uC/OS-II源码分析（三）

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             
     }
}