volatile uint32_t inventory = 100;
volatile uint32_t retailCount = 10;
volatile uint32_t onlineCount = 0;

void retailTask(void* pvParam)
{
  while(true)
  {
    uint32_t inv = inventory;
    for(int i=0; i<random(1, 10); i++)
      vTaskDelay(pdMS_TO_TICKS(i));

    if(inventory > 0)
    {
      inventory = inv - 1;
      retailCount++;
    }
    else
    {
      vTaskDelete(NULL);
    }
    vTaskDelay(10);
  }  
}

void onlineTask(void *pvParam) {
  while (true)
  {
    //以下实现了带有随机延迟的 inventory减1；
    //等效为 inventory--； retailCount++；
    uint32_t inv = inventory;
    for (int i; i < random(1, 10); i++)
      vTaskDelay(pdMS_TO_TICKS(i));
    
    if (inventory > 0) 
    {
      inventory = inv - 1;
      onlineCount++;
    }
    else
    {
      vTaskDelete(NULL);
    }
    vTaskDelay(10); //老板要求慢一些，客户升级后，可以再加快速度
  }
}

void showTask(void* pvParam)
{
  while(true)
  {
    printf("Inventory: %d\n", inventory);
    printf("  Retail : %d\n", retailCount);

    if (inventory == 0 ) 
    {
      uint32_t totalSales = retailCount + onlineCount;
      printf("\n-----SALES SUMMARY-----\n");
      printf("  Total Sales:  %d\n\n", totalSales);
      printf("  OverSales:  %d\n", 100 - totalSales);
      vTaskDelete(NULL);
    }

    vTaskDelay(pdMS_TO_TICKS(100));
  }
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  xTaskCreate(retailTask, "retailTask Channel", 1024 * 4, NULL, 1, NULL);
  xTaskCreate(onlineTask, "Online Channel", 1024 * 4, NULL, 1, NULL);
  xTaskCreate(showTask, "Display Inventory", 1024 * 4, NULL, 1, NULL);  
}

void loop() {
  // put your main code here, to run repeatedly:
  
}