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*/
}
}
2007112201.jpg
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：
2007112202.jpg
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：
本文转自Phinecos(洞庭散人)博客园博客，原文链接：http://www.cnblogs.com/phinecos/archive/2007/11/22/969028.html，如需转载请自行联系原作者