tasks.c

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			the list, and an occasional incorrect value will not matter.  If
			the ready list at the idle priority contains more than one task
			then a task other than the idle task is ready to execute. */
			if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )
			{
				taskYIELD();
			}
		}
		#endif

		#if ( configUSE_IDLE_HOOK == 1 )
		{
			extern void vApplicationIdleHook( void );

			/* Call the user defined function from within the idle task.  This
			allows the application designer to add background functionality
			without the overhead of a separate task.
			NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,
			CALL A FUNCTION THAT MIGHT BLOCK. */
			vApplicationIdleHook();
		}
		#endif
	}
} /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */







/*-----------------------------------------------------------
 * File private functions documented at the top of the file.
 *----------------------------------------------------------*/



static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )
{
	/* Store the function name in the TCB. */
	strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );
	pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';

	/* This is used as an array index so must ensure it's not too large. */
	if( uxPriority >= configMAX_PRIORITIES )
	{
		uxPriority = configMAX_PRIORITIES - 1;
	}

	pxTCB->uxPriority = uxPriority;
	#if ( configUSE_MUTEXES == 1 )
	{
		pxTCB->uxBasePriority = uxPriority;
	}
	#endif

	vListInitialiseItem( &( pxTCB->xGenericListItem ) );
	vListInitialiseItem( &( pxTCB->xEventListItem ) );

	/* Set the pxTCB as a link back from the xListItem.  This is so we can get
	back to	the containing TCB from a generic item in a list. */
	listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );

	/* Event lists are always in priority order. */
	listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );
	listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );

	#if ( portCRITICAL_NESTING_IN_TCB == 1 )
	{
		pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;
	}
	#endif

	#if ( configUSE_APPLICATION_TASK_TAG == 1 )
	{
		pxTCB->pxTaskTag = NULL;
	}
	#endif	
}
/*-----------------------------------------------------------*/

static void prvInitialiseTaskLists( void )
{
unsigned portBASE_TYPE uxPriority;

	for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )
	{
		vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );
	}

	vListInitialise( ( xList * ) &xDelayedTaskList1 );
	vListInitialise( ( xList * ) &xDelayedTaskList2 );
	vListInitialise( ( xList * ) &xPendingReadyList );

	#if ( INCLUDE_vTaskDelete == 1 )
	{
		vListInitialise( ( xList * ) &xTasksWaitingTermination );
	}
	#endif

	#if ( INCLUDE_vTaskSuspend == 1 )
	{
		vListInitialise( ( xList * ) &xSuspendedTaskList );
	}
	#endif

	/* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList
	using list2. */
	pxDelayedTaskList = &xDelayedTaskList1;
	pxOverflowDelayedTaskList = &xDelayedTaskList2;
}
/*-----------------------------------------------------------*/

static void prvCheckTasksWaitingTermination( void )
{							
	#if ( INCLUDE_vTaskDelete == 1 )
	{				
		portBASE_TYPE xListIsEmpty;

		/* ucTasksDeleted is used to prevent vTaskSuspendAll() being called
		too often in the idle task. */
		if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )
		{
			vTaskSuspendAll();
				xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );				
			xTaskResumeAll();

			if( !xListIsEmpty )
			{
				tskTCB *pxTCB;

				portENTER_CRITICAL();
				{			
					pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );
					vListRemove( &( pxTCB->xGenericListItem ) );
					--uxCurrentNumberOfTasks;
					--uxTasksDeleted;
				}
				portEXIT_CRITICAL();

				prvDeleteTCB( pxTCB );
			}
		}
	}
	#endif
}
/*-----------------------------------------------------------*/

static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )
{
tskTCB *pxNewTCB;

	/* Allocate space for the TCB.  Where the memory comes from depends on
	the implementation of the port malloc function. */
	pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );

	if( pxNewTCB != NULL )
	{
		/* Allocate space for the stack used by the task being created.
		The base of the stack memory stored in the TCB so the task can
		be deleted later if required. */
		pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );

		if( pxNewTCB->pxStack == NULL )
		{
			/* Could not allocate the stack.  Delete the allocated TCB. */
			vPortFree( pxNewTCB );			
			pxNewTCB = NULL;			
		}		
		else
		{
			/* Just to help debugging. */
			memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );
		}
	}

	return pxNewTCB;
}
/*-----------------------------------------------------------*/

#if ( configUSE_TRACE_FACILITY == 1 )

	static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )
	{
	volatile tskTCB *pxNextTCB, *pxFirstTCB;
	unsigned portSHORT usStackRemaining;

		/* Write the details of all the TCB's in pxList into the buffer. */
		listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );
		do
		{
			listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );
			usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );
			sprintf( pcStatusString, ( portCHAR * ) "%s\t\t%c\t%u\t%u\t%u\r\n", pxNextTCB->pcTaskName, cStatus, ( unsigned int ) pxNextTCB->uxPriority, usStackRemaining, ( unsigned int ) pxNextTCB->uxTCBNumber );
			strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );

		} while( pxNextTCB != pxFirstTCB );
	}

#endif
/*-----------------------------------------------------------*/

#if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )

	unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )
	{
	register unsigned portSHORT usCount = 0;

		while( *pucStackByte == tskSTACK_FILL_BYTE )
		{
			pucStackByte -= portSTACK_GROWTH;
			usCount++;
		}

		usCount /= sizeof( portSTACK_TYPE );

		return usCount;
	}

#endif
/*-----------------------------------------------------------*/

#if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )

	unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask )
	{
	tskTCB *pxTCB;
	unsigned portCHAR *pcEndOfStack;

		pxTCB = prvGetTCBFromHandle( xTask );

		#if portSTACK_GROWTH < 0
		{
			pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxStack;
		}
		#else
		{
			pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxEndOfStack;
		}
		#endif

		return usTaskCheckFreeStackSpace( pcEndOfStack );
	}

#endif
/*-----------------------------------------------------------*/

#if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )

	static void prvDeleteTCB( tskTCB *pxTCB )
	{
		/* Free up the memory allocated by the scheduler for the task.  It is up to
		the task to free any memory allocated at the application level. */
		vPortFree( pxTCB->pxStack );
		vPortFree( pxTCB );
	}

#endif


/*-----------------------------------------------------------*/

#if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )

	xTaskHandle xTaskGetCurrentTaskHandle( void )
	{
	xTaskHandle xReturn;

		portENTER_CRITICAL();
		{
			xReturn = ( xTaskHandle ) pxCurrentTCB;
		}
		portEXIT_CRITICAL();

		return xReturn;
	}

#endif

/*-----------------------------------------------------------*/

#if ( INCLUDE_xTaskGetSchedulerState == 1 )

	portBASE_TYPE xTaskGetSchedulerState( void )
	{
	portBASE_TYPE xReturn;
	
		if( xSchedulerRunning == pdFALSE )
		{
			xReturn = taskSCHEDULER_NOT_STARTED;
		}
		else
		{
			if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
			{
				xReturn = taskSCHEDULER_RUNNING;
			}
			else
			{
				xReturn = taskSCHEDULER_SUSPENDED;
			}
		}
		
		return xReturn;
	}

#endif
/*-----------------------------------------------------------*/

#if ( configUSE_MUTEXES == 1 )
	
	void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )
	{
	tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;

		if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )
		{
			/* Adjust the mutex holder state to account for its new priority. */
			listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );

			/* If the task being modified is in the ready state it will need to
			be moved in to a new list. */
			if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )
			{
				vListRemove( &( pxTCB->xGenericListItem ) );

				/* Inherit the priority before being moved into the new list. */
				pxTCB->uxPriority = pxCurrentTCB->uxPriority;
				prvAddTaskToReadyQueue( pxTCB );
			}
			else
			{
				/* Just inherit the priority. */
				pxTCB->uxPriority = pxCurrentTCB->uxPriority;
			}
		}
	}

#endif
/*-----------------------------------------------------------*/

#if ( configUSE_MUTEXES == 1 )	

	void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )
	{
	tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;

		if( pxMutexHolder != NULL )
		{
			if( pxTCB->uxPriority != pxTCB->uxBasePriority )
			{
				/* We must be the running task to be able to give the mutex back.
				Remove ourselves from the ready list we currently appear in. */
				vListRemove( &( pxTCB->xGenericListItem ) );

				/* Disinherit the priority before adding ourselves into the new
				ready list. */
				pxTCB->uxPriority = pxTCB->uxBasePriority;
				listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );
				prvAddTaskToReadyQueue( pxTCB );
			}
		}
	}

#endif
/*-----------------------------------------------------------*/

#if ( portCRITICAL_NESTING_IN_TCB == 1 )

	void vTaskEnterCritical( void )
	{
		portDISABLE_INTERRUPTS();

		if( xSchedulerRunning != pdFALSE )
		{
			pxCurrentTCB->uxCriticalNesting++;
		}
	}

#endif
/*-----------------------------------------------------------*/

#if ( portCRITICAL_NESTING_IN_TCB == 1 )

void vTaskExitCritical( void )
{
	if( xSchedulerRunning != pdFALSE )
	{
		if( pxCurrentTCB->uxCriticalNesting > 0 )
		{
			pxCurrentTCB->uxCriticalNesting--;

			if( pxCurrentTCB->uxCriticalNesting == 0 )
			{
				portENABLE_INTERRUPTS();
			}
		}
	}
}

#endif
/*-----------------------------------------------------------*/