os_flag.c

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                 OS_EXIT_CRITICAL();
                 *err                 = OS_ERR_TASK_WAITING;
                 return (pgrp);
             }

        case OS_DEL_ALWAYS:                                /* Always delete the event flag group       */
             pnode = pgrp->OSFlagWaitList;
             while (pnode != (OS_FLAG_NODE *)0) {          /* Ready ALL tasks waiting for flags        */
                 OS_FlagTaskRdy(pnode, (OS_FLAGS)0);
                 pnode = pnode->OSFlagNodeNext;
             }
             pgrp->OSFlagType     = OS_EVENT_TYPE_UNUSED;
             pgrp->OSFlagWaitList = (void *)OSFlagFreeList;/* Return group to free list                */
             OSFlagFreeList       = pgrp;
             OS_EXIT_CRITICAL();
             if (tasks_waiting == TRUE) {                  /* Reschedule only if task(s) were waiting  */
                 OS_Sched();                               /* Find highest priority task ready to run  */
             }
             *err = OS_NO_ERR;
             return ((OS_FLAG_GRP *)0);                    /* Event Flag Group has been deleted        */

        default:
             OS_EXIT_CRITICAL();
             *err = OS_ERR_INVALID_OPT;
             return (pgrp);
    }
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                        WAIT ON AN EVENT FLAG GROUP
*
* Description: This function is called to wait for a combination of bits to be set in an event flag 
*              group.  Your application can wait for ANY bit to be set or ALL bits to be set.
*
* Arguments  : pgrp          is a pointer to the desired event flag group.
*
*              flags         Is a bit pattern indicating which bit(s) (i.e. flags) you wish to wait for.  
*                            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.
*
*              wait_type     specifies whether you want ALL bits to be set or ANY of the bits to be set.
*                            You can specify the following argument:
*
*                            OS_FLAG_WAIT_CLR_ALL   You will wait for ALL bits in 'mask' to be clear (0)
*                            OS_FLAG_WAIT_SET_ALL   You will wait for ALL bits in 'mask' to be set   (1)
*                            OS_FLAG_WAIT_CLR_ANY   You will wait for ANY bit  in 'mask' to be clear (0)
*                            OS_FLAG_WAIT_SET_ANY   You will wait for ANY bit  in 'mask' to be set   (1)
*
*                            NOTE: Add OS_FLAG_CONSUME if you want the event flag to be 'consumed' by
*                                  the call.  Example, to wait for any flag in a group AND then clear
*                                  the flags that are present, set 'wait_type' to:
*
*                                  OS_FLAG_WAIT_SET_ANY + OS_FLAG_CONSUME
*
*              timeout       is an optional timeout (in clock ticks) that your task will wait for the
*                            desired bit combination.  If you specify 0, however, your task will wait
*                            forever at the specified event flag group or, until a message arrives.
*
*              err           is a pointer to an error code and can be:
*                            OS_NO_ERR              The desired bits have been set within the specified
*                                                   'timeout'.
*                            OS_ERR_PEND_ISR        If you tried to PEND from an ISR
*                            OS_FLAG_INVALID_PGRP   If 'pgrp' is a NULL pointer.
*                            OS_ERR_EVENT_TYPE      You are not pointing to an event flag group
*                            OS_TIMEOUT             The bit(s) have not been set in the specified 
*                                                   'timeout'.
*                            OS_FLAG_ERR_WAIT_TYPE  You didn't specify a proper 'wait_type' argument.
*
* Returns    : The new state of the flags in the event flag group when the task is resumed or,
*              0 if a timeout or an error occurred.
*
* Called from: Task ONLY
*********************************************************************************************************
*/

OS_FLAGS  OSFlagPend (OS_FLAG_GRP *pgrp, OS_FLAGS flags, INT8U wait_type, INT16U timeout, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register */
    OS_CPU_SR     cpu_sr;
#endif    
    OS_FLAG_NODE  node;
    OS_FLAGS      flags_cur;
    OS_FLAGS      flags_rdy;
    BOOLEAN       consume;


    if (OSIntNesting > 0) {                                /* See if called from ISR ...               */
        *err = OS_ERR_PEND_ISR;                            /* ... can't PEND from an ISR               */
        return ((OS_FLAGS)0);
    }
#if OS_ARG_CHK_EN > 0
    if (pgrp == (OS_FLAG_GRP *)0) {                        /* Validate 'pgrp'                          */
        *err = OS_FLAG_INVALID_PGRP;
        return ((OS_FLAGS)0);
    }
    if (pgrp->OSFlagType != OS_EVENT_TYPE_FLAG) {          /* Validate event block type                */
        *err = OS_ERR_EVENT_TYPE;
        return ((OS_FLAGS)0);
    }
#endif
    if (wait_type & OS_FLAG_CONSUME) {                     /* See if we need to consume the flags      */
        wait_type &= ~OS_FLAG_CONSUME;
        consume    = TRUE;
    } else {
        consume    = FALSE;
    }
/*$PAGE*/
    OS_ENTER_CRITICAL();
    switch (wait_type) {
        case OS_FLAG_WAIT_SET_ALL:                         /* See if all required flags are set        */
             flags_rdy = pgrp->OSFlagFlags & flags;        /* Extract only the bits we want            */
             if (flags_rdy == flags) {                     /* Must match ALL the bits that we want     */
                 if (consume == TRUE) {                    /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags &= ~flags_rdy;      /* Clear ONLY the flags that we wanted      */
                 }
                 flags_cur = pgrp->OSFlagFlags;            /* Will return the state of the group       */
                 OS_EXIT_CRITICAL();                       /* Yes, condition met, return to caller     */
                 *err      = OS_NO_ERR;
                 return (flags_cur);
             } else {                                      /* Block task until events occur or timeout */
                 OS_FlagBlock(pgrp, &node, flags, wait_type, timeout); 
                 OS_EXIT_CRITICAL();
             }
             break;

        case OS_FLAG_WAIT_SET_ANY:
             flags_rdy = pgrp->OSFlagFlags & flags;        /* Extract only the bits we want            */
             if (flags_rdy != (OS_FLAGS)0) {               /* See if any flag set                      */
                 if (consume == TRUE) {                    /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags &= ~flags_rdy;      /* Clear ONLY the flags that we got         */
                 }
                 flags_cur = pgrp->OSFlagFlags;            /* Will return the state of the group       */
                 OS_EXIT_CRITICAL();                       /* Yes, condition met, return to caller     */
                 *err      = OS_NO_ERR;
                 return (flags_cur);
             } else {                                      /* Block task until events occur or timeout */
                 OS_FlagBlock(pgrp, &node, flags, wait_type, timeout); 
                 OS_EXIT_CRITICAL();
             }
             break;

#if OS_FLAG_WAIT_CLR_EN > 0
        case OS_FLAG_WAIT_CLR_ALL:                         /* See if all required flags are cleared    */
             flags_rdy = ~pgrp->OSFlagFlags & flags;       /* Extract only the bits we want            */
             if (flags_rdy == flags) {                     /* Must match ALL the bits that we want     */
                 if (consume == TRUE) {                    /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags |= flags_rdy;       /* Set ONLY the flags that we wanted        */
                 }
                 flags_cur = pgrp->OSFlagFlags;            /* Will return the state of the group       */
                 OS_EXIT_CRITICAL();                       /* Yes, condition met, return to caller     */
                 *err      = OS_NO_ERR;
                 return (flags_cur);
             } else {                                      /* Block task until events occur or timeout */
                 OS_FlagBlock(pgrp, &node, flags, wait_type, timeout); 
                 OS_EXIT_CRITICAL();
             }
             break;

        case OS_FLAG_WAIT_CLR_ANY:
             flags_rdy = ~pgrp->OSFlagFlags & flags;       /* Extract only the bits we want            */
             if (flags_rdy != (OS_FLAGS)0) {               /* See if any flag cleared                  */
                 if (consume == TRUE) {                    /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags |= flags_rdy;       /* Set ONLY the flags that we got           */
                 }
                 flags_cur = pgrp->OSFlagFlags;            /* Will return the state of the group       */
                 OS_EXIT_CRITICAL();                       /* Yes, condition met, return to caller     */
                 *err      = OS_NO_ERR;
                 return (flags_cur);
             } else {                                      /* Block task until events occur or timeout */
                 OS_FlagBlock(pgrp, &node, flags, wait_type, timeout); 
                 OS_EXIT_CRITICAL();
             }
             break;
#endif

        default:
             OS_EXIT_CRITICAL();
             flags_cur = (OS_FLAGS)0;
             *err      = OS_FLAG_ERR_WAIT_TYPE;
             return (flags_cur);
    }
    OS_Sched();                                            /* Find next HPT ready to run               */
    OS_ENTER_CRITICAL();
    if (OSTCBCur->OSTCBStat & OS_STAT_FLAG) {              /* Have we timed-out?                       */
        OS_FlagUnlink(&node);
        OSTCBCur->OSTCBStat = OS_STAT_RDY;                 /* Yes, make task ready-to-run              */
        OS_EXIT_CRITICAL();
        flags_cur           = (OS_FLAGS)0;
        *err                = OS_TIMEOUT;                  /* Indicate that we timed-out waiting       */
    } else {
        if (consume == TRUE) {                             /* See if we need to consume the flags      */
            switch (wait_type) {
                case OS_FLAG_WAIT_SET_ALL:
                case OS_FLAG_WAIT_SET_ANY:                 /* Clear ONLY the flags we got              */
                     pgrp->OSFlagFlags &= ~OSTCBCur->OSTCBFlagsRdy;
                     break;
                     
#if OS_FLAG_WAIT_CLR_EN > 0
                case OS_FLAG_WAIT_CLR_ALL:
                case OS_FLAG_WAIT_CLR_ANY:                 /* Set   ONLY the flags we got              */
                     pgrp->OSFlagFlags |= OSTCBCur->OSTCBFlagsRdy;
                     break;
#endif
            }
        }
        flags_cur = pgrp->OSFlagFlags;
        OS_EXIT_CRITICAL();
        *err      = OS_NO_ERR;                             /* Event(s) must have occurred              */
    }
    return (flags_cur);
}
/*$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  : pgrp          is a pointer to the desired event flag group.
*
*              flags         If 'opt' (see below) is OS_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_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:
*                                set     (OS_FLAG_SET) or 
*                                cleared (OS_FLAG_CLR)
*
*              err           is a pointer to an error code and can be:
*                            OS_NO_ERR              The call was successfull
*                            OS_FLAG_INVALID_PGRP   You passed a NULL pointer
*                            OS_ERR_EVENT_TYPE      You are not pointing to an event flag group
*                            OS_FLAG_INVALID_OPT    You specified an invalid option
*
* Returns    : the new value of the event flags bits that are still set.
*
* Called From: Task or ISR
*
* WARNING(s) : 1) The execution time of this function depends on the number of tasks waiting on the event 
*                 flag group.
*              2) The amount of time interrupts are DISABLED depends on the number of tasks waiting on
*                 the event flag group.        
*********************************************************************************************************
*/
OS_FLAGS  OSFlagPost (OS_FLAG_GRP *pgrp, OS_FLAGS flags, INT8U opt, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3                          /* Allocate storage for CPU status register       */
    OS_CPU_SR     cpu_sr;
#endif    
    OS_FLAG_NODE *pnode;
    BOOLEAN       sched;
    OS_FLAGS      flags_cur;
    OS_FLAGS      flags_rdy;


#if OS_ARG_CHK_EN > 0
    if (pgrp == (OS_FLAG_GRP *)0) {                  /* Validate 'pgrp'                                */
        *err = OS_FLAG_INVALID_PGRP;
        return ((OS_FLAGS)0);
    }
    if (pgrp->OSFlagType != OS_EVENT_TYPE_FLAG) {    /* Make sure we are pointing to an event flag grp */
        *err = OS_ERR_EVENT_TYPE;
        return ((OS_FLAGS)0);
    }
#endif
/*$PAGE*/
    OS_ENTER_CRITICAL();
    switch (opt) {
        case OS_FLAG_CLR:
             pgrp->OSFlagFlags &= ~flags;            /* Clear the flags specified in the group         */
             break;
             
        case OS_FLAG_SET:
             pgrp->OSFlagFlags |=  flags;            /* Set   the flags specified in the group         */
             break;
          
        default:
             OS_EXIT_CRITICAL();                     /* INVALID option                                 */
             *err = OS_FLAG_INVALID_OPT;
             return ((OS_FLAGS)0);
    }
    sched = FALSE;                                   /* Indicate that we don't need rescheduling       */
    pnode = pgrp->OSFlagWaitList;                
    while (pnode != (OS_FLAG_NODE *)0) {             /* Go through all tasks waiting on event flag(s)  */
        switch (pnode->OSFlagNodeWaitType) {
            case OS_FLAG_WAIT_SET_ALL:               /* See if all req. flags are set for current node */
                 flags_rdy = pgrp->OSFlagFlags & pnode->OSFlagNodeFlags;