FreeRTOS/Demo/Common/Minimal/IntQueue.c

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*/

/*
 * This file defines one of the more complex set of demo/test tasks.  They are
 * designed to stress test the queue implementation though pseudo simultaneous
 * multiple reads and multiple writes from both tasks of varying priority and
 * interrupts.  The interrupts are prioritised such to ensure that nesting
 * occurs (for those ports that support it).
 *
 * The test ensures that, while being accessed from three tasks and two
 * interrupts, all the data sent to the queues is also received from
 * the same queue, and that no duplicate items are either sent or received.
 * The tests also ensure that a low priority task is never able to successfully
 * read from or write to a queue when a task of higher priority is attempting
 * the same operation.
 */

/* Standard includes. */
#include <string.h>

/* SafeRTOS includes. */
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"

/* Demo app includes. */
#include "IntQueue.h"
#include "IntQueueTimer.h"

#if( INCLUDE_eTaskGetState != 1 )
	#error INCLUDE_eTaskGetState must be set to 1 in FreeRTOSConfig.h to use this demo file.
#endif

/* Priorities used by test tasks. */
#ifndef intqHIGHER_PRIORITY
	#define intqHIGHER_PRIORITY		( configMAX_PRIORITIES - 2 )
#endif
#define intqLOWER_PRIORITY		( tskIDLE_PRIORITY )

/* The number of values to send/receive before checking that all values were
processed as expected. */
#define intqNUM_VALUES_TO_LOG	( 200 )
#define intqSHORT_DELAY			( 140 )

/* The value by which the value being sent to or received from a queue should
increment past intqNUM_VALUES_TO_LOG before we check that all values have been
sent/received correctly.  This is done to ensure that all tasks and interrupts
accessing the queue have completed their accesses with the
intqNUM_VALUES_TO_LOG range. */
#define intqVALUE_OVERRUN		( 50 )

/* The delay used by the polling task.  A short delay is used for code
coverage. */
#define intqONE_TICK_DELAY		( 1 )

/* Each task and interrupt is given a unique identifier.  This value is used to
identify which task sent or received each value.  The identifier is also used
to distinguish between two tasks that are running the same task function. */
#define intqHIGH_PRIORITY_TASK1	( ( UBaseType_t ) 1 )
#define intqHIGH_PRIORITY_TASK2	( ( UBaseType_t ) 2 )
#define intqLOW_PRIORITY_TASK	( ( UBaseType_t ) 3 )
#define intqFIRST_INTERRUPT		( ( UBaseType_t ) 4 )
#define intqSECOND_INTERRUPT	( ( UBaseType_t ) 5 )
#define intqQUEUE_LENGTH		( ( UBaseType_t ) 10 )

/* At least intqMIN_ACCEPTABLE_TASK_COUNT values should be sent to/received
from each queue by each task, otherwise an error is detected. */
#define intqMIN_ACCEPTABLE_TASK_COUNT		( 5 )

/* Send the next value to the queue that is normally empty.  This is called
from within the interrupts. */
#define timerNORMALLY_EMPTY_TX()																							\
	if( xQueueIsQueueFullFromISR( xNormallyEmptyQueue ) != pdTRUE )															\
	{																														\
	UBaseType_t uxSavedInterruptStatus;																						\
		uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();															\
		{																													\
			uxValueForNormallyEmptyQueue++;																					\
			if( xQueueSendFromISR( xNormallyEmptyQueue, ( void * ) &uxValueForNormallyEmptyQueue, &xHigherPriorityTaskWoken ) != pdPASS ) \
			{																												\
				uxValueForNormallyEmptyQueue--;																				\
			}																												\
		}																													\
		portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );														\
	}																														\

/* Send the next value to the queue that is normally full.  This is called
from within the interrupts. */
#define timerNORMALLY_FULL_TX()																								\
	if( xQueueIsQueueFullFromISR( xNormallyFullQueue ) != pdTRUE )															\
	{																														\
	UBaseType_t uxSavedInterruptStatus;																						\
		uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();															\
		{																													\
			uxValueForNormallyFullQueue++;																					\
			if( xQueueSendFromISR( xNormallyFullQueue, ( void * ) &uxValueForNormallyFullQueue, &xHigherPriorityTaskWoken ) != pdPASS ) \
			{																												\
				uxValueForNormallyFullQueue--;																				\
			} 																												\
		}																													\
		portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );														\
	}																														\

/* Receive a value from the normally empty queue.  This is called from within
an interrupt. */
#define timerNORMALLY_EMPTY_RX()																			\
	if( xQueueReceiveFromISR( xNormallyEmptyQueue, &uxRxedValue, &xHigherPriorityTaskWoken ) != pdPASS )	\
	{																										\
		prvQueueAccessLogError( __LINE__ );																	\
	}																										\
	else																									\
	{																										\
		prvRecordValue_NormallyEmpty( uxRxedValue, intqSECOND_INTERRUPT );									\
	}

/* Receive a value from the normally full queue.  This is called from within
an interrupt. */
#define timerNORMALLY_FULL_RX()																				\
	if( xQueueReceiveFromISR( xNormallyFullQueue, &uxRxedValue, &xHigherPriorityTaskWoken ) == pdPASS )		\
	{																										\
		prvRecordValue_NormallyFull( uxRxedValue, intqSECOND_INTERRUPT );									\
	}																										\


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

/* The two queues used by the test. */
static QueueHandle_t xNormallyEmptyQueue, xNormallyFullQueue;

/* Variables used to detect a stall in one of the tasks. */
static UBaseType_t uxHighPriorityLoops1 = 0, uxHighPriorityLoops2 = 0, uxLowPriorityLoops1 = 0, uxLowPriorityLoops2 = 0;

/* Any unexpected behaviour sets xErrorStatus to fail and log the line that
caused the error in xErrorLine. */
static BaseType_t xErrorStatus = pdPASS;
static volatile UBaseType_t xErrorLine = ( UBaseType_t ) 0;

/* Used for sequencing between tasks. */
static BaseType_t xWasSuspended = pdFALSE;

/* The values that are sent to the queues.  An incremented value is sent each
time to each queue. */
volatile UBaseType_t uxValueForNormallyEmptyQueue = 0, uxValueForNormallyFullQueue = 0;

/* A handle to some of the tasks is required so they can be suspended/resumed. */
TaskHandle_t xHighPriorityNormallyEmptyTask1, xHighPriorityNormallyEmptyTask2, xHighPriorityNormallyFullTask1, xHighPriorityNormallyFullTask2;

/* When a value is received in a queue the value is ticked off in the array
the array position of the value is set to a the identifier of the task or
interrupt that accessed the queue.  This way missing or duplicate values can be
detected. */
static uint8_t ucNormallyEmptyReceivedValues[ intqNUM_VALUES_TO_LOG ] = { 0 };
static uint8_t ucNormallyFullReceivedValues[ intqNUM_VALUES_TO_LOG ] = { 0 };

/* The test tasks themselves. */
static void prvLowerPriorityNormallyEmptyTask( void *pvParameters );
static void prvLowerPriorityNormallyFullTask( void *pvParameters );
static void prvHigherPriorityNormallyEmptyTask( void *pvParameters );
static void prv1stHigherPriorityNormallyFullTask( void *pvParameters );
static void prv2ndHigherPriorityNormallyFullTask( void *pvParameters );

/* Used to mark the positions within the ucNormallyEmptyReceivedValues and
ucNormallyFullReceivedValues arrays, while checking for duplicates. */
static void prvRecordValue_NormallyEmpty( UBaseType_t uxValue, UBaseType_t uxSource );
static void prvRecordValue_NormallyFull( UBaseType_t uxValue, UBaseType_t uxSource );

/* Logs the line on which an error occurred. */
static void prvQueueAccessLogError( UBaseType_t uxLine );

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

void vStartInterruptQueueTasks( void )
{
	/* Start the test tasks. */
	xTaskCreate( prvHigherPriorityNormallyEmptyTask, "H1QRx", configMINIMAL_STACK_SIZE, ( void * ) intqHIGH_PRIORITY_TASK1, intqHIGHER_PRIORITY, &xHighPriorityNormallyEmptyTask1 );
	xTaskCreate( prvHigherPriorityNormallyEmptyTask, "H2QRx", configMINIMAL_STACK_SIZE, ( void * ) intqHIGH_PRIORITY_TASK2, intqHIGHER_PRIORITY, &xHighPriorityNormallyEmptyTask2 );
	xTaskCreate( prvLowerPriorityNormallyEmptyTask, "L1QRx", configMINIMAL_STACK_SIZE, NULL, intqLOWER_PRIORITY, NULL );
	xTaskCreate( prv1stHigherPriorityNormallyFullTask, "H1QTx", configMINIMAL_STACK_SIZE, ( void * ) intqHIGH_PRIORITY_TASK1, intqHIGHER_PRIORITY, &xHighPriorityNormallyFullTask1 );
	xTaskCreate( prv2ndHigherPriorityNormallyFullTask, "H2QTx", configMINIMAL_STACK_SIZE, ( void * ) intqHIGH_PRIORITY_TASK2, intqHIGHER_PRIORITY, &xHighPriorityNormallyFullTask2 );
	xTaskCreate( prvLowerPriorityNormallyFullTask, "L2QRx", configMINIMAL_STACK_SIZE, NULL, intqLOWER_PRIORITY, NULL );

	/* Create the queues that are accessed by multiple tasks and multiple
	interrupts. */
	xNormallyFullQueue = xQueueCreate( intqQUEUE_LENGTH, ( UBaseType_t ) sizeof( UBaseType_t ) );
	xNormallyEmptyQueue = xQueueCreate( intqQUEUE_LENGTH, ( UBaseType_t ) sizeof( UBaseType_t ) );

	/* vQueueAddToRegistry() adds the queue to the queue registry, if one is
	in use.  The queue registry is provided as a means for kernel aware
	debuggers to locate queues and has no purpose if a kernel aware debugger
	is not being used.  The call to vQueueAddToRegistry() will be removed
	by the pre-processor if configQUEUE_REGISTRY_SIZE is not defined or is
	defined to be less than 1. */
	vQueueAddToRegistry( xNormallyFullQueue, "NormallyFull" );
	vQueueAddToRegistry( xNormallyEmptyQueue, "NormallyEmpty" );
}
/*-----------------------------------------------------------*/

static void prvRecordValue_NormallyFull( UBaseType_t uxValue, UBaseType_t uxSource )
{
	if( uxValue < intqNUM_VALUES_TO_LOG )
	{
		/* We don't expect to receive the same value twice, so if the value
		has already been marked as received an error has occurred. */
		if( ucNormallyFullReceivedValues[ uxValue ] != 0x00 )
		{
			prvQueueAccessLogError( __LINE__ );
		}

		/* Log that this value has been received. */
		ucNormallyFullReceivedValues[ uxValue ] = ( uint8_t ) uxSource;
	}
}
/*-----------------------------------------------------------*/

static void prvRecordValue_NormallyEmpty( UBaseType_t uxValue, UBaseType_t uxSource )
{
	if( uxValue < intqNUM_VALUES_TO_LOG )
	{
		/* We don't expect to receive the same value twice, so if the value
		has already been marked as received an error has occurred. */
		if( ucNormallyEmptyReceivedValues[ uxValue ] != 0x00 )
		{
			prvQueueAccessLogError( __LINE__ );
		}

		/* Log that this value has been received. */
		ucNormallyEmptyReceivedValues[ uxValue ] = ( uint8_t ) uxSource;
	}
}
/*-----------------------------------------------------------*/

static void prvQueueAccessLogError( UBaseType_t uxLine )
{
	/* Latch the line number that caused the error. */
	xErrorLine = uxLine;
	xErrorStatus = pdFAIL;
}
/*-----------------------------------------------------------*/

static void prvHigherPriorityNormallyEmptyTask( void *pvParameters )
{
UBaseType_t uxRxed, ux, uxTask1, uxTask2, uxInterrupts, uxErrorCount1 = 0, uxErrorCount2 = 0;

	/* The timer should not be started until after the scheduler has started.
	More than one task is running this code so we check the parameter value
	to determine which task should start the timer. */
	if( ( UBaseType_t ) pvParameters == intqHIGH_PRIORITY_TASK1 )
	{
		vInitialiseTimerForIntQueueTest();
	}

	for( ;; )
	{
		/* Block waiting to receive a value from the normally empty queue.
		Interrupts will write to the queue so we should receive a value. */
		if( xQueueReceive( xNormallyEmptyQueue, &uxRxed, intqSHORT_DELAY ) != pdPASS )
		{
			prvQueueAccessLogError( __LINE__ );
		}
		else
		{
			/* Note which value was received so we can check all expected
			values are received and no values are duplicated. */
			prvRecordValue_NormallyEmpty( uxRxed, ( UBaseType_t ) pvParameters );
		}

		/* Ensure the other task running this code gets a chance to execute. */
		taskYIELD();

		if( ( UBaseType_t ) pvParameters == intqHIGH_PRIORITY_TASK1 )
		{
			/* Have we received all the expected values? */
			if( uxValueForNormallyEmptyQueue > ( intqNUM_VALUES_TO_LOG + intqVALUE_OVERRUN ) )
			{
				vTaskSuspend( xHighPriorityNormallyEmptyTask2 );

				uxTask1 = 0;
				uxTask2 = 0;
				uxInterrupts = 0;

				/* Loop through the array, checking that both tasks have
				placed values into the array, and that no values are missing.
				Start at 1 as we expect position 0 to be unused. */
				for( ux = 1; ux < intqNUM_VALUES_TO_LOG; ux++ )
				{
					if( ucNormallyEmptyReceivedValues[ ux ] == 0 )
					{
						/* A value is missing. */
						prvQueueAccessLogError( __LINE__ );
					}
					else
					{
						if( ucNormallyEmptyReceivedValues[ ux ] == intqHIGH_PRIORITY_TASK1 )
						{
							/* Value was placed into the array by task 1. */
							uxTask1++;
						}
						else if( ucNormallyEmptyReceivedValues[ ux ] == intqHIGH_PRIORITY_TASK2 )
						{
							/* Value was placed into the array by task 2. */
							uxTask2++;
						}
						else if( ucNormallyEmptyReceivedValues[ ux ] == intqSECOND_INTERRUPT )
						{
							uxInterrupts++;
						}
					}
				}

				if( uxTask1 < intqMIN_ACCEPTABLE_TASK_COUNT )
				{
					/* Only task 2 seemed to log any values. */
					uxErrorCount1++;
					if( uxErrorCount1 > 2 )
					{
						prvQueueAccessLogError( __LINE__ );
					}
				}
				else
				{
					uxErrorCount1 = 0;
				}

				if( uxTask2 < intqMIN_ACCEPTABLE_TASK_COUNT  )
				{
					/* Only task 1 seemed to log any values. */
					uxErrorCount2++;
					if( uxErrorCount2 > 2 )
					{
						prvQueueAccessLogError( __LINE__ );
					}
				}
				else
				{
					uxErrorCount2 = 0;
				}

				if( uxInterrupts == 0 )
				{
					prvQueueAccessLogError( __LINE__ );
				}

				/* Clear the array again, ready to start a new cycle. */
				memset( ucNormallyEmptyReceivedValues, 0x00, sizeof( ucNormallyEmptyReceivedValues ) );

				uxHighPriorityLoops1++;
				uxValueForNormallyEmptyQueue = 0;

				/* Suspend ourselves, allowing the lower priority task to
				actually receive something from the queue.  Until now it
				will have been prevented from doing so by the higher
				priority tasks.  The lower priority task will resume us
				if it receives something.  We will then resume the other
				higher priority task. */
				vTaskSuspend( NULL );
				vTaskResume( xHighPriorityNormallyEmptyTask2 );
			}
		}
	}
}
/*-----------------------------------------------------------*/

static void prvLowerPriorityNormallyEmptyTask( void *pvParameters )
{
UBaseType_t uxValue, uxRxed;

	/* The parameters are not being used so avoid compiler warnings. */
	( void ) pvParameters;

	for( ;; )
	{
		if( xQueueReceive( xNormallyEmptyQueue, &uxRxed, intqONE_TICK_DELAY ) != errQUEUE_EMPTY )
		{
			/* A value should only be obtained when the high priority task is
			suspended. */
			if( eTaskGetState( xHighPriorityNormallyEmptyTask1 ) != eSuspended )
			{
				prvQueueAccessLogError( __LINE__ );
			}

			prvRecordValue_NormallyEmpty( uxRxed, intqLOW_PRIORITY_TASK );

			/* Wake the higher priority task again. */
			vTaskResume( xHighPriorityNormallyEmptyTask1 );
			uxLowPriorityLoops1++;
		}
		else
		{
			/* Raise our priority while we send so we can preempt the higher
			priority task, and ensure we get the Tx value into the queue. */
			vTaskPrioritySet( NULL, intqHIGHER_PRIORITY + 1 );

			portENTER_CRITICAL();
			{
				uxValueForNormallyEmptyQueue++;
				uxValue = uxValueForNormallyEmptyQueue;
			}
			portEXIT_CRITICAL();

			if( xQueueSend( xNormallyEmptyQueue, &uxValue, portMAX_DELAY ) != pdPASS )
			{
				prvQueueAccessLogError( __LINE__ );
			}

			vTaskPrioritySet( NULL, intqLOWER_PRIORITY );
		}
	}
}
/*-----------------------------------------------------------*/

static void prv1stHigherPriorityNormallyFullTask( void *pvParameters )
{
UBaseType_t uxValueToTx, ux, uxInterrupts;

	/* The parameters are not being used so avoid compiler warnings. */
	( void ) pvParameters;

	/* Make sure the queue starts full or near full.  >> 1 as there are two
	high priority tasks. */
	for( ux = 0; ux < ( intqQUEUE_LENGTH >> 1 ); ux++ )
	{
		portENTER_CRITICAL();
		{
			uxValueForNormallyFullQueue++;
			uxValueToTx = uxValueForNormallyFullQueue;
		}
		portEXIT_CRITICAL();

		xQueueSend( xNormallyFullQueue, &uxValueToTx, intqSHORT_DELAY );
	}

	for( ;; )
	{
		portENTER_CRITICAL();
		{
			uxValueForNormallyFullQueue++;
			uxValueToTx = uxValueForNormallyFullQueue;
		}
		portEXIT_CRITICAL();

		if( xQueueSend( xNormallyFullQueue, &uxValueToTx, intqSHORT_DELAY ) != pdPASS )
		{
			/* intqHIGH_PRIORITY_TASK2 is never suspended so we would not
			expect it to ever time out. */
			prvQueueAccessLogError( __LINE__ );
		}

		/* Allow the other task running this code to run. */
		taskYIELD();

		/* Have all the expected values been sent to the queue? */
		if( uxValueToTx > ( intqNUM_VALUES_TO_LOG + intqVALUE_OVERRUN ) )
		{
			/* Make sure the other high priority task completes its send of
			any values below intqNUM_VALUE_TO_LOG. */
			vTaskDelay( intqSHORT_DELAY );

			vTaskSuspend( xHighPriorityNormallyFullTask2 );

			if( xWasSuspended == pdTRUE )
			{
				/* We would have expected the other high priority task to have
				set this back to false by now. */
				prvQueueAccessLogError( __LINE__ );
			}

			/* Set the suspended flag so an error is not logged if the other
			task recognises a time out when it is unsuspended. */
			xWasSuspended = pdTRUE;

			/* Check interrupts are also sending. */
			uxInterrupts = 0U;

			/* Start at 1 as we expect position 0 to be unused. */
			for( ux = 1; ux < intqNUM_VALUES_TO_LOG; ux++ )
			{
				if( ucNormallyFullReceivedValues[ ux ] == 0 )
				{
					/* A value was missing. */
					prvQueueAccessLogError( __LINE__ );
				}
				else if( ucNormallyFullReceivedValues[ ux ] == intqSECOND_INTERRUPT )
				{
					uxInterrupts++;
				}
			}

			if( uxInterrupts == 0 )
			{
				/* No writes from interrupts were found.  Are interrupts
				actually running? */
				prvQueueAccessLogError( __LINE__ );
			}

			/* Reset the array ready for the next cycle. */
			memset( ucNormallyFullReceivedValues, 0x00, sizeof( ucNormallyFullReceivedValues ) );

			uxHighPriorityLoops2++;
			uxValueForNormallyFullQueue = 0;

			/* Suspend ourselves, allowing the lower priority task to
			actually receive something from the queue.  Until now it
			will have been prevented from doing so by the higher
			priority tasks.  The lower priority task will resume us
			if it receives something.  We will then resume the other
			higher priority task. */
			vTaskSuspend( NULL );
			vTaskResume( xHighPriorityNormallyFullTask2 );
		}
	}
}
/*-----------------------------------------------------------*/

static void prv2ndHigherPriorityNormallyFullTask( void *pvParameters )
{
UBaseType_t uxValueToTx, ux;

	/* The parameters are not being used so avoid compiler warnings. */
	( void ) pvParameters;

	/* Make sure the queue starts full or near full.  >> 1 as there are two
	high priority tasks. */
	for( ux = 0; ux < ( intqQUEUE_LENGTH >> 1 ); ux++ )
	{
		portENTER_CRITICAL();
		{
			uxValueForNormallyFullQueue++;
			uxValueToTx = uxValueForNormallyFullQueue;
		}
		portEXIT_CRITICAL();

		xQueueSend( xNormallyFullQueue, &uxValueToTx, intqSHORT_DELAY );
	}

	for( ;; )
	{
		portENTER_CRITICAL();
		{
			uxValueForNormallyFullQueue++;
			uxValueToTx = uxValueForNormallyFullQueue;
		}
		portEXIT_CRITICAL();

		if( xQueueSend( xNormallyFullQueue, &uxValueToTx, intqSHORT_DELAY ) != pdPASS )
		{
			if( xWasSuspended != pdTRUE )
			{
				/* It is ok to time out if the task has been suspended. */
				prvQueueAccessLogError( __LINE__ );
			}
		}

		xWasSuspended = pdFALSE;

		taskYIELD();
	}
}
/*-----------------------------------------------------------*/

static void prvLowerPriorityNormallyFullTask( void *pvParameters )
{
UBaseType_t uxValue, uxTxed = 9999;

	/* The parameters are not being used so avoid compiler warnings. */
	( void ) pvParameters;

	for( ;; )
	{
		if( xQueueSend( xNormallyFullQueue, &uxTxed, intqONE_TICK_DELAY ) != errQUEUE_FULL )
		{
			/* Should only succeed when the higher priority task is suspended */
			if( eTaskGetState( xHighPriorityNormallyFullTask1 ) != eSuspended )
			{
				prvQueueAccessLogError( __LINE__ );
			}

			vTaskResume( xHighPriorityNormallyFullTask1 );
			uxLowPriorityLoops2++;
		}
		else
		{
			/* Raise our priority while we receive so we can preempt the higher
			priority task, and ensure we get the value from the queue. */
			vTaskPrioritySet( NULL, intqHIGHER_PRIORITY + 1 );

			if( xQueueReceive( xNormallyFullQueue, &uxValue, portMAX_DELAY ) != pdPASS )
			{
				prvQueueAccessLogError( __LINE__ );
			}
			else
			{
				prvRecordValue_NormallyFull( uxValue, intqLOW_PRIORITY_TASK );
			}

			vTaskPrioritySet( NULL, intqLOWER_PRIORITY );
		}
	}
}
/*-----------------------------------------------------------*/

BaseType_t xFirstTimerHandler( void )
{
BaseType_t xHigherPriorityTaskWoken = pdFALSE;
UBaseType_t uxRxedValue;
static UBaseType_t uxNextOperation = 0;

	/* Called from a timer interrupt.  Perform various read and write
	accesses on the queues. */

	uxNextOperation++;

	if( uxNextOperation & ( UBaseType_t ) 0x01 )
	{
		timerNORMALLY_EMPTY_TX();
		timerNORMALLY_EMPTY_TX();
		timerNORMALLY_EMPTY_TX();
	}
	else
	{
		timerNORMALLY_FULL_RX();
		timerNORMALLY_FULL_RX();
		timerNORMALLY_FULL_RX();
	}

	return xHigherPriorityTaskWoken;
}
/*-----------------------------------------------------------*/

BaseType_t xSecondTimerHandler( void )
{
UBaseType_t uxRxedValue;
BaseType_t xHigherPriorityTaskWoken = pdFALSE;
static UBaseType_t uxNextOperation = 0;

	/* Called from a timer interrupt.  Perform various read and write
	accesses on the queues. */

	uxNextOperation++;

	if( uxNextOperation & ( UBaseType_t ) 0x01 )
	{
		timerNORMALLY_EMPTY_TX();
		timerNORMALLY_EMPTY_TX();

		timerNORMALLY_EMPTY_RX();
		timerNORMALLY_EMPTY_RX();
	}
	else
	{
		timerNORMALLY_FULL_RX();
		timerNORMALLY_FULL_TX();
		timerNORMALLY_FULL_TX();
		timerNORMALLY_FULL_TX();
		timerNORMALLY_FULL_TX();
	}

	return xHigherPriorityTaskWoken;
}
/*-----------------------------------------------------------*/


BaseType_t xAreIntQueueTasksStillRunning( void )
{
static UBaseType_t uxLastHighPriorityLoops1 = 0, uxLastHighPriorityLoops2 = 0, uxLastLowPriorityLoops1 = 0, uxLastLowPriorityLoops2 = 0;

	/* xErrorStatus can be set outside of this function.  This function just
	checks that all the tasks are still cycling. */

	if( uxHighPriorityLoops1 == uxLastHighPriorityLoops1 )
	{
		/* The high priority 1 task has stalled. */
		prvQueueAccessLogError( __LINE__ );
	}

	uxLastHighPriorityLoops1 = uxHighPriorityLoops1;

	if( uxHighPriorityLoops2 == uxLastHighPriorityLoops2 )
	{
		/* The high priority 2 task has stalled. */
		prvQueueAccessLogError( __LINE__ );
	}

	uxLastHighPriorityLoops2 = uxHighPriorityLoops2;

	if( uxLowPriorityLoops1 == uxLastLowPriorityLoops1 )
	{
		/* The low priority 1 task has stalled. */
		prvQueueAccessLogError( __LINE__ );
	}

	uxLastLowPriorityLoops1 = uxLowPriorityLoops1;

	if( uxLowPriorityLoops2 == uxLastLowPriorityLoops2 )
	{
		/* The low priority 2 task has stalled. */
		prvQueueAccessLogError( __LINE__ );
	}

	uxLastLowPriorityLoops2 = uxLowPriorityLoops2;

	return xErrorStatus;
}