任务挂起和恢复

任务挂起和恢复API函数

下面用按键和震动传感器验证任务挂起和恢复API函数：

PA7接震动传感器，按键引脚为PA0，提前初始化好GPIO引脚

key.c

#include "key.h"
#include "stm32f10x.h"void KeyInit()
{GPIO_InitTypeDef  KeyInitSruct;RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA, ENABLE);KeyInitSruct.GPIO_Mode = GPIO_Mode_IPU;KeyInitSruct.GPIO_Pin = GPIO_Pin_7;GPIO_Init(GPIOA,&KeyInitSruct);KeyInitSruct.GPIO_Mode = GPIO_Mode_IPU;KeyInitSruct.GPIO_Pin = GPIO_Pin_0;GPIO_Init(GPIOA,&KeyInitSruct);}

main.c

#include "sys.h"
#include "delay.h"
#include "usart.h"
#include "led.h"
#include "FreeRTOS.h"
#include "task.h"
#include "key.h"//开始任务
#define START_TASK_SIZE 256
#define START_TASK_PRIO 1
StackType_t  StartTaskStack[START_TASK_SIZE];
StaticTask_t StartTask_TCB;
TaskHandle_t StartTask_Handle;
void start_task( void * pvParameters );//任务1
#define TASK1_TASK_SIZE 120
#define TASK1_TASK_PRIO 4
StackType_t  Task1TaskStack[TASK1_TASK_SIZE];
StaticTask_t Task1Task_TCB;
TaskHandle_t Task1Task_Handle;
void task1_task( void * pvParameters );//任务2
#define TASK2_TASK_SIZE 120
#define TASK2_TASK_PRIO 3
StackType_t  Task2TaskStack[TASK2_TASK_SIZE];
StaticTask_t Task2Task_TCB;
TaskHandle_t Task2Task_Handle;
void task2_task( void * pvParameters );//任务3
#define KEY_TASK_SIZE 120
#define KEY_TASK_PRIO 2
StackType_t  KeyaskStack[KEY_TASK_SIZE];
StaticTask_t KeyTask_TCB;
TaskHandle_t KeyTask_Handle;
void key_task( void * pvParameters );//空闲任务
static StaticTask_t IdleTaskTCB;
static StackType_t  IdleTaskStack[configMINIMAL_STACK_SIZE];void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,StackType_t ** ppxIdleTaskStackBuffer,uint32_t * pulIdleTaskStackSize ){*ppxIdleTaskTCBBuffer = &IdleTaskTCB;*ppxIdleTaskStackBuffer = IdleTaskStack;*pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;}//定时器任务
static StaticTask_t TimerTaskTCB;
static StackType_t  TimerTaskStack[configTIMER_TASK_STACK_DEPTH];void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,StackType_t ** ppxTimerTaskStackBuffer,uint32_t * pulTimerTaskStackSize ){* ppxTimerTaskTCBBuffer = &TimerTaskTCB;* ppxTimerTaskStackBuffer = TimerTaskStack;*pulTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;}int main(void)
{NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);//设置系统中断优先级分组4	 delay_init();	    				//延时函数初始化	  uart_init(115200);					//串口初始化LED_Init();		  					//LED初始化KeyInit();               //引脚初始化StartTask_Handle =  xTaskCreateStatic( (TaskFunction_t) start_task,(char * )        "start_task", (uint32_t)       START_TASK_SIZE,(void *)         NULL,(UBaseType_t)    START_TASK_PRIO,(StackType_t *)  StartTaskStack,(StaticTask_t *) &StartTask_TCB );vTaskStartScheduler();          //开启任务调度
}
//开始任务
void start_task( void * pvParameters )
{while(1){//任务1Task1Task_Handle =  xTaskCreateStatic( (TaskFunction_t) task1_task,(char * )        "task1_task", (uint32_t)       TASK1_TASK_SIZE,(void *)         NULL,(UBaseType_t)    TASK1_TASK_PRIO,(StackType_t *)  Task1TaskStack,(StaticTask_t *) &Task1Task_TCB );//任务2													Task2Task_Handle =  xTaskCreateStatic( (TaskFunction_t) task2_task,(char * )        "task2_task", (uint32_t)       TASK2_TASK_SIZE,(void *)         NULL,(UBaseType_t)    TASK2_TASK_PRIO,(StackType_t *)  Task2TaskStack,(StaticTask_t *) &Task2Task_TCB );//任务3											KeyTask_Handle =  xTaskCreateStatic( (TaskFunction_t) key_task,(char * )        "key_task", (uint32_t)       KEY_TASK_SIZE,(void *)         NULL,(UBaseType_t)    KEY_TASK_PRIO,(StackType_t *)  KeyaskStack,(StaticTask_t *) &KeyTask_TCB );														vTaskDelete(StartTask_Handle);}}
//任务1
void task1_task( void * pvParameters )
{char Task1_num = 0;
while(1)
{Task1_num++;LED2 = !LED2;vTaskDelay(1000);printf("Task1 is Runing %d \r\n",Task1_num);}}
//任务2
void task2_task( void * pvParameters )
{ char Task2_num = 0;
while(1)
{Task2_num++;LED3 = !LED3;vTaskDelay(1000);printf("Task2 is Runing %d \r\n",Task2_num);}}//任务3
void key_task( void * pvParameters )
{ while(1)
{if( GPIO_ReadInputDataBit(GPIOA,  GPIO_Pin_7) == 0){ vTaskDelay(100);vTaskSuspend(Task1Task_Handle);//当震动传感器工作将任务1挂起printf("Task1 is Suspend!   \r\n");}if( GPIO_ReadInputDataBit(GPIOA,GPIO_Pin_0) == 0){ vTaskDelay(100);vTaskResume(Task1Task_Handle);//当按键按下将任务1解挂printf("Task1 is Resume!   \r\n");}}}

下面用串口验证：

下面我们在中断服务函数中恢复任务1：

xTaskResumeFromISR();该函数的参数依旧是任务句柄，但是该函数有两个返回值

返回值:
pdTRUE:    恢复运行的任务的任务优先级等于或者高于正在运行的任务(被中断打    
断的任务)，这意味着在退出中断服务函数以后必须进行一次上下文切换。
pdFALSE:    恢复运行的任务的任务优先级低于当前正在运行的任务(被中断打断的    
任务)，这意味着在退出中断服务函数的以后不需要进行上下文切换。

修改main.c:当震动传感器工作将任务1挂起

//任务3
void key_task( void * pvParameters )
{ while(1)
{if( GPIO_ReadInputDataBit(GPIOA,  GPIO_Pin_7) == 0){ vTaskDelay(100);vTaskSuspend(Task1Task_Handle);printf("Task1 is Suspend!   \r\n");}}}

exti.c:

#include "exti.h"
#include "stm32f10x.h"
#include "FreeRTOS.h"
#include "task.h"
#include "delay.h"void EXTIInit(void)
{EXTI_InitTypeDef Exti_Initstruct;NVIC_InitTypeDef NVIC_Initstruct;RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);Exti_Initstruct.EXTI_Line = EXTI_Line0;Exti_Initstruct.EXTI_LineCmd = ENABLE;Exti_Initstruct.EXTI_Mode = EXTI_Mode_Interrupt;Exti_Initstruct.EXTI_Trigger = EXTI_Trigger_Rising;EXTI_Init(&Exti_Initstruct);NVIC_Initstruct.NVIC_IRQChannel = EXTI0_IRQn;NVIC_Initstruct.NVIC_IRQChannelCmd = ENABLE;NVIC_Initstruct.NVIC_IRQChannelPreemptionPriority = 6;//定义抢占优先级为6，小于5的中断不受FreeRtos管控！NVIC_Initstruct.NVIC_IRQChannelSubPriority = 0;NVIC_Init(&NVIC_Initstruct);}extern TaskHandle_t Task1Task_Handle;void EXTI0_IRQHandler()//外部中断函数
{BaseType_t YieldRequired;delay_xms(20);//消抖if ( EXTI_GetITStatus(EXTI_Line0) != RESET)    //检测中断标志位{YieldRequired = xTaskResumeFromISR(Task1Task_Handle);//恢复任务1printf("恢复任务1的运行! \r\n");if(YieldRequired == pdTRUE)//如果函数返回值是pdTRUE，进行一次上下文切换{portYIELD_FROM_ISR(YieldRequired);//上下文切换函数}}			EXTI_ClearITPendingBit(EXTI_Line0);//清除中断}

下面用串口验证结果：