一、任務間通信
- 計數鎖
概述
計數鎖提供了一種“計數信息”同步的概念，計數鎖創建的時候會指定一個計數值，每當有任務執行tos_countdownlatch_post時，該計數鎖的計數值減一，直到計數鎖的計數值爲零時，等待此計數鎖的任務纔會被喚醒。
API講解
編程實例
1、在tos_config.h中，配置隊列組件開關TOS_CFG_COUNTDOWNLATCH_EN：
#define TOS_CFG_COUNTDOWNLATCH_EN 1u
2、編寫main.c示例代碼：
/* 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 */
/*
假設有這樣的業務場景，共有三個勇士，此三個勇士分頭去尋找三個武器的碎片，只有這三個勇士都找到碎片後，法師才能將三個碎片合成爲武器。用代碼看具體如何使用計數鎖來完成這個模型。
*/
#define STK_SIZE_TASK_WIZARD 512
#define STK_SIZE_TASK_WARRIOR 512
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
k_stack_t stack_task_wizard[STK_SIZE_TASK_WIZARD];
k_stack_t stack_task_warrior_0[STK_SIZE_TASK_WARRIOR];
k_stack_t stack_task_warrior_1[STK_SIZE_TASK_WARRIOR];
k_stack_t stack_task_warrior_2[STK_SIZE_TASK_WARRIOR];
k_task_t task_wizard;
k_task_t task_warrior_0;
k_task_t task_warrior_1;
k_task_t task_warrior_2;
k_countdownlatch_t countdownlatch;
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
void entry_task_warrior_0(void *arg)
{
printf("warrior 0: I have done my job\n");
tos_countdownlatch_post(&countdownlatch);
}
void entry_task_warrior_1(void *arg)
{
printf("warrior 1: I have done my job\n");
tos_countdownlatch_post(&countdownlatch);
}
void entry_task_warrior_2(void *arg)
{
printf("warrior 2: I have done my job\n");
tos_countdownlatch_post(&countdownlatch);
}
void entry_task_wizard(void *arg)
{
printf("wizard: I will set 3 warriors to find the fragments\n");
tos_countdownlatch_create(&countdownlatch, 3);
(void)tos_task_create(&task_warrior_0, "warrior_0", entry_task_warrior_0, NULL,
4, stack_task_warrior_0, STK_SIZE_TASK_WIZARD, 0);
(void)tos_task_create(&task_warrior_1, "warrior_1", entry_task_warrior_1, NULL,
4, stack_task_warrior_1, STK_SIZE_TASK_WIZARD, 0);
(void)tos_task_create(&task_warrior_2, "warrior_2", entry_task_warrior_2, NULL,
4, stack_task_warrior_2, STK_SIZE_TASK_WIZARD, 0);
printf("wizard: now warriors are on their way, I will wait here until they all done the job\n");
tos_countdownlatch_pend(&countdownlatch);
printf("wizard: the warriors all have done their jobs, let's make the weapon\n");
}
/* 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();
(void)tos_task_create(&task_wizard, "wizard", entry_task_wizard, NULL,
3, stack_task_wizard, STK_SIZE_TASK_WIZARD, 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、運行效果：
源碼鏈接：Git