TencentOS-tiny 任务间通信（十 一）- 优先级邮箱队列

一、任务间通信

1. 优先级邮箱队列

概述

优先级邮箱队列相对邮箱队列来说，给邮件附加了一个优先级的概念，较高优先级的邮件会比较低优先级的邮件更快地被其他任务收到（本质上，邮箱队列的底层数据容器是环形队列，优先级邮箱队列的底层数据容器是优先级队列）。

API讲解

编程实例

1、在tos_config.h中，配置优先级邮箱队列组件开关TOS_CFG_PRIORITY_MAIL_QUEUE_EN：

#define TOS_CFG_PRIORITY_MAIL_QUEUE_EN 1u

2、编写main.c示例代码：

/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "usart.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "cmsis_os.h" 
#include "stdio.h"

#include "tos_k.h"
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/*
 这里演示了优先级邮箱队列的使用，从sender任务中的逻辑可以看出来，依次post了三个mail，优先级按时间顺序依次为2、1、0（数值越高优先级越低）。如果是传统的邮箱队列，那个receiver应该是依次收到优先级为2、1、0的邮件；但这是优先级邮箱队列，因而receiver会按优先级顺序收到这三个邮件，也就是依次收到优先级为0、1、2的邮件。
 */
#define STK_SIZE_TASK_RECEIVER      512
#define STK_SIZE_TASK_SENDER        512

#define MAIL_MAX    10
 
/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
k_stack_t stack_task_receiver[STK_SIZE_TASK_RECEIVER];
k_stack_t stack_task_sender[STK_SIZE_TASK_SENDER];

typedef struct mail_st {
    char   *message;
    int     payload;
} mail_t;

uint8_t mail_pool[MAIL_MAX * sizeof(mail_t)];

k_task_t task_receiver;
k_task_t task_sender;

k_prio_mail_q_t prio_mail_q;

extern void entry_task_receiver(void *arg);
extern void entry_task_sender(void *arg);

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
void entry_task_receiver(void *arg)
{
    k_err_t err;
    mail_t mail;
    size_t mail_size;

    while (K_TRUE) {
        err = tos_prio_mail_q_pend(&prio_mail_q, &mail, &mail_size, TOS_TIME_FOREVER);
        if (err == K_ERR_NONE) {
            TOS_ASSERT(mail_size == sizeof(mail_t));
            printf("receiver: msg incoming[%s], payload[%d]\n", mail.message, mail.payload);
        }
    }
}

void entry_task_sender(void *arg)
{
    mail_t mail_0, mail_1, mail_2;

    printf("sender: post a mail with priority 2\n");
    mail_2.message = "priority 2";
    mail_2.payload = 2;
    tos_prio_mail_q_post(&prio_mail_q, &mail_2, sizeof(mail_t), 2);

    printf("sender: post a mail with priority 1\n");
    mail_1.message = "priority 1";
    mail_1.payload = 1;
    tos_prio_mail_q_post_all(&prio_mail_q, &mail_1, sizeof(mail_t), 1);

    printf("sender: post a mail with priority 0\n");
    mail_0.message = "priority 0";
    mail_0.payload = 0;
    tos_prio_mail_q_post(&prio_mail_q, &mail_0, sizeof(mail_t), 0);
}
/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */
	
	tos_knl_init();
	tos_prio_mail_q_create(&prio_mail_q, mail_pool, MAIL_MAX, sizeof(mail_t));
	(void)tos_task_create(&task_receiver, "receiver", entry_task_receiver, NULL,
													6, stack_task_receiver, STK_SIZE_TASK_RECEIVER, 0);
	(void)tos_task_create(&task_sender, "sender", entry_task_sender, NULL,
													5, stack_task_sender, STK_SIZE_TASK_SENDER, 0);
	tos_knl_start();
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
		
  }
  /* USER CODE END 3 */
}

3、运行效果：

源码链接：Git​​​​​​​