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

    configASSERT( pxQueue );
    configASSERT( !( ( pvBuffer == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );

    /* 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;

        /* Cannot block in an ISR, so check there is data available. */
        if( uxMessagesWaiting > ( UBaseType_t ) 0 )
        {
            const int8_t cRxLock = pxQueue->cRxLock;

            traceQUEUE_RECEIVE_FROM_ISR( pxQueue );

            prvCopyDataFromQueue( pxQueue, pvBuffer );
            pxQueue->uxMessagesWaiting = uxMessagesWaiting - ( UBaseType_t ) 1;

            /* If the queue is locked the event list will not be modified.
             * Instead update the lock count so the task that unlocks the queue
             * will know that an ISR has removed data while the queue was
             * locked. */
            if( cRxLock == queueUNLOCKED )
            {
                if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )
                {
                    if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
                    {
                        /* The task waiting has a higher priority than us so
                         * force a context switch. */
                        if( pxHigherPriorityTaskWoken != NULL )
                        {
                            *pxHigherPriorityTaskWoken = pdTRUE;
                        }
                        else
                        {
                            mtCOVERAGE_TEST_MARKER();
                        }
                    }
                    else
                    {
                        mtCOVERAGE_TEST_MARKER();
                    }
                }
                else
                {
                    mtCOVERAGE_TEST_MARKER();
                }
            }
            else
            {
                /* Increment the lock count so the task that unlocks the queue
                 * knows that data was removed while it was locked. */
                configASSERT( cRxLock != queueINT8_MAX );

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

            xReturn = pdPASS;
        }
        else
        {
            xReturn = pdFAIL;
            traceQUEUE_RECEIVE_FROM_ISR_FAILED( pxQueue );
        }
    }
    portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );

    return xReturn;
}

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

    configASSERT( pxQueue );
    configASSERT( !( ( pvBuffer == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );

     
    portASSERT_IF_INTERRUPT_PRIORITY_INVALID();

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

         
        if( uxMessagesWaiting > ( UBaseType_t ) 0 )
        {
            const int8_t cRxLock = pxQueue->cRxLock;

            traceQUEUE_RECEIVE_FROM_ISR( pxQueue );

            prvCopyDataFromQueue( pxQueue, pvBuffer );
            pxQueue->uxMessagesWaiting = uxMessagesWaiting - ( UBaseType_t ) 1;

             
            if( cRxLock == queueUNLOCKED )
            {
                if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )
                {
                    if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
                    {
                         
                        if( pxHigherPriorityTaskWoken != NULL )
                        {
                            *pxHigherPriorityTaskWoken = pdTRUE;
                        }
                        else
                        {
                            mtCOVERAGE_TEST_MARKER();
                        }
                    }
                    else
                    {
                        mtCOVERAGE_TEST_MARKER();
                    }
                }
                else
                {
                    mtCOVERAGE_TEST_MARKER();
                }
            }
            else
            {
                 
                configASSERT( cRxLock != queueINT8_MAX );

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

            xReturn = pdPASS;
        }
        else
        {
            xReturn = pdFAIL;
            traceQUEUE_RECEIVE_FROM_ISR_FAILED( pxQueue );
        }
    }
    portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );

    return xReturn;
}
