os_flag.c

UCOS-III

                             OS_ERR       *p_err)
{
    OS_PEND_LIST  *p_pend_list;
    OS_TCB        *p_tcb;
    CPU_TS         ts;
    OS_OBJ_QTY     nbr_tasks;
    CPU_SR_ALLOC();



#ifdef OS_SAFETY_CRITICAL
    if (p_err == (OS_ERR *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
        return ((OS_OBJ_QTY)0u);
    }
#endif

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0u) {             /* Not allowed to Pend Abort from an ISR                  */
       *p_err =  OS_ERR_PEND_ABORT_ISR;
        return ((OS_OBJ_QTY)0u);
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_grp == (OS_FLAG_GRP *)0) {                        /* Validate 'p_grp'                                       */
       *p_err =  OS_ERR_OBJ_PTR_NULL;
        return ((OS_OBJ_QTY)0u);
    }
    switch (opt) {                                          /* Validate 'opt'                                         */
        case OS_OPT_PEND_ABORT_1:
        case OS_OPT_PEND_ABORT_ALL:
        case OS_OPT_PEND_ABORT_1   | OS_OPT_POST_NO_SCHED:
        case OS_OPT_PEND_ABORT_ALL | OS_OPT_POST_NO_SCHED:
             break;

        default:
            *p_err =  OS_ERR_OPT_INVALID;
             return ((OS_OBJ_QTY)0u);
    }
#endif

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_grp->Type != OS_OBJ_TYPE_FLAG) {                  /* Make sure event flag group was created                 */
       *p_err =  OS_ERR_OBJ_TYPE;
        return ((OS_OBJ_QTY)0u);
    }
#endif

    CPU_CRITICAL_ENTER();
    p_pend_list = &p_grp->PendList;
    if (p_pend_list->NbrEntries == (OS_OBJ_QTY)0u) {        /* Any task waiting on flag group?                        */
        CPU_CRITICAL_EXIT();                                /* No                                                     */
       *p_err =  OS_ERR_PEND_ABORT_NONE;
        return ((OS_OBJ_QTY)0u);
    }

    OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT();
    nbr_tasks = 0u;
    ts        = OS_TS_GET();                                /* Get local time stamp so all tasks get the same time    */
    while (p_pend_list->NbrEntries > (OS_OBJ_QTY)0u) {
        p_tcb = p_pend_list->HeadPtr->TCBPtr;
        OS_PendAbort((OS_PEND_OBJ *)((void *)p_grp),
                     p_tcb,
                     ts);
        nbr_tasks++;
        if (opt != OS_OPT_PEND_ABORT_ALL) {                 /* Pend abort all tasks waiting?                          */
            break;                                          /* No                                                     */
        }
    }
    OS_CRITICAL_EXIT_NO_SCHED();

    if ((opt & OS_OPT_POST_NO_SCHED) == (OS_OPT)0u) {
        OSSched();                                          /* Run the scheduler                                      */
    }

   *p_err = OS_ERR_NONE;
    return (nbr_tasks);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                       GET FLAGS WHO CAUSED TASK TO BECOME READY
*
* Description: This function is called to obtain the flags that caused the task to become ready to run.
*              In other words, this function allows you to tell "Who done it!".
*
* Arguments  : p_err     is a pointer to an error code
*
*                            OS_ERR_NONE       if the call was successful
*                            OS_ERR_PEND_ISR   if called from an ISR
*
* Returns    : The flags that caused the task to be ready.
************************************************************************************************************************
*/

OS_FLAGS  OSFlagPendGetFlagsRdy (OS_ERR  *p_err)
{
    OS_FLAGS   flags;
    CPU_SR_ALLOC();



#ifdef OS_SAFETY_CRITICAL
    if (p_err == (OS_ERR *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
        return ((OS_FLAGS)0);
    }
#endif

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* See if called from ISR ...                             */
       *p_err = OS_ERR_PEND_ISR;                            /* ... can't get from an ISR                              */
        return ((OS_FLAGS)0);
    }
#endif

    CPU_CRITICAL_ENTER();
    flags  = OSTCBCurPtr->FlagsRdy;
    CPU_CRITICAL_EXIT();
    *p_err = OS_ERR_NONE;
    return (flags);
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                                POST EVENT FLAG BIT(S)
*
* Description: This function is called to set or clear some bits in an event flag group.  The bits to set or clear are
*              specified by a 'bit mask'.
*
* Arguments  : p_grp         is a pointer to the desired event flag group.
*
*              flags         If 'opt' (see below) is OS_OPT_POST_FLAG_SET, each bit that is set in 'flags' will
*                            set the corresponding bit in the event flag group.  e.g. to set bits 0, 4
*                            and 5 you would set 'flags' to:
*
*                                0x31     (note, bit 0 is least significant bit)
*
*                            If 'opt' (see below) is OS_OPT_POST_FLAG_CLR, each bit that is set in 'flags' will
*                            CLEAR the corresponding bit in the event flag group.  e.g. to clear bits 0,
*                            4 and 5 you would specify 'flags' as:
*
*                                0x31     (note, bit 0 is least significant bit)
*
*              opt           indicates whether the flags will be:
*
*                                OS_OPT_POST_FLAG_SET       set
*                                OS_OPT_POST_FLAG_CLR       cleared
*
*                            you can also 'add' OS_OPT_POST_NO_SCHED to prevent the scheduler from being called.
*
*              p_err         is a pointer to an error code and can be:
*
*                                OS_ERR_NONE                The call was successful
*                                OS_ERR_OBJ_PTR_NULL        You passed a NULL pointer
*                                OS_ERR_OBJ_TYPE            You are not pointing to an event flag group
*                                OS_ERR_OPT_INVALID         You specified an invalid option
*
* Returns    : the new value of the event flags bits that are still set.
*
* Note(s)    : 1) The execution time of this function depends on the number of tasks waiting on the event flag group.
************************************************************************************************************************
*/
OS_FLAGS  OSFlagPost (OS_FLAG_GRP  *p_grp,
                      OS_FLAGS      flags,
                      OS_OPT        opt,
                      OS_ERR       *p_err)
{
    OS_FLAGS  flags_cur;
    CPU_TS    ts;



#ifdef OS_SAFETY_CRITICAL
    if (p_err == (OS_ERR *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
        return ((OS_FLAGS)0);
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_grp == (OS_FLAG_GRP *)0) {                        /* Validate 'p_grp'                                       */
       *p_err  = OS_ERR_OBJ_PTR_NULL;
        return ((OS_FLAGS)0);
    }

    switch (opt) {
        case OS_OPT_POST_FLAG_SET:
        case OS_OPT_POST_FLAG_CLR:
        case OS_OPT_POST_FLAG_SET | OS_OPT_POST_NO_SCHED:
        case OS_OPT_POST_FLAG_CLR | OS_OPT_POST_NO_SCHED:
             break;

        default:
             *p_err = OS_ERR_OPT_INVALID;
             return ((OS_FLAGS)0);
    }

#endif

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_grp->Type != OS_OBJ_TYPE_FLAG) {                  /* Make sure we are pointing to an event flag grp         */
        *p_err = OS_ERR_OBJ_TYPE;
        return ((OS_FLAGS)0);
    }
#endif

    ts = OS_TS_GET();                                       /* Get timestamp                                          */
#if OS_CFG_ISR_POST_DEFERRED_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* See if called from an ISR                              */
        OS_IntQPost((OS_OBJ_TYPE)OS_OBJ_TYPE_FLAG,          /* Post to ISR queue                                      */
                    (void      *)p_grp,
                    (void      *)0,
                    (OS_MSG_SIZE)0,
                    (OS_FLAGS   )flags,
                    (OS_OPT     )opt,
                    (CPU_TS     )ts,
                    (OS_ERR    *)p_err);
        return ((OS_FLAGS)0);
    }
#endif

    flags_cur = OS_FlagPost(p_grp,
                            flags,
                            opt,
                            ts,
                            p_err);

    return (flags_cur);
}

/*$PAGE*/
/*
************************************************************************************************************************
*                         SUSPEND TASK UNTIL EVENT FLAG(s) RECEIVED OR TIMEOUT OCCURS
*
* Description: This function is internal to uC/OS-III and is used to put a task to sleep until the desired
*              event flag bit(s) are set.
*
* Arguments  : p_pend_data    is a pointer to an object used to link the task being blocked to the list of task(s)
*              -----------    pending on the desired event flag group.
*
*              p_grp         is a pointer to the desired event flag group.
*              -----
*
*              flags         Is a bit pattern indicating which bit(s) (i.e. flags) you wish to check.
*                            The bits you want are specified by setting the corresponding bits in
*                            'flags'.  e.g. if your application wants to wait for bits 0 and 1 then
*                            'flags' would contain 0x03.
*
*              opt           specifies whether you want ALL bits to be set/cleared or ANY of the bits
*                            to be set/cleared.
*                            You can specify the following argument:
*
*                                OS_OPT_PEND_FLAG_CLR_ALL   You will check ALL bits in 'mask' to be clear (0)
*                                OS_OPT_PEND_FLAG_CLR_ANY   You will check ANY bit  in 'mask' to be clear (0)
*                                OS_OPT_PEND_FLAG_SET_ALL   You will check ALL bits in 'mask' to be set   (1)
*                                OS_OPT_PEND_FLAG_SET_ANY   You will check ANY bit  in 'mask' to be set   (1)
*
*              timeout       is the desired amount of time that the task will wait for the event flag
*                            bit(s) to be set.
*
* Returns    : none
*
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/

void  OS_FlagBlock (OS_PEND_DATA  *p_pend_data,
                    OS_FLAG_GRP   *p_grp,
                    OS_FLAGS       flags,
                    OS_OPT         opt,
                    OS_TICK        timeout)
{
    OSTCBCurPtr->FlagsPend = flags;                         /* Save the flags that we need to wait for                */
    OSTCBCurPtr->FlagsOpt  = opt;                           /* Save the type of wait we are doing                     */
    OSTCBCurPtr->FlagsRdy  = (OS_FLAGS)0;

    OS_Pend(p_pend_data,
            (OS_PEND_OBJ *)((void *)p_grp),
             OS_TASK_PEND_ON_FLAG,
             timeout);
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                      CLEAR THE CONTENTS OF AN EVENT FLAG GROUP
*
* Description: This function is called by OSFlagDel() to clear the contents of an event flag group
*

* Argument(s): p_grp     is a pointer to the event flag group to clear
*              -----
*
* Returns    : none
*
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/

void  OS_FlagClr (OS_FLAG_GRP  *p_grp)
{
    OS_PEND_LIST  *p_pend_list;