FreeRTOS队列操作

秒速五厘米 2022-06-01 03:15 177阅读 0赞

**API函数**

//创建
    #if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
        #define xQueueCreate( uxQueueLength, uxItemSize ) 
                xQueueGenericCreate( ( uxQueueLength ), ( uxItemSize ), ( queueQUEUE_TYPE_BASE ) )
    #endif
    QueueHandle_t xQueueGenericCreate( const UBaseType_t uxQueueLength, 
                                    const UBaseType_t uxItemSize, const uint8_t ucQueueType )
    
    #define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) 
            xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
    BaseType_t xQueueGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, 
                                TickType_t xTicksToWait, const BaseType_t xCopyPosition )
    
    #define xQueueReceive( xQueue, pvBuffer, xTicksToWait ) 
            xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
    BaseType_t xQueueGenericReceive( QueueHandle_t xQueue, void * const pvBuffer, 
                                    TickType_t xTicksToWait, const BaseType_t xJustPeeking )
    
    //队列剩余大小
    UBaseType_t uxQueueSpacesAvailable( const QueueHandle_t xQueue )
    
    //队列使用大小
    UBaseType_t uxQueueMessagesWaiting( const QueueHandle_t xQueue )

**使用举例**

QueueHandle_t Key_Queue //按键值消息队列句柄
    
    void start_task(void *pvParameters)
    {
        Key_Queue = xQueueCreate(1, sizeof(u8));
        if(Key_Queue == 0)
        {
            printf("xQueueCreate err\r\n");
        }
    }
    
    void key_task(void *pvParameters)
    {
        BaseType_t ret;
    
        while(1)
        {
            key = KEY_Scan(0);              //扫描按键
            if((Key_Queue != 0) && (key))   //消息队列Key_Queue创建成功,并且按键被按下
            {
                ret = xQueueSend(Key_Queue, &key, 10);
                if(ret != pdPASS)           //发送按键值
                {
                    printf("xQueueSend err\r\n");
                }
            }
    
            vTaskDelay(10);
        }
    }
    
    void recv_task(void *pvParameters)
    {
        while(1)
        {
            if(Key_Queue != 0)
            {
                if(xQueueReceive(Key_Queue, &key, portMAX_DELAY))
                {
                    printf("recv_task key %d\r\n", key);
                }
            }
        }
    }

**实验现象**  
点击按键  
![1][]

**中断相关API函数**

#define xQueueSendFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) 
                            xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), 
                            ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
    BaseType_t xQueueGenericSendFromISR( QueueHandle_t xQueue, const void * const pvItemToQueue, 
                        BaseType_t * const pxHigherPriorityTaskWoken, const BaseType_t xCopyPosition )
    
    BaseType_t xQueueReceiveFromISR( QueueHandle_t xQueue, void * const pvBuffer, 
                                    BaseType_t * const pxHigherPriorityTaskWoken )

**使用举例**

void start_task(void *pvParameters)
    {
        Message_Queue = xQueueCreate(1, sizeof(u8));
        if(Message_Queue == 0)
        {
            printf("xQueueCreate err\r\n");
        }
    }
    
    void USART1_IRQHandler(void)
    {
        u8 Res;
        BaseType_t xHigherPriorityTaskWoken;
    
        if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
        {
            Res = USART_ReceiveData(USART1);
    
            xQueueSendFromISR(Message_Queue, &Res, &xHigherPriorityTaskWoken);
    
            portYIELD_FROM_ISR(xHigherPriorityTaskWoken); //如果需要的话进行一次任务切换
        }
    }
    
    void TIM2_IRQHandler(void)
    {
        u8 Res;
        BaseType_t ret;
        BaseType_t xTaskWokenByReceive = pdFALSE;
    
        if(TIM_GetITStatus(TIM2, TIM_IT_Update) == SET)
        {
            TIM_ClearITPendingBit(TIM2, TIM_IT_Update); 
    
            ret = xQueueReceiveFromISR(Message_Queue, &Res, &xTaskWokenByReceive);
            if(ret == pdTRUE)
            {
                printf("xQueueReceiveFromISR Res %c\r\n", Res);
            }
    
            portYIELD_FROM_ISR(xTaskWokenByReceive); //如果需要的话进行一次任务切换
        }
    }

**实验现象**  
![1][1 1]

[1]: /images/20220601/342412c591f04c04bef291ce948b5415.png
[1 1]: /images/20220601/736e148647644049bdbb48490a50b8dc.png