os_sem.c

UCOS-III

        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 OS_CFG_ARG_CHK_EN > 0u
    if (p_sem == (OS_SEM *)0) {                             /* Validate arguments                                     */
        *p_err = OS_ERR_OBJ_PTR_NULL;
        return ((OS_SEM_CTR)0);
    }

    switch (opt) {
        case OS_OPT_PEND_BLOCKING:
        case OS_OPT_PEND_NON_BLOCKING:
             break;

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

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_sem->Type != OS_OBJ_TYPE_SEM) {                   /* Make sure semaphore was created                        */
        *p_err = OS_ERR_OBJ_TYPE;
        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 (p_sem->Ctr > (OS_SEM_CTR)0) {                       /* Resource available?                                    */
        p_sem->Ctr--;                                       /* Yes, caller may proceed                                */
        if (p_ts != (CPU_TS *)0) {
           *p_ts  = p_sem->TS;                              /*      get timestamp of last post                        */
        }
        ctr    = p_sem->Ctr;
        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?                */
        ctr    = p_sem->Ctr;                                /* No                                                     */
        CPU_CRITICAL_EXIT();
        *p_err = OS_ERR_PEND_WOULD_BLOCK;
        return (ctr);
    } 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(&pend_data,                                     /* Block task pending on Semaphore                        */
            (OS_PEND_OBJ *)((void *)p_sem),
            OS_TASK_PEND_ON_SEM,
            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:                             /* We got the semaphore                                   */
             if (p_ts != (CPU_TS *)0) {
                *p_ts  =  OSTCBCurPtr->TS;
             }
             *p_err = OS_ERR_NONE;
             break;

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

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

        case OS_STATUS_PEND_DEL:                            /* Indicate that object pended on has been deleted        */
             if (p_ts != (CPU_TS *)0) {
                *p_ts  =  OSTCBCurPtr->TS;
             }
             *p_err = OS_ERR_OBJ_DEL;
             break;

        default:
             *p_err = OS_ERR_STATUS_INVALID;
             CPU_CRITICAL_EXIT();
             return ((OS_SEM_CTR)0);
    }
    ctr = p_sem->Ctr;
    CPU_CRITICAL_EXIT();
    return (ctr);
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                             ABORT WAITING ON A SEMAPHORE
*
* Description: This function aborts & readies any tasks currently waiting on a semaphore.  This function should be used
*              to fault-abort the wait on the semaphore, rather than to normally signal the semaphore via OSSemPost().
*
* Arguments  : p_sem     is a pointer to the semaphore
*
*              opt       determines the type of ABORT performed:
*
*                            OS_OPT_PEND_ABORT_1          ABORT wait for a single task (HPT) waiting on the semaphore
*                            OS_OPT_PEND_ABORT_ALL        ABORT wait for ALL tasks that are  waiting on the semaphore
*                            OS_OPT_POST_NO_SCHED         Do not call the scheduler
*
*              p_err     is a pointer to a variable that will contain an error code returned by this function.
*
*                            OS_ERR_NONE                  At least one task waiting on the semaphore was readied and
*                                                         informed of the aborted wait; check return value for the
*                                                         number of tasks whose wait on the semaphore was aborted.
*                            OS_ERR_OBJ_PTR_NULL          If 'p_sem' is a NULL pointer.
*                            OS_ERR_OBJ_TYPE              If 'p_sem' is not pointing at a semaphore
*                            OS_ERR_OPT_INVALID           If you specified an invalid option
*                            OS_ERR_PEND_ABORT_ISR        If you called this function from an ISR
*                            OS_ERR_PEND_ABORT_NONE       No task were pending
*
* Returns    : == 0          if no tasks were waiting on the semaphore, or upon error.
*              >  0          if one or more tasks waiting on the semaphore are now readied and informed.
************************************************************************************************************************
*/

#if OS_CFG_SEM_PEND_ABORT_EN > 0u
OS_OBJ_QTY  OSSemPendAbort (OS_SEM  *p_sem,
                            OS_OPT   opt,
                            OS_ERR  *p_err)
{
    OS_PEND_LIST  *p_pend_list;
    OS_TCB        *p_tcb;
    CPU_TS         ts;
    OS_OBJ_QTY     nbr_tasks;
    CPU_SR_ALLOC();



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

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

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_sem == (OS_SEM *)0) {                             /* Validate 'p_sem'                                       */
       *p_err =  OS_ERR_OBJ_PTR_NULL;
        return ((OS_OBJ_QTY)0u);
    }
    switch (opt) {                                          /* Validate 'opt'                                         */
        case OS_OPT_PEND_ABORT_1:
        case OS_OPT_PEND_ABORT_ALL:
             break;

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

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_sem->Type != OS_OBJ_TYPE_SEM) {                   /* Make sure semaphore was created                        */
       *p_err =  OS_ERR_OBJ_TYPE;
        return ((OS_OBJ_QTY)0u);
    }
#endif

    CPU_CRITICAL_ENTER();
    p_pend_list = &p_sem->PendList;
    if (p_pend_list->NbrEntries == (OS_OBJ_QTY)0u) {        /* Any task waiting on semaphore?                         */
        CPU_CRITICAL_EXIT();                                /* No                                                     */
       *p_err =  OS_ERR_PEND_ABORT_NONE;
        return ((OS_OBJ_QTY)0u);
    }

    OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT();
    nbr_tasks = 0u;
    ts        = OS_TS_GET();                                /* Get local time stamp so all tasks get the same time    */
    while (p_pend_list->NbrEntries > (OS_OBJ_QTY)0u) {
        p_tcb = p_pend_list->HeadPtr->TCBPtr;
        OS_PendAbort((OS_PEND_OBJ *)((void *)p_sem),
                     p_tcb,
                     ts);
        nbr_tasks++;
        if (opt != OS_OPT_PEND_ABORT_ALL) {                 /* Pend abort all tasks waiting?                          */
            break;                                          /* No                                                     */
        }
    }
    OS_CRITICAL_EXIT_NO_SCHED();

    if ((opt & OS_OPT_POST_NO_SCHED) == (OS_OPT)0u) {
        OSSched();                                          /* Run the scheduler                                      */
    }

   *p_err = OS_ERR_NONE;
    return (nbr_tasks);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                 POST TO A SEMAPHORE
*
* Description: This function signals a semaphore
*
* Arguments  : p_sem    is a pointer to the semaphore
*
*              opt      determines the type of POST performed:
*
*                           OS_OPT_POST_1            POST and ready only the highest priority task waiting on semaphore
*                                                    (if tasks are waiting).
*                           OS_OPT_POST_ALL          POST to ALL tasks that are waiting on the semaphore
*
*                           OS_OPT_POST_NO_SCHED     Do not call the scheduler
*
*                           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 contain an error code returned by this function.
*
*                           OS_ERR_NONE          The call was successful and the semaphore was signaled.
*                           OS_ERR_OBJ_PTR_NULL  If 'p_sem' is a NULL pointer.
*                           OS_ERR_OBJ_TYPE      If 'p_sem' is not pointing at a semaphore
*                           OS_ERR_SEM_OVF       If the post would cause the semaphore count to overflow.
*
* Returns    : The current value of the semaphore counter or 0 upon error.
************************************************************************************************************************
*/

OS_SEM_CTR  OSSemPost (OS_SEM  *p_sem,
                       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

#if OS_CFG_ARG_CHK_EN > 0u
    if (p_sem == (OS_SEM *)0) {                             /* Validate 'p_sem'                                       */
       *p_err  = OS_ERR_OBJ_PTR_NULL;
        return ((OS_SEM_CTR)0);
    }
#endif

#if OS_CFG_OBJ_TYPE_CHK_EN > 0u
    if (p_sem->Type != OS_OBJ_TYPE_SEM) {                   /* Make sure semaphore was created                        */
        *p_err = OS_ERR_OBJ_TYPE;
        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_SEM,           /* Post to ISR queue                                      */
                    (void      *)p_sem,
                    (void      *)0,
                    (OS_MSG_SIZE)0,
                    (OS_FLAGS   )0,
                    (OS_OPT     )opt,
                    (CPU_TS     )ts,
                    (OS_ERR    *)p_err);
        return ((OS_SEM_CTR)0);
    }
#endif

    ctr = OS_SemPost(p_sem,                                 /* Post to semaphore                                      */
                     opt,
                     ts,
                     p_err);

    return (ctr);
}

/*$PAGE*/
/*
************************************************************************************************************************
*                                                    SET SEMAPHORE