os_task.c

uC/OS2.88最新版,micrium-ucos-ii-v288

*********************************************************************************************************
*                                        GET THE NAME OF A TASK
*
* Description: This function is called to obtain the name of a task.
*
* Arguments  : prio      is the priority of the task that you want to obtain the name from.
*
*              pname     is a pointer to an ASCII string that will receive the name of the task.  
*
*              perr      is a pointer to an error code that can contain one of the following values:
*
*                        OS_ERR_NONE                if the requested task is resumed
*                        OS_ERR_TASK_NOT_EXIST      if the task has not been created or is assigned to a Mutex
*                        OS_ERR_PRIO_INVALID        if you specified an invalid priority:
*                                                   A higher value than the idle task or not OS_PRIO_SELF.
*                        OS_ERR_PNAME_NULL          You passed a NULL pointer for 'pname'
*                        OS_ERR_NAME_GET_ISR        You called this function from an ISR
*                        
*
* Returns    : The length of the string or 0 if the task does not exist.
*********************************************************************************************************
*/

#if OS_TASK_NAME_EN > 0
INT8U  OSTaskNameGet (INT8U   prio, 
                      INT8U  *pname, 
                      INT8U  *perr)
{
    OS_TCB    *ptcb;
    INT8U      len;
#if OS_CRITICAL_METHOD == 3                              /* Allocate storage for CPU status register   */
    OS_CPU_SR  cpu_sr = 0;
#endif



#if OS_ARG_CHK_EN > 0
    if (perr == (INT8U *)0) {                            /* Validate 'perr'                            */
        return (0);
    }
    if (prio > OS_LOWEST_PRIO) {                         /* Task priority valid ?                      */
        if (prio != OS_PRIO_SELF) {
            *perr = OS_ERR_PRIO_INVALID;                 /* No                                         */
            return (0);
        }
    }
    if (pname == (INT8U *)0) {                           /* Is 'pname' a NULL pointer?                 */
        *perr = OS_ERR_PNAME_NULL;                       /* Yes                                        */
        return (0);
    }
#endif
    if (OSIntNesting > 0) {                              /* See if trying to call from an ISR          */
        *perr = OS_ERR_NAME_GET_ISR;
        return (0);
    }
    OS_ENTER_CRITICAL();
    if (prio == OS_PRIO_SELF) {                          /* See if caller desires it's own name        */
        prio = OSTCBCur->OSTCBPrio;
    }
    ptcb = OSTCBPrioTbl[prio];
    if (ptcb == (OS_TCB *)0) {                           /* Does task exist?                           */
        OS_EXIT_CRITICAL();                              /* No                                         */
        *perr = OS_ERR_TASK_NOT_EXIST;
        return (0);
    }
    if (ptcb == OS_TCB_RESERVED) {                       /* Task assigned to a Mutex?                  */
        OS_EXIT_CRITICAL();                              /* Yes                                        */
        *perr = OS_ERR_TASK_NOT_EXIST;
        return (0);
    }
    pname = ptcb->OSTCBTaskName;
    len   = OS_StrLen(pname); 
    OS_EXIT_CRITICAL();
    *perr = OS_ERR_NONE;
    return (len);
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                        ASSIGN A NAME TO A TASK
*
* Description: This function is used to set the name of a task.
*
* Arguments  : prio      is the priority of the task that you want the assign a name to.
*
*              pname     is a pointer to an ASCII string that contains the name of the task.
*
*              perr       is a pointer to an error code that can contain one of the following values:
*
*                        OS_ERR_NONE                if the requested task is resumed
*                        OS_ERR_TASK_NOT_EXIST      if the task has not been created or is assigned to a Mutex
*                        OS_ERR_PNAME_NULL          You passed a NULL pointer for 'pname'
*                        OS_ERR_PRIO_INVALID        if you specified an invalid priority:
*                                                   A higher value than the idle task or not OS_PRIO_SELF.
*                        OS_ERR_NAME_SET_ISR        if you called this function from an ISR
*
* Returns    : None
*********************************************************************************************************
*/
#if OS_TASK_NAME_EN > 0
void  OSTaskNameSet (INT8U   prio, 
                     INT8U  *pname, 
                     INT8U  *perr)
{
    OS_TCB    *ptcb;
#if OS_CRITICAL_METHOD == 3                          /* Allocate storage for CPU status register       */
    OS_CPU_SR  cpu_sr = 0;
#endif



#if OS_ARG_CHK_EN > 0
    if (perr == (INT8U *)0) {                        /* Validate 'perr'                                */
        return;
    }
    if (prio > OS_LOWEST_PRIO) {                     /* Task priority valid ?                          */
        if (prio != OS_PRIO_SELF) {
            *perr = OS_ERR_PRIO_INVALID;             /* No                                             */
            return;
        }
    }
    if (pname == (INT8U *)0) {                       /* Is 'pname' a NULL pointer?                     */
        *perr = OS_ERR_PNAME_NULL;                   /* Yes                                            */
        return;
    }
#endif
    if (OSIntNesting > 0) {                          /* See if trying to call from an ISR              */
        *perr = OS_ERR_NAME_SET_ISR;
        return;
    }
    OS_ENTER_CRITICAL();
    if (prio == OS_PRIO_SELF) {                      /* See if caller desires to set it's own name     */
        prio = OSTCBCur->OSTCBPrio;
    }
    ptcb = OSTCBPrioTbl[prio];
    if (ptcb == (OS_TCB *)0) {                       /* Does task exist?                               */
        OS_EXIT_CRITICAL();                          /* No                                             */
        *perr = OS_ERR_TASK_NOT_EXIST;
        return;
    }
    if (ptcb == OS_TCB_RESERVED) {                   /* Task assigned to a Mutex?                      */
        OS_EXIT_CRITICAL();                          /* Yes                                            */
        *perr = OS_ERR_TASK_NOT_EXIST;
        return;
    }
    ptcb->OSTCBTaskName = pname;
    OS_EXIT_CRITICAL();
    *perr               = OS_ERR_NONE;
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                        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_ERR_NONE                if the requested task is resumed
*              OS_ERR_PRIO_INVALID        if the priority you specify is higher that the maximum allowed
*                                         (i.e. >= OS_LOWEST_PRIO)
*              OS_ERR_TASK_RESUME_PRIO    if the task to resume does not exist
*              OS_ERR_TASK_NOT_EXIST      if the task is assigned to a Mutex PIP
*              OS_ERR_TASK_NOT_SUSPENDED  if the task to resume has not been suspended
*********************************************************************************************************
*/

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



#if OS_ARG_CHK_EN > 0
    if (prio >= OS_LOWEST_PRIO) {                             /* Make sure task priority is valid      */
        return (OS_ERR_PRIO_INVALID);
    }
#endif
    OS_ENTER_CRITICAL();
    ptcb = OSTCBPrioTbl[prio];
    if (ptcb == (OS_TCB *)0) {                                /* Task to suspend must exist            */
        OS_EXIT_CRITICAL();
        return (OS_ERR_TASK_RESUME_PRIO);
    }
    if (ptcb == OS_TCB_RESERVED) {                            /* See if assigned to Mutex              */
        OS_EXIT_CRITICAL();
        return (OS_ERR_TASK_NOT_EXIST);
    }
    if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) != OS_STAT_RDY) { /* Task must be suspended                */
        ptcb->OSTCBStat &= ~(INT8U)OS_STAT_SUSPEND;           /* Remove suspension                     */
        if (ptcb->OSTCBStat == OS_STAT_RDY) {                 /* See if task is now ready              */
            if (ptcb->OSTCBDly == 0) {
                OSRdyGrp               |= ptcb->OSTCBBitY;    /* Yes, Make task ready to run           */
                OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
                OS_EXIT_CRITICAL();
                if (OSRunning == OS_TRUE) {
                    OS_Sched();                               /* Find new highest priority task        */
                }
            } else {
                OS_EXIT_CRITICAL();
            }
        } else {                                              /* Must be pending on event              */
            OS_EXIT_CRITICAL();
        }
        return (OS_ERR_NONE);
    }
    OS_EXIT_CRITICAL();
    return (OS_ERR_TASK_NOT_SUSPENDED);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                             STACK CHECKING
*
* Description: This function is called to check the amount of free memory left on the specified task's
*              stack.
*
* Arguments  : prio          is the task priority
*
*              p_stk_data    is a pointer to a data structure of type OS_STK_DATA.
*
* Returns    : OS_ERR_NONE            upon success
*              OS_ERR_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_ERR_TASK_NOT_EXIST  if the desired task has not been created or is assigned to a Mutex PIP
*              OS_ERR_TASK_OPT        if you did NOT specified OS_TASK_OPT_STK_CHK when the task was created
*              OS_ERR_PDATA_NULL      if 'p_stk_data' is a NULL pointer
*********************************************************************************************************
*/
#if (OS_TASK_STAT_STK_CHK_EN > 0) && (OS_TASK_CREATE_EXT_EN > 0)
INT8U  OSTaskStkChk (INT8U         prio, 
                     OS_STK_DATA  *p_stk_data)
{
    OS_TCB    *ptcb;
    OS_STK    *pchk;
    INT32U     nfree;
    INT32U     size;
#if OS_CRITICAL_METHOD == 3                            /* Allocate storage for CPU status register     */
    OS_CPU_SR  cpu_sr = 0;
#endif



#if OS_ARG_CHK_EN > 0
    if (prio > OS_LOWEST_PRIO) {                       /* Make sure task priority is valid             */
        if (prio != OS_PRIO_SELF) {
            return (OS_ERR_PRIO_INVALID);
        }
    }
    if (p_stk_data == (OS_STK_DATA *)0) {              /* Validate 'p_stk_data'                        */
        return (OS_ERR_PDATA_NULL);
    }
#endif
    p_stk_data->OSFree = 0;                            /* Assume failure, set to 0 size                */
    p_stk_data->OSUsed = 0;
    OS_ENTER_CRITICAL();
    if (prio == OS_PRIO_SELF) {                        /* See if check for SELF                        */
        prio = OSTCBCur->OSTCBPrio;
    }
    ptcb = OSTCBPrioTbl[prio];
    if (ptcb == (OS_TCB *)0) {                         /* Make sure task exist                         */
        OS_EXIT_CRITICAL();
        return (OS_ERR_TASK_NOT_EXIST);
    }
    if (ptcb == OS_TCB_RESERVED) {
        OS_EXIT_CRITICAL();
        return (OS_ERR_TASK_NOT_EXIST);
    }
    if ((ptcb->OSTCBOpt & OS_TASK_OPT_STK_CHK) == 0) { /* Make sure stack checking option is set       */
        OS_EXIT_CRITICAL();
        return (OS_ERR_TASK_OPT);
    }
    nfree = 0;
    size  = ptcb->OSTCBStkSize;
    pchk  = ptcb->OSTCBStkBottom;
    OS_EXIT_CRITICAL();
#if OS_STK_GROWTH == 1
    while (*pchk++ == (OS_STK)0) {                    /* Compute the number of zero entries on the stk */
        nfree++;
    }
#else
    while (*pchk-- == (OS_STK)0) {
        nfree++;
    }
#endif
    p_stk_data->OSFree = nfree * sizeof(OS_STK);          /* Compute number of free bytes on the stack */
    p_stk_data->OSUsed = (size - nfree) * sizeof(OS_STK); /* Compute number of bytes used on the stack */
    return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                            SUSPEND A TASK
*
* Description: This function is called to suspend a task.  The task can be the calling task if the