os_task.c.bak

uCOS 嵌入式操作系统的改进版,增加了网络通讯.

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

#if OS_TASK_SUSPEND_EN > 0
INT8U  OSTaskSuspend (INT8U prio)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif
    BOOLEAN    self;
    OS_TCB    *ptcb;
	INT8U      y;


#if OS_ARG_CHK_EN > 0
    if (prio == OS_IDLE_PRIO) {                                 /* Not allowed to suspend idle task    */
        return (OS_TASK_SUSPEND_IDLE);
    }
    if (prio >= OS_LOWEST_PRIO) {								/* Task priority valid ?               */
        if (prio != OS_PRIO_SELF) {
            return (OS_PRIO_INVALID);
        }
    }
#endif
    OS_ENTER_CRITICAL();
    if (prio == OS_PRIO_SELF) {                                 /* See if suspend SELF                 */
        prio = OSTCBCur->OSTCBPrio;
        self = TRUE;
    } else if (prio == OSTCBCur->OSTCBPrio) {                   /* See if suspending self              */
        self = TRUE;
    } else {
        self = FALSE;                                           /* No suspending another task          */
    }
    ptcb = OSTCBPrioTbl[prio];
    if (ptcb == (OS_TCB *)0) {                                  /* Task to suspend must exist          */
        OS_EXIT_CRITICAL();
        return (OS_TASK_SUSPEND_PRIO);
    }
	y            = ptcb->OSTCBY;
	OSRdyTbl[y] &= ~ptcb->OSTCBBitX;							/* Make task not ready                 */
    if (OSRdyTbl[y] == 0x00) { 
        OSRdyGrp &= ~ptcb->OSTCBBitY;
    }
    ptcb->OSTCBStat |= OS_STAT_SUSPEND;                         /* Status of task is 'SUSPENDED'       */
    OS_EXIT_CRITICAL();
    if (self == TRUE) {                                         /* Context switch only if SELF         */
        OS_Sched();
    }
    return (OS_NO_ERR);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                            QUERY A TASK
*
* Description: This function is called to obtain a copy of the desired task's TCB.
*
* Arguments  : prio     is the priority of the task to obtain information from.
*
* Returns    : OS_NO_ERR       if the requested task is suspended
*              OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed
*                              (i.e. > OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.
*              OS_PRIO_ERR     if the desired task has not been created
*********************************************************************************************************
*/

#if OS_TASK_QUERY_EN > 0
INT8U  OSTaskQuery (INT8U prio, OS_TCB *pdata)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif
    OS_TCB    *ptcb;


#if OS_ARG_CHK_EN > 0
    if (prio > OS_LOWEST_PRIO) {						   /* Task priority valid ?                    */
        if (prio != OS_PRIO_SELF) {   
            return (OS_PRIO_INVALID);
        }
    }
#endif
    OS_ENTER_CRITICAL();
    if (prio == OS_PRIO_SELF) {                            /* See if suspend SELF                      */
        prio = OSTCBCur->OSTCBPrio;
    }
    ptcb = OSTCBPrioTbl[prio];
    if (ptcb == (OS_TCB *)0) {                             /* Task to query must exist                 */
        OS_EXIT_CRITICAL();
        return (OS_PRIO_ERR);
    }
    memcpy(pdata, ptcb, sizeof(OS_TCB));                   /* Copy TCB into user storage area          */
    OS_EXIT_CRITICAL();
    return (OS_NO_ERR);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                        CLEAR TASK STACK
*
* Description: This function is used to clear the stack of a task (i.e. write all zeros)
*
* Arguments  : pbos     is a pointer to the task's bottom of stack.  If the configuration constant
*                       OS_STK_GROWTH is set to 1, the stack is assumed to grow downward (i.e. from high
*                       memory to low memory).  'pbos' will thus point to the lowest (valid) memory
*                       location of the stack.  If OS_STK_GROWTH is set to 0, 'pbos' will point to the
*                       highest memory location of the stack and the stack will grow with increasing
*                       memory locations.  'pbos' MUST point to a valid 'free' data item.
*
*              size     is the number of 'stack elements' to clear.
*
*              opt      contains additional information (or options) about the behavior of the task.  The
*                       LOWER 8-bits are reserved by uC/OS-II while the upper 8 bits can be application
*                       specific.  See OS_TASK_OPT_??? in uCOS-II.H.
*
* Returns    : none
*********************************************************************************************************
*/
#if OS_TASK_CREATE_EXT_EN > 0
void  OS_TaskStkClr (OS_STK *pbos, INT32U size, INT16U opt)
{
    if ((opt & OS_TASK_OPT_STK_CHK) != 0x0000) {       /* See if stack checking has been enabled       */
        if ((opt & OS_TASK_OPT_STK_CLR) != 0x0000) {   /* See if stack needs to be cleared             */
            #if OS_STK_GROWTH == 1                     
            while (size > 0) {                         /* Stack grows from HIGH to LOW memory          */
                size--;
                *pbos++ = (OS_STK)0;                   /* Clear from bottom of stack and up!           */
            }
            #else
            while (size > 0) {                         /* Stack grows from LOW to HIGH memory          */
                size--;
                *pbos-- = (OS_STK)0;                   /* Clear from bottom of stack and down          */
            }
            #endif
        }
    }
}

#endif

/*
*********************************************************************************************************
*                                         PROCESS SYSTEM TICK
*
* Description: This function is used to signal to uC/OS-II the occurrence of a 'system tick' (also known
*              as a 'clock tick').  This function should be called by the ticker ISR but, can also be
*              called by a high priority task.
*
* Arguments  : none
*
* Returns    : none
*********************************************************************************************************
*/

void  OSTimeTick (void)
{
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register     */
    OS_CPU_SR  cpu_sr;
#endif    
    OS_TCB    *ptcb;
    BOOLEAN    step;


#if OS_TIME_TICK_HOOK_EN > 0
    OSTimeTickHook();                                      /* Call user definable hook                     */
#endif    
#if OS_TIME_GET_SET_EN > 0   
    OS_ENTER_CRITICAL();                                   /* Update the 32-bit tick counter               */
    OSTime++;
    OS_EXIT_CRITICAL();
#endif
    if (OSRunning == TRUE) {    
#if OS_TICK_STEP_EN > 0
        switch (OSTickStepState) {                         /* Determine whether we need to process a tick  */
            case OS_TICK_STEP_DIS:                         /* Yes, stepping is disabled                    */
                 step = TRUE;
                 break;
        
            case OS_TICK_STEP_WAIT:                        /* No,  waiting for uC/OS-View to set ...       */
                 step = FALSE;                             /*      .. OSTickStepState to OS_TICK_STEP_ONCE */
                 break;

            case OS_TICK_STEP_ONCE:                        /* Yes, process tick once and wait for next ... */
                 step            = TRUE;                   /*      ... step command from uC/OS-View        */
                 OSTickStepState = OS_TICK_STEP_WAIT;
                 break;  

            default:                                       /* Invalid case, correct situation              */
                 step            = TRUE;
                 OSTickStepState = OS_TICK_STEP_DIS;
                 break;
        }
#else
        step = TRUE;
#endif
        if (step == TRUE) {
            ptcb = OSTCBList;                              /* Point at first TCB in TCB list               */
            while (ptcb->OSTCBPrio != OS_IDLE_PRIO) {      /* Go through all TCBs in TCB list              */
                OS_ENTER_CRITICAL();
                if (ptcb->OSTCBDly != 0) {                 /* Delayed or waiting for event with TO         */
                    if (--ptcb->OSTCBDly == 0) {           /* Decrement nbr of ticks to end of delay       */
                        if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) == OS_STAT_RDY) { /* Is task suspended?    */
                            OSRdyGrp               |= ptcb->OSTCBBitY; /* No,  Make task R-to-R (timed out)*/
                            OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
                        }
                    }
                }
                ptcb = ptcb->OSTCBNext;                    /* Point at next TCB in TCB list                */
                OS_EXIT_CRITICAL();
            }
        }
    }
}

/*
*********************************************************************************************************
*                                        RESUME A SUSPENDED TASK
*
* Description: This function is called to resume a previously suspended task.  This is the only call that
*              will remove an explicit task suspension.
*
* Arguments  : prio     is the priority of the task to resume.
*
* Returns    : OS_NO_ERR                if the requested task is resumed
*              OS_PRIO_INVALID          if the priority you specify is higher that the maximum allowed
*                                       (i.e. >= OS_LOWEST_PRIO)
*              OS_TASK_RESUME_PRIO      if the task to resume does not exist
*              OS_TASK_NOT_SUSPENDED    if the task to resume has not been suspended
*********************************************************************************************************
*/

#if OS_TASK_SUSPEND_EN > 0
INT8U  OSTaskResume (INT8U prio)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif
    OS_TCB    *ptcb;


#if OS_ARG_CHK_EN > 0
    if (prio >= OS_LOWEST_PRIO) {                               /* Make sure task priority is valid    */
        return (OS_PRIO_INVALID);
    }
#endif
    OS_ENTER_CRITICAL();
    ptcb = OSTCBPrioTbl[prio];
    if (ptcb == (OS_TCB *)0) {                                  /* Task to suspend must exist          */
        OS_EXIT_CRITICAL();
        return (OS_TASK_RESUME_PRIO);
    }
    if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) != OS_STAT_RDY) {   /* Task must be suspended              */
        ptcb->OSTCBStat &= ~OS_STAT_SUSPEND;					/* Remove suspension                   */
        if (ptcb->OSTCBDly == 0) {                              /* Must not be delayed                 */
            OSRdyGrp               |= ptcb->OSTCBBitY;          /* Make task ready to run              */
            OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
            OS_EXIT_CRITICAL();
            OS_Sched();
		} else {
		    OS_EXIT_CRITICAL();
		}
        return (OS_NO_ERR);
    }
    OS_EXIT_CRITICAL();
    return (OS_TASK_NOT_SUSPENDED);
}
#endif