/*
*********************************************************************************************************
*                                                uC/OS-II
*                                          The Real-Time Kernel
*                                         EVENT FLAG  MANAGEMENT
*
*                              (c) Copyright 1992-2009, Micrium, Weston, FL
*                                           All Rights Reserved
*
* File    : OS_FLAG.C
* By      : Jean J. Labrosse
* Version : V2.91
*
* LICENSING TERMS:
* ---------------
*   uC/OS-II is provided in source form for FREE evaluation, for educational use or for peaceful research.
* If you plan on using  uC/OS-II  in a commercial product you need to contact Micri祄 to properly license
* its use in your product. We provide ALL the source code for your convenience and to help you experience
* uC/OS-II.   The fact that the  source is provided does  NOT  mean that you can use it without  paying a
* licensing fee.
*********************************************************************************************************
*/

#ifndef  OS_MASTER_FILE
#include <ucos_ii.h>
#endif

#if (OS_FLAG_EN > 0u) && (OS_MAX_FLAGS > 0u)
/*
*********************************************************************************************************
*                                            LOCAL PROTOTYPES
*********************************************************************************************************
*/

static  void     OS_FlagBlock(OS_FLAG_GRP *pgrp, OS_FLAG_NODE *pnode, OS_FLAGS flags, INT8U wait_type, INT32U timeout);
static  BOOLEAN  OS_FlagTaskRdy(OS_FLAG_NODE *pnode, OS_FLAGS flags_rdy);

/*$PAGE*/
/*
*********************************************************************************************************
*                              CHECK THE STATUS OF FLAGS IN AN EVENT FLAG GROUP
*
* Description: This function is called to check the status of a combination of bits to be set or cleared
*              in an event flag group.  Your application can check for ANY bit to be set/cleared or ALL
*              bits to be set/cleared.
*
*              This call does not block if the desired flags are not present.
*
* 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 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.
*
*              wait_type     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_FLAG_WAIT_CLR_ALL   You will check ALL bits in 'flags' to be clear (0)
*                            OS_FLAG_WAIT_CLR_ANY   You will check ANY bit  in 'flags' to be clear (0)
*                            OS_FLAG_WAIT_SET_ALL   You will check ALL bits in 'flags' to be set   (1)
*                            OS_FLAG_WAIT_SET_ANY   You will check ANY bit  in 'flags' 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
*
*              perr          is a pointer to an error code and can be:
*                            OS_ERR_NONE               No error
*                            OS_ERR_EVENT_TYPE         You are not pointing to an event flag group
*                            OS_ERR_FLAG_WAIT_TYPE     You didn't specify a proper 'wait_type' argument.
*                            OS_ERR_FLAG_INVALID_PGRP  You passed a NULL pointer instead of the event flag
*                                                      group handle.
*                            OS_ERR_FLAG_NOT_RDY       The desired flags you are waiting for are not
*                                                      available.
*
* Returns    : The flags in the event flag group that made the task ready or, 0 if a timeout or an error
*              occurred.
*
* Called from: Task or ISR
*
* Note(s)    : 1) IMPORTANT, the behavior of this function has changed from PREVIOUS versions.  The
*                 function NOW returns the flags that were ready INSTEAD of the current state of the
*                 event flags.
*********************************************************************************************************
*/

#if OS_FLAG_ACCEPT_EN > 0u
OS_FLAGS  OSFlagAccept (OS_FLAG_GRP  *pgrp,
                        OS_FLAGS      flags,
                        INT8U         wait_type,
                        INT8U        *perr)
{
    OS_FLAGS      flags_rdy;
    INT8U         result;
    BOOLEAN       consume;
#if OS_CRITICAL_METHOD == 3u                               /* Allocate storage for CPU status register */
    OS_CPU_SR     cpu_sr = 0u;
#endif



#ifdef OS_SAFETY_CRITICAL
    if (perr == (INT8U *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
    }
#endif

#if OS_ARG_CHK_EN > 0u
    if (pgrp == (OS_FLAG_GRP *)0) {                        /* Validate 'pgrp'                          */
        *perr = OS_ERR_FLAG_INVALID_PGRP;
        return ((OS_FLAGS)0);
    }
#endif
    if (pgrp->OSFlagType != OS_EVENT_TYPE_FLAG) {          /* Validate event block type                */
        *perr = OS_ERR_EVENT_TYPE;
        return ((OS_FLAGS)0);
    }
    result = (INT8U)(wait_type & OS_FLAG_CONSUME);
    if (result != (INT8U)0) {                              /* See if we need to consume the flags      */
        wait_type &= ~OS_FLAG_CONSUME;
        consume    = OS_TRUE;
    } else {
        consume    = OS_FALSE;
    }
/*$PAGE*/
    *perr = OS_ERR_NONE;                                   /* Assume NO error until proven otherwise.  */
    OS_ENTER_CRITICAL();
    switch (wait_type) {
        case OS_FLAG_WAIT_SET_ALL:                         /* See if all required flags are set        */
             flags_rdy = (OS_FLAGS)(pgrp->OSFlagFlags & flags);     /* Extract only the bits we want   */
             if (flags_rdy == flags) {                     /* Must match ALL the bits that we want     */
                 if (consume == OS_TRUE) {                 /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags &= (OS_FLAGS)~flags_rdy;     /* Clear ONLY the flags we wanted  */
                 }
             } else {
                 *perr = OS_ERR_FLAG_NOT_RDY;
             }
             OS_EXIT_CRITICAL();
             break;

        case OS_FLAG_WAIT_SET_ANY:
             flags_rdy = (OS_FLAGS)(pgrp->OSFlagFlags & flags);     /* Extract only the bits we want   */
             if (flags_rdy != (OS_FLAGS)0) {               /* See if any flag set                      */
                 if (consume == OS_TRUE) {                 /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags &= (OS_FLAGS)~flags_rdy;     /* Clear ONLY the flags we got     */
                 }
             } else {
                 *perr = OS_ERR_FLAG_NOT_RDY;
             }
             OS_EXIT_CRITICAL();
             break;

#if OS_FLAG_WAIT_CLR_EN > 0u
        case OS_FLAG_WAIT_CLR_ALL:                         /* See if all required flags are cleared    */
             flags_rdy = (OS_FLAGS)~pgrp->OSFlagFlags & flags;    /* Extract only the bits we want     */
             if (flags_rdy == flags) {                     /* Must match ALL the bits that we want     */
                 if (consume == OS_TRUE) {                 /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags |= flags_rdy;       /* Set ONLY the flags that we wanted        */
                 }
             } else {
                 *perr = OS_ERR_FLAG_NOT_RDY;
             }
             OS_EXIT_CRITICAL();
             break;

        case OS_FLAG_WAIT_CLR_ANY:
             flags_rdy = (OS_FLAGS)~pgrp->OSFlagFlags & flags;   /* Extract only the bits we want      */
             if (flags_rdy != (OS_FLAGS)0) {               /* See if any flag cleared                  */
                 if (consume == OS_TRUE) {                 /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags |= flags_rdy;       /* Set ONLY the flags that we got           */
                 }
             } else {
                 *perr = OS_ERR_FLAG_NOT_RDY;
             }
             OS_EXIT_CRITICAL();
             break;
#endif

        default:
             OS_EXIT_CRITICAL();
             flags_rdy = (OS_FLAGS)0;
             *perr     = OS_ERR_FLAG_WAIT_TYPE;
             break;
    }
    return (flags_rdy);
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                           CREATE AN EVENT FLAG
*
* Description: This function is called to create an event flag group.
*
* Arguments  : flags         Contains the initial value to store in the event flag group.
*
*              perr          is a pointer to an error code which will be returned to your application:
*                               OS_ERR_NONE               if the call was successful.
*                               OS_ERR_CREATE_ISR         if you attempted to create an Event Flag from an
*                                                         ISR.
*                               OS_ERR_FLAG_GRP_DEPLETED  if there are no more event flag groups
*
* Returns    : A pointer to an event flag group or a NULL pointer if no more groups are available.
*
* Called from: Task ONLY
*********************************************************************************************************
*/

OS_FLAG_GRP  *OSFlagCreate (OS_FLAGS  flags,
                            INT8U    *perr)
{
    OS_FLAG_GRP *pgrp;
#if OS_CRITICAL_METHOD == 3u                        /* Allocate storage for CPU status register        */
    OS_CPU_SR    cpu_sr = 0u;
#endif



#ifdef OS_SAFETY_CRITICAL
    if (perr == (INT8U *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
    }
#endif

#ifdef OS_SAFETY_CRITICAL_IEC61508
    if (OSSafetyCriticalStartFlag == OS_TRUE) {
        OS_SAFETY_CRITICAL_EXCEPTION();
    }
#endif

    if (OSIntNesting > 0u) {                        /* See if called from ISR ...                      */
        *perr = OS_ERR_CREATE_ISR;                  /* ... can't CREATE from an ISR                    */
        return ((OS_FLAG_GRP *)0);
    }
    OS_ENTER_CRITICAL();
    pgrp = OSFlagFreeList;                          /* Get next free event flag                        */
    if (pgrp != (OS_FLAG_GRP *)0) {                 /* See if we have event flag groups available      */
                                                    /* Adjust free list                                */
        OSFlagFreeList       = (OS_FLAG_GRP *)OSFlagFreeList->OSFlagWaitList;
        pgrp->OSFlagType     = OS_EVENT_TYPE_FLAG;  /* Set to event flag group type                    */
        pgrp->OSFlagFlags    = flags;               /* Set to desired initial value                    */
        pgrp->OSFlagWaitList = (void *)0;           /* Clear list of tasks waiting on flags            */
#if OS_FLAG_NAME_EN > 0u
        pgrp->OSFlagName     = (INT8U *)(void *)"?";
#endif
        OS_EXIT_CRITICAL();
        *perr                = OS_ERR_NONE;
    } else {
        OS_EXIT_CRITICAL();
        *perr                = OS_ERR_FLAG_GRP_DEPLETED;
    }
    return (pgrp);                                  /* Return pointer to event flag group              */
}

/*$PAGE*/
/*
*********************************************************************************************************
*                                     DELETE AN EVENT FLAG GROUP
*
* Description: This function deletes an event flag group and readies all tasks pending on the event flag
*              group.
*
* Arguments  : pgrp          is a pointer to the desired event flag group.
*
*              opt           determines delete options as follows:
*                            opt == OS_DEL_NO_PEND   Deletes the event flag group ONLY if no task pending
*                            opt == OS_DEL_ALWAYS    Deletes the event flag group even if tasks are
*                                                    waiting.  In this case, all the tasks pending will be
*                                                    readied.
*
*              perr          is a pointer to an error code that can contain one of the following values:
*                            OS_ERR_NONE               The call was successful and the event flag group was
*                                                      deleted
*                            OS_ERR_DEL_ISR            If you attempted to delete the event flag group from
*                                                      an ISR
*                            OS_ERR_FLAG_INVALID_PGRP  If 'pgrp' is a NULL pointer.
*                            OS_ERR_EVENT_TYPE         If you didn't pass a pointer to an event flag group
*                            OS_ERR_INVALID_OPT        An invalid option was specified
*                            OS_ERR_TASK_WAITING       One or more tasks were waiting on the event flag
*                                                      group.
*
* Returns    : pgrp          upon error
*              (OS_EVENT *)0 if the event flag group was successfully deleted.
*
* Note(s)    : 1) This function must be used with care.  Tasks that would normally expect the presence of
*                 the event flag group MUST check the return code of OSFlagAccept() and OSFlagPend().
*              2) This call can potentially disable interrupts for a long time.  The interrupt disable
*                 time is directly proportional to the number of tasks waiting on the event flag group.
*********************************************************************************************************
*/

#if OS_FLAG_DEL_EN > 0u
OS_FLAG_GRP  *OSFlagDel (OS_FLAG_GRP  *pgrp,
                         INT8U         opt,
                         INT8U        *perr)
{
    BOOLEAN       tasks_waiting;
    OS_FLAG_NODE *pnode;
    OS_FLAG_GRP  *pgrp_return;