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