Function prvSelectHighestPriorityTask

tasks.c:820–1037

#if ( configUSE_PORT_OPTIMISED_TASK_SELECTION == 0 )

    static BaseType_t prvSelectHighestPriorityTask( const BaseType_t xCoreID )
    {
        UBaseType_t uxCurrentPriority = uxTopReadyPriority;
        BaseType_t xTaskScheduled = pdFALSE;
        BaseType_t xDecrementTopPriority = pdTRUE;

        #if ( configUSE_CORE_AFFINITY == 1 )
            TCB_t * pxPreviousTCB = NULL;
        #endif
        #if ( ( configRUN_MULTIPLE_PRIORITIES == 0 ) && ( configNUM_CORES > 1 ) )
            BaseType_t xPriorityDropped = pdFALSE;
        #endif

        while( xTaskScheduled == pdFALSE )
        {
            #if ( ( configRUN_MULTIPLE_PRIORITIES == 0 ) && ( configNUM_CORES > 1 ) )
                {
                    if( uxCurrentPriority < uxTopReadyPriority )
                    {
                        /* We can't schedule any tasks, other than idle, that have a
                         * priority lower than the priority of a task currently running
                         * on another core. */
                        uxCurrentPriority = tskIDLE_PRIORITY;
                    }
                }
            #endif

            if( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxCurrentPriority ] ) ) == pdFALSE )
            {
                List_t * const pxReadyList = &( pxReadyTasksLists[ uxCurrentPriority ] );
                ListItem_t * pxLastTaskItem = pxReadyList->pxIndex->pxPrevious;
                ListItem_t * pxTaskItem = pxLastTaskItem;

                if( ( void * ) pxLastTaskItem == ( void * ) &( pxReadyList->xListEnd ) )
                {
                    pxLastTaskItem = pxLastTaskItem->pxPrevious;
                }

                /* The ready task list for uxCurrentPriority is not empty, so uxTopReadyPriority
                 * must not be decremented any further */
                xDecrementTopPriority = pdFALSE;

                do
                {
                    TCB_t * pxTCB;

                    pxTaskItem = pxTaskItem->pxNext;

                    if( ( void * ) pxTaskItem == ( void * ) &( pxReadyList->xListEnd ) )
                    {
                        pxTaskItem = pxTaskItem->pxNext;
                    }

                    pxTCB = pxTaskItem->pvOwner;

                    /*debug_printf("Attempting to schedule %s on core %d\n", pxTCB->pcTaskName, portGET_CORE_ID() ); */

                    #if ( ( configRUN_MULTIPLE_PRIORITIES == 0 ) && ( configNUM_CORES > 1 ) )