BaseType_t xQueueGiveFromISR( QueueHandle_t xQueue,
                              BaseType_t * const pxHigherPriorityTaskWoken )
{
    BaseType_t xReturn;
    UBaseType_t uxSavedInterruptStatus;
    Queue_t * const pxQueue = xQueue;

    /* Similar to xQueueGenericSendFromISR() but used with semaphores where the
     * item size is 0.  Don't directly wake a task that was blocked on a queue
     * read, instead return a flag to say whether a context switch is required or
     * not (i.e. has a task with a higher priority than us been woken by this
     * post). */

    configASSERT( pxQueue );

    /* xQueueGenericSendFromISR() should be used instead of xQueueGiveFromISR()
     * if the item size is not 0. */
    configASSERT( pxQueue->uxItemSize == 0 );

    /* Normally a mutex would not be given from an interrupt, especially if
     * there is a mutex holder, as priority inheritance makes no sense for an
     * interrupts, only tasks. */
    configASSERT( !( ( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX ) && ( pxQueue->u.xSemaphore.xMutexHolder != NULL ) ) );

    /* RTOS ports that support interrupt nesting have the concept of a maximum
     * system call (or maximum API call) interrupt priority.  Interrupts that are
     * above the maximum system call priority are kept permanently enabled, even
     * when the RTOS kernel is in a critical section, but cannot make any calls to
     * FreeRTOS API functions.  If configASSERT() is defined in FreeRTOSConfig.h
     * then portASSERT_IF_INTERRUPT_PRIORITY_INVALID() will result in an assertion
     * failure if a FreeRTOS API function is called from an interrupt that has been
     * assigned a priority above the configured maximum system call priority.
     * Only FreeRTOS functions that end in FromISR can be called from interrupts
     * that have been assigned a priority at or (logically) below the maximum
     * system call interrupt priority.  FreeRTOS maintains a separate interrupt
     * safe API to ensure interrupt entry is as fast and as simple as possible.
     * More information (albeit Cortex-M specific) is provided on the following
     * link: https://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */
    portASSERT_IF_INTERRUPT_PRIORITY_INVALID();

    uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();
    {
        const UBaseType_t uxMessagesWaiting = pxQueue->uxMessagesWaiting;

        /* When the queue is used to implement a semaphore no data is ever
         * moved through the queue but it is still valid to see if the queue 'has
         * space'. */
        if( uxMessagesWaiting < pxQueue->uxLength )
        {
            const int8_t cTxLock = pxQueue->cTxLock;

            traceQUEUE_SEND_FROM_ISR( pxQueue );

            /* A task can only have an inherited priority if it is a mutex
             * holder - and if there is a mutex holder then the mutex cannot be
             * given from an ISR.  As this is the ISR version of the function it
             * can be assumed there is no mutex holder and no need to determine if
             * priority disinheritance is needed.  Simply increase the count of
             * messages (semaphores) available. */
            pxQueue->uxMessagesWaiting = uxMessagesWaiting + ( UBaseType_t ) 1;

            /* The event list is not altered if the queue is locked.  This will
             * be done when the queue is unlocked later. */
            if( cTxLock == queueUNLOCKED )
            {
                #if ( configUSE_QUEUE_SETS == 1 )
                    {
                        if( pxQueue->pxQueueSetContainer != NULL )
                        {
                            if( prvNotifyQueueSetContainer( pxQueue ) != pdFALSE )
                            {
                                /* The semaphore is a member of a queue set, and
                                 * posting to the queue set caused a higher priority
                                 * task to unblock.  A context switch is required. */
                                if( pxHigherPriorityTaskWoken != NULL )
                                {
                                    *pxHigherPriorityTaskWoken = pdTRUE;
                                }
                                else
                                {
                                    mtCOVERAGE_TEST_MARKER();
                                }
                            }
                            else
                            {
                                mtCOVERAGE_TEST_MARKER();
                            }
                        }
                        else
                        {
                            if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )
                            {
                                if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
                                {
                                    /* The task waiting has a higher priority so
                                     *  record that a context switch is required. */
                                    if( pxHigherPriorityTaskWoken != NULL )
                                    {
                                        *pxHigherPriorityTaskWoken = pdTRUE;
                                    }
                                    else
                                    {
                                        mtCOVERAGE_TEST_MARKER();
                                    }
                                }
                                else
                                {
                                    mtCOVERAGE_TEST_MARKER();
                                }
                            }
                            else
                            {
                                mtCOVERAGE_TEST_MARKER();
                            }
                        }
                    }
                #else /* configUSE_QUEUE_SETS */
                    {
                        if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )
                        {
                            if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
                            {
                                /* The task waiting has a higher priority so record that a
                                 * context switch is required. */
                                if( pxHigherPriorityTaskWoken != NULL )
                                {
                                    *pxHigherPriorityTaskWoken = pdTRUE;
                                }
                                else
                                {
                                    mtCOVERAGE_TEST_MARKER();
                                }
                            }
                            else
                            {
                                mtCOVERAGE_TEST_MARKER();
                            }
                        }
                        else
                        {
                            mtCOVERAGE_TEST_MARKER();
                        }
                    }
                #endif /* configUSE_QUEUE_SETS */
            }
            else
            {
                /* Increment the lock count so the task that unlocks the queue
                 * knows that data was posted while it was locked. */
                configASSERT( cTxLock != queueINT8_MAX );

                pxQueue->cTxLock = ( int8_t ) ( cTxLock + 1 );
            }

            xReturn = pdPASS;
        }
        else
        {
            traceQUEUE_SEND_FROM_ISR_FAILED( pxQueue );
            xReturn = errQUEUE_FULL;
        }
    }
    portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );

    return xReturn;
}
