TrainCamp-Jiangyunsong-PLSR/cmsis/uCOS-III/Source/os_tmr.c

/*
************************************************************************************************************************
*                                                      uC/OS-III
*                                                 The Real-Time Kernel
*
*                                  (c) Copyright 2009-2014; Micrium, Inc.; Weston, FL
*                           All rights reserved.  Protected by international copyright laws.
*
*                                                   TIMER MANAGEMENT
*
* File    : OS_TMR.C
* By      : JJL
* Version : V3.04.04
*
* LICENSING TERMS:
* ---------------
*           uC/OS-III is provided in source form for FREE short-term evaluation, for educational use or 
*           for peaceful research.  If you plan or intend to use uC/OS-III in a commercial application/
*           product then, you need to contact Micrium to properly license uC/OS-III for its use in your 
*           application/product.   We provide ALL the source code for your convenience and to help you 
*           experience uC/OS-III.  The fact that the source is provided does NOT mean that you can use 
*           it commercially without paying a licensing fee.
*
*           Knowledge of the source code may NOT be used to develop a similar product.
*
*           Please help us continue to provide the embedded community with the finest software available.
*           Your honesty is greatly appreciated.
*
*           You can find our product's user manual, API reference, release notes and
*           more information at https://doc.micrium.com.
*           You can contact us at www.micrium.com.
************************************************************************************************************************
*/

#define  MICRIUM_SOURCE
#include "os.h"

#ifdef VSC_INCLUDE_SOURCE_FILE_NAMES
const  CPU_CHAR  *os_tmr__c = "$Id: $";
#endif


#if OS_CFG_TMR_EN > 0u
/*
************************************************************************************************************************
*                                                     CONSTANTS
************************************************************************************************************************
*/

#define   OS_OPT_LINK_DLY       (OS_OPT)(0u)
#define   OS_OPT_LINK_PERIODIC  (OS_OPT)(1u)

/*
************************************************************************************************************************
*                                               LOCAL FUNCTION PROTOTYPES
************************************************************************************************************************
*/

static  void  OS_TmrLock   (void);
static  void  OS_TmrUnlock (void);


/*
************************************************************************************************************************
*                                                   CREATE A TIMER
*
* Description: This function is called by your application code to create a timer.
*
* Arguments  : p_tmr           Is a pointer to a timer control block
*
*              p_name          Is a pointer to an ASCII string that is used to name the timer.  Names are useful for
*                              debugging.
*
*              dly             Initial delay.
*                              If the timer is configured for ONE-SHOT mode, this is the timeout used
*                              If the timer is configured for PERIODIC mode, this is the first timeout to wait for
*                              before the timer starts entering periodic mode
*
*              period          The 'period' being repeated for the timer.
*                              If you specified 'OS_OPT_TMR_PERIODIC' as an option, when the timer expires, it will
*                              automatically restart with the same period.
*
*              opt             Specifies either:
*
*                                  OS_OPT_TMR_ONE_SHOT       The timer counts down only once
*                                  OS_OPT_TMR_PERIODIC       The timer counts down and then reloads itself
*
*              p_callback      Is a pointer to a callback function that will be called when the timer expires.  The
*                              callback function must be declared as follows:
*
*                                  void  MyCallback (OS_TMR *p_tmr, void *p_arg);
*
*              p_callback_arg  Is an argument (a pointer) that is passed to the callback function when it is called.
*
*              p_err           Is a pointer to an error code.  '*p_err' will contain one of the following:
*
*                                 OS_ERR_NONE
*                                 OS_ERR_ILLEGAL_CREATE_RUN_TIME if you are trying to create the timer after you called
*                                                                  OSSafetyCriticalStart().
*                                 OS_ERR_OBJ_CREATED             if the timer has already been created
*                                 OS_ERR_OBJ_PTR_NULL            is 'p_tmr' is a NULL pointer
*                                 OS_ERR_OBJ_TYPE                if the object type is invalid
*                                 OS_ERR_OPT_INVALID             you specified an invalid option
*                                 OS_ERR_TMR_INVALID_DLY         you specified an invalid delay
*                                 OS_ERR_TMR_INVALID_PERIOD      you specified an invalid period
*                                 OS_ERR_TMR_ISR                 if the call was made from an ISR
*
* Returns    : none
*
* Note(s)    : 1) This function only creates the timer.  In other words, the timer is not started when created.  To
*                 start the timer, call OSTmrStart().
************************************************************************************************************************
*/

void  OSTmrCreate (OS_TMR               *p_tmr,
                   CPU_CHAR             *p_name,
                   OS_TICK               dly,
                   OS_TICK               period,
                   OS_OPT                opt,
                   OS_TMR_CALLBACK_PTR   p_callback,
                   void                 *p_callback_arg,
                   OS_ERR               *p_err)
{
#ifdef OS_SAFETY_CRITICAL
    if (p_err == (OS_ERR *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
        return;
    }
#endif

#ifdef OS_SAFETY_CRITICAL_IEC61508
    if (OSSafetyCriticalStartFlag == DEF_TRUE) {
       *p_err = OS_ERR_ILLEGAL_CREATE_RUN_TIME;
        return;
    }
#endif

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* See if trying to call from an ISR                      */
       *p_err = OS_ERR_TMR_ISR;
        return;
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_tmr == (OS_TMR *)0) {                             /* Validate 'p_tmr'                                       */
       *p_err = OS_ERR_OBJ_PTR_NULL;
        return;
    }

    switch (opt) {
        case OS_OPT_TMR_PERIODIC:
             if (period == (OS_TICK)0) {
                *p_err = OS_ERR_TMR_INVALID_PERIOD;
                 return;
             }
             break;

        case OS_OPT_TMR_ONE_SHOT:
             if (dly == (OS_TICK)0) {
                *p_err = OS_ERR_TMR_INVALID_DLY;
                 return;
             }
             break;

        default:
            *p_err = OS_ERR_OPT_INVALID;
             return;
    }
#endif

    OS_TmrLock();

    p_tmr->State          = (OS_STATE           )OS_TMR_STATE_STOPPED;     /* Initialize the timer fields             */
#if OS_OBJ_TYPE_REQ > 0u
    p_tmr->Type           = (OS_OBJ_TYPE        )OS_OBJ_TYPE_TMR;
#endif
#if OS_CFG_DBG_EN > 0u
    p_tmr->NamePtr        = (CPU_CHAR          *)p_name;
#else
    (void)&p_name;
#endif
    p_tmr->Dly            = (OS_TICK            )dly;
    p_tmr->Remain         = (OS_TICK            )0;
    p_tmr->Period         = (OS_TICK            )period;
    p_tmr->Opt            = (OS_OPT             )opt;
    p_tmr->CallbackPtr    = (OS_TMR_CALLBACK_PTR)p_callback;
    p_tmr->CallbackPtrArg = (void              *)p_callback_arg;
    p_tmr->NextPtr        = (OS_TMR            *)0;
    p_tmr->PrevPtr        = (OS_TMR            *)0;

#if OS_CFG_DBG_EN > 0u
    OS_TmrDbgListAdd(p_tmr);
#endif
    OSTmrQty++;                                             /* Keep track of the number of timers created             */

    OS_TmrUnlock();
   *p_err = OS_ERR_NONE;
}


/*
************************************************************************************************************************
*                                                   DELETE A TIMER
*
* Description: This function is called by your application code to delete a timer.
*
* Arguments  : p_tmr          Is a pointer to the timer to stop and delete.
*
*              p_err          Is a pointer to an error code.  '*p_err' will contain one of the following:
*
*                                 OS_ERR_NONE
*                                 OS_ERR_OBJ_TYPE             'p_tmr' is not pointing to a timer
*                                 OS_ERR_TMR_INVALID          'p_tmr' is a NULL pointer
*                                 OS_ERR_TMR_ISR              if the function was called from an ISR
*                                 OS_ERR_TMR_INACTIVE         if the timer was not created
*                                 OS_ERR_TMR_INVALID_STATE    the timer is in an invalid state
*
* Returns    : DEF_TRUE   if the timer was deleted
*              DEF_FALSE  if not or upon an error
************************************************************************************************************************
*/

#if OS_CFG_TMR_DEL_EN > 0u
CPU_BOOLEAN  OSTmrDel (OS_TMR  *p_tmr,
                       OS_ERR  *p_err)
{
    CPU_BOOLEAN  success;



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* See if trying to call from an ISR                      */
       *p_err  = OS_ERR_TMR_ISR;
        return (DEF_FALSE);
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_tmr == (OS_TMR *)0) {
       *p_err = OS_ERR_TMR_INVALID;
        return (DEF_FALSE);
    }
#endif

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_tmr->Type != OS_OBJ_TYPE_TMR) {                   /* Make sure timer was created                            */
       *p_err = OS_ERR_OBJ_TYPE;
        return (DEF_FALSE);
    }
#endif

    OS_TmrLock();

#if OS_CFG_DBG_EN > 0u
    OS_TmrDbgListRemove(p_tmr);
#endif

    switch (p_tmr->State) {
        case OS_TMR_STATE_RUNNING:
             OS_TmrUnlink(p_tmr);                           /* Remove from the list                                   */
             OS_TmrClr(p_tmr);
             OS_TmrUnlock();
             OSTmrQty--;                                    /* One less timer                                         */
            *p_err   = OS_ERR_NONE;
             success = DEF_TRUE;
             break;

        case OS_TMR_STATE_STOPPED:                          /* Timer has not started or ...                           */
        case OS_TMR_STATE_COMPLETED:                        /* ... timer has completed the ONE-SHOT time              */
             OS_TmrClr(p_tmr);                              /* Clear timer fields                                     */
             OS_TmrUnlock();
             OSTmrQty--;                                    /* One less timer                                         */
            *p_err   = OS_ERR_NONE;
             success = DEF_TRUE;
             break;
             
        case OS_TMR_STATE_UNUSED:                           /* Already deleted                                        */
             OS_TmrUnlock();
            *p_err   = OS_ERR_TMR_INACTIVE;
             success = DEF_FALSE;
             break;

        default:
             OS_TmrUnlock();
            *p_err   = OS_ERR_TMR_INVALID_STATE;
             success = DEF_FALSE;
             break;
    }
    return (success);
}
#endif


/*
************************************************************************************************************************
*                                    GET HOW MUCH TIME IS LEFT BEFORE A TIMER EXPIRES
*
* Description: This function is called to get the number of ticks before a timer times out.
*
* Arguments  : p_tmr    Is a pointer to the timer to obtain the remaining time from.
*
*              p_err    Is a pointer to an error code.  '*p_err' will contain one of the following:
*
*                           OS_ERR_NONE
*                           OS_ERR_OBJ_TYPE           'p_tmr' is not pointing to a timer
*                           OS_ERR_TMR_INVALID        'p_tmr' is a NULL pointer
*                           OS_ERR_TMR_ISR            if the call was made from an ISR
*                           OS_ERR_TMR_INACTIVE       'p_tmr' points to a timer that is not active
*                           OS_ERR_TMR_INVALID_STATE  the timer is in an invalid state
*
* Returns    : The time remaining for the timer to expire.  The time represents 'timer' increments.  In other words, if
*              OS_TmrTask() is signaled every 1/10 of a second then the returned value represents the number of 1/10 of
*              a second remaining before the timer expires.
************************************************************************************************************************
*/

OS_TICK  OSTmrRemainGet (OS_TMR  *p_tmr,
                         OS_ERR  *p_err)
{
    OS_TICK  remain;
    OS_ERR   err;



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* See if trying to call from an ISR                      */
       *p_err = OS_ERR_TMR_ISR;
        return ((OS_TICK)0);
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_tmr == (OS_TMR *)0) {
       *p_err = OS_ERR_TMR_INVALID;
        return ((OS_TICK)0);
    }
#endif

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_tmr->Type != OS_OBJ_TYPE_TMR) {                   /* Make sure timer was created                            */
       *p_err = OS_ERR_OBJ_TYPE;
        return ((OS_TICK)0);
    }
#endif

    OSSchedLock(&err);
    (void)&err;

    switch (p_tmr->State) {
        case OS_TMR_STATE_RUNNING:
             remain = p_tmr->Remain;
            *p_err  = OS_ERR_NONE;
             break;

        case OS_TMR_STATE_STOPPED:                          /* It's assumed that the timer has not started yet        */
             if (p_tmr->Opt == OS_OPT_TMR_PERIODIC) {
                 if (p_tmr->Dly == 0u) {
                     remain = p_tmr->Period;
                 } else {
                     remain = p_tmr->Dly;
                 }
             } else {
                 remain = p_tmr->Dly;
             }
            *p_err = OS_ERR_NONE;
             break;

        case OS_TMR_STATE_COMPLETED:                        /* Only ONE-SHOT that timed out can be in this state      */
            *p_err  = OS_ERR_NONE;
             remain = (OS_TICK)0;
             break;

        case OS_TMR_STATE_UNUSED:
            *p_err  = OS_ERR_TMR_INACTIVE;
             remain = (OS_TICK)0;
             break;

        default:
            *p_err = OS_ERR_TMR_INVALID_STATE;
             remain = (OS_TICK)0;
             break;
    }

    OSSchedUnlock(&err);
    (void)&err;

    return (remain);
}


/*
************************************************************************************************************************
*                                                   START A TIMER
*
* Description: This function is called by your application code to start a timer.
*
* Arguments  : p_tmr    Is a pointer to an OS_TMR
*
*              p_err    Is a pointer to an error code.  '*p_err' will contain one of the following:
*
*                           OS_ERR_NONE
*                           OS_ERR_OBJ_TYPE            if 'p_tmr' is not pointing to a timer
*                           OS_ERR_TMR_INVALID
*                           OS_ERR_TMR_INACTIVE        if the timer was not created
*                           OS_ERR_TMR_INVALID_STATE   the timer is in an invalid state
*                           OS_ERR_TMR_ISR             if the call was made from an ISR
*
* Returns    : DEF_TRUE      is the timer was started
*              DEF_FALSE     if not or upon an error
*
* Note(s)    : 1) When starting/restarting a timer, regardless if it is in PERIODIC or ONE-SHOT mode, the timer is 
*                 linked to the timer list with the OS_OPT_LINK_DLY option. This option sets the initial expiration 
*                 time for the timer. For timers in PERIODIC mode, subsequent expiration times are handled by 
*                 the OS_TmrTask().
************************************************************************************************************************
*/

CPU_BOOLEAN  OSTmrStart (OS_TMR  *p_tmr,
                         OS_ERR  *p_err)
{
    OS_TMR      *p_next;
    CPU_BOOLEAN  success;
    CPU_SR_ALLOC();



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* See if trying to call from an ISR                      */
       *p_err = OS_ERR_TMR_ISR;
        return (DEF_FALSE);
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_tmr == (OS_TMR *)0) {
       *p_err = OS_ERR_TMR_INVALID;
        return (DEF_FALSE);
    }
#endif

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_tmr->Type != OS_OBJ_TYPE_TMR) {                   /* Make sure timer was created                            */
       *p_err = OS_ERR_OBJ_TYPE;
        return (DEF_FALSE);
    }
#endif

    switch (p_tmr->State) {
        case OS_TMR_STATE_RUNNING:                          /* Restart the timer                                      */
             CPU_CRITICAL_ENTER();
             p_tmr->Remain = p_tmr->Dly;
             CPU_CRITICAL_EXIT();
            *p_err         = OS_ERR_NONE;
             success       = DEF_TRUE;
             break;

        case OS_TMR_STATE_STOPPED:                          /* Start the timer                                        */
        case OS_TMR_STATE_COMPLETED:
             OS_TmrLock();
             p_tmr->State  = OS_TMR_STATE_RUNNING;
			 if (p_tmr->Dly == (OS_TICK)0) {
                 p_tmr->Remain = p_tmr->Period;
			 } else {
                 p_tmr->Remain = p_tmr->Dly;
             }
             if (OSTmrListPtr ==  (OS_TMR *)0) {            /* Link into timer list                                   */
                 p_tmr->NextPtr   = (OS_TMR *)0;            /* This is the first timer in the list                    */
                 p_tmr->PrevPtr   = (OS_TMR *)0;
                 OSTmrListPtr     = p_tmr;
                 OSTmrListEntries = 1u;
             } else {
                 p_next           = OSTmrListPtr;           /* Insert at the beginning of the list                    */
                 p_tmr->NextPtr   = OSTmrListPtr;
                 p_tmr->PrevPtr   = (OS_TMR *)0;
                 p_next->PrevPtr  = p_tmr;
                 OSTmrListPtr     = p_tmr;
                 OSTmrListEntries++;
             }
             OS_TmrUnlock();
            *p_err   = OS_ERR_NONE;
             success = DEF_TRUE;
             break;

        case OS_TMR_STATE_UNUSED:                           /* Timer not created                                      */
            *p_err   = OS_ERR_TMR_INACTIVE;
             success = DEF_FALSE;
             break;

        default:
            *p_err = OS_ERR_TMR_INVALID_STATE;
             success = DEF_FALSE;
             break;
    }
    return (success);
}


/*
************************************************************************************************************************
*                                           FIND OUT WHAT STATE A TIMER IS IN
*
* Description: This function is called to determine what state the timer is in:
*
*                  OS_TMR_STATE_UNUSED     the timer has not been created
*                  OS_TMR_STATE_STOPPED    the timer has been created but has not been started or has been stopped
*                  OS_TMR_STATE_COMPLETED  the timer is in ONE-SHOT mode and has completed it's timeout
*                  OS_TMR_SATE_RUNNING     the timer is currently running
*
* Arguments  : p_tmr    Is a pointer to the desired timer
*
*              p_err    Is a pointer to an error code.  '*p_err' will contain one of the following:
*
*                           OS_ERR_NONE
*                           OS_ERR_OBJ_TYPE           if 'p_tmr' is not pointing to a timer
*                           OS_ERR_TMR_INVALID        'p_tmr' is a NULL pointer
*                           OS_ERR_TMR_INVALID_STATE  if the timer is not in a valid state
*                           OS_ERR_TMR_ISR            if the call was made from an ISR
*
* Returns    : The current state of the timer (see description).
************************************************************************************************************************
*/

OS_STATE  OSTmrStateGet (OS_TMR  *p_tmr,
                         OS_ERR  *p_err)
{
    OS_STATE  state;



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* See if trying to call from an ISR                      */
       *p_err = OS_ERR_TMR_ISR;
        return (OS_TMR_STATE_UNUSED);
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_tmr == (OS_TMR *)0) {
       *p_err = OS_ERR_TMR_INVALID;
        return (OS_TMR_STATE_UNUSED);
    }
#endif

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_tmr->Type != OS_OBJ_TYPE_TMR) {                   /* Make sure timer was created                            */
       *p_err = OS_ERR_OBJ_TYPE;
        return (OS_TMR_STATE_UNUSED);
    }
#endif

    state = p_tmr->State;
    switch (state) {
        case OS_TMR_STATE_UNUSED:
        case OS_TMR_STATE_STOPPED:
        case OS_TMR_STATE_COMPLETED:
        case OS_TMR_STATE_RUNNING:
            *p_err = OS_ERR_NONE;
             break;

        default:
            *p_err = OS_ERR_TMR_INVALID_STATE;
             break;
    }
    return (state);
}


/*
************************************************************************************************************************
*                                                    STOP A TIMER
*
* Description: This function is called by your application code to stop a timer.
*
* Arguments  : p_tmr          Is a pointer to the timer to stop.
*
*              opt            Allows you to specify an option to this functions which can be:
*
*                               OS_OPT_TMR_NONE            Do nothing special but stop the timer
*                               OS_OPT_TMR_CALLBACK        Execute the callback function, pass it the callback argument
*                                                          specified when the timer was created.
*                               OS_OPT_TMR_CALLBACK_ARG    Execute the callback function, pass it the callback argument
*                                                          specified in THIS function call
*
*              callback_arg   Is a pointer to a 'new' callback argument that can be passed to the callback function
*                               instead of the timer's callback argument.  In other words, use 'callback_arg' passed in
*                               THIS function INSTEAD of p_tmr->OSTmrCallbackArg
*
*              p_err          Is a pointer to an error code.  '*p_err' will contain one of the following:
*                               OS_ERR_NONE
*                               OS_ERR_OBJ_TYPE            if 'p_tmr' is not pointing to a timer
*                               OS_ERR_OPT_INVALID         if you specified an invalid option for 'opt'
*                               OS_ERR_TMR_INACTIVE        if the timer was not created
*                               OS_ERR_TMR_INVALID         'p_tmr' is a NULL pointer
*                               OS_ERR_TMR_INVALID_STATE   the timer is in an invalid state
*                               OS_ERR_TMR_ISR             if the function was called from an ISR
*                               OS_ERR_TMR_NO_CALLBACK     if the timer does not have a callback function defined
*                               OS_ERR_TMR_STOPPED         if the timer was already stopped
*
* Returns    : DEF_TRUE       If we stopped the timer (if the timer is already stopped, we also return DEF_TRUE)
*              DEF_FALSE      If not
************************************************************************************************************************
*/

CPU_BOOLEAN  OSTmrStop (OS_TMR  *p_tmr,
                        OS_OPT   opt,
                        void    *p_callback_arg,
                        OS_ERR  *p_err)
{
    OS_TMR_CALLBACK_PTR  p_fnct;
    CPU_BOOLEAN          success;



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {                        /* See if trying to call from an ISR            */
       *p_err = OS_ERR_TMR_ISR;
        return (DEF_FALSE);
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_tmr == (OS_TMR *)0) {
       *p_err = OS_ERR_TMR_INVALID;
        return (DEF_FALSE);
    }
#endif

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_tmr->Type != OS_OBJ_TYPE_TMR) {                             /* Make sure timer was created                  */
       *p_err = OS_ERR_OBJ_TYPE;
        return (DEF_FALSE);
    }
#endif

    switch (p_tmr->State) {
        case OS_TMR_STATE_RUNNING:
             OS_TmrLock();
             OS_TmrUnlink(p_tmr);                                     /* Remove from timer list                       */
            *p_err = OS_ERR_NONE;
             switch (opt) {
                 case OS_OPT_TMR_CALLBACK:
                      p_fnct = p_tmr->CallbackPtr;                         /* Execute callback function ...           */
                      if (p_fnct != (OS_TMR_CALLBACK_PTR)0) {              /* ... if available                        */
                        (*p_fnct)((void *)p_tmr, p_tmr->CallbackPtrArg);   /* Use callback arg when timer was created */
                      } else {
                         *p_err = OS_ERR_TMR_NO_CALLBACK;
                      }
                      break;

                 case OS_OPT_TMR_CALLBACK_ARG:
                      p_fnct = p_tmr->CallbackPtr;                    /* Execute callback function if available ...   */
                      if (p_fnct != (OS_TMR_CALLBACK_PTR)0) {
                        (*p_fnct)((void *)p_tmr, p_callback_arg);     /* .. using the 'callback_arg' provided in call */
                      } else {
                         *p_err = OS_ERR_TMR_NO_CALLBACK;
                      }
                      break;

                 case OS_OPT_TMR_NONE:
                      break;

                 default:
                     OS_TmrUnlock();
                    *p_err = OS_ERR_OPT_INVALID;
                     return (DEF_FALSE);
             }
             OS_TmrUnlock();
             success = DEF_TRUE;
             break;

        case OS_TMR_STATE_COMPLETED:                                  /* Timer has already completed the ONE-SHOT or  */
        case OS_TMR_STATE_STOPPED:                                    /* ... timer has not started yet.               */
            *p_err   = OS_ERR_TMR_STOPPED;
             success = DEF_TRUE;
             break;

        case OS_TMR_STATE_UNUSED:                                     /* Timer was not created                        */
            *p_err   = OS_ERR_TMR_INACTIVE;
             success = DEF_FALSE;
             break;

        default:
            *p_err   = OS_ERR_TMR_INVALID_STATE;
             success = DEF_FALSE;
             break;
    }
    return (success);
}


/*
************************************************************************************************************************
*                                                 CLEAR TIMER FIELDS
*
* Description: This function is called to clear all timer fields.
*
* Argument(s): p_tmr    Is a pointer to the timer to clear
*              -----
*
* Returns    : none
*
* Note(s)    : 1) This function is INTERNAL to uC/OS-III and your application MUST NOT call it.
************************************************************************************************************************
*/

void  OS_TmrClr (OS_TMR  *p_tmr)
{
    p_tmr->State          = OS_TMR_STATE_UNUSED;            /* Clear timer fields                                     */
#if OS_OBJ_TYPE_REQ > 0u
    p_tmr->Type           = OS_OBJ_TYPE_NONE;
#endif
#if OS_CFG_DBG_EN > 0u
    p_tmr->NamePtr        = (CPU_CHAR          *)((void *)"?TMR");
#endif
    p_tmr->Dly            = (OS_TICK            )0;
    p_tmr->Remain         = (OS_TICK            )0;
    p_tmr->Period         = (OS_TICK            )0;
    p_tmr->Opt            = (OS_OPT             )0;
    p_tmr->CallbackPtr    = (OS_TMR_CALLBACK_PTR)0;
    p_tmr->CallbackPtrArg = (void              *)0;
    p_tmr->NextPtr        = (OS_TMR            *)0;
    p_tmr->PrevPtr        = (OS_TMR            *)0;
}


/*
************************************************************************************************************************
*                                         ADD/REMOVE TIMER TO/FROM DEBUG TABLE
*
* Description: These functions are called by uC/OS-III to add or remove a timer to/from a timer debug table.
*
* Arguments  : p_tmr     is a pointer to the timer to add/remove
*
* Returns    : none
*
* Note(s)    : These functions are INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/


#if OS_CFG_DBG_EN > 0u
void  OS_TmrDbgListAdd (OS_TMR  *p_tmr)
{
    p_tmr->DbgPrevPtr               = (OS_TMR *)0;
    if (OSTmrDbgListPtr == (OS_TMR *)0) {
        p_tmr->DbgNextPtr           = (OS_TMR *)0;
    } else {
        p_tmr->DbgNextPtr           =  OSTmrDbgListPtr;
        OSTmrDbgListPtr->DbgPrevPtr =  p_tmr;
    }
    OSTmrDbgListPtr                 =  p_tmr;
}



void  OS_TmrDbgListRemove (OS_TMR  *p_tmr)
{
    OS_TMR  *p_tmr_next;
    OS_TMR  *p_tmr_prev;


    p_tmr_prev = p_tmr->DbgPrevPtr;
    p_tmr_next = p_tmr->DbgNextPtr;

    if (p_tmr_prev == (OS_TMR *)0) {
        OSTmrDbgListPtr = p_tmr_next;
        if (p_tmr_next != (OS_TMR *)0) {
            p_tmr_next->DbgPrevPtr = (OS_TMR *)0;
        }
        p_tmr->DbgNextPtr = (OS_TMR *)0;

    } else if (p_tmr_next == (OS_TMR *)0) {
        p_tmr_prev->DbgNextPtr = (OS_TMR *)0;
        p_tmr->DbgPrevPtr      = (OS_TMR *)0;

    } else {
        p_tmr_prev->DbgNextPtr =  p_tmr_next;
        p_tmr_next->DbgPrevPtr =  p_tmr_prev;
        p_tmr->DbgNextPtr      = (OS_TMR *)0;
        p_tmr->DbgPrevPtr      = (OS_TMR *)0;
    }
}
#endif


/*
************************************************************************************************************************
*                                             INITIALIZE THE TIMER MANAGER
*
* Description: This function is called by OSInit() to initialize the timer manager module.
*
* Argument(s): p_err    is a pointer to a variable that will contain an error code returned by this function.
*
*                           OS_ERR_NONE
*                           OS_ERR_TMR_STK_INVALID       if you didn't specify a stack for the timer task
*                           OS_ERR_TMR_STK_SIZE_INVALID  if you didn't allocate enough space for the timer stack
*                           OS_ERR_PRIO_INVALID          if you specified the same priority as the idle task
*                           OS_ERR_xxx                   any error code returned by OSTaskCreate()
*
* Returns    : none
*
* Note(s)    : 1) This function is INTERNAL to uC/OS-III and your application MUST NOT call it.
************************************************************************************************************************
*/

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

#if OS_CFG_DBG_EN > 0u
    OSTmrDbgListPtr = (OS_TMR *)0;
#endif

    OSTmrListPtr        = (OS_TMR *)0;                      /* Create an empty timer list                             */
    OSTmrListEntries    = 0u;

    if (OSCfg_TmrTaskRate_Hz > (OS_RATE_HZ)0) {
        OSTmrUpdateCnt  = OSCfg_TickRate_Hz / OSCfg_TmrTaskRate_Hz;
    } else {
        OSTmrUpdateCnt  = OSCfg_TickRate_Hz / (OS_RATE_HZ)10;
    }
    OSTmrUpdateCtr      = OSTmrUpdateCnt;

    OSTmrTickCtr        = (OS_TICK)0;

    OSTmrTaskTimeMax    = (CPU_TS)0;

#if   OS_CFG_MUTEX_EN > 0u
    OSMutexCreate(&OSTmrMutex,                              /* Use a mutex to protect the timers                      */
                  "OS Tmr Mutex", 
                  p_err);
    if (*p_err != OS_ERR_NONE) {
        return;
    }
#endif

                                                            /* ---------------- CREATE THE TIMER TASK --------------- */
    if (OSCfg_TmrTaskStkBasePtr == (CPU_STK*)0) {
       *p_err = OS_ERR_TMR_STK_INVALID;
        return;
    }

    if (OSCfg_TmrTaskStkSize < OSCfg_StkSizeMin) {
       *p_err = OS_ERR_TMR_STK_SIZE_INVALID;
        return;
    }

    if (OSCfg_TmrTaskPrio >= (OS_CFG_PRIO_MAX - 1u)) {
       *p_err = OS_ERR_TMR_PRIO_INVALID;
        return;
    }

    OSTaskCreate((OS_TCB     *)&OSTmrTaskTCB,
                 (CPU_CHAR   *)((void *)"uC/OS-III Timer Task"),
                 (OS_TASK_PTR )OS_TmrTask,
                 (void       *)0,
                 (OS_PRIO     )OSCfg_TmrTaskPrio,
                 (CPU_STK    *)OSCfg_TmrTaskStkBasePtr,
                 (CPU_STK_SIZE)OSCfg_TmrTaskStkLimit,
                 (CPU_STK_SIZE)OSCfg_TmrTaskStkSize,
                 (OS_MSG_QTY  )0,
                 (OS_TICK     )0,
                 (void       *)0,
                 (OS_OPT      )(OS_OPT_TASK_STK_CHK | OS_OPT_TASK_STK_CLR | OS_OPT_TASK_NO_TLS),
                 (OS_ERR     *)p_err);
}


/*
************************************************************************************************************************
*                                              RESET TIMER LIST PEAK DETECTOR
*
* Description: This function is used to reset the peak detector for the number of entries in the timer list
*
* Arguments  : void
*
* Returns    : none
*
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/

void  OS_TmrResetPeak (void)
{
}


/*
************************************************************************************************************************
*                                         REMOVE A TIMER FROM THE TIMER LIST
*
* Description: This function is called to remove the timer from the timer list.
*
* Arguments  : p_tmr          Is a pointer to the timer to remove.
*              -----
*
* Returns    : none
*
* Note(s)    : 1) This function is INTERNAL to uC/OS-III and your application MUST NOT call it.
************************************************************************************************************************
*/

void  OS_TmrUnlink (OS_TMR  *p_tmr)
{
    OS_TMR  *p_tmr1;
    OS_TMR  *p_tmr2;



    if (OSTmrListPtr == p_tmr) {                            /* See if timer to remove is at the beginning of list     */
        p_tmr1       = (OS_TMR *)p_tmr->NextPtr;
        OSTmrListPtr = (OS_TMR *)p_tmr1;
        if (p_tmr1 != (OS_TMR *)0) {
            p_tmr1->PrevPtr = (OS_TMR *)0;
        }
    } else {
        p_tmr1          = (OS_TMR *)p_tmr->PrevPtr;         /* Remove timer from somewhere in the list                */
        p_tmr2          = (OS_TMR *)p_tmr->NextPtr;
        p_tmr1->NextPtr = p_tmr2;
        if (p_tmr2 != (OS_TMR *)0) {
            p_tmr2->PrevPtr = (OS_TMR *)p_tmr1;
        }
    }
    p_tmr->State   = OS_TMR_STATE_STOPPED;
    p_tmr->NextPtr = (OS_TMR *)0;
    p_tmr->PrevPtr = (OS_TMR *)0;
    OSTmrListEntries--;
}


/*
************************************************************************************************************************
*                                                 TIMER MANAGEMENT TASK
*
* Description: This task is created by OS_TmrInit().
*
* Arguments  : none
*
* Returns    : none
*
* Note(s)    : 1) This function is INTERNAL to uC/OS-III and your application MUST NOT call it.
************************************************************************************************************************
*/

void  OS_TmrTask (void  *p_arg)
{
    OS_ERR               err;
    OS_TMR_CALLBACK_PTR  p_fnct;
    OS_TMR              *p_tmr;
    OS_TMR              *p_tmr_next;
    CPU_TS               ts;
    CPU_TS               ts_start;
    CPU_TS               ts_delta;



    (void)&p_arg;                                                /* Not using 'p_arg', prevent compiler warning       */
    while (DEF_ON) {
        (void)OSTaskSemPend((OS_TICK )0,                         /* Wait for signal indicating time to update tmrs    */
                            (OS_OPT  )OS_OPT_PEND_BLOCKING,
                            (CPU_TS *)&ts,
                            (OS_ERR *)&err);


        OS_TmrLock();
        ts_start = OS_TS_GET();
        OSTmrTickCtr++;                                          /* Increment the current time                        */
        p_tmr    = OSTmrListPtr;
        while (p_tmr != (OS_TMR *)0) {                           /* Update all the timers in the list                 */
            OSSchedLock(&err);
            (void)&err;
            p_tmr_next = p_tmr->NextPtr;
            p_tmr->Remain--;
            if (p_tmr->Remain == 0) {
                if (p_tmr->Opt == OS_OPT_TMR_PERIODIC) {
                    p_tmr->Remain = p_tmr->Period;               /* Reload the time remaining                         */
                } else {
                    OS_TmrUnlink(p_tmr);                         /* Remove from list                                  */
                    p_tmr->State = OS_TMR_STATE_COMPLETED;       /* Indicate that the timer has completed             */
                }
                p_fnct = p_tmr->CallbackPtr;                     /* Execute callback function if available            */
                if (p_fnct != (OS_TMR_CALLBACK_PTR)0) {
                    (*p_fnct)((void *)p_tmr,
                              p_tmr->CallbackPtrArg);
                }
            }
            p_tmr = p_tmr_next;
            OSSchedUnlock(&err);
            (void)&err;
        }

        ts_delta = OS_TS_GET() - ts_start;                      /* Measure execution time of timer task              */
        OS_TmrUnlock();

        if (OSTmrTaskTimeMax < ts_delta) {
            OSTmrTaskTimeMax = ts_delta;
        }
    }
}


/*
************************************************************************************************************************
*                                          TIMER MANAGEMENT LOCKING MECHANISM
*
* Description: These functions are use to handle timer critical sections.  The preferred method is to use a mutex in 
*              order to avoid locking the scheduler and also, to avoid calling callback functions while the scheduler is 
*              locked.
*
* Arguments  : none
*
* Returns    : none
*
* Note(s)    : 1) These function is INTERNAL to uC/OS-III and your application MUST NOT call it.
************************************************************************************************************************
*/

static  void  OS_TmrLock (void)
{
    OS_ERR  err;
#if OS_CFG_MUTEX_EN > 0u
    CPU_TS  ts;


    OSMutexPend(&OSTmrMutex,                                /* Use a mutex to protect the timers                      */
                0u,
                OS_OPT_PEND_BLOCKING,
                &ts,
                &err);
#else
    OSSchedLock(&err);                                      /* Lock the scheduler to protect the timers               */
#endif
    (void)&err;
}




static  void  OS_TmrUnlock (void)
{
    OS_ERR  err;


#if OS_CFG_MUTEX_EN > 0u
    OSMutexPost(&OSTmrMutex,                                /* Use a mutex to protect the timers                      */
                OS_OPT_POST_NONE,
                &err);
#else
    OSSchedUnlock(&err);                                    /* Lock the scheduler to protect the timers               */
#endif
    (void)&err;
}

#endif