(void* handler_args, esp_event_base_t base, int32_t id, void* event_data)
 86 {
 87     int iteration = *((int*) event_data);
 88     ESP_LOGI(TAG, "%s:%s: task_iteration_handler, executed %d times", base, get_id_string(base, id), iteration);
 89 }
 90
 91 //任务时间源
 92 static void task_event_source(void* args)
 93 {
 94     for(int iteration = 1; iteration <= TASK_ITERATIONS_COUNT; iteration++) {
 95
 96         ESP_LOGI(TAG, "%s:%s: posting to default loop, %d out of %d", TASK_EVENTS,
 97                 get_id_string(TASK_EVENTS, TASK_ITERATION_EVENT), iteration, TASK_ITERATIONS_COUNT);
 98
 99         //发布该循环已迭代。注意，迭代计数已传递给处理程序。事件发布期间传递的数据是原始数据的深层副本。
100         ESP_ERROR_CHECK(esp_event_post(TASK_EVENTS, TASK_ITERATION_EVENT, &iteration, sizeof(iteration), portMAX_DELAY));
101
102         if (iteration == TASK_ITERATIONS_UNREGISTER) {
103             ESP_LOGI(TAG, "%s:%s: unregistering task_iteration_handler", TASK_EVENTS, get_id_string(TASK_EVENTS, TASK_ITERATION_EVENT));
104             ESP_ERROR_CHECK(esp_event_handler_unregister(TASK_EVENTS, TASK_ITERATION_EVENT, task_iteration_handler));
105         }
106
107         vTaskDelay(pdMS_TO_TICKS(TASK_PERIOD));
108     }
109
110     vTaskDelay(pdMS_TO_TICKS(TASK_PERIOD));
111
112     ESP_LOGI(TAG, "%s:%s: deleting task event source", TASK_EVENTS, get_id_string(TASK_EVENTS, TASK_ITERATION_EVENT));
113
114     vTaskDelete(NULL);
115 }
116
117 //所有时间的处理程序
118 static void all_event_handler(void* handler_args, esp_event_base_t base, int32_t id, void* event_data)
119 {
120     ESP_LOGI(TAG, "%s:%s: all_event_handler", base, get_id_string(base, id));
121 }
122
123 //入口
124 void app_main(void)
125 {
126     ESP_LOGI(TAG, "setting up");
127
128     //创建默认的事件循环
129     ESP_ERROR_CHECK(esp_event_loop_create_default());
130
131     // 注册特定计时器事件处理程序
132     ESP_ERROR_CHECK(esp_event_handler_register(TIMER_EVENTS, TIMER_EVENT_STARTED, timer_started_handler, NULL));
133     ESP_ERROR_CHECK(esp_event_handler_register(TIMER_EVENTS, TIMER_EVENT_EXPIRY, timer_expiry_handler, NULL));
134     ESP_ERROR_CHECK(esp_event_handler_register(TIMER_EVENTS, TIMER_EVENT_STOPPED, timer_stopped_handler, NULL));
135
136     //注册所有计时器系列事件处理程序。将在计时器启动、到期或者停止时执行
137     ESP_ERROR_CHECK(esp_event_handler_register(TIMER_EVENTS, ESP_EVENT_ANY_ID, timer_any_handler, NULL));
138
139     //注册任务迭代事件的处理程序
140     ESP_ERROR_CHECK(esp_event_handler_register(TASK_EVENTS, TASK_ITERATION_EVENT, task_iteration_handler, NULL));
141
142     //为所有事件注册处理程序。如果计时器事件或者任务迭代事件发布到默认循环则执行此操作。
143     ESP_ERROR_CHECK(esp_event_handler_register(ESP_EVENT_ANY_BASE, ESP_EVENT_ANY_ID, all_event_handler, NULL));
144
145     //创建并启动事件源
146     esp_timer_create_args_t timer_args = {
147         .callback = &timer_callback,
148     };
149     ESP_ERROR_CHECK(esp_timer_create(&timer_args, &TIMER));
150     ESP_LOGI(TAG, "starting event sources");
151
152      // 创建与当前任务具有相同优先级的事件源任务
153     xTaskCreate(task_event_source, "task_event_source", 2048, NULL, uxTaskPriorityGet(NULL), NULL);
154
155     ESP_ERROR_CHECK(esp_timer_start_periodic(TIMER, TIMER_PERIOD));
156
157     //发布计时器启动事件
158     ESP_LOGI(TAG, "%s:%s: posting to default loop", TIMER_EVENTS, get_id_string(TIMER_EVENTS, TIMER_EVENT_STARTED));
159     ESP_ERROR_CHECK(esp_event_post(TIMER_EVENTS, TIMER_EVENT_STARTED, NULL, 0, portMAX_DELAY));
160 }

原文：https://gitee.com/EspressifSystems/esp-idf/tree/master/examples/system/esp_event/default_event_loop