一、任务间通信
1、消息队列
概述
消息队列提供了任务间传递指针数据的机制，所谓的“消息“就是指针。消息本身如何解析使用，由传递消息的两个任务自行规定，消息队列不对消息本身做任何规定和限制，消息队列仅承担指针数据的传递义务。
API讲解
编程实例
1、在tos_config.h中，配置消息队列组件开关TOS_CFG_MESSAGE_QUEUE_EN：
#define TOS_CFG_MESSAGE_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 */
/*
这里演示如何使用消息队列在sender和receiver任务之间传递消息（一个指针，此案例中这个指针信息指向的是一个字符串）
*/
#define STK_SIZE_TASK_RECEIVER 512
#define STK_SIZE_TASK_SENDER 512
#define PRIO_TASK_RECEIVER_HIGHER_PRIO 4
#define PRIO_TASK_RECEIVER_LOWER_PRIO (PRIO_TASK_RECEIVER_HIGHER_PRIO + 1)
#define MESSAGE_MAX 10
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
k_stack_t stack_task_receiver_higher_prio[STK_SIZE_TASK_RECEIVER];
k_stack_t stack_task_receiver_lower_prio[STK_SIZE_TASK_RECEIVER];
k_stack_t stack_task_sender[STK_SIZE_TASK_SENDER];
uint8_t msg_pool[MESSAGE_MAX * sizeof(void *)];
k_task_t task_receiver_higher_prio;
k_task_t task_receiver_lower_prio;
k_task_t task_sender;
k_msg_q_t msg_q;
extern void entry_task_receiver_higher_prio(void *arg);
extern void entry_task_receiver_lower_prio(void *arg);
extern void entry_task_sender(void *arg);
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
void entry_task_receiver_higher_prio(void *arg)
{
k_err_t err;
void *msg_received;
while (K_TRUE) {
err = tos_msg_q_pend(&msg_q, &msg_received, TOS_TIME_FOREVER);
if (err == K_ERR_NONE) {
printf("higher: msg incoming[%s]\n", (char *)msg_received);
}
}
}
void entry_task_receiver_lower_prio(void *arg)
{
k_err_t err;
void *msg_received;
while (K_TRUE) {
err = tos_msg_q_pend(&msg_q, &msg_received, TOS_TIME_FOREVER);
if (err == K_ERR_NONE) {
printf("lower: msg incoming[%s]\n", (char *)msg_received);
}
}
}
void entry_task_sender(void *arg)
{
int i = 1;
char *msg_to_one_receiver = "message for one receiver(with highest priority)";
char *msg_to_all_receiver = "message for all receivers";
while (K_TRUE) {
if (i == 2) {
printf("sender: send a message to one receiver, and shoud be the highest priority one\n");
tos_msg_q_post(&msg_q, msg_to_one_receiver);
}
if (i == 3) {
printf("sender: send a message to all recevier\n");
tos_msg_q_post_all(&msg_q, msg_to_all_receiver);
}
if (i == 4) {
printf("sender: send a message to one receiver, and shoud be the highest priority one\n");
tos_msg_q_post(&msg_q, msg_to_one_receiver);
}
if (i == 5) {
printf("sender: send a message to all recevier\n");
tos_msg_q_post_all(&msg_q, msg_to_all_receiver);
}
tos_task_delay(1000);
++i;
}
}
/* 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_msg_q_create(&msg_q, msg_pool, MESSAGE_MAX);
(void)tos_task_create(&task_receiver_higher_prio, "receiver_higher_prio",
entry_task_receiver_higher_prio, NULL, PRIO_TASK_RECEIVER_HIGHER_PRIO,
stack_task_receiver_higher_prio, STK_SIZE_TASK_RECEIVER, 0);
(void)tos_task_create(&task_receiver_lower_prio, "receiver_lower_prio",
entry_task_receiver_lower_prio, NULL, PRIO_TASK_RECEIVER_LOWER_PRIO,
stack_task_receiver_lower_prio, STK_SIZE_TASK_RECEIVER, 0);
(void)tos_task_create(&task_sender, "sender", entry_task_sender, NULL,
4, 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
