0201_APP/_uCOS-III/uC-OS-Source/os_task.c

/*
************************************************************************************************************************
*                                                      uC/OS-III
*                                                 The Real-Time Kernel
*
*                                  (c) Copyright 2009-2011; Micrium, Inc.; Weston, FL
*                           All rights reserved.  Protected by international copyright laws.
*
*                                                   TASK MANAGEMENT
*
* File    : OS_TASK.C
* By      : JJL
* Version : V3.02.00
*
* 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 contact us at www.micrium.com, or by phone at +1 (954) 217-2036.
************************************************************************************************************************
*/

#include <os.h>

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

/*
************************************************************************************************************************
*                                                CHANGE PRIORITY OF A TASK
*
* Description: This function allows you to change the priority of a task dynamically.  Note that the new
*              priority MUST be available.
*
* Arguments  : p_tcb      is the TCB of the tack to change the priority for
*
*              prio_new   is the new priority
*
*              p_err      is a pointer to an error code returned by this function:
*
*                             OS_ERR_NONE                 is the call was successful
*                             OS_ERR_PRIO_INVALID         if the priority you specify is higher that the maximum allowed
*                                                         (i.e. >= (OS_CFG_PRIO_MAX-1))
*                             OS_ERR_STATE_INVALID        if the task is in an invalid state
*                             OS_ERR_TASK_CHANGE_PRIO_ISR if you tried to change the task's priority from an ISR
************************************************************************************************************************
*/

#if OS_CFG_TASK_CHANGE_PRIO_EN > 0u
void  OSTaskChangePrio (OS_TCB   *p_tcb,
                        OS_PRIO   prio_new,
                        OS_ERR   *p_err)
{
    CPU_BOOLEAN   self;
    CPU_SR_ALLOC();



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* ---------- CANNOT CREATE A TASK FROM AN ISR ---------- */
       *p_err = OS_ERR_TASK_CHANGE_PRIO_ISR;
        return;
    }
#endif

    if (prio_new >= (OS_CFG_PRIO_MAX - 1u)) {               /* Cannot set to Idle Task priority                       */
        *p_err = OS_ERR_PRIO_INVALID;
        return;
    }

    if (p_tcb == (OS_TCB *)0) {                             /* See if want to change priority of 'self'               */
        CPU_CRITICAL_ENTER();
        p_tcb = OSTCBCurPtr;
        CPU_CRITICAL_EXIT();
        self  = DEF_TRUE;
    } else {
        self  = DEF_FALSE;
    }

    OS_CRITICAL_ENTER();
    switch (p_tcb->TaskState) {
        case OS_TASK_STATE_RDY:
             OS_RdyListRemove(p_tcb);                       /* Remove from current priority                           */
             p_tcb->Prio = prio_new;                        /* Set new task priority                                  */
             OS_PrioInsert(p_tcb->Prio);
             if (self == DEF_TRUE) {
                 OS_RdyListInsertHead(p_tcb);
             } else {
                 OS_RdyListInsertTail(p_tcb);
             }
             break;

        case OS_TASK_STATE_DLY:                             /* Nothing to do except change the priority in the OS_TCB */
        case OS_TASK_STATE_SUSPENDED:
        case OS_TASK_STATE_DLY_SUSPENDED:
             p_tcb->Prio = prio_new;                        /* Set new task priority                                  */
             break;

        case OS_TASK_STATE_PEND:
        case OS_TASK_STATE_PEND_TIMEOUT:
        case OS_TASK_STATE_PEND_SUSPENDED:
        case OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED:
             switch (p_tcb->PendOn) {                       /* What to do depends on what we are pending on           */
                 case OS_TASK_PEND_ON_TASK_Q:               /* Nothing to do except change the priority in the OS_TCB */
                 case OS_TASK_PEND_ON_TASK_SEM:
                 case OS_TASK_PEND_ON_FLAG:
                      p_tcb->Prio = prio_new;               /* Set new task priority                                  */
                      break;

                 case OS_TASK_PEND_ON_MUTEX:
                 case OS_TASK_PEND_ON_MULTI:
                 case OS_TASK_PEND_ON_Q:
                 case OS_TASK_PEND_ON_SEM:
                      OS_PendListChangePrio(p_tcb,
                                            prio_new);
                      break;

                 default:
                      break;
            }
             break;

        default:
             OS_CRITICAL_EXIT();
             *p_err = OS_ERR_STATE_INVALID;
             return;
    }

    OS_CRITICAL_EXIT_NO_SCHED();

    OSSched();                                              /* Run highest priority task ready                        */

    *p_err = OS_ERR_NONE;
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                    CREATE A TASK
*
* Description: This function is used to have uC/OS-III manage the execution of a task.  Tasks can either be created
*              prior to the start of multitasking or by a running task.  A task cannot be created by an ISR.
*
* Arguments  : p_tcb          is a pointer to the task's TCB
*
*              p_name         is a pointer to an ASCII string to provide a name to the task.
*
*              p_task         is a pointer to the task's code
*
*              p_arg          is a pointer to an optional data area which can be used to pass parameters to
*                             the task when the task first executes.  Where the task is concerned it thinks
*                             it was invoked and passed the argument 'p_arg' as follows:
*
*                                 void Task (void *p_arg)
*                                 {
*                                     for (;;) {
*                                         Task code;
*                                     }
*                                 }
*
*              prio           is the task's priority.  A unique priority MUST be assigned to each task and the
*                             lower the number, the higher the priority.
*
*              p_stk_base     is a pointer to the base address of the stack (i.e. low address).
*
*              stk_limit      is the number of stack elements to set as 'watermark' limit for the stack.  This value
*                             represents the number of CPU_STK entries left before the stack is full.  For example,
*                             specifying 10% of the 'stk_size' value indicates that the stack limit will be reached
*                             when the stack reaches 90% full.
*
*              stk_size       is the size of the stack in number of elements.  If CPU_STK is set to CPU_INT08U,
*                             'stk_size' corresponds to the number of bytes available.  If CPU_STK is set to
*                             CPU_INT16U, 'stk_size' contains the number of 16-bit entries available.  Finally, if
*                             CPU_STK is set to CPU_INT32U, 'stk_size' contains the number of 32-bit entries
*                             available on the stack.
*
*              q_size         is the maximum number of messages that can be sent to the task
*
*              time_quanta    amount of time (in ticks) for time slice when round-robin between tasks.  Specify 0 to use
*                             the default.
*
*              p_ext          is a pointer to a user supplied memory location which is used as a TCB extension.
*                             For example, this user memory can hold the contents of floating-point registers
*                             during a context switch, the time each task takes to execute, the number of times
*                             the task has been switched-in, etc.
*
*              opt            contains additional information (or options) about the behavior of the task.
*                             See OS_OPT_TASK_xxx in OS.H.  Current choices are:
*
*                                 OS_OPT_TASK_NONE            No option selected
*                                 OS_OPT_TASK_STK_CHK         Stack checking to be allowed for the task
*                                 OS_OPT_TASK_STK_CLR         Clear the stack when the task is created
*                                 OS_OPT_TASK_SAVE_FP         If the CPU has floating-point registers, save them
*                                                             during a context switch.
*
*              p_err          is a pointer to an error code that will be set during this call.  The value pointer
*                             to by 'p_err' can be:
*
*                                 OS_ERR_NONE                    if the function was successful.
*                                 OS_ERR_ILLEGAL_CREATE_RUN_TIME if you are trying to create the task after you called
*                                                                   OSSafetyCriticalStart().
*                                 OS_ERR_NAME                    if 'p_name' is a NULL pointer
*                                 OS_ERR_PRIO_INVALID            if the priority you specify is higher that the maximum
*                                                                   allowed (i.e. >= OS_CFG_PRIO_MAX-1) or,
*                                                                if OS_CFG_ISR_POST_DEFERRED_EN is set to 1 and you tried
*                                                                   to use priority 0 which is reserved.
*                                 OS_ERR_STK_INVALID             if you specified a NULL pointer for 'p_stk_base'
*                                 OS_ERR_STK_SIZE_INVALID        if you specified zero for the 'stk_size'
*                                 OS_ERR_STK_LIMIT_INVALID       if you specified a 'stk_limit' greater than or equal
*                                                                   to 'stk_size'
*                                 OS_ERR_TASK_CREATE_ISR         if you tried to create a task from an ISR.
*                                 OS_ERR_TASK_INVALID            if you specified a NULL pointer for 'p_task'
*                                 OS_ERR_TCB_INVALID             if you specified a NULL pointer for 'p_tcb'
*
* Returns    : A pointer to the TCB of the task created.  This pointer must be used as an ID (i.e handle) to the task.
************************************************************************************************************************
*/
/*$PAGE*/
void  OSTaskCreate (OS_TCB        *p_tcb,
                    CPU_CHAR      *p_name,
                    OS_TASK_PTR    p_task,
                    void          *p_arg,
                    OS_PRIO        prio,
                    CPU_STK       *p_stk_base,
                    CPU_STK_SIZE   stk_limit,
                    CPU_STK_SIZE   stk_size,
                    OS_MSG_QTY     q_size,
                    OS_TICK        time_quanta,
                    void          *p_ext,
                    OS_OPT         opt,
                    OS_ERR        *p_err)
{
    CPU_STK_SIZE   i;
#if OS_CFG_TASK_REG_TBL_SIZE > 0u
    OS_OBJ_QTY     reg_nbr;
#endif
    CPU_STK       *p_sp;
    CPU_STK       *p_stk_limit;
    CPU_SR_ALLOC();



#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) {              /* ---------- CANNOT CREATE A TASK FROM AN ISR ---------- */
        *p_err = OS_ERR_TASK_CREATE_ISR;
        return;
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u                                  /* ---------------- VALIDATE ARGUMENTS ------------------ */
    if (p_tcb == (OS_TCB *)0) {                             /* User must supply a valid OS_TCB                        */
        *p_err = OS_ERR_TCB_INVALID;
        return;
    }
    if (p_task == (OS_TASK_PTR)0) {                         /* User must supply a valid task                          */
        *p_err = OS_ERR_TASK_INVALID;
        return;
    }
    if (p_stk_base == (CPU_STK *)0) {                       /* User must supply a valid stack base address            */
        *p_err = OS_ERR_STK_INVALID;
        return;
    }
    if (stk_size < OSCfg_StkSizeMin) {                      /* User must supply a valid minimum stack size            */
        *p_err = OS_ERR_STK_SIZE_INVALID;
        return;
    }
    if (stk_limit >= stk_size) {                            /* User must supply a valid stack limit                   */
        *p_err = OS_ERR_STK_LIMIT_INVALID;
        return;
    }
    if (prio >= OS_CFG_PRIO_MAX) {                          /* Priority must be within 0 and OS_CFG_PRIO_MAX-1        */
        *p_err = OS_ERR_PRIO_INVALID;
        return;
    }
#endif

#if OS_CFG_ISR_POST_DEFERRED_EN > 0u
    if (prio == (OS_PRIO)0) {
        if (p_tcb != &OSIntQTaskTCB) {
            *p_err = OS_ERR_PRIO_INVALID;                   /* Not allowed to use priority 0                          */
            return;
        }
    }
#endif

    if (prio == (OS_CFG_PRIO_MAX - 1u)) {
        if (p_tcb != &OSIdleTaskTCB) {
            *p_err = OS_ERR_PRIO_INVALID;                   /* Not allowed to use same priority as idle task          */
            return;
        }
    }

    OS_TaskInitTCB(p_tcb);                                  /* Initialize the TCB to default values                   */

    *p_err = OS_ERR_NONE;
                                                            /* --------------- CLEAR THE TASK'S STACK --------------- */
    if ((opt & OS_OPT_TASK_STK_CHK) != (OS_OPT)0) {         /* See if stack checking has been enabled                 */
        if ((opt & OS_OPT_TASK_STK_CLR) != (OS_OPT)0) {     /* See if stack needs to be cleared                       */
            p_sp = p_stk_base;
            for (i = 0u; i < stk_size; i++) {               /* Stack grows from HIGH to LOW memory                    */
                *p_sp = (CPU_STK)0;                         /* Clear from bottom of stack and up!                     */
                p_sp++;
            }
        }
    }
                                                            /* ------- INITIALIZE THE STACK FRAME OF THE TASK ------- */
#if (CPU_CFG_STK_GROWTH == CPU_STK_GROWTH_HI_TO_LO)
    p_stk_limit = p_stk_base + stk_limit;
#else
    p_stk_limit = p_stk_base + (stk_size - 1u) - stk_limit;
#endif

    p_sp = OSTaskStkInit(p_task,
                         p_arg,
                         p_stk_base,
                         p_stk_limit,
                         stk_size,
                         opt);

                                                            /* -------------- INITIALIZE THE TCB FIELDS ------------- */
    p_tcb->TaskEntryAddr = p_task;                          /* Save task entry point address                          */
    p_tcb->TaskEntryArg  = p_arg;                           /* Save task entry argument                               */

    p_tcb->NamePtr       = p_name;                          /* Save task name                                         */

    p_tcb->Prio          = prio;                            /* Save the task's priority                               */

    p_tcb->StkPtr        = p_sp;                            /* Save the new top-of-stack pointer                      */
    p_tcb->StkLimitPtr   = p_stk_limit;                     /* Save the stack limit pointer                           */

    p_tcb->TimeQuanta    = time_quanta;                     /* Save the #ticks for time slice (0 means not sliced)    */
#if OS_CFG_SCHED_ROUND_ROBIN_EN > 0u
    if (time_quanta == (OS_TICK)0) {
        p_tcb->TimeQuantaCtr = OSSchedRoundRobinDfltTimeQuanta;
    } else {
        p_tcb->TimeQuantaCtr = time_quanta;
    }
#endif
    p_tcb->ExtPtr        = p_ext;                           /* Save pointer to TCB extension                          */
    p_tcb->StkBasePtr    = p_stk_base;                      /* Save pointer to the base address of the stack          */
    p_tcb->StkSize       = stk_size;                        /* Save the stack size (in number of CPU_STK elements)    */
    p_tcb->Opt           = opt;                             /* Save task options                                      */

#if OS_CFG_TASK_REG_TBL_SIZE > 0u
    for (reg_nbr = 0u; reg_nbr < OS_CFG_TASK_REG_TBL_SIZE; reg_nbr++) {
        p_tcb->RegTbl[reg_nbr] = (OS_REG)0;
    }
#endif

#if OS_CFG_TASK_Q_EN > 0u
    OS_MsgQInit(&p_tcb->MsgQ,                               /* Initialize the task's message queue                    */
                q_size);
#endif

    OSTaskCreateHook(p_tcb);                                /* Call user defined hook                                 */

                                                            /* --------------- ADD TASK TO READY LIST --------------- */
    OS_CRITICAL_ENTER();
    OS_PrioInsert(p_tcb->Prio);
    OS_RdyListInsertTail(p_tcb);

#if OS_CFG_DBG_EN > 0u
    OS_TaskDbgListAdd(p_tcb);
#endif

    OSTaskQty++;                                            /* Increment the #tasks counter                           */

    if (OSRunning != OS_STATE_OS_RUNNING) {                 /* Return if multitasking has not started                 */
        OS_CRITICAL_EXIT();
        return;
    }

    OS_CRITICAL_EXIT_NO_SCHED();

    OSSched();
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                                     DELETE A TASK
*
* Description: This function allows you to delete a task.  The calling task can delete itself by specifying a NULL
*              pointer for 'p_tcb'.  The deleted task is returned to the dormant state and can be re-activated by
*              creating the deleted task again.
*
* Arguments  : p_tcb      is the TCB of the tack to delete
*
*              p_err      is a pointer to an error code returned by this function:
*
*                             OS_ERR_NONE                  if the call is successful
*                             OS_ERR_STATE_INVALID         if the state of the task is invalid
*                             OS_ERR_TASK_DEL_IDLE         if you attempted to delete uC/OS-III's idle task
*                             OS_ERR_TASK_DEL_INVALID      if you attempted to delete uC/OS-III's ISR handler task
*                             OS_ERR_TASK_DEL_ISR          if you tried to delete a task from an ISR
************************************************************************************************************************
*/

#if OS_CFG_TASK_DEL_EN > 0u
void  OSTaskDel (OS_TCB  *p_tcb,
                 OS_ERR  *p_err)
{
    CPU_SR_ALLOC();



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

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

    if (p_tcb == &OSIdleTaskTCB) {                          /* Not allowed to delete the idle task                    */
        *p_err = OS_ERR_TASK_DEL_IDLE;
        return;
    }

#if OS_CFG_ISR_POST_DEFERRED_EN > 0u
    if (p_tcb == &OSIntQTaskTCB) {                          /* Cannot delete the ISR handler task                     */
        *p_err = OS_ERR_TASK_DEL_INVALID;
        return;
    }
#endif

    if (p_tcb == (OS_TCB *)0) {                             /* Delete 'Self'?                                         */
        CPU_CRITICAL_ENTER();
        p_tcb  = OSTCBCurPtr;                               /* Yes.                                                   */
        CPU_CRITICAL_EXIT();
    }

    OS_CRITICAL_ENTER();
    switch (p_tcb->TaskState) {
        case OS_TASK_STATE_RDY:
             OS_RdyListRemove(p_tcb);
             break;

        case OS_TASK_STATE_SUSPENDED:
             break;

        case OS_TASK_STATE_DLY:                             /* Task is only delayed, not on any wait list             */
        case OS_TASK_STATE_DLY_SUSPENDED:
             OS_TickListRemove(p_tcb);
             break;

        case OS_TASK_STATE_PEND:
        case OS_TASK_STATE_PEND_SUSPENDED:
        case OS_TASK_STATE_PEND_TIMEOUT:
        case OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED:
             OS_TickListRemove(p_tcb);
             switch (p_tcb->PendOn) {                       /* See what we are pending on                             */
                 case OS_TASK_PEND_ON_NOTHING:
                 case OS_TASK_PEND_ON_TASK_Q:               /* There is no wait list for these two                    */
                 case OS_TASK_PEND_ON_TASK_SEM:
                      break;

                 case OS_TASK_PEND_ON_FLAG:                 /* Remove from wait list                                  */
                 case OS_TASK_PEND_ON_MULTI:
                 case OS_TASK_PEND_ON_MUTEX:
                 case OS_TASK_PEND_ON_Q:
                 case OS_TASK_PEND_ON_SEM:
                      OS_PendListRemove(p_tcb);
                      break;

                 default:
                      break;
             }
             break;

        default:
            OS_CRITICAL_EXIT();
            *p_err = OS_ERR_STATE_INVALID;
            return;
    }

#if OS_CFG_TASK_Q_EN > 0u
    (void)OS_MsgQFreeAll(&p_tcb->MsgQ);                     /* Free task's message queue messages                     */
#endif

    OSTaskDelHook(p_tcb);                                   /* Call user defined hook                                 */

#if OS_CFG_DBG_EN > 0u
    OS_TaskDbgListRemove(p_tcb);
#endif
    OSTaskQty--;                                            /* One less task being managed                            */

    OS_TaskInitTCB(p_tcb);                                  /* Initialize the TCB to default values                   */
    p_tcb->TaskState = (OS_STATE)OS_TASK_STATE_DEL;         /* Indicate that the task was deleted                     */

    OS_CRITICAL_EXIT_NO_SCHED();
    OSSched();                                              /* Find new highest priority task                         */

    *p_err = OS_ERR_NONE;
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                    FLUSH TASK's QUEUE
*
* Description: This function is used to flush the task's internal message queue.
*
* Arguments  : p_tcb       is a pointer to the task's OS_TCB.  Specifying a NULL pointer indicates that you wish to
*                          flush the message queue of the calling task.
*
*              p_err       is a pointer to a variable that will contain an error code returned by this function.
*
*                              OS_ERR_NONE           upon success
*                              OS_ERR_FLUSH_ISR      if you called this function from an ISR
*
* Returns     : The number of entries freed from the queue
*
* Note(s)     : 1) You should use this function with great care because, when to flush the queue, you LOOSE the
*                  references to what the queue entries are pointing to and thus, you could cause 'memory leaks'.  In
*                  other words, the data you are pointing to that's being referenced by the queue entries should, most
*                  likely, need to be de-allocated (i.e. freed).
************************************************************************************************************************
*/

#if OS_CFG_TASK_Q_EN > 0u
OS_MSG_QTY  OSTaskQFlush (OS_TCB  *p_tcb,
                          OS_ERR  *p_err)
{
    OS_MSG_QTY  entries;
    CPU_SR_ALLOC();



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* Can't flush a message queue from an ISR                */
       *p_err = OS_ERR_FLUSH_ISR;
        return ((OS_MSG_QTY)0);
    }
#endif

    if (p_tcb == (OS_TCB *)0) {                             /* Flush message queue of calling task?                   */
        CPU_CRITICAL_ENTER();
        p_tcb = OSTCBCurPtr;
        CPU_CRITICAL_EXIT();
    }

    OS_CRITICAL_ENTER();
    entries = OS_MsgQFreeAll(&p_tcb->MsgQ);                 /* Return all OS_MSGs to the OS_MSG pool                  */
    OS_CRITICAL_EXIT();
    *p_err  = OS_ERR_NONE;
    return (entries);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                  WAIT FOR A MESSAGE
*
* Description: This function causes the current task to wait for a message to be posted to it.
*
* Arguments  : timeout       is an optional timeout period (in clock ticks).  If non-zero, your task will wait for a
*                            message to arrive up to the amount of time specified by this argument.
*                            If you specify 0, however, your task will wait forever or, until a message arrives.
*
*              opt           determines whether the user wants to block if the task's queue is empty or not:
*
*                                OS_OPT_PEND_BLOCKING
*                                OS_OPT_PEND_NON_BLOCKING
*
*              p_msg_size    is a pointer to a variable that will receive the size of the message
*
*              p_ts          is a pointer to a variable that will receive the timestamp of when the message was
*                            received.  If you pass a NULL pointer (i.e. (CPU_TS *)0) then you will not get the
*                            timestamp.  In other words, passing a NULL pointer is valid and indicates that you don't
*                            need the timestamp.
*
*              p_err         is a pointer to where an error message will be deposited.  Possible error
*                            messages are:
*
*                                OS_ERR_NONE               The call was successful and your task received a message.
*                                OS_ERR_PEND_ABORT
*                                OS_ERR_PEND_ISR           If you called this function from an ISR and the result
*                                OS_ERR_PEND_WOULD_BLOCK   If you specified non-blocking but the queue was not empty
*                                OS_ERR_Q_EMPTY
*                                OS_ERR_SCHED_LOCKED       If the scheduler is locked
*                                OS_ERR_TIMEOUT            A message was not received within the specified timeout
*                                                          would lead to a suspension.
*
* Returns    : A pointer to the message received or a NULL pointer upon error.
*
* Note(s)    : 1) It is possible to receive NULL pointers when there are no errors.
************************************************************************************************************************
*/

#if OS_CFG_TASK_Q_EN > 0u
void  *OSTaskQPend (OS_TICK        timeout,
                    OS_OPT         opt,
                    OS_MSG_SIZE   *p_msg_size,
                    CPU_TS        *p_ts,
                    OS_ERR        *p_err)
{
    OS_MSG_Q     *p_msg_q;
    void         *p_void;
    CPU_SR_ALLOC();



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* Can't Pend from an ISR                                 */
       *p_err = OS_ERR_PEND_ISR;
        return ((void *)0);
    }
#endif

#if OS_CFG_ARG_CHK_EN > 0u                                  /* ---------------- VALIDATE ARGUMENTS ------------------ */
    if (p_msg_size == (OS_MSG_SIZE *)0) {                   /* User must supply a valid destination for msg size      */
        *p_err = OS_ERR_PTR_INVALID;
        return ((void *)0);
    }
    switch (opt) {                                          /* User must supply a valid option                        */
        case OS_OPT_PEND_BLOCKING:
        case OS_OPT_PEND_NON_BLOCKING:
             break;

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

    if (p_ts != (CPU_TS *)0) {
        *p_ts = (CPU_TS  )0;                                /* Initialize the returned timestamp                      */
    }

    CPU_CRITICAL_ENTER();
    p_msg_q = &OSTCBCurPtr->MsgQ;                           /* Any message waiting in the message queue?              */
    p_void  = OS_MsgQGet(p_msg_q,
                         p_msg_size,
                         p_ts,
                         p_err);
    if (*p_err == OS_ERR_NONE) {
#if OS_CFG_TASK_PROFILE_EN > 0u
        if (p_ts != (CPU_TS *)0) {
            OSTCBCurPtr->MsgQPendTime = OS_TS_GET() - *p_ts;
            if (OSTCBCurPtr->MsgQPendTime > OSTCBCurPtr->MsgQPendTimeMax) {
                OSTCBCurPtr->MsgQPendTimeMax = OSTCBCurPtr->MsgQPendTime;
            }
        }
#endif
        CPU_CRITICAL_EXIT();
        return (p_void);                                    /* Yes, Return oldest message received                    */
    }

    if ((opt & OS_OPT_PEND_NON_BLOCKING) != (OS_OPT)0) {    /* Caller wants to block if not available?                */
        *p_err = OS_ERR_PEND_WOULD_BLOCK;                   /* No                                                     */
        CPU_CRITICAL_EXIT();
        return ((void *)0);
    } else {                                                /* Yes                                                    */
        if (OSSchedLockNestingCtr > (OS_NESTING_CTR)0) {    /*     Can't block when the scheduler is locked           */
            CPU_CRITICAL_EXIT();
            *p_err = OS_ERR_SCHED_LOCKED;
            return ((void *)0);
        }
    }

    OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT();                  /* Lock the scheduler/re-enable interrupts                */
    OS_Pend((OS_PEND_DATA *)0,                              /* Block task pending on Message                          */
            (OS_PEND_OBJ  *)0,
            (OS_STATE      )OS_TASK_PEND_ON_TASK_Q,
            (OS_TICK       )timeout);
    OS_CRITICAL_EXIT_NO_SCHED();

    OSSched();                                              /* Find the next highest priority task ready to run       */

    CPU_CRITICAL_ENTER();
    switch (OSTCBCurPtr->PendStatus) {
        case OS_STATUS_PEND_OK:                             /* Extract message from TCB (Put there by Post)           */
             p_void      = OSTCBCurPtr->MsgPtr;
             *p_msg_size = OSTCBCurPtr->MsgSize;
             if (p_ts != (CPU_TS *)0) {
                *p_ts  = OSTCBCurPtr->TS;
#if OS_CFG_TASK_PROFILE_EN > 0u
                OSTCBCurPtr->MsgQPendTime = OS_TS_GET() - OSTCBCurPtr->TS;
                if (OSTCBCurPtr->MsgQPendTime > OSTCBCurPtr->MsgQPendTimeMax) {
                    OSTCBCurPtr->MsgQPendTimeMax = OSTCBCurPtr->MsgQPendTime;
                }
#endif
             }
             *p_err = OS_ERR_NONE;
             break;

        case OS_STATUS_PEND_ABORT:                          /* Indicate that we aborted                               */
             p_void      = (void      *)0;
             *p_msg_size = (OS_MSG_SIZE)0;
             if (p_ts != (CPU_TS *)0) {
                *p_ts  = (CPU_TS  )0;
             }
             *p_err =  OS_ERR_PEND_ABORT;
             break;

        case OS_STATUS_PEND_TIMEOUT:                        /* Indicate that we didn't get event within TO            */
        default:
             p_void      = (void      *)0;
             *p_msg_size = (OS_MSG_SIZE)0;
             if (p_ts != (CPU_TS *)0) {
                *p_ts  =  OSTCBCurPtr->TS;
             }
             *p_err =  OS_ERR_TIMEOUT;
             break;
    }
    CPU_CRITICAL_EXIT();
    return (p_void);                                        /* Return received message                                */
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                              ABORT WAITING FOR A MESSAGE
*
* Description: This function aborts & readies the task specified.  This function should be used to fault-abort the wait
*              for a message, rather than to normally post the message to the task via OSTaskQPost().
*
* Arguments  : p_tcb     is a pointer to the task to pend abort
*
*              opt       provides options for this function:
*
*                            OS_OPT_POST_NONE         No option specified
*                            OS_OPT_POST_NO_SCHED     Indicates that the scheduler will not be called.
*
*              p_err     is a pointer to a variable that will contain an error code returned by this function.
*
*                            OS_ERR_NONE              If the task was readied and informed of the aborted wait
*                            OS_ERR_PEND_ABORT_ISR    If you called this function from an ISR
*                            OS_ERR_PEND_ABORT_NONE   If task was not pending on a message and thus there is nothing to
*                                                     abort.
*                            OS_ERR_PEND_ABORT_SELF   If you passed a NULL pointer for 'p_tcb'
*
* Returns    : == DEF_FALSE   if task was not waiting for a message, or upon error.
*              == DEF_TRUE    if task was waiting for a message and was readied and informed.
************************************************************************************************************************
*/

#if (OS_CFG_TASK_Q_EN > 0u) && (OS_CFG_TASK_Q_PEND_ABORT_EN > 0u)
CPU_BOOLEAN  OSTaskQPendAbort (OS_TCB  *p_tcb,
                               OS_OPT   opt,
                               OS_ERR  *p_err)
{
    CPU_TS         ts;
    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 called from ISR ...                             */
       *p_err = OS_ERR_PEND_ABORT_ISR;                      /* ... can't Pend Abort from an ISR                       */
        return (DEF_FALSE);
    }
#endif

    CPU_CRITICAL_ENTER();
#if OS_CFG_ARG_CHK_EN > 0u
    if ((p_tcb == (OS_TCB *)0) ||                           /* Pend abort self?                                       */
        (p_tcb == OSTCBCurPtr)) {
        CPU_CRITICAL_EXIT();
        *p_err = OS_ERR_PEND_ABORT_SELF;                    /* ... doesn't make sense                                 */
        return (DEF_FALSE);
    }
#endif

    if (p_tcb->PendOn != OS_TASK_PEND_ON_TASK_Q) {          /* Is task waiting for a message?                         */
        CPU_CRITICAL_EXIT();                                /* No                                                     */
        *p_err = OS_ERR_PEND_ABORT_NONE;
        return (DEF_FALSE);
    }

    OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT();
    ts = OS_TS_GET();                                       /* Get timestamp of when the abort occurred               */
    OS_PendAbort((OS_PEND_OBJ *)0,                          /* Abort the pend                                         */
                 p_tcb,
                 ts);
    OS_CRITICAL_EXIT_NO_SCHED();
    if ((opt & OS_OPT_POST_NO_SCHED) == (OS_OPT)0) {
        OSSched();                                          /* Run the scheduler                                      */
    }
    *p_err = OS_ERR_NONE;
    return (DEF_TRUE);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                               POST MESSAGE TO A TASK
*
* Description: This function sends a message to a task
*
* Arguments  : p_tcb      is a pointer to the TCB of the task receiving a message.  If you specify a NULL pointer then
*                         the message will be posted to the task's queue of the calling task.  In other words, you'd be
*                         posting a message to yourself.
*
*              p_void     is a pointer to the message to send.
*
*              msg_size   is the size of the message sent (in #bytes)
*
*              opt        specifies whether the post will be FIFO or LIFO:
*
*                             OS_OPT_POST_FIFO       Post at the end   of the queue
*                             OS_OPT_POST_LIFO       Post at the front of the queue
*
*                             OS_OPT_POST_NO_SCHED   Do not run the scheduler after the post
*
*                          Note(s): 1) OS_OPT_POST_NO_SCHED can be added with one of the other options.
*
*
*              p_err      is a pointer to a variable that will hold the error code associated
*                         with the outcome of this call.  Errors can be:
*
*                             OS_ERR_NONE            The call was successful and the message was sent
*                             OS_ERR_Q_MAX           If the queue is full
*                             OS_ERR_MSG_POOL_EMPTY  If there are no more OS_MSGs available from the pool
*
* Returns    : none
************************************************************************************************************************
*/

#if OS_CFG_TASK_Q_EN > 0u
void  OSTaskQPost (OS_TCB      *p_tcb,
                   void        *p_void,
                   OS_MSG_SIZE  msg_size,
                   OS_OPT       opt,
                   OS_ERR      *p_err)
{
    CPU_TS   ts;



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

    ts = OS_TS_GET();                                       /* Get timestamp                                          */

#if OS_CFG_ISR_POST_DEFERRED_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {
        OS_IntQPost((OS_OBJ_TYPE)OS_OBJ_TYPE_TASK_MSG,      /* Post to ISR queue                                      */
                    (void      *)p_tcb,
                    (void      *)p_void,
                    (OS_MSG_SIZE)msg_size,
                    (OS_FLAGS   )0,
                    (OS_OPT     )opt,
                    (CPU_TS     )ts,
                    (OS_ERR    *)p_err);
        return;
    }
#endif

    OS_TaskQPost(p_tcb,
                 p_void,
                 msg_size,
                 opt,
                 ts,
                 p_err);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                       GET THE CURRENT VALUE OF A TASK REGISTER
*
* Description: This function is called to obtain the current value of a task register.  Task registers are application
*              specific and can be used to store task specific values such as 'error numbers' (i.e. errno), statistics,
*              etc.
*
* Arguments  : p_tcb     is a pointer to the OS_TCB of the task you want to read the register from.  If 'p_tcb' is a
*                        NULL pointer then you will get the register of the current task.
*
*              id        is the 'id' of the desired task variable.  Note that the 'id' must be less than
*                        OS_CFG_TASK_REG_TBL_SIZE
*
*              p_err     is a pointer to a variable that will hold an error code related to this call.
*
*                            OS_ERR_NONE            if the call was successful
*                            OS_ERR_REG_ID_INVALID  if the 'id' is not between 0 and OS_CFG_TASK_REG_TBL_SIZE-1
*
* Returns    : The current value of the task's register or 0 if an error is detected.
************************************************************************************************************************
*/

#if OS_CFG_TASK_REG_TBL_SIZE > 0u
OS_REG  OSTaskRegGet (OS_TCB     *p_tcb,
                      OS_REG_ID   id,
                      OS_ERR     *p_err)
{
    OS_REG     value;
    CPU_SR_ALLOC();



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

#if OS_CFG_ARG_CHK_EN > 0u
    if (id >= OS_CFG_TASK_REG_TBL_SIZE) {
       *p_err = OS_ERR_REG_ID_INVALID;
        return ((OS_REG)0);
    }
#endif

    CPU_CRITICAL_ENTER();
    if (p_tcb == (OS_TCB *)0) {
        p_tcb = OSTCBCurPtr;
    }
    value  = p_tcb->RegTbl[id];
    CPU_CRITICAL_EXIT();
    *p_err = OS_ERR_NONE;
    return ((OS_REG)value);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                       SET THE CURRENT VALUE OF A TASK REGISTER
*
* Description: This function is called to change the current value of a task register.  Task registers are application
*              specific and can be used to store task specific values such as 'error numbers' (i.e. errno), statistics,
*              etc.
*
* Arguments  : p_tcb     is a pointer to the OS_TCB of the task you want to set the register for.  If 'p_tcb' is a NULL
*                        pointer then you will change the register of the current task.
*
*              id        is the 'id' of the desired task register.  Note that the 'id' must be less than
*                        OS_CFG_TASK_REG_TBL_SIZE
*
*              value     is the desired value for the task register.
*
*              p_err     is a pointer to a variable that will hold an error code related to this call.
*
*                            OS_ERR_NONE            if the call was successful
*                            OS_ERR_REG_ID_INVALID  if the 'id' is not between 0 and OS_CFG_TASK_REG_TBL_SIZE-1
*
* Returns    : none
************************************************************************************************************************
*/

#if OS_CFG_TASK_REG_TBL_SIZE > 0u
void  OSTaskRegSet (OS_TCB    *p_tcb,
                    OS_REG_ID  id,
                    OS_REG     value,
                    OS_ERR    *p_err)
{
    CPU_SR_ALLOC();



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

#if OS_CFG_ARG_CHK_EN > 0u
    if (id >= OS_CFG_TASK_REG_TBL_SIZE) {
       *p_err = OS_ERR_REG_ID_INVALID;
        return;
    }
#endif

    CPU_CRITICAL_ENTER();
    if (p_tcb == (OS_TCB *)0) {
        p_tcb = OSTCBCurPtr;
    }
    p_tcb->RegTbl[id] = value;
    CPU_CRITICAL_EXIT();
    *p_err            = 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  : p_tcb      Is a pointer to the task's OS_TCB to resume
*
*              p_err      Is a pointer to a variable that will contain an error code returned by this function
*
*                             OS_ERR_NONE                  if the requested task is resumed
*                             OS_ERR_STATE_INVALID         if the task is in an invalid state
*                             OS_ERR_TASK_RESUME_ISR       if you called this function from an ISR
*                             OS_ERR_TASK_RESUME_SELF      You cannot resume 'self'
*                             OS_ERR_TASK_NOT_SUSPENDED    if the task to resume has not been suspended
*
* Returns    : none
************************************************************************************************************************
*/

#if OS_CFG_TASK_SUSPEND_EN > 0u
void  OSTaskResume (OS_TCB  *p_tcb,
                    OS_ERR  *p_err)
{
    CPU_SR_ALLOC();



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

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


    CPU_CRITICAL_ENTER();
#if OS_CFG_ARG_CHK_EN > 0u
    if ((p_tcb == (OS_TCB *)0) ||                           /* We cannot resume 'self'                                */
        (p_tcb == OSTCBCurPtr)) {
        CPU_CRITICAL_EXIT();
        *p_err = OS_ERR_TASK_RESUME_SELF;
        return;
    }
#endif

    *p_err  = OS_ERR_NONE;
    switch (p_tcb->TaskState) {
        case OS_TASK_STATE_RDY:
        case OS_TASK_STATE_DLY:
        case OS_TASK_STATE_PEND:
        case OS_TASK_STATE_PEND_TIMEOUT:
             CPU_CRITICAL_EXIT();
             *p_err = OS_ERR_TASK_NOT_SUSPENDED;
             break;

        case OS_TASK_STATE_SUSPENDED:
             OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT();
             p_tcb->SuspendCtr--;
             if (p_tcb->SuspendCtr == (OS_NESTING_CTR)0) {
                 p_tcb->TaskState = OS_TASK_STATE_RDY;
                 OS_TaskRdy(p_tcb);
             }
             OS_CRITICAL_EXIT_NO_SCHED();
             break;

        case OS_TASK_STATE_DLY_SUSPENDED:
             p_tcb->SuspendCtr--;
             if (p_tcb->SuspendCtr == (OS_NESTING_CTR)0) {
                 p_tcb->TaskState = OS_TASK_STATE_DLY;
             }
             CPU_CRITICAL_EXIT();
             break;

        case OS_TASK_STATE_PEND_SUSPENDED:
             p_tcb->SuspendCtr--;
             if (p_tcb->SuspendCtr == (OS_NESTING_CTR)0) {
                 p_tcb->TaskState = OS_TASK_STATE_PEND;
             }
             CPU_CRITICAL_EXIT();
             break;

        case OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED:
             p_tcb->SuspendCtr--;
             if (p_tcb->SuspendCtr == (OS_NESTING_CTR)0) {
                 p_tcb->TaskState = OS_TASK_STATE_PEND_TIMEOUT;
             }
             CPU_CRITICAL_EXIT();
             break;

        default:
             CPU_CRITICAL_EXIT();
             *p_err = OS_ERR_STATE_INVALID;
             return;
    }

    OSSched();
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                              WAIT FOR A TASK SEMAPHORE
*
* Description: This function is called to block the current task until a signal is sent by another task or ISR.
*
* Arguments  : timeout       is the amount of time you are will to wait for the signal
*
*              opt           determines whether the user wants to block if a semaphore post was not received:
*
*                                OS_OPT_PEND_BLOCKING
*                                OS_OPT_PEND_NON_BLOCKING
*
*              p_ts          is a pointer to a variable that will receive the timestamp of when the semaphore was posted
*                            or pend aborted.  If you pass a NULL pointer (i.e. (CPU_TS *)0) then you will not get the
*                            timestamp.  In other words, passing a NULL pointer is valid and indicates that you don't
*                            need the timestamp.
*
*              p_err         is a pointer to an error code that will be set by this function
*
*                                OS_ERR_NONE               The call was successful and your task received a message.
*                                OS_ERR_PEND_ABORT
*                                OS_ERR_PEND_ISR           If you called this function from an ISR and the result
*                                OS_ERR_PEND_WOULD_BLOCK   If you specified non-blocking but no signal was received
*                                OS_ERR_SCHED_LOCKED       If the scheduler is locked
*                                OS_ERR_STATUS_INVALID     If the pend status is invalid
*                                OS_ERR_TIMEOUT            A message was not received within the specified timeout
*                                                          would lead to a suspension.
*
* Returns    : The current count of signals the task received, 0 if none.
************************************************************************************************************************
*/

OS_SEM_CTR  OSTaskSemPend (OS_TICK   timeout,
                           OS_OPT    opt,
                           CPU_TS   *p_ts,
                           OS_ERR   *p_err)
{
    OS_SEM_CTR    ctr;
    CPU_SR_ALLOC();



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* Not allowed to call from an ISR                        */
       *p_err = OS_ERR_PEND_ISR;
        return ((OS_SEM_CTR)0);
    }
#endif

    if (p_ts != (CPU_TS *)0) {
       *p_ts  = (CPU_TS  )0;                                /* Initialize the returned timestamp                      */
    }

    CPU_CRITICAL_ENTER();
    if (OSTCBCurPtr->SemCtr > (OS_SEM_CTR)0) {              /* See if task already been signaled                      */
        OSTCBCurPtr->SemCtr--;
        ctr    = OSTCBCurPtr->SemCtr;
        if (p_ts != (CPU_TS *)0) {
           *p_ts  = OSTCBCurPtr->TS;
        }
#if OS_CFG_TASK_PROFILE_EN > 0u
        OSTCBCurPtr->SemPendTime = OS_TS_GET() - OSTCBCurPtr->TS;
        if (OSTCBCurPtr->SemPendTime > OSTCBCurPtr->SemPendTimeMax) {
            OSTCBCurPtr->SemPendTimeMax = OSTCBCurPtr->SemPendTime;
        }
#endif
        CPU_CRITICAL_EXIT();
        *p_err = OS_ERR_NONE;
        return (ctr);
    }

    if ((opt & OS_OPT_PEND_NON_BLOCKING) != (OS_OPT)0) {    /* Caller wants to block if not available?                */
        CPU_CRITICAL_EXIT();
        *p_err = OS_ERR_PEND_WOULD_BLOCK;                   /* No                                                     */
        return ((OS_SEM_CTR)0);
    } else {                                                /* Yes                                                    */
        if (OSSchedLockNestingCtr > (OS_NESTING_CTR)0) {    /* Can't pend when the scheduler is locked                */
            CPU_CRITICAL_EXIT();
            *p_err = OS_ERR_SCHED_LOCKED;
            return ((OS_SEM_CTR)0);
        }
    }

    OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT();                  /* Lock the scheduler/re-enable interrupts                */
    OS_Pend((OS_PEND_DATA *)0,                              /* Block task pending on Signal                           */
            (OS_PEND_OBJ  *)0,
            (OS_STATE      )OS_TASK_PEND_ON_TASK_SEM,
            (OS_TICK       )timeout);
    OS_CRITICAL_EXIT_NO_SCHED();

    OSSched();                                              /* Find next highest priority task ready to run           */

    CPU_CRITICAL_ENTER();
    switch (OSTCBCurPtr->PendStatus) {                      /* See if we timed-out or aborted                         */
        case OS_STATUS_PEND_OK:
             if (p_ts != (CPU_TS *)0) {
                *p_ts                    =  OSTCBCurPtr->TS;
#if OS_CFG_TASK_PROFILE_EN > 0u
                OSTCBCurPtr->SemPendTime = OS_TS_GET() - OSTCBCurPtr->TS;
                if (OSTCBCurPtr->SemPendTime > OSTCBCurPtr->SemPendTimeMax) {
                    OSTCBCurPtr->SemPendTimeMax = OSTCBCurPtr->SemPendTime;
                }
#endif
             }
             *p_err = OS_ERR_NONE;
             break;

        case OS_STATUS_PEND_ABORT:
             if (p_ts != (CPU_TS *)0) {
                *p_ts  =  OSTCBCurPtr->TS;
             }
             *p_err = OS_ERR_PEND_ABORT;                    /* Indicate that we aborted                               */
             break;

        case OS_STATUS_PEND_TIMEOUT:
             if (p_ts != (CPU_TS *)0) {
                *p_ts  = (CPU_TS  )0;
             }
             *p_err = OS_ERR_TIMEOUT;                       /* Indicate that we didn't get event within TO            */
             break;

        default:
             *p_err = OS_ERR_STATUS_INVALID;
             break;
    }
    ctr = OSTCBCurPtr->SemCtr;
    CPU_CRITICAL_EXIT();
    return (ctr);
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                               ABORT WAITING FOR A SIGNAL
*
* Description: This function aborts & readies the task specified.  This function should be used to fault-abort the wait
*              for a signal, rather than to normally post the signal to the task via OSTaskSemPost().
*
* Arguments  : p_tcb     is a pointer to the task to pend abort
*
*              opt       provides options for this function:
*
*                            OS_OPT_POST_NONE         No option selected
*                            OS_OPT_POST_NO_SCHED     Indicates that the scheduler will not be called.
*
*              p_err     is a pointer to a variable that will contain an error code returned by this function.
*
*                            OS_ERR_NONE              If the task was readied and informed of the aborted wait
*                            OS_ERR_PEND_ABORT_ISR    If you tried calling this function from an ISR
*                            OS_ERR_PEND_ABORT_NONE   If the task was not waiting for a signal
*                            OS_ERR_PEND_ABORT_SELF   If you attempted to pend abort the calling task.  This is not
*                                                     possible since the calling task cannot be pending because it's
*                                                     running.
*
* Returns    : == DEF_FALSE   if task was not waiting for a message, or upon error.
*              == DEF_TRUE    if task was waiting for a message and was readied and informed.
************************************************************************************************************************
*/

#if OS_CFG_TASK_SEM_PEND_ABORT_EN > 0u
CPU_BOOLEAN  OSTaskSemPendAbort (OS_TCB  *p_tcb,
                                 OS_OPT   opt,
                                 OS_ERR  *p_err)
{
    CPU_TS         ts;
    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 called from ISR ...                             */
       *p_err = OS_ERR_PEND_ABORT_ISR;                      /* ... can't Pend Abort from an ISR                       */
        return (DEF_FALSE);
    }
#endif

    CPU_CRITICAL_ENTER();
    if ((p_tcb == (OS_TCB *)0) ||                           /* Pend abort self?                                       */
        (p_tcb == OSTCBCurPtr)) {
        CPU_CRITICAL_EXIT();                                /* ... doesn't make sense!                                */
        *p_err = OS_ERR_PEND_ABORT_SELF;
        return (DEF_FALSE);
    }

    if (p_tcb->PendOn != OS_TASK_PEND_ON_TASK_SEM) {        /* Is task waiting for a signal?                          */
        CPU_CRITICAL_EXIT();
        *p_err = OS_ERR_PEND_ABORT_NONE;
        return (DEF_FALSE);
    }
    CPU_CRITICAL_EXIT();

    OS_CRITICAL_ENTER();
    ts = OS_TS_GET();
    OS_PendAbort((OS_PEND_OBJ *)0,
                 p_tcb,
                 ts);
    OS_CRITICAL_EXIT_NO_SCHED();
    if ((opt & OS_OPT_POST_NO_SCHED) == (OS_OPT)0) {
        OSSched();                                          /* Run the scheduler                                      */
    }
    *p_err = OS_ERR_NONE;
    return (DEF_TRUE);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                    SIGNAL A TASK
*
* Description: This function is called to signal a task waiting for a signal.
*
* Arguments  : p_tcb     is the pointer to the TCB of the task to signal.  A NULL pointer indicates that you are sending
*                        a signal to yourself.
*
*              opt       determines the type of POST performed:
*
*                             OS_OPT_POST_NONE         No option
*                             OS_OPT_POST_NO_SCHED     Do not call the scheduler
*
*              p_err     is a pointer to an error code returned by this function:
*
*                            OS_ERR_NONE              If the requested task is signaled
*                            OS_ERR_SEM_OVF           If the post would cause the semaphore count to overflow.
*
* Returns    : The current value of the task's signal counter or 0 if called from an ISR
************************************************************************************************************************
*/

OS_SEM_CTR  OSTaskSemPost (OS_TCB  *p_tcb,
                           OS_OPT   opt,
                           OS_ERR  *p_err)
{
    OS_SEM_CTR  ctr;
    CPU_TS      ts;



#ifdef OS_SAFETY_CRITICAL
    if (p_err == (OS_ERR *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
        return ((OS_SEM_CTR)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_TASK_SIGNAL,   /* Post to ISR queue                                      */
                    (void      *)p_tcb,
                    (void      *)0,
                    (OS_MSG_SIZE)0,
                    (OS_FLAGS   )0,
                    (OS_OPT     )0,
                    (CPU_TS     )ts,
                    (OS_ERR    *)p_err);
        return ((OS_SEM_CTR)0);
    }
#endif

    ctr = OS_TaskSemPost(p_tcb,
                         opt,
                         ts,
                         p_err);

    return (ctr);
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                            SET THE SIGNAL COUNTER OF A TASK
*
* Description: This function is called to clear the signal counter
*
* Arguments  : p_tcb      is the pointer to the TCB of the task to clear the counter.  If you specify a NULL pointer
*                         then the signal counter of the current task will be cleared.
*
*              cnt        is the desired value of the semaphore counter
*
*              p_err      is a pointer to an error code returned by this function
*
*                             OS_ERR_NONE        if the signal counter of the requested task is cleared
*                             OS_ERR_SET_ISR     if the function was called from an ISR
*
* Returns    : none
************************************************************************************************************************
*/

OS_SEM_CTR  OSTaskSemSet (OS_TCB      *p_tcb,
                          OS_SEM_CTR   cnt,
                          OS_ERR      *p_err)
{
    OS_SEM_CTR  ctr;
    CPU_SR_ALLOC();



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* Not allowed to call from an ISR                        */
       *p_err = OS_ERR_SET_ISR;
        return ((OS_SEM_CTR)0);
    }
#endif

    CPU_CRITICAL_ENTER();
    if (p_tcb == (OS_TCB *)0) {
        p_tcb = OSTCBCurPtr;
    }
    ctr           = p_tcb->SemCtr;
    p_tcb->SemCtr = (OS_SEM_CTR)cnt;
    CPU_CRITICAL_EXIT();
    *p_err        =  OS_ERR_NONE;
    return (ctr);
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                                    STACK CHECKING
*
* Description: This function is called to calculate the amount of free memory left on the specified task's stack.
*
* Arguments  : p_tcb       is a pointer to the TCB of the task to check.  If you specify a NULL pointer then
*                          you are specifying that you want to check the stack of the current task.
*
*              p_free      is a pointer to a variable that will receive the number of free 'entries' on the task's stack.
*
*              p_used      is a pointer to a variable that will receive the number of used 'entries' on the task's stack.
*
*              p_err       is a pointer to a variable that will contain an error code.
*
*                              OS_ERR_NONE               upon success
*                              OS_ERR_PTR_INVALID        if either 'p_free' or 'p_used' are NULL pointers
*                              OS_ERR_TASK_NOT_EXIST     if the stack pointer of the task is a NULL pointer
*                              OS_ERR_TASK_OPT           if you did NOT specified OS_OPT_TASK_STK_CHK when the task
*                                                        was created
*                              OS_ERR_TASK_STK_CHK_ISR   you called this function from an ISR
************************************************************************************************************************
*/

#if OS_CFG_STAT_TASK_STK_CHK_EN > 0u
void  OSTaskStkChk (OS_TCB       *p_tcb,
                    CPU_STK_SIZE *p_free,
                    CPU_STK_SIZE *p_used,
                    OS_ERR       *p_err)
{
    CPU_STK_SIZE  free_stk;
    CPU_STK      *p_stk;
    CPU_SR_ALLOC();



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

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

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_free == (CPU_STK_SIZE*)0) {                       /* User must specify valid destinations for the sizes     */
        *p_err = OS_ERR_PTR_INVALID;
        return;
    }

    if (p_used == (CPU_STK_SIZE*)0) {
        *p_err = OS_ERR_PTR_INVALID;
        return;
    }
#endif

    CPU_CRITICAL_ENTER();
    if (p_tcb == (OS_TCB *)0) {                             /* Check the stack of the current task?                   */
        p_tcb = OSTCBCurPtr;                                /* Yes                                                    */
    }

    if (p_tcb->StkPtr == (CPU_STK*)0) {                     /* Make sure task exist                                   */
        CPU_CRITICAL_EXIT();
        *p_free = (CPU_STK_SIZE)0;
        *p_used = (CPU_STK_SIZE)0;
        *p_err  =  OS_ERR_TASK_NOT_EXIST;
        return;
    }

    if ((p_tcb->Opt & OS_OPT_TASK_STK_CHK) == (OS_OPT)0) {  /* Make sure stack checking option is set                 */
        CPU_CRITICAL_EXIT();
        *p_free = (CPU_STK_SIZE)0;
        *p_used = (CPU_STK_SIZE)0;
        *p_err  =  OS_ERR_TASK_OPT;
        return;
    }
    CPU_CRITICAL_EXIT();

    free_stk  = 0u;
#if CPU_CFG_STK_GROWTH == CPU_STK_GROWTH_HI_TO_LO
    p_stk = p_tcb->StkBasePtr;                              /* Start at the lowest memory and go up                   */
    while (*p_stk == (CPU_STK)0) {                          /* Compute the number of zero entries on the stk          */
        p_stk++;
        free_stk++;
    }
#else
    p_stk = p_tcb->StkBasePtr + p_tcb->StkSize - 1u;        /* Start at the highest memory and go down                */
    while (*p_stk == (CPU_STK)0) {
        free_stk++;
        p_stk--;
    }
#endif
    *p_free = free_stk;
    *p_used = (p_tcb->StkSize - free_stk);                  /* Compute number of entries used on the stack            */
    *p_err  = 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 'p_tcb' is a NULL pointer
*              or the pointer to the TCB of the calling task.
*
* Arguments  : p_tcb    is a pointer to the TCB to suspend.
*                       If p_tcb is a NULL pointer then, suspend the current task.
*
*              p_err    is a pointer to a variable that will receive an error code from this function.
*
*                           OS_ERR_NONE                      if the requested task is suspended
*                           OS_ERR_SCHED_LOCKED              you can't suspend the current task is the scheduler is
*                                                            locked
*                           OS_ERR_TASK_SUSPEND_ISR          if you called this function from an ISR
*                           OS_ERR_TASK_SUSPEND_IDLE         if you attempted to suspend the idle task which is not
*                                                            allowed.
*                           OS_ERR_TASK_SUSPEND_INT_HANDLER  if you attempted to suspend the idle task which is not
*                                                            allowed.
*
* Note(s)    : 1) You should use this function with great care.  If you suspend a task that is waiting for an event
*                 (i.e. a message, a semaphore, a queue ...) you will prevent this task from running when the event
*                 arrives.
************************************************************************************************************************
*/

#if OS_CFG_TASK_SUSPEND_EN > 0u
void   OSTaskSuspend (OS_TCB  *p_tcb,
                      OS_ERR  *p_err)
{
    CPU_SR_ALLOC();



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

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

    if (p_tcb == &OSIdleTaskTCB) {                          /* Make sure not suspending the idle task                 */
        *p_err = OS_ERR_TASK_SUSPEND_IDLE;
        return;
    }

#if OS_CFG_ISR_POST_DEFERRED_EN > 0u
    if (p_tcb == &OSIntQTaskTCB) {                          /* Not allowed to suspend the ISR handler task            */
        *p_err = OS_ERR_TASK_SUSPEND_INT_HANDLER;
        return;
    }
#endif

    CPU_CRITICAL_ENTER();
    if (p_tcb == (OS_TCB *)0) {                             /* See if specified to suspend self                       */
        p_tcb = OSTCBCurPtr;
    }

    if (p_tcb == OSTCBCurPtr) {
        if (OSSchedLockNestingCtr > (OS_NESTING_CTR)0) {    /* Can't suspend when the scheduler is locked             */
            CPU_CRITICAL_EXIT();
            *p_err = OS_ERR_SCHED_LOCKED;
            return;
        }
    }

    *p_err = OS_ERR_NONE;
    switch (p_tcb->TaskState) {
        case OS_TASK_STATE_RDY:
             OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT();
             p_tcb->TaskState  =  OS_TASK_STATE_SUSPENDED;
             p_tcb->SuspendCtr = (OS_NESTING_CTR)1;
             OS_RdyListRemove(p_tcb);
             OS_CRITICAL_EXIT_NO_SCHED();
             break;

        case OS_TASK_STATE_DLY:
             p_tcb->TaskState  = OS_TASK_STATE_DLY_SUSPENDED;
             p_tcb->SuspendCtr = (OS_NESTING_CTR)1;
             CPU_CRITICAL_EXIT();
             break;

        case OS_TASK_STATE_PEND:
             p_tcb->TaskState  = OS_TASK_STATE_PEND_SUSPENDED;
             p_tcb->SuspendCtr = (OS_NESTING_CTR)1;
             CPU_CRITICAL_EXIT();
             break;

        case OS_TASK_STATE_PEND_TIMEOUT:
             p_tcb->TaskState  = OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED;
             p_tcb->SuspendCtr = (OS_NESTING_CTR)1;
             CPU_CRITICAL_EXIT();
             break;

        case OS_TASK_STATE_SUSPENDED:
        case OS_TASK_STATE_DLY_SUSPENDED:
        case OS_TASK_STATE_PEND_SUSPENDED:
        case OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED:
             p_tcb->SuspendCtr++;
             CPU_CRITICAL_EXIT();
             break;

        default:
             CPU_CRITICAL_EXIT();
             *p_err = OS_ERR_STATE_INVALID;
             return;
    }

    OSSched();
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                CHANGE A TASK'S TIME SLICE
*
* Description: This function is called to change the value of the task's specific time slice.
*
* Arguments  : p_tcb        is the pointer to the TCB of the task to change. If you specify an NULL pointer, the current
*                           task is assumed.
*
*              time_quanta  is the number of ticks before the CPU is taken away when round-robin scheduling is enabled.
*
*              p_err        is a pointer to an error code returned by this function:
*
*                               OS_ERR_NONE       upon success
*                               OS_ERR_SET_ISR    if you called this function from an ISR
*
* Returns    : none
************************************************************************************************************************
*/

#if OS_CFG_SCHED_ROUND_ROBIN_EN > 0u
void  OSTaskTimeQuantaSet (OS_TCB   *p_tcb,
                           OS_TICK   time_quanta,
                           OS_ERR   *p_err)
{
    CPU_SR_ALLOC();



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

#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* Can't call this function from an ISR                   */
       *p_err = OS_ERR_SET_ISR;
        return;
    }
#endif

    CPU_CRITICAL_ENTER();
    if (p_tcb == (OS_TCB *)0) {
        p_tcb = OSTCBCurPtr;
    }

    if (time_quanta == 0u) {
        p_tcb->TimeQuanta    = OSSchedRoundRobinDfltTimeQuanta;
    } else {
        p_tcb->TimeQuanta    = time_quanta;
    }
    if (p_tcb->TimeQuanta > p_tcb->TimeQuantaCtr) {
        p_tcb->TimeQuantaCtr = p_tcb->TimeQuanta;
    }
    CPU_CRITICAL_EXIT();
    *p_err = OS_ERR_NONE;
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                            ADD/REMOVE TASK TO/FROM DEBUG LIST
*
* Description: These functions are called by uC/OS-III to add or remove an OS_TCB from the debug list.
*
* Arguments  : p_tcb     is a pointer to the OS_TCB 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_TaskDbgListAdd (OS_TCB  *p_tcb)
{
    p_tcb->DbgPrevPtr                = (OS_TCB *)0;
    if (OSTaskDbgListPtr == (OS_TCB *)0) {
        p_tcb->DbgNextPtr            = (OS_TCB *)0;
    } else {
        p_tcb->DbgNextPtr            =  OSTaskDbgListPtr;
        OSTaskDbgListPtr->DbgPrevPtr =  p_tcb;
    }
    OSTaskDbgListPtr                 =  p_tcb;
}



void  OS_TaskDbgListRemove (OS_TCB  *p_tcb)
{
    OS_TCB  *p_tcb_next;
    OS_TCB  *p_tcb_prev;


    p_tcb_prev = p_tcb->DbgPrevPtr;
    p_tcb_next = p_tcb->DbgNextPtr;

    if (p_tcb_prev == (OS_TCB *)0) {
        OSTaskDbgListPtr = p_tcb_next;
        if (p_tcb_next != (OS_TCB *)0) {
            p_tcb_next->DbgPrevPtr = (OS_TCB *)0;
        }
        p_tcb->DbgNextPtr = (OS_TCB *)0;

    } else if (p_tcb_next == (OS_TCB *)0) {
        p_tcb_prev->DbgNextPtr = (OS_TCB *)0;
        p_tcb->DbgPrevPtr      = (OS_TCB *)0;

    } else {
        p_tcb_prev->DbgNextPtr =  p_tcb_next;
        p_tcb_next->DbgPrevPtr =  p_tcb_prev;
        p_tcb->DbgNextPtr      = (OS_TCB *)0;
        p_tcb->DbgPrevPtr      = (OS_TCB *)0;
    }
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                             TASK MANAGER INITIALIZATION
*
* Description: This function is called by OSInit() to initialize the task management.
*

* Argument(s): p_err        is a pointer to a variable that will contain an error code returned by this function.
*
*                                OS_ERR_NONE     the call was successful
*
* Returns    : none
*
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/

void  OS_TaskInit (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
    OSTaskDbgListPtr = (OS_TCB      *)0;
#endif

    OSTaskQty        = (OS_OBJ_QTY   )0;                    /* Clear the number of tasks                              */
    OSTaskCtxSwCtr   = (OS_CTX_SW_CTR)0;                    /* Clear the context switch counter                       */

   *p_err            = OS_ERR_NONE;
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                               INITIALIZE TCB FIELDS
*
* Description: This function is called to initialize a TCB to default values
*
* Arguments  : p_tcb    is a pointer to the TCB to initialize
*
* Returns    : none
*
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/

void  OS_TaskInitTCB (OS_TCB *p_tcb)
{
#if OS_CFG_TASK_REG_TBL_SIZE > 0u
    OS_REG_ID   id;
#endif
#if OS_CFG_TASK_PROFILE_EN > 0u
    CPU_TS      ts;
#endif


    p_tcb->StkPtr             = (CPU_STK       *)0;
    p_tcb->StkLimitPtr        = (CPU_STK       *)0;

    p_tcb->ExtPtr             = (void          *)0;

    p_tcb->NextPtr            = (OS_TCB        *)0;
    p_tcb->PrevPtr            = (OS_TCB        *)0;

    p_tcb->TickNextPtr        = (OS_TCB        *)0;
    p_tcb->TickPrevPtr        = (OS_TCB        *)0;
    p_tcb->TickSpokePtr       = (OS_TICK_SPOKE *)0;

    p_tcb->NamePtr            = (CPU_CHAR      *)((void *)"?Task");

    p_tcb->StkBasePtr         = (CPU_STK       *)0;

    p_tcb->TaskEntryAddr      = (OS_TASK_PTR    )0;
    p_tcb->TaskEntryArg       = (void          *)0;

#if (OS_CFG_PEND_MULTI_EN > 0u)
    p_tcb->PendDataTblPtr     = (OS_PEND_DATA  *)0;
    p_tcb->PendDataTblEntries = (OS_OBJ_QTY     )0u;
#endif

    p_tcb->TS                 = (CPU_TS         )0u;

#if (OS_MSG_EN > 0u)
    p_tcb->MsgPtr             = (void          *)0;
    p_tcb->MsgSize            = (OS_MSG_SIZE    )0u;
#endif

#if OS_CFG_TASK_Q_EN > 0u
    OS_MsgQInit(&p_tcb->MsgQ,
                (OS_MSG_QTY)0u);
#if OS_CFG_TASK_PROFILE_EN > 0u
    p_tcb->MsgQPendTime       = (CPU_TS         )0u;
    p_tcb->MsgQPendTimeMax    = (CPU_TS         )0u;
#endif
#endif

#if OS_CFG_FLAG_EN > 0u
    p_tcb->FlagsPend          = (OS_FLAGS       )0u;
    p_tcb->FlagsOpt           = (OS_OPT         )0u;
    p_tcb->FlagsRdy           = (OS_FLAGS       )0u;
#endif

#if OS_CFG_TASK_REG_TBL_SIZE > 0u
    for (id = 0u; id < OS_CFG_TASK_REG_TBL_SIZE; id++) {
        p_tcb->RegTbl[id] = (OS_REG)0u;
    }
#endif

    p_tcb->SemCtr             = (OS_SEM_CTR     )0u;
#if OS_CFG_TASK_PROFILE_EN > 0u
    p_tcb->SemPendTime        = (CPU_TS         )0u;
    p_tcb->SemPendTimeMax     = (CPU_TS         )0u;
#endif

    p_tcb->StkSize            = (CPU_STK_SIZE   )0u;


#if OS_CFG_TASK_SUSPEND_EN > 0u
    p_tcb->SuspendCtr         = (OS_NESTING_CTR )0u;
#endif

#if OS_CFG_STAT_TASK_STK_CHK_EN > 0u
    p_tcb->StkFree            = (CPU_STK_SIZE   )0u;
    p_tcb->StkUsed            = (CPU_STK_SIZE   )0u;
#endif

    p_tcb->Opt                = (OS_OPT         )0u;

    p_tcb->TickCtrPrev        = (OS_TICK        )OS_TICK_TH_INIT;
    p_tcb->TickCtrMatch       = (OS_TICK        )0u;
    p_tcb->TickRemain         = (OS_TICK        )0u;

    p_tcb->TimeQuanta         = (OS_TICK        )0u;
    p_tcb->TimeQuantaCtr      = (OS_TICK        )0u;

#if OS_CFG_TASK_PROFILE_EN > 0u
    p_tcb->CPUUsage           = (OS_CPU_USAGE   )0u;
    p_tcb->CtxSwCtr           = (OS_CTX_SW_CTR  )0u;
    p_tcb->CyclesDelta        = (CPU_TS         )0u;
    ts                        = OS_TS_GET();                /* Read the current timestamp and save                    */
    p_tcb->CyclesStart        = ts;
    p_tcb->CyclesTotal        = (OS_CYCLES      )0u;
#endif
#ifdef CPU_CFG_INT_DIS_MEAS_EN
    p_tcb->IntDisTimeMax      = (CPU_TS         )0u;
#endif
#if OS_CFG_SCHED_LOCK_TIME_MEAS_EN > 0u
    p_tcb->SchedLockTimeMax   = (CPU_TS         )0u;
#endif

    p_tcb->PendOn             = (OS_STATE       )OS_TASK_PEND_ON_NOTHING;
    p_tcb->PendStatus         = (OS_STATUS      )OS_STATUS_PEND_OK;
    p_tcb->TaskState          = (OS_STATE       )OS_TASK_STATE_RDY;

    p_tcb->Prio               = (OS_PRIO        )OS_PRIO_INIT;

#if OS_CFG_DBG_EN > 0u
    p_tcb->DbgPrevPtr         = (OS_TCB        *)0;
    p_tcb->DbgNextPtr         = (OS_TCB        *)0;
    p_tcb->DbgNamePtr         = (CPU_CHAR      *)((void *)" ");
#endif
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                               POST MESSAGE TO A TASK
*
* Description: This function sends a message to a task
*
* Arguments  : p_tcb      is a pointer to the TCB of the task receiving a message.  If you specify a NULL pointer then
*                         the message will be posted to the task's queue of the calling task.  In other words, you'd be
*                         posting a message to yourself.
*
*              p_void     is a pointer to the message to send.
*
*              msg_size   is the size of the message sent (in #bytes)
*
*              opt        specifies whether the post will be FIFO or LIFO:
*
*                             OS_OPT_POST_FIFO       Post at the end   of the queue
*                             OS_OPT_POST_LIFO       Post at the front of the queue
*
*                             OS_OPT_POST_NO_SCHED   Do not run the scheduler after the post
*
*                          Note(s): 1) OS_OPT_POST_NO_SCHED can be added with one of the other options.
*
*
*              ts         is a timestamp indicating when the post occurred.
*
*              p_err      is a pointer to a variable that will hold the error code associated
*                         with the outcome of this call.  Errors can be:
*
*                             OS_ERR_NONE            The call was successful and the message was sent
*                             OS_ERR_MSG_POOL_EMPTY  If there are no more OS_MSGs available from the pool
*                             OS_ERR_Q_MAX           If the queue is full
*                             OS_ERR_STATE_INVALID   If the task is in an invalid state.  This should never happen
*                                                    and if it does, would be considered a system failure.
*
* Returns    : none
*
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/

#if OS_CFG_TASK_Q_EN > 0u
void  OS_TaskQPost (OS_TCB      *p_tcb,
                    void        *p_void,
                    OS_MSG_SIZE  msg_size,
                    OS_OPT       opt,
                    CPU_TS       ts,
                    OS_ERR      *p_err)
{
    CPU_SR_ALLOC();



    OS_CRITICAL_ENTER();
    if (p_tcb == (OS_TCB *)0) {                             /* Post msg to 'self'?                                    */
        p_tcb = OSTCBCurPtr;
    }
    *p_err  = OS_ERR_NONE;                                  /* Assume we won't have any errors                        */
    switch (p_tcb->TaskState) {
        case OS_TASK_STATE_RDY:
        case OS_TASK_STATE_DLY:
        case OS_TASK_STATE_SUSPENDED:
        case OS_TASK_STATE_DLY_SUSPENDED:
             OS_MsgQPut(&p_tcb->MsgQ,                       /* Deposit the message in the queue                       */
                        p_void,
                        msg_size,
                        opt,
                        ts,
                        p_err);
             OS_CRITICAL_EXIT();
             break;

        case OS_TASK_STATE_PEND:
        case OS_TASK_STATE_PEND_TIMEOUT:
        case OS_TASK_STATE_PEND_SUSPENDED:
        case OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED:
             if (p_tcb->PendOn == OS_TASK_PEND_ON_TASK_Q) { /* Is task waiting for a message to be sent to it?        */
                 OS_Post((OS_PEND_OBJ *)0,
                         p_tcb,
                         p_void,
                         msg_size,
                         ts);
                 OS_CRITICAL_EXIT_NO_SCHED();
                 if ((opt & OS_OPT_POST_NO_SCHED) == (OS_OPT)0u) {
                     OSSched();                             /* Run the scheduler                                      */
                 }
             } else {
                 OS_MsgQPut(&p_tcb->MsgQ,                   /* No,  Task is pending on something else ...             */
                            p_void,                         /*      ... Deposit the message in the task's queue       */
                            msg_size,
                            opt,
                            ts,
                            p_err);
                 OS_CRITICAL_EXIT();
             }
             break;

        default:
             OS_CRITICAL_EXIT();
             *p_err = OS_ERR_STATE_INVALID;
             break;
    }
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                              CATCH ACCIDENTAL TASK RETURN
*
* Description: This function is called if a task accidentally returns without deleting itself.  In other words, a task
*              should either be an infinite loop or delete itself if it's done.
*
* Arguments  : none
*
* Returns    : none
*
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/

void  OS_TaskReturn (void)
{
    OS_ERR  err;



    OSTaskReturnHook(OSTCBCurPtr);                          /* Call hook to let user decide on what to do             */
#if OS_CFG_TASK_DEL_EN > 0u
    OSTaskDel((OS_TCB *)0,                                  /* Delete task if it accidentally returns!                */
              (OS_ERR *)&err);
#else
    for (;;) {
        OSTimeDly((OS_TICK )OSCfg_TickRate_Hz,
                  (OS_OPT  )OS_OPT_TIME_DLY,
                  (OS_ERR *)&err);
    }
#endif
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                                    SIGNAL A TASK
*
* Description: This function is called to signal a task waiting for a signal.
*
* Arguments  : p_tcb     is the pointer to the TCB of the task to signal.  A NULL pointer indicates that you are sending
*                        a signal to yourself.
*
*              opt       determines the type of POST performed:
*
*                             OS_OPT_POST_NONE         No option
*
*                             OS_OPT_POST_NO_SCHED     Do not call the scheduler
*
*              ts        is a timestamp indicating when the post occurred.
*
*              p_err     is a pointer to an error code returned by this function:
*
*                            OS_ERR_NONE           If the requested task is signaled
*                            OS_ERR_SEM_OVF        If the post would cause the semaphore count to overflow.
*                            OS_ERR_STATE_INVALID  If the task is in an invalid state.  This should never happen
*                                                  and if it does, would be considered a system failure.
*
* Returns    : The current value of the task's signal counter or 0 if called from an ISR
*
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it.
************************************************************************************************************************
*/

OS_SEM_CTR  OS_TaskSemPost (OS_TCB  *p_tcb,
                            OS_OPT   opt,
                            CPU_TS   ts,
                            OS_ERR  *p_err)
{
    OS_SEM_CTR  ctr;
    CPU_SR_ALLOC();



    OS_CRITICAL_ENTER();
    if (p_tcb == (OS_TCB *)0) {                             /* Post signal to 'self'?                                 */
        p_tcb = OSTCBCurPtr;
    }
    p_tcb->TS = ts;
    *p_err    = OS_ERR_NONE;                                /* Assume we won't have any errors                        */
    switch (p_tcb->TaskState) {
        case OS_TASK_STATE_RDY:
        case OS_TASK_STATE_DLY:
        case OS_TASK_STATE_SUSPENDED:
        case OS_TASK_STATE_DLY_SUSPENDED:
             switch (sizeof(OS_SEM_CTR)) {
                 case 1u:
                      if (p_tcb->SemCtr == DEF_INT_08U_MAX_VAL) {
                          OS_CRITICAL_EXIT();
                          *p_err = OS_ERR_SEM_OVF;
                          return ((OS_SEM_CTR)0);
                      }
                      break;

                 case 2u:
                      if (p_tcb->SemCtr == DEF_INT_16U_MAX_VAL) {
                          OS_CRITICAL_EXIT();
                          *p_err = OS_ERR_SEM_OVF;
                          return ((OS_SEM_CTR)0);
                      }
                      break;

                 case 4u:
                      if (p_tcb->SemCtr == DEF_INT_32U_MAX_VAL) {
                          OS_CRITICAL_EXIT();
                          *p_err = OS_ERR_SEM_OVF;
                          return ((OS_SEM_CTR)0);
                      }
                      break;

                 default:
                      break;
             }
             p_tcb->SemCtr++;                               /* Task signaled is not pending on anything               */
             ctr = p_tcb->SemCtr;
             OS_CRITICAL_EXIT();
             break;

        case OS_TASK_STATE_PEND:
        case OS_TASK_STATE_PEND_TIMEOUT:
        case OS_TASK_STATE_PEND_SUSPENDED:
        case OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED:
             if (p_tcb->PendOn == OS_TASK_PEND_ON_TASK_SEM) {   /* Is task signaled waiting for a signal?             */
                 OS_Post((OS_PEND_OBJ *)0,                      /*      Task is pending on signal                     */
                         (OS_TCB      *)p_tcb,
                         (void        *)0,
                         (OS_MSG_SIZE  )0u,
                         (CPU_TS       )ts);
                 ctr = p_tcb->SemCtr;
                 OS_CRITICAL_EXIT_NO_SCHED();
                 if ((opt & OS_OPT_POST_NO_SCHED) == (OS_OPT)0) {
                     OSSched();                                 /* Run the scheduler                                  */
                 }
             } else {
                 p_tcb->SemCtr++;                           /* No,  Task signaled is NOT pending on semaphore ...     */
                 ctr = p_tcb->SemCtr;                       /*      ... it must be waiting on something else          */
                 OS_CRITICAL_EXIT();
             }
             break;

        default:
             OS_CRITICAL_EXIT();
             *p_err = OS_ERR_STATE_INVALID;
             ctr = (OS_SEM_CTR)0;
             break;
    }
    return (ctr);
}