BaseType_t xTaskGenericNotifyFromISR()

in tasks.c [4992:5124]
80 lines of code
12 McCabe index (conditional complexity)

    BaseType_t xTaskGenericNotifyFromISR( TaskHandle_t xTaskToNotify,
                                          UBaseType_t uxIndexToNotify,
                                          uint32_t ulValue,
                                          eNotifyAction eAction,
                                          uint32_t * pulPreviousNotificationValue,
                                          BaseType_t * pxHigherPriorityTaskWoken )
    {
        TCB_t * pxTCB;
        uint8_t ucOriginalNotifyState;
        BaseType_t xReturn = pdPASS;
        UBaseType_t uxSavedInterruptStatus;

        configASSERT( xTaskToNotify );
        configASSERT( uxIndexToNotify < configTASK_NOTIFICATION_ARRAY_ENTRIES );

        /* 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 keep
         * 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();

        pxTCB = xTaskToNotify;

        uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();
        {
            if( pulPreviousNotificationValue != NULL )
            {
                *pulPreviousNotificationValue = pxTCB->ulNotifiedValue[ uxIndexToNotify ];
            }

            ucOriginalNotifyState = pxTCB->ucNotifyState[ uxIndexToNotify ];
            pxTCB->ucNotifyState[ uxIndexToNotify ] = taskNOTIFICATION_RECEIVED;

            switch( eAction )
            {
                case eSetBits:
                    pxTCB->ulNotifiedValue[ uxIndexToNotify ] |= ulValue;
                    break;

                case eIncrement:
                    ( pxTCB->ulNotifiedValue[ uxIndexToNotify ] )++;
                    break;

                case eSetValueWithOverwrite:
                    pxTCB->ulNotifiedValue[ uxIndexToNotify ] = ulValue;
                    break;

                case eSetValueWithoutOverwrite:

                    if( ucOriginalNotifyState != taskNOTIFICATION_RECEIVED )
                    {
                        pxTCB->ulNotifiedValue[ uxIndexToNotify ] = ulValue;
                    }
                    else
                    {
                        /* The value could not be written to the task. */
                        xReturn = pdFAIL;
                    }

                    break;

                case eNoAction:

                    /* The task is being notified without its notify value being
                     * updated. */
                    break;

                default:

                    /* Should not get here if all enums are handled.
                     * Artificially force an assert by testing a value the
                     * compiler can't assume is const. */
                    configASSERT( xTickCount == ( TickType_t ) 0 );
                    break;
            }

            traceTASK_NOTIFY_FROM_ISR( uxIndexToNotify );

            /* If the task is in the blocked state specifically to wait for a
             * notification then unblock it now. */
            if( ucOriginalNotifyState == taskWAITING_NOTIFICATION )
            {
                /* The task should not have been on an event list. */
                configASSERT( listLIST_ITEM_CONTAINER( &( pxTCB->xEventListItem ) ) == NULL );

                if( uxSchedulerSuspended == ( UBaseType_t ) pdFALSE )
                {
                    listREMOVE_ITEM( &( pxTCB->xStateListItem ) );
                    prvAddTaskToReadyList( pxTCB );
                }
                else
                {
                    /* The delayed and ready lists cannot be accessed, so hold
                     * this task pending until the scheduler is resumed. */
                    listINSERT_END( &( xPendingReadyList ), &( pxTCB->xEventListItem ) );
                }

                if( pxTCB->uxPriority > pxCurrentTCB->uxPriority )
                {
                    /* The notified task has a priority above the currently
                     * executing task so a yield is required. */
                    if( pxHigherPriorityTaskWoken != NULL )
                    {
                        *pxHigherPriorityTaskWoken = pdTRUE;
                    }

                    /* Mark that a yield is pending in case the user is not
                     * using the "xHigherPriorityTaskWoken" parameter to an ISR
                     * safe FreeRTOS function. */
                    xYieldPending = pdTRUE;
                }
                else
                {
                    mtCOVERAGE_TEST_MARKER();
                }
            }
        }
        portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );

        return xReturn;
    }