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
