/* 如何给任务分配内存
1) 创建任务句柄
TaskHandle_t taskHandle;
int taskMem = 1024;	//以k字节为单位

2) 定义任务
void task(void *ptParam) {
  while (1) {
  }
}

3) 在setup()里创建任务
void setup() {
  int heapSize = ESP.getHeapSize();	//获取总的heap size，单位为byte
  Serial.print(heapSize);

  int heapFree = ESP.getFreeHeap();	//获取free heap size，单位为byte
  Serial.print(heapFree);

  int usedHeapSize = heapSize - ESP.getFreeHeap();	//二者相减得到被占用的heapSize


  为每个任务分配内存后，可查看该任务得到的内存够不够用。
  假设分配内存为x字节，任务占用y字节，水位线watermark=x-y (即未被利用的内存空间)
  为保证任务正常运行，给任务分配的内存应该为watermark x 2
  int waterMark = uxTaskGetStackHighWaterMark(taskHandle);	//获取水位线

  Serial.print("Task Free Memory: ");
  Serial.print(waterMark);
  Serial.println(" Bytes");

  Serial.print("Task Used Memory: ");
  Serial.print(taskMem - waterMark);
  Serial.println(" Bytes");

}
******************** the end *****************************
*/


/*
  程序： 内存管理
  公众号：孤独的二进制
  API：
    ESP.getHeapSize() //本程序Heap最大尺寸
    ESP.getFreeHeap() //当前Free Heap最大尺寸
    uxTaskGetStackHighWaterMark(taskHandle) //Task内存使用最大水位线，内存是水
     
    What is the Highest Water Mark?
    the minimum amount of remaining stack space that was available to the task 
    since the task started executing - that is the amount of stack that remained 
    unused when the task stack was at its greatest (deepest) value. This is what 
    is referred to as the stack 'high water mark'.
*/
TaskHandle_t taskHandle;
int taskMem = 1024;

void task(void *ptParam) {
  //volatile char hello[1000] = {0}; //必须要用volatile修饰语，否则会被编译器优化掉
  while (1) {

    //不推荐在task中执行，因为Serial.print也会消耗内存
    // vTaskDelay(2000);
    // int waterMark = uxTaskGetStackHighWaterMark(nullptr);
    // Serial.print("Task Free Memory: ");
    // Serial.print(waterMark);
    // Serial.println(" Bytes");
    // Serial.print("Task Used Memory: ");
    // Serial.print(taskMem - waterMark);
    // Serial.println(" Bytes");
    // Serial.println("");

  }
}
void setup() {
  Serial.begin(115200);

  int heapSize = ESP.getHeapSize();
  Serial.print("Total Heap Size:  ");
  Serial.print(heapSize);
  Serial.println(" Bytes");

  int heapFree = ESP.getFreeHeap();
  Serial.print("Free Heap Size:  ");
  Serial.print(heapFree);
  Serial.println(" Bytes");
  Serial.println("");


  Serial.println("Create Task ...");
  xTaskCreate(task, "", taskMem, NULL, 1, &taskHandle);

  Serial.print("Free Heap Size:  ");
  Serial.print(ESP.getFreeHeap());
  Serial.println(" Bytes");
  Serial.println("");

  vTaskDelay(2000);
  int waterMark = uxTaskGetStackHighWaterMark(taskHandle);
  Serial.print("Task Free Memory: ");
  Serial.print(waterMark);
  Serial.println(" Bytes");
  Serial.print("Task Used Memory: ");
  Serial.print(taskMem - waterMark);
  Serial.println(" Bytes");

}

void loop() {

}