os_task.c

STM3240G-Eval_uCOS-III

       *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->MsgQPendTimeMax < OSTCBCurPtr->MsgQPendTime) {
                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);
        }
    }
                                                            /* Lock the scheduler/re-enable interrupts                */
    OS_CRITICAL_ENTER_CPU_EXIT();
    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->MsgQPendTimeMax < OSTCBCurPtr->MsgQPendTime) {
                    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

#if OS_CFG_ARG_CHK_EN > 0u                                  /* ---------------- VALIDATE ARGUMENTS ------------------ */
    switch (opt) {                                          /* User must supply a valid option                        */
        case OS_OPT_POST_NONE:
        case OS_OPT_POST_NO_SCHED:
             break;

        default:
            *p_err = OS_ERR_OPT_INVALID;
             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_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.