//Core
static const int app_cpu = 0;

//Global variable
static unsigned int count = UINT_MAX;

//Mutex
static SemaphoreHandle_t count_mutex;

//Task to decrease count
void vDec(void* param){
  while(1){
    //Lock count_mutex
    xSemaphoreTake(count_mutex, portMAX_DELAY);
    
    //Check if count cannot be decremented any more
    if(count == 0){ break; }

    //Decrement and print the result
    --count;
    Serial.print("Decremented. Current: ");
    Serial.println(count);
    
    //Unlock count_mutex, or tell if error occured
    if(xSemaphoreGive(count_mutex) == pdFALSE){
      Serial.println("ERROR OCCURED!");
    }

    //Delay 1sec
    vTaskDelay(1000 / portTICK_PERIOD_MS);
  }
}

void setup(){
  //Init serial
  Serial.begin(9600);
  vTaskDelay(100 / portTICK_PERIOD_MS);

  //Init mutex
  count_mutex = xSemaphoreCreateMutex();

  //Run first instance of vDec task
  xTaskCreatePinnedToCore(
    vDec,
    "Decrease counter - 1",
    1024,
    NULL,
    1,
    NULL,
    app_cpu
  );

  //Run second instance of vDec task
  xTaskCreatePinnedToCore(
    vDec,
    "Decrease counter - 2",
    1024,
    NULL,
    1,
    NULL,
    app_cpu
  );

  //Delete setup and loop task
  vTaskDelete(NULL);
}

void loop(){
  //Kosong
}