[mw_shl_code=c,true]/*

*********************************************************************************************************

*

*

* 火牛开发板uCOSII + STM32V3.4固件函数库+USART1驱动(实例二)

* MAIN 文件

* 创 建 人：LJ128

* 修改时间：2010年12月11日

*

*

*********************************************************************************************************

*/

#include "includes.h"

static OS_STK App_TaskStartStk[APP_TASK_START_STK_SIZE]; // TaskStart 任务堆栈

static void App_TaskStart(void* p_arg); // 声明 TaskStart 函数

static OS_STK App_TaskPrintfStk[APP_TASK_PRINTF_STK_SIZE]; // TaskPrintf 任务堆栈

static void App_TaskPrintf(void* p_arg); // 声明 TaskPrintf 函数

void LED1234_ON_OFF(CPU_INT08U Num); // 声明流水灯函数

OS_EVENT *Mutex_USART1;// 定义互斥型事件

/*

*********************************************************************************************************

main()

*********************************************************************************************************

*/

int main(void)

{

OSInit();

SysClock_Init(); /* 初始化系统外设、 CPU 时钟，仅此而已 */

/* 建立系统的第一个任务 */

OSTaskCreateExt(App_TaskStart, (void *) 0, (OS_STK *) &App_TaskStartStk[APP_TASK_START_STK_SIZE - 1], APP_TASK_START_PRIO,

APP_TASK_START_PRIO, (OS_STK *) &App_TaskStartStk[0], APP_TASK_START_STK_SIZE , (void *) 0, OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR

);

OSStart(); /* 开始任务调度 */

return (0);

}

/*

*********************************************************************************************************

系统的第一个任务，负责开OS时钟，建立其他任务

*********************************************************************************************************

*/

static void App_TaskStart(void* p_arg)

{

INT8U err;

INT8U i;

p_arg = p_arg;

/* 初始化 OS 时钟 */

OS_CPU_SysTickInit();

/* 统计任务 */

#if (OS_TASK_STAT_EN > 0)

OSStatInit();

#endif

Mutex_USART1 = OSMutexCreate(USART1_MUTEX_PRIO, &err); // 建立USART1互斥型信号量

// 建立打印任务

OSTaskCreateExt(App_TaskPrintf, (void *) 0, (OS_STK *) &App_TaskPrintfStk[APP_TASK_PRINTF_STK_SIZE - 1], APP_TASK_PRINTF_PRIO,

APP_TASK_PRINTF_PRIO, (OS_STK *) &App_TaskPrintfStk[0], APP_TASK_PRINTF_STK_SIZE , (void *) 0, OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR

);

/* 初始化外设 */

BSP_Init();

while (1) {

for(i = 0 ; i < 4; i++){

LED1234_ON_OFF(i);

OSTimeDlyHMSM(0,0,1,0);// 延时一秒

OSMutexPend(Mutex_USART1, 0, &err); // 等待信号量

USART1_Printf("******任务一输出********\r\n");

OSMutexPost(Mutex_USART1); // 释放信号量

}

}

}

/*

*********************************************************************************************************

打印线程，将串口1接收到的数据打印出来

*********************************************************************************************************

*/

static void App_TaskPrintf(void* p_arg)

{

INT8U err;

INT8U temp;

p_arg = p_arg;

while (1) {

OSTaskSuspend(OS_PRIO_SELF);// 先将任务挂起，在串口接收中断中恢复任务

OSMutexPend(Mutex_USART1, 0, &err); // 等待信号量

while(USART1_GetByte(&temp)){// 如果串口接收到数据打印出来

USART1_SendByte(temp);

}

OSMutexPost(Mutex_USART1); // 释放信号量

}

}

/*

*********************************************************************************************************

*********************************************************************************************************

* uC/OS-II APP HOOKS

*********************************************************************************************************

*********************************************************************************************************

*/

#if (OS_APP_HOOKS_EN > 0)

/*

*********************************************************************************************************

* TASK CREATION HOOK (APPLICATION)

*

* Description : This function is called when a task is created.

*

* Argument : ptcb is a pointer to the task control block of the task being created.

*

* Note : (1) Interrupts are disabled during this call.

*********************************************************************************************************

*/

void App_TaskCreateHook(OS_TCB* ptcb)

{

}

/*

*********************************************************************************************************

* TASK DELETION HOOK (APPLICATION)

*

* Description : This function is called when a task is deleted.

*

* Argument : ptcb is a pointer to the task control block of the task being deleted.

*

* Note : (1) Interrupts are disabled during this call.

*********************************************************************************************************

*/

void App_TaskDelHook(OS_TCB* ptcb)

{

(void) ptcb;

}

/*

*********************************************************************************************************

* IDLE TASK HOOK (APPLICATION)

*

* Description : This function is called by OSTaskIdleHook(), which is called by the idle task. This hook

* has been added to allow you to do such things as STOP the CPU to conserve power.

*

* Argument : none.

*

* Note : (1) Interrupts are enabled during this call.

*********************************************************************************************************

*/

#if OS_VERSION >= 251

void App_TaskIdleHook(void)

{

}

#endif

/*

*********************************************************************************************************

* STATISTIC TASK HOOK (APPLICATION)

*

* Description : This function is called by OSTaskStatHook(), which is called every second by uC/OS-II's

* statistics task. This allows your application to add functionality to the statistics task.

*

* Argument : none.

*********************************************************************************************************

*/

void App_TaskStatHook(void)

{

}

/*

*********************************************************************************************************

* TASK SWITCH HOOK (APPLICATION)

*

* Description : This function is called when a task switch is performed. This allows you to perform other

* operations during a context switch.

*

* Argument : none.

*

* Note : 1 Interrupts are disabled during this call.

*

* 2 It is assumed that the global pointer 'OSTCBHighRdy' points to the TCB of the task that

* will be 'switched in' (i.e. the highest priority task) and, 'OSTCBCur' points to the

* task being switched out (i.e. the preempted task).

*********************************************************************************************************

*/

#if OS_TASK_SW_HOOK_EN > 0

void App_TaskSwHook(void)

{

}

#endif

/*

*********************************************************************************************************

* OS_TCBInit() HOOK (APPLICATION)

*

* Description : This function is called by OSTCBInitHook(), which is called by OS_TCBInit() after setting

* up most of the TCB.

*

* Argument : ptcb is a pointer to the TCB of the task being created.

*

* Note : (1) Interrupts may or may not be ENABLED during this call.

*********************************************************************************************************

*/

#if OS_VERSION >= 204

void App_TCBInitHook(OS_TCB* ptcb)

{

(void) ptcb;

}

#endif

#endif

/******************************************

*

* LED 流水灯

*

****************************************/

void LED1234_ON_OFF(CPU_INT08U Num)

{

switch (Num) {

case 0:

GPIO_SetBits(GPIOD, GPIO_Pin_8);

GPIO_ResetBits(GPIOD, GPIO_Pin_9);

GPIO_ResetBits(GPIOD, GPIO_Pin_10);

GPIO_ResetBits(GPIOD, GPIO_Pin_11);

break;

case 1:

GPIO_ResetBits(GPIOD, GPIO_Pin_8);

GPIO_SetBits(GPIOD, GPIO_Pin_9);

GPIO_ResetBits(GPIOD, GPIO_Pin_10);

GPIO_ResetBits(GPIOD, GPIO_Pin_11);

break;

case 2:

GPIO_ResetBits(GPIOD, GPIO_Pin_8);

GPIO_ResetBits(GPIOD, GPIO_Pin_9);

GPIO_SetBits(GPIOD, GPIO_Pin_10);

GPIO_ResetBits(GPIOD, GPIO_Pin_11);

break;

case 3:

GPIO_ResetBits(GPIOD, GPIO_Pin_8);

GPIO_ResetBits(GPIOD, GPIO_Pin_9);

GPIO_ResetBits(GPIOD, GPIO_Pin_10);

GPIO_SetBits(GPIOD, GPIO_Pin_11);

break;

default:

break;

}

}

[/mw_shl_code]

[mw_shl_code=c,true]static void App_TaskPrintf(void* p_arg)

[/mw_shl_code]

static  void App_TaskStart(void* p_arg)  我的理解是先执行任务static void App_TaskStart(void* p_arg)，然后碰到延时一秒转而去执行static void App_TaskPrintf(void* p_arg)这个任务，执行到任务挂起时，去执行TaskStart开始任务，此时碰到OSMutexPend(Mutex_USART1, 0, &err);等待信号量，此时两个任务都不执行，等待串口中断来临，当串口中断来了时

void USART1_IRQHandler(void)

{

OS_CPU_SR  cpu_sr;

OS_ENTER_CRITICAL();  //保存全局中断标志,关总中断/* Tell uC/OS-II that we are starting an ISR*/

OSIntNesting++;

OS_EXIT_CRITICAL();  //恢复全局中断标志

if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET){// 如果是串口接收中断

USART1_RXLoop(USART_ReceiveData(USART1)); // 将数据放入环形队列

OSTaskResume(APP_TASK_PRINTF_PRIO);

}

OSIntExit();

}

这是串口中断函数，执行完OSIntExit(); 后，再进行任务调度，可是那两个任务都是在等待信号量啊，难道执行完中断函数后会释放一个信号量吗？