uC/OS-II源码分析（二）-白红宇

在真正开始分析源代码前，先来看使用uC/OS-II的三个例子

1）使用信号量

#define TASK_STK_SIZE 512 /* 每个任务堆栈的大小(以字计算)*/

#define N_TASKS 10 /* 任务数*/

OS_STK TaskStk[N_TASKS][TASK_STK_SIZE]; /*任务堆栈*/

OS_STK TaskStartStk[TASK_STK_SIZE]; //开始任务的堆栈

char TaskData[N_TASKS]; /*传给每个任务的数据*/

OS_EVENT *RandomSem; //互斥型信号量

void main (void)

{

PC_DispClrScr(DISP_FGND_WHITE + DISP_BGND_BLACK); /*清空屏幕*/

OSInit(); /* 初始化uC/OS-II*/

PC_DOSSaveReturn(); /* 保存环境以便稍后可以返回DOS环境*/

PC_VectSet(uCOS, OSCtxSw); /*设置uC/OS-II的切换处理函数*/

RandomSem = OSSemCreate(1); /* 建立一个信号量*/

OSTaskCreate(TaskStart, (void *)0, &TaskStartStk[TASK_STK_SIZE - 1], 0);//创建第一个任务，优先级设置为最大值

OSStart(); /* 开始多任务*/

}

void TaskStart (void *pdata)

{

#if OS_CRITICAL_METHOD == 3 /* 为CPU的状态寄存器分配内存*/

OS_CPU_SR cpu_sr;

#endif

char s[100];

INT16S key;

pdata = pdata; /* 这步是为了防止编译错误*/

TaskStartDispInit(); /* 初始化显示屏*/

OS_ENTER_CRITICAL();

PC_VectSet(0x08, OSTickISR); /*替换机器的时钟中断函数为uC/OS-II所需要的中断函数*/

PC_SetTickRate(OS_TICKS_PER_SEC); /* 调整时钟频率*/

OS_EXIT_CRITICAL();

OSStatInit(); /* 初始化统计任务*/

TaskStartCreateTasks(); /*创建其他任务*/

for (;;) {

TaskStartDisp();

if (PC_GetKey(&key) == TRUE) { /* 是否按键*/

if (key == 0x1B) { /* ESCAPE按下了*/

PC_DOSReturn(); /* 返回DOS*/

}

OSCtxSwCtr = 0; /* 切换次数计数器清零*/

OSTimeDlyHMSM(0, 0, 1, 0); /*挂起秒,让给其他任务运行*/

}

static void TaskStartCreateTasks (void)

{

INT8U i;

for (i = 0; i < N_TASKS; i++) { /* 创建N_TASKS个任务*/

TaskData[i] = '0' + i; /* 每个任务显示其数据*/

OSTaskCreate(Task, (void *)&TaskData[i], &TaskStk[i][TASK_STK_SIZE - 1], i + 1);

}

void Task (void *pdata)

{

INT8U x;

INT8U y;

INT8U err;

for (;;) {

OSSemPend(RandomSem, 0, &err); /* 获取信号量*/

x = random(80); /* 计算X坐标*/

y = random(16); /* 计算Y坐标*/

OSSemPost(RandomSem); /* 释放信号量*/

/* Display the task number on the screen */

PC_DispChar(x, y + 5, *(char *)pdata, DISP_FGND_BLACK + DISP_BGND_LIGHT_GRAY);

OSTimeDly(1); /* 挂起秒，让给其他任务运行*/

}

2）使用消息邮箱

#define TASK_STK_SIZE 512

#define TASK_START_ID 0 /* 任务ID*/

#define TASK_CLK_ID 1

#define TASK_1_ID 2

#define TASK_2_ID 3

#define TASK_3_ID 4

#define TASK_4_ID 5

#define TASK_5_ID 6

#define TASK_START_PRIO 10 /* 任务优先级*/

#define TASK_CLK_PRIO 11

#define TASK_1_PRIO 12

#define TASK_2_PRIO 13

#define TASK_3_PRIO 14

#define TASK_4_PRIO 15

#define TASK_5_PRIO 16

OS_STK TaskStartStk[TASK_STK_SIZE];

OS_STK TaskClkStk[TASK_STK_SIZE];

OS_STK Task1Stk[TASK_STK_SIZE];

OS_STK Task2Stk[TASK_STK_SIZE];

OS_STK Task3Stk[TASK_STK_SIZE];

OS_STK Task4Stk[TASK_STK_SIZE];

OS_STK Task5Stk[TASK_STK_SIZE];

OS_EVENT *AckMbox; /* 任务和使用的消息邮箱*/

OS_EVENT *TxMbox;

void main (void)

{

OS_STK *ptos;

OS_STK *pbos;

INT32U size;

PC_DispClrScr(DISP_FGND_WHITE);

OSInit();

PC_DOSSaveReturn();

PC_VectSet(uCOS, OSCtxSw);

PC_ElapsedInit();

ptos = &TaskStartStk[TASK_STK_SIZE - 1];

pbos = &TaskStartStk[0];

size = TASK_STK_SIZE;

OSTaskStkInit_FPE_x86(&ptos, &pbos, &size);

OSTaskCreateExt(TaskStart,

(void *)0,

ptos,

TASK_START_PRIO,

TASK_START_ID,

pbos,

size,

(void *)0,

OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR);

OSStart();

}

void TaskStart (void *pdata)

{

#if OS_CRITICAL_METHOD == 3

OS_CPU_SR cpu_sr;

#endif

INT16S key;

pdata = pdata;

TaskStartDispInit();

OS_ENTER_CRITICAL();

PC_VectSet(0x08, OSTickISR);

PC_SetTickRate(OS_TICKS_PER_SEC);

OS_EXIT_CRITICAL();

OSStatInit();

AckMbox = OSMboxCreate((void *)0); /* 创建两个消息邮箱*/

TxMbox = OSMboxCreate((void *)0);

TaskStartCreateTasks();

for (;;) {

TaskStartDisp();

if (PC_GetKey(&key)) {

if (key == 0x1B) {

PC_DOSReturn();

}

OSCtxSwCtr = 0;

OSTimeDly(OS_TICKS_PER_SEC);

}

void Task1 (void *pdata)

{

INT8U err;

OS_STK_DATA data; /* 任务堆栈数据*/

INT16U time;

INT8U i;

char s[80];

pdata = pdata;

for (;;) {

for (i = 0; i < 7; i++) {

PC_ElapsedStart();

err = OSTaskStkChk(TASK_START_PRIO + i, &data);//执行堆栈检查

time = PC_ElapsedStop();

if (err == OS_NO_ERR) {

sprintf(s, "%4ld %4ld %4ld %6d",

data.OSFree + data.OSUsed,

data.OSFree,

data.OSUsed,

time);

PC_DispStr(19, 12 + i, s, DISP_FGND_BLACK + DISP_BGND_LIGHT_GRAY);

}

OSTimeDlyHMSM(0, 0, 0, 100); /* 挂起mS*/

}

void Task4 (void *data)

{

char txmsg;

INT8U err;

data = data;

txmsg = 'A';

for (;;) {

OSMboxPost(TxMbox, (void *)&txmsg); /* 发消息给Task #5*/

OSMboxPend(AckMbox, 0, &err); /* 等待Task #5的应答消息*/

txmsg++; /*下一个要发的消息数据*/

if (txmsg == 'Z') {

txmsg = 'A'; /* 循环发送A-Z*/

}

void Task5 (void *data)

{

char *rxmsg;

INT8U err;

data = data;

for (;;) {

rxmsg = (char *)OSMboxPend(TxMbox, 0, &err); /* 等待来自Task #4的数据*/

PC_DispChar(70, 18, *rxmsg, DISP_FGND_YELLOW + DISP_BGND_BLUE);

OSTimeDlyHMSM(0, 0, 1, 0); /* 挂起秒，让给其他任务运行*/

OSMboxPost(AckMbox, (void *)1); /*发送接收到数据的应答消息*/

}

运行结果：

3）使用消息队列

#define TASK_STK_SIZE 512

#define TASK_START_ID 0

#define TASK_CLK_ID 1

#define TASK_1_ID 2

#define TASK_2_ID 3

#define TASK_3_ID 4

#define TASK_4_ID 5

#define TASK_5_ID 6

#define TASK_START_PRIO 10

#define TASK_CLK_PRIO 11

#define TASK_1_PRIO 12

#define TASK_2_PRIO 13

#define TASK_3_PRIO 14

#define TASK_4_PRIO 15

#define TASK_5_PRIO 16

#define MSG_QUEUE_SIZE 20 /* 消息队列大小*/

typedef struct {

char TaskName[30];

INT16U TaskCtr;

INT16U TaskExecTime;

INT32U TaskTotExecTime;

} TASK_USER_DATA;

OS_STK TaskStartStk[TASK_STK_SIZE];

OS_STK TaskClkStk[TASK_STK_SIZE];

OS_STK Task1Stk[TASK_STK_SIZE];

OS_STK Task2Stk[TASK_STK_SIZE];

OS_STK Task3Stk[TASK_STK_SIZE];

OS_STK Task4Stk[TASK_STK_SIZE];

OS_STK Task5Stk[TASK_STK_SIZE];

TASK_USER_DATA TaskUserData[7];

OS_EVENT *MsgQueue; /*消息队列指针*/

void *MsgQueueTbl[20]; /*消息存储*/

void main (void)

{

PC_DispClrScr(DISP_BGND_BLACK);

OSInit();

PC_DOSSaveReturn();

PC_VectSet(uCOS, OSCtxSw);

PC_ElapsedInit();

strcpy(TaskUserData[TASK_START_ID].TaskName, "StartTask");

OSTaskCreateExt(TaskStart,

(void *)0,

&TaskStartStk[TASK_STK_SIZE - 1],

TASK_START_PRIO,

TASK_START_ID,

&TaskStartStk[0],

TASK_STK_SIZE,

&TaskUserData[TASK_START_ID],

0);

OSStart();

}

void TaskStart (void *pdata)

{

#if OS_CRITICAL_METHOD == 3

OS_CPU_SR cpu_sr;

#endif

INT16S key;

pdata = pdata;

TaskStartDispInit();

OS_ENTER_CRITICAL();

PC_VectSet(0x08, OSTickISR);

PC_SetTickRate(OS_TICKS_PER_SEC);

OS_EXIT_CRITICAL();

OSStatInit();

MsgQueue = OSQCreate(&MsgQueueTbl[0], MSG_QUEUE_SIZE); /*创建消息队列，大小为*/

TaskStartCreateTasks();

for (;;) {

TaskStartDisp();

if (PC_GetKey(&key)) {

if (key == 0x1B) {

PC_DOSReturn();

}

OSCtxSwCtr = 0;

OSTimeDly(OS_TICKS_PER_SEC);

}

void Task1 (void *pdata)

{

char *msg;

INT8U err;

pdata = pdata;

for (;;) {

msg = (char *)OSQPend(MsgQueue, 0, &err);//从消息队列中取消息

PC_DispStr(70, 13, msg, DISP_FGND_YELLOW + DISP_BGND_BLUE);

OSTimeDlyHMSM(0, 0, 0, 100);

}

void Task2 (void *pdata)

{

char msg[20];

pdata = pdata;

strcpy(&msg[0], "Task 2");

for (;;) {

OSQPost(MsgQueue, (void *)&msg[0]);//发送消息到队列中

OSTimeDlyHMSM(0, 0, 0, 500);

}

void Task3 (void *pdata)

{

char msg[20];

pdata = pdata;

strcpy(&msg[0], "Task 3");

for (;;) {

OSQPost(MsgQueue, (void *)&msg[0]);//发送消息到队列中

OSTimeDlyHMSM(0, 0, 0, 500);

}

void Task4 (void *pdata)

{

char msg[20];

pdata = pdata;

strcpy(&msg[0], "Task 4");

for (;;) {

OSQPost(MsgQueue, (void *)&msg[0]);//发送消息到队列中

OSTimeDlyHMSM(0, 0, 0, 500);

}

void OSTaskStatHook (void)

{

char s[80];

INT8U i;

INT32U total;

INT8U pct;

total = 0L; /* Totalize TOT. EXEC. TIME for each task

for (i = 0; i < 7; i++) {

total += TaskUserData[i].TaskTotExecTime;

DispTaskStat(i); /* Display task data

}

if (total > 0) {

for (i = 0; i < 7; i++) { /* Derive percentage of each task */

pct = 100 * TaskUserData[i].TaskTotExecTime / total;

sprintf(s, "%3d %%", pct);

PC_DispStr(62, i + 11, s, DISP_FGND_BLACK + DISP_BGND_LIGHT_GRAY);

}

if (total > 1000000000L) { /* Reset total time counters at 1 billion

for (i = 0; i < 7; i++) {

TaskUserData[i].TaskTotExecTime = 0L;

}

void OSTaskSwHook (void)

{

INT16U time;

TASK_USER_DATA *puser;

time = PC_ElapsedStop(); /* This task is done

PC_ElapsedStart(); /* Start for next task

puser = OSTCBCur->OSTCBExtPtr; /* Point to used data

if (puser != (TASK_USER_DATA *)0) {

puser->TaskCtr++; /* Increment task counter

puser->TaskExecTime = time; /* Update the task's execution time

puser->TaskTotExecTime += time; /* Update the task's total execution time

}

运行结果：

作者：

出处：　　　　

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