ESP32 Forum

Posted: **Wed Dec 28, 2022 1:20 am**

task1 : webServerTask,
task2 : guiTask (use mutex)
I assigned task1 to cpu0 and task2 to cpu1 using the xTaskCreatePinnedToCore function in esp32. Then I expected task1 and task2 to run concurrently on each other’s cpu regardless of their respective priorities, isn’t that right?
If I increase the priority of task1 over task2, task2 will not run. If I set the priorities to be the same, both tasks will run. Even if I assign tasks to different CPUs, does the execution of the tasks differ according to their priority? Or is it related to the use of semaphore in task2?

Code: Select all

case 1: webServerTask run, guiTask does not work (priority: task1 > task2, task2 with mutex)
  xTaskCreatePinnedToCore(webServerTask, "webServer",  4096,       NULL,  2, NULL, 0); 
  xTaskCreatePinnedToCore(guiTask,             "gui",            4096 * 2,   NULL,  1, NULL, 1);   

case 2: both webServerTask and guiTask run (priority: task1 = task2, task2 with mutex)
  xTaskCreatePinnedToCore(webServerTask, "webServer",  4096,       NULL,  1, NULL, 0);  
  xTaskCreatePinnedToCore(guiTask,             "gui",            4096 * 2,   NULL,  1, NULL, 1);  

case 3: both webServerTask and guiTask run (priority: task1 > task2, task2 without mutex)
  xTaskCreatePinnedToCore(webServerTask, "webServer",  4096,       NULL,  2, NULL, 0);  
  xTaskCreatePinnedToCore(guiTask,             "gui",            4096 * 2,   NULL,  1, NULL, 1);

Task1 and Task2 are implemented as below:

Code: Select all

static void webServerTask(void *pvParameters)
{
  // initialize wifi and the web server
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED)
  {
    vTaskDelay(500 / portTICK_PERIOD_MS);
    Serial.print(".");
  }

  // Run the web server loop indefinitely
  while(1)
  {
    WiFiClient client = server.available();
    if (client)
    {
      ...
     }
    vTaskDelay(10 / portTICK_PERIOD_MS);
  } 
}


static void guiTask(void *pvParameter)
{
  xGuiSemaphore = xSemaphoreCreateMutex(); 
  ...  // display

  while (1)
  {
    vTaskDelay(pdMS_TO_TICKS(10));

    if (pdTRUE == xSemaphoreTake(xGuiSemaphore, portMAX_DELAY))
    {
      lv_task_handler();
      xSemaphoreGive(xGuiSemaphore);
    }
  }
}

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Esp32 dual core multi task and priorities