freertos 调度,freertos线程调度方式

介绍两个定时器任务如何通过定时器 handle 共用一个回调函数。

1、头文件声明和函数定义

#include "FreeRTOS.h"#include "task.h"#include "timers.h"#include "supporting_functions.h"#define mainONE_SHOT_TIMER_PERIOD( pdMS_TO_TICKS( 3333UL ) )#define mainAUTO_RELOAD_TIMER_PERIOD( pdMS_TO_TICKS( 500UL ) )// 定时器共用回调函数static void prvTimerCallback( TimerHandle_t xTimer );// 定时器 handle 定义static TimerHandle_t xAutoReloadTimer, xOneShotTimer;

2、启动定时任务

int main( void ){BaseType_t xTimer1Started, xTimer2Started;// 定义 one-shot 定时任务xOneShotTimer = xTimerCreate( "OneShot", mainONE_SHOT_TIMER_PERIOD, pdFALSE, 0, prvTimerCallback );// 定义自动重载定时任务xAutoReloadTimer = xTimerCreate( "AutoReload", mainAUTO_RELOAD_TIMER_PERIOD, pdTRUE, 0, prvTimerCallback );if( ( xOneShotTimer != NULL ) && ( xAutoReloadTimer != NULL ) ){// 启动定时任务xTimer1Started = xTimerStart( xOneShotTimer, 0 );xTimer2Started = xTimerStart( xAutoReloadTimer, 0 );if( ( xTimer1Started == pdPASS ) && ( xTimer2Started == pdPASS ) ){/* Start the scheduler. */vTaskStartScheduler();}}for( ;; );return 0;}

3、软件定时器回调函数

static void prvTimerCallback( TimerHandle_t xTimer ){TickType_t xTimeNow;uint32_t ulExecutionCount;ulExecutionCount = ( uint32_t ) pvTimerGetTimerID( xTimer );ulExecutionCount++;vTimerSetTimerID( xTimer, ( void * ) ulExecutionCount );xTimeNow = xTaskGetTickCount();if( xTimer == xOneShotTimer ){vPrintStringAndNumber( "One-shot timer callback executing", xTimeNow );}else{vPrintStringAndNumber( "Auto-reload timer callback executing", xTimeNow );if( ulExecutionCount == 5 ){xTimerStop( xTimer, 0 );}}}