FreeRTOS学习笔记-Stream Buffer概述关键函数课程示例

60 阅读 0 评论 40 点赞

我是靠谱客的博主朴素小兔子，最近开发中收集的这篇文章主要介绍FreeRTOS学习笔记-Stream Buffer概述关键函数课程示例，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

FreeRTOS学习笔记-Stream Buffer

概述
关键函数
课程示例
- StreamBuffer 创建、发送与接收
- StreamBuffer查询接收
- 添加监控任务，确定StreamBuffer大小

概述

关键函数

#include "freertos/stream_buffer.h"

//创建stream_buffer
StreamBufferHandle_t xStreamBufferCreate( 
			size_t xBufferSizeBytes,//buffer 大小
			size_t xTriggerLevelBytes );//触发大小
			
//查看stream_buffer有效数据量
size_t xStreamBufferBytesAvailable( StreamBufferHandle_t xStreamBuffer );

//发送stream_buffer
size_t xStreamBufferSend( 
			StreamBufferHandle_t xStreamBuffer,//buffer 句柄
			const void *pvTxData, //发送数据指针
			size_t xDataLengthBytes,//从pvTxData拷贝到stream_buffer的数据量
			TickType_t xTicksToWait );//若stream_buffer空间不够则需要等待的时间
//返回值： 写入stream_buffer的字节数，即便buffer空间不足，在函数退出前会尽可能写满buffer

//从stream_buffer中接收数据
size_t xStreamBufferReceive( 
			StreamBufferHandle_t xStreamBuffer,//buffer 句柄
			void *pvRxData,//接收数据指针
			size_t xBufferLengthBytes,//接收的字节数
			TickType_t xTicksToWait );//若stream_buffer为空则需要等待的时间

//获取buffer可用空间
size_t xStreamBufferSpacesAvailable( StreamBufferHandle_t xStreamBuffer );

课程示例

StreamBuffer 创建、发送与接收

#include <stdio.h>
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_spi_flash.h"


#include "string.h"
#include "freertos/stream_buffer.h"


StreamBufferHandle_t sbuffer1;

void mytask1(void *pvParameter)
{
    size_t send_size;
    size_t send_len;
    char send_str[50];
    printf("task1 start n");
    int i = 0;
    while (1)
    {
        i++;
        send_len = sprintf(send_str, "Hello World %d n", i);
        send_size = xStreamBufferSend(
            sbuffer1,         // buffer 句柄
            (void *)send_str, //发送数据指针
            send_len,         //从pvTxData拷贝到stream_buffer的数据量
            portMAX_DELAY);   //若stream_buffer空间不够则需要等待的时间
        printf("task1 send len=%d , size = %d n", send_len, send_size);
        vTaskDelay(pdMS_TO_TICKS(5000));
    }
}

void mytask2(void *pvParameter)
{
    size_t rx_size;
    char rx_str[50];
    printf("task2 start n");
    while (1)
    {
        memset(rx_str, 0, sizeof(rx_str)); //三个参数分别为：数据指针、初始化值、初始化大小
        rx_size = xStreamBufferReceive(
            sbuffer1,       // buffer 句柄
            (void *)rx_str, //接收数据指针
            sizeof(rx_str), //接收的字节数
            portMAX_DELAY); //若stream_buffer为空则需要等待的时间
        printf("task2 rx size = %d , rx str = %sn", rx_size,rx_str);
    }
}

void app_main(void)
{
    sbuffer1 = xStreamBufferCreate(1000, 10);
    if (sbuffer1 != NULL)
    {
        xTaskCreate(mytask1, "mytask1", 1024 * 5, NULL, 1, NULL);
        xTaskCreate(mytask2, "mytask2", 1024 * 5, NULL, 1, NULL);
    }
}

效果

task1 start
task2 start 
task2 rx size = 15 , rx str = Hello World 1

task1 send len=15 , size = 15
task1 send len=15 , size = 15 
task2 rx size = 15 , rx str = Hello World 2 

task1 send len=15 , size = 15 
task2 rx size = 15 , rx str = Hello World 3 

task1 send len=15 , size = 15 
task2 rx size = 15 , rx str = Hello World 4

打印接收数据有2个换行是因为发送时也加入了n
修改触发门限为40，效果如下：

task1 start
task2 start
task1 send len=15 , size = 15
task1 send len=15 , size = 15 
task1 send len=15 , size = 15 
task2 rx size = 45 , rx str = Hello World 1 
Hello World 2
Hello World 3

收满40个数据时才会触发接收。

StreamBuffer查询接收

#include <stdio.h>
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_spi_flash.h"

#include "string.h"
#include "freertos/stream_buffer.h"

StreamBufferHandle_t sbuffer1;

void mytask1(void *pvParameter)
{
    size_t send_size;
    size_t send_len;
    char send_str[50];
    printf("task1 start n");
    int i = 0;
    while (1)
    {
        i++;
        send_len = sprintf(send_str, "Hello World %d n", i);
        send_size = xStreamBufferSend(
            sbuffer1,         // buffer 句柄
            (void *)send_str, //发送数据指针
            send_len,         //从pvTxData拷贝到stream_buffer的数据量
            portMAX_DELAY);   //若stream_buffer空间不够则需要等待的时间
        printf("task1 send len=%d , size = %d n", send_len, send_size);
        vTaskDelay(pdMS_TO_TICKS(5000));
    }
}

void mytask2(void *pvParameter)
{
    size_t rx_size;
    char rx_str[50];
    printf("task2 start n");
    while (1)
    {
        if (xStreamBufferBytesAvailable(sbuffer1) > 50)
        {
            memset(rx_str, 0, sizeof(rx_str)); //需包含："string.h" 三个参数分别为：数据指针、初始化值、初始化大小
            rx_size = xStreamBufferReceive(
                sbuffer1,       // buffer 句柄
                (void *)rx_str, //接收数据指针
                sizeof(rx_str), //接收的字节数
                0);             //若stream_buffer为空则需要等待的时间
            printf("task2 rx size = %d , rx str = %sn", rx_size, rx_str);
        }
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

void app_main(void)
{
    sbuffer1 = xStreamBufferCreate(1000, 40);
    if (sbuffer1 != NULL)
    {
        xTaskCreate(mytask1, "mytask1", 1024 * 5, NULL, 1, NULL);
        xTaskCreate(mytask2, "mytask2", 1024 * 5, NULL, 1, NULL);
    }
}

效果

task1 start
task2 start
task1 send len=15 , size = 15
task1 send len=15 , size = 15
task1 send len=15 , size = 15
task1 send len=15 , size = 15
task2 rx size = 50 , rx str = Hello World 1
Hello World 2
Hello World 3
Hello�?
task1 send len=15 , size = 15

添加监控任务，确定StreamBuffer大小

#include <stdio.h>
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_spi_flash.h"

#include "string.h"
#include "freertos/stream_buffer.h"

StreamBufferHandle_t sbuffer1;

void mytask1(void *pvParameter)
{
    size_t send_size;
    size_t send_len;
    char send_str[50];
    printf("task1 start n");
    int i = 0;
    while (1)
    {
        i++;
        send_len = sprintf(send_str, "Hello World %d n", i);
        send_size = xStreamBufferSend(
            sbuffer1,         // buffer 句柄
            (void *)send_str, //发送数据指针
            send_len,         //从pvTxData拷贝到stream_buffer的数据量
            portMAX_DELAY);   //若stream_buffer空间不够则需要等待的时间
        printf("task1 send len=%d , size = %d n", send_len, send_size);
        vTaskDelay(pdMS_TO_TICKS(2000));
    }
}

void mytask2(void *pvParameter)
{
    size_t rx_size;
    char rx_str[50];
    printf("task2 start n");
    while (1)
    {
        if (xStreamBufferBytesAvailable(sbuffer1) >= 50)
        {
            memset(rx_str, 0, sizeof(rx_str)); //三个参数分别为：数据指针、初始化值、初始化大小
            rx_size = xStreamBufferReceive(
                sbuffer1,       // buffer 句柄
                (void *)rx_str, //接收数据指针
                sizeof(rx_str), //接收的字节数
                0);             //若stream_buffer为空则需要等待的时间
            printf("task2 rx size = %d , rx str = %sn", rx_size, rx_str);
        }
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

void mytask3(void *pvParameter)
{
    size_t buffer_space;
    size_t min_space = 0;
    printf("task3 start n");
    min_space = xStreamBufferSpacesAvailable(sbuffer1);
    while (1)
    {
        buffer_space = xStreamBufferSpacesAvailable(sbuffer1);
        if (buffer_space < min_space)
        {
            min_space = buffer_space;
        }
        printf("task3 StreamBuffer space = %d, min_space = %d n",buffer_space,min_space);
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

void app_main(void)
{
    sbuffer1 = xStreamBufferCreate(1000, 40);
    if (sbuffer1 != NULL)
    {
        xTaskCreate(mytask1, "mytask1", 1024 * 5, NULL, 1, NULL);
        xTaskCreate(mytask2, "mytask2", 1024 * 5, NULL, 1, NULL);
        xTaskCreate(mytask3, "mytask3", 1024 * 5, NULL, 1, NULL);
    }
}

效果：

task1 start
task2 start
task1 send len=15 , size = 15
task3 start
task3 StreamBuffer space = 985, min_space = 985
task3 StreamBuffer space = 985, min_space = 985
task1 send len=15 , size = 15
task3 StreamBuffer space = 970, min_space = 970
task3 StreamBuffer space = 970, min_space = 970
task1 send len=15 , size = 15
task3 StreamBuffer space = 955, min_space = 955
task3 StreamBuffer space = 955, min_space = 955
task1 send len=15 , size = 15
task2 rx size = 50 , rx str = Hello World 1
Hello World 2
Hello World 3
Hello�?
task3 StreamBuffer space = 990, min_space = 955
task3 StreamBuffer space = 990, min_space = 955
task1 send len=15 , size = 15
task3 StreamBuffer space = 975, min_space = 955
task3 StreamBuffer space = 975, min_space = 955
task1 send len=15 , size = 15
task3 StreamBuffer space = 960, min_space = 955
task3 StreamBuffer space = 960, min_space = 955
task1 send len=15 , size = 15
task2 rx size = 50 , rx str = World 4
Hello World 5
Hello World 6
Hello Worl�?