FreeRTOS/Demo/Common/Minimal/GenQTest.c - nest-detect/1.1.1/freertos - Git at Google

 /*
     FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd.
     All rights reserved

     VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

     ***************************************************************************
      *                                                                       *
      *    FreeRTOS provides completely free yet professionally developed,    *
      *    robust, strictly quality controlled, supported, and cross          *
      *    platform software that has become a de facto standard.             *
      *                                                                       *
      *    Help yourself get started quickly and support the FreeRTOS         *
      *    project by purchasing a FreeRTOS tutorial book, reference          *
      *    manual, or both from: http://www.FreeRTOS.org/Documentation        *
      *                                                                       *
      *    Thank you!                                                         *
      *                                                                       *
     ***************************************************************************

     This file is part of the FreeRTOS distribution.

     FreeRTOS is free software; you can redistribute it and/or modify it under
     the terms of the GNU General Public License (version 2) as published by the
     Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.

     >>!   NOTE: The modification to the GPL is included to allow you to     !<<
     >>!   distribute a combined work that includes FreeRTOS without being   !<<
     >>!   obliged to provide the source code for proprietary components     !<<
     >>!   outside of the FreeRTOS kernel.                                   !<<

     FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
     FOR A PARTICULAR PURPOSE.  Full license text is available from the following
     link: http://www.freertos.org/a00114.html

     1 tab == 4 spaces!

     ***************************************************************************
      *                                                                       *
      *    Having a problem?  Start by reading the FAQ "My application does   *
      *    not run, what could be wrong?"                                     *
      *                                                                       *
      *    http://www.FreeRTOS.org/FAQHelp.html                               *
      *                                                                       *
     ***************************************************************************

     http://www.FreeRTOS.org - Documentation, books, training, latest versions,
     license and Real Time Engineers Ltd. contact details.

     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
     including FreeRTOS+Trace - an indispensable productivity tool, a DOS
     compatible FAT file system, and our tiny thread aware UDP/IP stack.

     http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
     Integrity Systems to sell under the OpenRTOS brand.  Low cost OpenRTOS
     licenses offer ticketed support, indemnification and middleware.

     http://www.SafeRTOS.com - High Integrity Systems also provide a safety
     engineered and independently SIL3 certified version for use in safety and
     mission critical applications that require provable dependability.

     1 tab == 4 spaces!
 */


 /*
  * Tests the extra queue functionality introduced in FreeRTOS.org V4.5.0 -
  * including xQueueSendToFront(), xQueueSendToBack(), xQueuePeek() and
  * mutex behaviour.
  *
  * See the comments above the prvSendFrontAndBackTest() and
  * prvLowPriorityMutexTask() prototypes below for more information.
  */


 #include <stdlib.h>

 /* Scheduler include files. */
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
 #include "semphr.h"

 /* Demo program include files. */
 #include "GenQTest.h"

 #define genqQUEUE_LENGTH		( 5 )
 #define genqNO_BLOCK			( 0 )

 #define genqMUTEX_LOW_PRIORITY		( tskIDLE_PRIORITY )
 #define genqMUTEX_TEST_PRIORITY		( tskIDLE_PRIORITY + 1 )
 #define genqMUTEX_MEDIUM_PRIORITY	( tskIDLE_PRIORITY + 2 )
 #define genqMUTEX_HIGH_PRIORITY		( tskIDLE_PRIORITY + 3 )

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

 /*
  * Tests the behaviour of the xQueueSendToFront() and xQueueSendToBack()
  * macros by using both to fill a queue, then reading from the queue to
  * check the resultant queue order is as expected.  Queue data is also
  * peeked.
  */
 static void prvSendFrontAndBackTest( void *pvParameters );

 /*
  * The following three tasks are used to demonstrate the mutex behaviour.
  * Each task is given a different priority to demonstrate the priority
  * inheritance mechanism.
  *
  * The low priority task obtains a mutex.  After this a high priority task
  * attempts to obtain the same mutex, causing its priority to be inherited
  * by the low priority task.  The task with the inherited high priority then
  * resumes a medium priority task to ensure it is not blocked by the medium
  * priority task while it holds the inherited high priority.  Once the mutex
  * is returned the task with the inherited priority returns to its original
  * low priority, and is therefore immediately preempted by first the high
  * priority task and then the medium prioroity task before it can continue.
  */
 static void prvLowPriorityMutexTask( void *pvParameters );
 static void prvMediumPriorityMutexTask( void *pvParameters );
 static void prvHighPriorityMutexTask( void *pvParameters );

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

 /* Flag that will be latched to pdTRUE should any unexpected behaviour be
 detected in any of the tasks. */
 static volatile portBASE_TYPE xErrorDetected = pdFALSE;

 /* Counters that are incremented on each cycle of a test.  This is used to
 detect a stalled task - a test that is no longer running. */
 static volatile unsigned long ulLoopCounter = 0;
 static volatile unsigned long ulLoopCounter2 = 0;

 /* The variable that is guarded by the mutex in the mutex demo tasks. */
 static volatile unsigned long ulGuardedVariable = 0;

 /* Handles used in the mutext test to suspend and resume the high and medium
 priority mutex test tasks. */
 static TaskHandle_t xHighPriorityMutexTask, xMediumPriorityMutexTask;

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

 void vStartGenericQueueTasks( unsigned portBASE_TYPE uxPriority )
 {
 QueueHandle_t xQueue;
 SemaphoreHandle_t xMutex;

 	/* Create the queue that we are going to use for the
 	prvSendFrontAndBackTest demo. */
 	xQueue = xQueueCreate( genqQUEUE_LENGTH, sizeof( unsigned long ) );

 	/* 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( xQueue, "Gen_Queue_Test" );

 	/* Create the demo task and pass it the queue just created.  We are
 	passing the queue handle by value so it does not matter that it is
 	declared on the stack here. */
 	xTaskCreate( prvSendFrontAndBackTest, "GenQ", configMINIMAL_STACK_SIZE, ( void * ) xQueue, uxPriority, NULL );

 	/* Create the mutex used by the prvMutexTest task. */
 	xMutex = xSemaphoreCreateMutex();

 	/* vQueueAddToRegistry() adds the mutex to the registry, if one is
 	in use.  The registry is provided as a means for kernel aware
 	debuggers to locate mutexes 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( ( QueueHandle_t ) xMutex, "Gen_Queue_Mutex" );

 	/* Create the mutex demo tasks and pass it the mutex just created.  We are
 	passing the mutex handle by value so it does not matter that it is declared
 	on the stack here. */
 	xTaskCreate( prvLowPriorityMutexTask, "MuLow", configMINIMAL_STACK_SIZE, ( void * ) xMutex, genqMUTEX_LOW_PRIORITY, NULL );
 	xTaskCreate( prvMediumPriorityMutexTask, "MuMed", configMINIMAL_STACK_SIZE, NULL, genqMUTEX_MEDIUM_PRIORITY, &xMediumPriorityMutexTask );
 	xTaskCreate( prvHighPriorityMutexTask, "MuHigh", configMINIMAL_STACK_SIZE, ( void * ) xMutex, genqMUTEX_HIGH_PRIORITY, &xHighPriorityMutexTask );
 }
 /*-----------------------------------------------------------*/

 static void prvSendFrontAndBackTest( void *pvParameters )
 {
 unsigned long ulData, ulData2;
 QueueHandle_t xQueue;

 	#ifdef USE_STDIO
 	void vPrintDisplayMessage( const char * const * ppcMessageToSend );

 		const char * const pcTaskStartMsg = "Queue SendToFront/SendToBack/Peek test started.\r\n";

 		/* Queue a message for printing to say the task has started. */
 		vPrintDisplayMessage( &pcTaskStartMsg );
 	#endif

 	xQueue = ( QueueHandle_t ) pvParameters;

 	for( ;; )
 	{
 		/* The queue is empty, so sending an item to the back of the queue
 		should have the same efect as sending it to the front of the queue.

 		First send to the front and check everything is as expected. */
 		xQueueSendToFront( xQueue, ( void * ) &ulLoopCounter, genqNO_BLOCK );

 		if( uxQueueMessagesWaiting( xQueue ) != 1 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		if( xQueueReceive( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != pdPASS )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* The data we sent to the queue should equal the data we just received
 		from the queue. */
 		if( ulLoopCounter != ulData )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* Then do the same, sending the data to the back, checking everything
 		is as expected. */
 		if( uxQueueMessagesWaiting( xQueue ) != 0 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		xQueueSendToBack( xQueue, ( void * ) &ulLoopCounter, genqNO_BLOCK );

 		if( uxQueueMessagesWaiting( xQueue ) != 1 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		if( xQueueReceive( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != pdPASS )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		if( uxQueueMessagesWaiting( xQueue ) != 0 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* The data we sent to the queue should equal the data we just received
 		from the queue. */
 		if( ulLoopCounter != ulData )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		#if configUSE_PREEMPTION == 0
 			taskYIELD();
 		#endif


 		/* Place 2, 3, 4 into the queue, adding items to the back of the queue. */
 		for( ulData = 2; ulData < 5; ulData++ )
 		{
 			xQueueSendToBack( xQueue, ( void * ) &ulData, genqNO_BLOCK );
 		}

 		/* Now the order in the queue should be 2, 3, 4, with 2 being the first
 		thing to be read out.  Now add 1 then 0 to the front of the queue. */
 		if( uxQueueMessagesWaiting( xQueue ) != 3 )
 		{
 			xErrorDetected = pdTRUE;
 		}
 		ulData = 1;
 		xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK );
 		ulData = 0;
 		xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK );

 		/* Now the queue should be full, and when we read the data out we
 		should receive 0, 1, 2, 3, 4. */
 		if( uxQueueMessagesWaiting( xQueue ) != 5 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		if( xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != errQUEUE_FULL )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		if( xQueueSendToBack( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != errQUEUE_FULL )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		#if configUSE_PREEMPTION == 0
 			taskYIELD();
 		#endif

 		/* Check the data we read out is in the expected order. */
 		for( ulData = 0; ulData < genqQUEUE_LENGTH; ulData++ )
 		{
 			/* Try peeking the data first. */
 			if( xQueuePeek( xQueue, &ulData2, genqNO_BLOCK ) != pdPASS )
 			{
 				xErrorDetected = pdTRUE;
 			}

 			if( ulData != ulData2 )
 			{
 				xErrorDetected = pdTRUE;
 			}


 			/* Now try receiving the data for real.  The value should be the
 			same.  Clobber the value first so we know we really received it. */
 			ulData2 = ~ulData2;
 			if( xQueueReceive( xQueue, &ulData2, genqNO_BLOCK ) != pdPASS )
 			{
 				xErrorDetected = pdTRUE;
 			}

 			if( ulData != ulData2 )
 			{
 				xErrorDetected = pdTRUE;
 			}
 		}

 		/* The queue should now be empty again. */
 		if( uxQueueMessagesWaiting( xQueue ) != 0 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		#if configUSE_PREEMPTION == 0
 			taskYIELD();
 		#endif


 		/* Our queue is empty once more, add 10, 11 to the back. */
 		ulData = 10;
 		if( xQueueSend( xQueue, &ulData, genqNO_BLOCK ) != pdPASS )
 		{
 			xErrorDetected = pdTRUE;
 		}
 		ulData = 11;
 		if( xQueueSend( xQueue, &ulData, genqNO_BLOCK ) != pdPASS )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		if( uxQueueMessagesWaiting( xQueue ) != 2 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* Now we should have 10, 11 in the queue.  Add 7, 8, 9 to the
 		front. */
 		for( ulData = 9; ulData >= 7; ulData-- )
 		{
 			if( xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != pdPASS )
 			{
 				xErrorDetected = pdTRUE;
 			}
 		}

 		/* Now check that the queue is full, and that receiving data provides
 		the expected sequence of 7, 8, 9, 10, 11. */
 		if( uxQueueMessagesWaiting( xQueue ) != 5 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		if( xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != errQUEUE_FULL )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		if( xQueueSendToBack( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != errQUEUE_FULL )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		#if configUSE_PREEMPTION == 0
 			taskYIELD();
 		#endif

 		/* Check the data we read out is in the expected order. */
 		for( ulData = 7; ulData < ( 7 + genqQUEUE_LENGTH ); ulData++ )
 		{
 			if( xQueueReceive( xQueue, &ulData2, genqNO_BLOCK ) != pdPASS )
 			{
 				xErrorDetected = pdTRUE;
 			}

 			if( ulData != ulData2 )
 			{
 				xErrorDetected = pdTRUE;
 			}
 		}

 		if( uxQueueMessagesWaiting( xQueue ) != 0 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		ulLoopCounter++;
 	}
 }
 /*-----------------------------------------------------------*/

 static void prvLowPriorityMutexTask( void *pvParameters )
 {
 SemaphoreHandle_t xMutex = ( SemaphoreHandle_t ) pvParameters;

 	#ifdef USE_STDIO
 	void vPrintDisplayMessage( const char * const * ppcMessageToSend );

 		const char * const pcTaskStartMsg = "Mutex with priority inheritance test started.\r\n";

 		/* Queue a message for printing to say the task has started. */
 		vPrintDisplayMessage( &pcTaskStartMsg );
 	#endif

 	for( ;; )
 	{
 		/* Take the mutex.  It should be available now. */
 		if( xSemaphoreTake( xMutex, genqNO_BLOCK ) != pdPASS )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* Set our guarded variable to a known start value. */
 		ulGuardedVariable = 0;

 		/* Our priority should be as per that assigned when the task was
 		created. */
 		if( uxTaskPriorityGet( NULL ) != genqMUTEX_LOW_PRIORITY )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* Now unsuspend the high priority task.  This will attempt to take the
 		mutex, and block when it finds it cannot obtain it. */
 		vTaskResume( xHighPriorityMutexTask );

 		#if configUSE_PREEMPTION == 0
 			taskYIELD();
 		#endif

 		/* Ensure the task is reporting it priority as blocked and not
 		suspended (as it would have done in versions up to V7.5.3). */
 		#if( INCLUDE_eTaskGetState == 1 )
 		{
 			configASSERT( eTaskGetState( xHighPriorityMutexTask ) == eBlocked );
 		}
 		#endif /* INCLUDE_eTaskGetState */

 		/* We should now have inherited the prioritoy of the high priority task,
 		as by now it will have attempted to get the mutex. */
 		if( uxTaskPriorityGet( NULL ) != genqMUTEX_HIGH_PRIORITY )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* We can attempt to set our priority to the test priority - between the
 		idle priority and the medium/high test priorities, but our actual
 		prioroity should remain at the high priority. */
 		vTaskPrioritySet( NULL, genqMUTEX_TEST_PRIORITY );
 		if( uxTaskPriorityGet( NULL ) != genqMUTEX_HIGH_PRIORITY )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* Now unsuspend the medium priority task.  This should not run as our
 		inherited priority is above that of the medium priority task. */
 		vTaskResume( xMediumPriorityMutexTask );

 		/* If the did run then it will have incremented our guarded variable. */
 		if( ulGuardedVariable != 0 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* When we give back the semaphore our priority should be disinherited
 		back to the priority to which we attempted to set ourselves.  This means
 		that when the high priority task next blocks, the medium priority task
 		should execute and increment the guarded variable.   When we next run
 		both the high and medium priority tasks will have been suspended again. */
 		if( xSemaphoreGive( xMutex ) != pdPASS )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		#if configUSE_PREEMPTION == 0
 			taskYIELD();
 		#endif

 		/* Check that the guarded variable did indeed increment... */
 		if( ulGuardedVariable != 1 )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* ... and that our priority has been disinherited to
 		genqMUTEX_TEST_PRIORITY. */
 		if( uxTaskPriorityGet( NULL ) != genqMUTEX_TEST_PRIORITY )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* Set our priority back to our original priority ready for the next
 		loop around this test. */
 		vTaskPrioritySet( NULL, genqMUTEX_LOW_PRIORITY );

 		/* Just to show we are still running. */
 		ulLoopCounter2++;

 		#if configUSE_PREEMPTION == 0
 			taskYIELD();
 		#endif
 	}
 }
 /*-----------------------------------------------------------*/

 static void prvMediumPriorityMutexTask( void *pvParameters )
 {
 	( void ) pvParameters;

 	for( ;; )
 	{
 		/* The medium priority task starts by suspending itself.  The low
 		priority task will unsuspend this task when required. */
 		vTaskSuspend( NULL );

 		/* When this task unsuspends all it does is increment the guarded
 		variable, this is so the low priority task knows that it has
 		executed. */
 		ulGuardedVariable++;
 	}
 }
 /*-----------------------------------------------------------*/

 static void prvHighPriorityMutexTask( void *pvParameters )
 {
 SemaphoreHandle_t xMutex = ( SemaphoreHandle_t ) pvParameters;

 	for( ;; )
 	{
 		/* The high priority task starts by suspending itself.  The low
 		priority task will unsuspend this task when required. */
 		vTaskSuspend( NULL );

 		/* When this task unsuspends all it does is attempt to obtain
 		the mutex.  It should find the mutex is not available so a
 		block time is specified. */
 		if( xSemaphoreTake( xMutex, portMAX_DELAY ) != pdPASS )
 		{
 			xErrorDetected = pdTRUE;
 		}

 		/* When we eventually obtain the mutex we just give it back then
 		return to suspend ready for the next test. */
 		if( xSemaphoreGive( xMutex ) != pdPASS )
 		{
 			xErrorDetected = pdTRUE;
 		}
 	}
 }
 /*-----------------------------------------------------------*/

 /* This is called to check that all the created tasks are still running. */
 portBASE_TYPE xAreGenericQueueTasksStillRunning( void )
 {
 static unsigned long ulLastLoopCounter = 0, ulLastLoopCounter2 = 0;

 	/* If the demo task is still running then we expect the loopcounters to
 	have incremented since this function was last called. */
 	if( ulLastLoopCounter == ulLoopCounter )
 	{
 		xErrorDetected = pdTRUE;
 	}

 	if( ulLastLoopCounter2 == ulLoopCounter2 )
 	{
 		xErrorDetected = pdTRUE;
 	}

 	ulLastLoopCounter = ulLoopCounter;
 	ulLastLoopCounter2 = ulLoopCounter2;

 	/* Errors detected in the task itself will have latched xErrorDetected
 	to true. */

 	return ( portBASE_TYPE ) !xErrorDetected;
 }
	/*
	FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd.
	All rights reserved

	VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

	***************************************************************************
	* *
	* FreeRTOS provides completely free yet professionally developed, *
	* robust, strictly quality controlled, supported, and cross *
	* platform software that has become a de facto standard. *
	* *
	* Help yourself get started quickly and support the FreeRTOS *
	* project by purchasing a FreeRTOS tutorial book, reference *
	* manual, or both from: http://www.FreeRTOS.org/Documentation *
	* *
	* Thank you! *
	* *
	***************************************************************************

	This file is part of the FreeRTOS distribution.

	FreeRTOS is free software; you can redistribute it and/or modify it under
	the terms of the GNU General Public License (version 2) as published by the
	Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.

	>>! NOTE: The modification to the GPL is included to allow you to !<<
	>>! distribute a combined work that includes FreeRTOS without being !<<
	>>! obliged to provide the source code for proprietary components !<<
	>>! outside of the FreeRTOS kernel. !<<

	FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
	FOR A PARTICULAR PURPOSE. Full license text is available from the following
	link: http://www.freertos.org/a00114.html

	1 tab == 4 spaces!

	***************************************************************************
	* *
	* Having a problem? Start by reading the FAQ "My application does *
	* not run, what could be wrong?" *
	* *
	* http://www.FreeRTOS.org/FAQHelp.html *
	* *
	***************************************************************************

	http://www.FreeRTOS.org - Documentation, books, training, latest versions,
	license and Real Time Engineers Ltd. contact details.

	http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
	including FreeRTOS+Trace - an indispensable productivity tool, a DOS
	compatible FAT file system, and our tiny thread aware UDP/IP stack.

	http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
	Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
	licenses offer ticketed support, indemnification and middleware.

	http://www.SafeRTOS.com - High Integrity Systems also provide a safety
	engineered and independently SIL3 certified version for use in safety and
	mission critical applications that require provable dependability.

	1 tab == 4 spaces!
	*/


	/*
	* Tests the extra queue functionality introduced in FreeRTOS.org V4.5.0 -
	* including xQueueSendToFront(), xQueueSendToBack(), xQueuePeek() and
	* mutex behaviour.
	*
	* See the comments above the prvSendFrontAndBackTest() and
	* prvLowPriorityMutexTask() prototypes below for more information.
	*/


	#include <stdlib.h>

	/* Scheduler include files. */
	#include "FreeRTOS.h"
	#include "task.h"
	#include "queue.h"
	#include "semphr.h"

	/* Demo program include files. */
	#include "GenQTest.h"

	#define genqQUEUE_LENGTH ( 5 )
	#define genqNO_BLOCK ( 0 )

	#define genqMUTEX_LOW_PRIORITY ( tskIDLE_PRIORITY )
	#define genqMUTEX_TEST_PRIORITY ( tskIDLE_PRIORITY + 1 )
	#define genqMUTEX_MEDIUM_PRIORITY ( tskIDLE_PRIORITY + 2 )
	#define genqMUTEX_HIGH_PRIORITY ( tskIDLE_PRIORITY + 3 )

	/-----------------------------------------------------------/

	/*
	* Tests the behaviour of the xQueueSendToFront() and xQueueSendToBack()
	* macros by using both to fill a queue, then reading from the queue to
	* check the resultant queue order is as expected. Queue data is also
	* peeked.
	*/
	static void prvSendFrontAndBackTest( void *pvParameters );

	/*
	* The following three tasks are used to demonstrate the mutex behaviour.
	* Each task is given a different priority to demonstrate the priority
	* inheritance mechanism.
	*
	* The low priority task obtains a mutex. After this a high priority task
	* attempts to obtain the same mutex, causing its priority to be inherited
	* by the low priority task. The task with the inherited high priority then
	* resumes a medium priority task to ensure it is not blocked by the medium
	* priority task while it holds the inherited high priority. Once the mutex
	* is returned the task with the inherited priority returns to its original
	* low priority, and is therefore immediately preempted by first the high
	* priority task and then the medium prioroity task before it can continue.
	*/
	static void prvLowPriorityMutexTask( void *pvParameters );
	static void prvMediumPriorityMutexTask( void *pvParameters );
	static void prvHighPriorityMutexTask( void *pvParameters );

	/-----------------------------------------------------------/

	/* Flag that will be latched to pdTRUE should any unexpected behaviour be
	detected in any of the tasks. */
	static volatile portBASE_TYPE xErrorDetected = pdFALSE;

	/* Counters that are incremented on each cycle of a test. This is used to
	detect a stalled task - a test that is no longer running. */
	static volatile unsigned long ulLoopCounter = 0;
	static volatile unsigned long ulLoopCounter2 = 0;

	/* The variable that is guarded by the mutex in the mutex demo tasks. */
	static volatile unsigned long ulGuardedVariable = 0;

	/* Handles used in the mutext test to suspend and resume the high and medium
	priority mutex test tasks. */
	static TaskHandle_t xHighPriorityMutexTask, xMediumPriorityMutexTask;

	/-----------------------------------------------------------/

	void vStartGenericQueueTasks( unsigned portBASE_TYPE uxPriority )
	{
	QueueHandle_t xQueue;
	SemaphoreHandle_t xMutex;

	/* Create the queue that we are going to use for the
	prvSendFrontAndBackTest demo. */
	xQueue = xQueueCreate( genqQUEUE_LENGTH, sizeof( unsigned long ) );

	/* 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( xQueue, "Gen_Queue_Test" );

	/* Create the demo task and pass it the queue just created. We are
	passing the queue handle by value so it does not matter that it is
	declared on the stack here. */
	xTaskCreate( prvSendFrontAndBackTest, "GenQ", configMINIMAL_STACK_SIZE, ( void * ) xQueue, uxPriority, NULL );

	/* Create the mutex used by the prvMutexTest task. */
	xMutex = xSemaphoreCreateMutex();

	/* vQueueAddToRegistry() adds the mutex to the registry, if one is
	in use. The registry is provided as a means for kernel aware
	debuggers to locate mutexes 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( ( QueueHandle_t ) xMutex, "Gen_Queue_Mutex" );

	/* Create the mutex demo tasks and pass it the mutex just created. We are
	passing the mutex handle by value so it does not matter that it is declared
	on the stack here. */
	xTaskCreate( prvLowPriorityMutexTask, "MuLow", configMINIMAL_STACK_SIZE, ( void * ) xMutex, genqMUTEX_LOW_PRIORITY, NULL );
	xTaskCreate( prvMediumPriorityMutexTask, "MuMed", configMINIMAL_STACK_SIZE, NULL, genqMUTEX_MEDIUM_PRIORITY, &xMediumPriorityMutexTask );
	xTaskCreate( prvHighPriorityMutexTask, "MuHigh", configMINIMAL_STACK_SIZE, ( void * ) xMutex, genqMUTEX_HIGH_PRIORITY, &xHighPriorityMutexTask );
	}
	/-----------------------------------------------------------/

	static void prvSendFrontAndBackTest( void *pvParameters )
	{
	unsigned long ulData, ulData2;
	QueueHandle_t xQueue;

	#ifdef USE_STDIO
	void vPrintDisplayMessage( const char * const * ppcMessageToSend );

	const char * const pcTaskStartMsg = "Queue SendToFront/SendToBack/Peek test started.\r\n";

	/* Queue a message for printing to say the task has started. */
	vPrintDisplayMessage( &pcTaskStartMsg );
	#endif

	xQueue = ( QueueHandle_t ) pvParameters;

	for( ;; )
	{
	/* The queue is empty, so sending an item to the back of the queue
	should have the same efect as sending it to the front of the queue.

	First send to the front and check everything is as expected. */
	xQueueSendToFront( xQueue, ( void * ) &ulLoopCounter, genqNO_BLOCK );

	if( uxQueueMessagesWaiting( xQueue ) != 1 )
	{
	xErrorDetected = pdTRUE;
	}

	if( xQueueReceive( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	/* The data we sent to the queue should equal the data we just received
	from the queue. */
	if( ulLoopCounter != ulData )
	{
	xErrorDetected = pdTRUE;
	}

	/* Then do the same, sending the data to the back, checking everything
	is as expected. */
	if( uxQueueMessagesWaiting( xQueue ) != 0 )
	{
	xErrorDetected = pdTRUE;
	}

	xQueueSendToBack( xQueue, ( void * ) &ulLoopCounter, genqNO_BLOCK );

	if( uxQueueMessagesWaiting( xQueue ) != 1 )
	{
	xErrorDetected = pdTRUE;
	}

	if( xQueueReceive( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	if( uxQueueMessagesWaiting( xQueue ) != 0 )
	{
	xErrorDetected = pdTRUE;
	}

	/* The data we sent to the queue should equal the data we just received
	from the queue. */
	if( ulLoopCounter != ulData )
	{
	xErrorDetected = pdTRUE;
	}

	#if configUSE_PREEMPTION == 0
	taskYIELD();
	#endif



	/* Place 2, 3, 4 into the queue, adding items to the back of the queue. */
	for( ulData = 2; ulData < 5; ulData++ )
	{
	xQueueSendToBack( xQueue, ( void * ) &ulData, genqNO_BLOCK );
	}

	/* Now the order in the queue should be 2, 3, 4, with 2 being the first
	thing to be read out. Now add 1 then 0 to the front of the queue. */
	if( uxQueueMessagesWaiting( xQueue ) != 3 )
	{
	xErrorDetected = pdTRUE;
	}
	ulData = 1;
	xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK );
	ulData = 0;
	xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK );

	/* Now the queue should be full, and when we read the data out we
	should receive 0, 1, 2, 3, 4. */
	if( uxQueueMessagesWaiting( xQueue ) != 5 )
	{
	xErrorDetected = pdTRUE;
	}

	if( xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != errQUEUE_FULL )
	{
	xErrorDetected = pdTRUE;
	}

	if( xQueueSendToBack( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != errQUEUE_FULL )
	{
	xErrorDetected = pdTRUE;
	}

	#if configUSE_PREEMPTION == 0
	taskYIELD();
	#endif

	/* Check the data we read out is in the expected order. */
	for( ulData = 0; ulData < genqQUEUE_LENGTH; ulData++ )
	{
	/* Try peeking the data first. */
	if( xQueuePeek( xQueue, &ulData2, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	if( ulData != ulData2 )
	{
	xErrorDetected = pdTRUE;
	}


	/* Now try receiving the data for real. The value should be the
	same. Clobber the value first so we know we really received it. */
	ulData2 = ~ulData2;
	if( xQueueReceive( xQueue, &ulData2, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	if( ulData != ulData2 )
	{
	xErrorDetected = pdTRUE;
	}
	}

	/* The queue should now be empty again. */
	if( uxQueueMessagesWaiting( xQueue ) != 0 )
	{
	xErrorDetected = pdTRUE;
	}

	#if configUSE_PREEMPTION == 0
	taskYIELD();
	#endif


	/* Our queue is empty once more, add 10, 11 to the back. */
	ulData = 10;
	if( xQueueSend( xQueue, &ulData, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}
	ulData = 11;
	if( xQueueSend( xQueue, &ulData, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	if( uxQueueMessagesWaiting( xQueue ) != 2 )
	{
	xErrorDetected = pdTRUE;
	}

	/* Now we should have 10, 11 in the queue. Add 7, 8, 9 to the
	front. */
	for( ulData = 9; ulData >= 7; ulData-- )
	{
	if( xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}
	}

	/* Now check that the queue is full, and that receiving data provides
	the expected sequence of 7, 8, 9, 10, 11. */
	if( uxQueueMessagesWaiting( xQueue ) != 5 )
	{
	xErrorDetected = pdTRUE;
	}

	if( xQueueSendToFront( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != errQUEUE_FULL )
	{
	xErrorDetected = pdTRUE;
	}

	if( xQueueSendToBack( xQueue, ( void * ) &ulData, genqNO_BLOCK ) != errQUEUE_FULL )
	{
	xErrorDetected = pdTRUE;
	}

	#if configUSE_PREEMPTION == 0
	taskYIELD();
	#endif

	/* Check the data we read out is in the expected order. */
	for( ulData = 7; ulData < ( 7 + genqQUEUE_LENGTH ); ulData++ )
	{
	if( xQueueReceive( xQueue, &ulData2, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	if( ulData != ulData2 )
	{
	xErrorDetected = pdTRUE;
	}
	}

	if( uxQueueMessagesWaiting( xQueue ) != 0 )
	{
	xErrorDetected = pdTRUE;
	}

	ulLoopCounter++;
	}
	}
	/-----------------------------------------------------------/

	static void prvLowPriorityMutexTask( void *pvParameters )
	{
	SemaphoreHandle_t xMutex = ( SemaphoreHandle_t ) pvParameters;

	#ifdef USE_STDIO
	void vPrintDisplayMessage( const char * const * ppcMessageToSend );

	const char * const pcTaskStartMsg = "Mutex with priority inheritance test started.\r\n";

	/* Queue a message for printing to say the task has started. */
	vPrintDisplayMessage( &pcTaskStartMsg );
	#endif

	for( ;; )
	{
	/* Take the mutex. It should be available now. */
	if( xSemaphoreTake( xMutex, genqNO_BLOCK ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	/* Set our guarded variable to a known start value. */
	ulGuardedVariable = 0;

	/* Our priority should be as per that assigned when the task was
	created. */
	if( uxTaskPriorityGet( NULL ) != genqMUTEX_LOW_PRIORITY )
	{
	xErrorDetected = pdTRUE;
	}

	/* Now unsuspend the high priority task. This will attempt to take the
	mutex, and block when it finds it cannot obtain it. */
	vTaskResume( xHighPriorityMutexTask );

	#if configUSE_PREEMPTION == 0
	taskYIELD();
	#endif

	/* Ensure the task is reporting it priority as blocked and not
	suspended (as it would have done in versions up to V7.5.3). */
	#if( INCLUDE_eTaskGetState == 1 )
	{
	configASSERT( eTaskGetState( xHighPriorityMutexTask ) == eBlocked );
	}
	#endif /* INCLUDE_eTaskGetState */

	/* We should now have inherited the prioritoy of the high priority task,
	as by now it will have attempted to get the mutex. */
	if( uxTaskPriorityGet( NULL ) != genqMUTEX_HIGH_PRIORITY )
	{
	xErrorDetected = pdTRUE;
	}

	/* We can attempt to set our priority to the test priority - between the
	idle priority and the medium/high test priorities, but our actual
	prioroity should remain at the high priority. */
	vTaskPrioritySet( NULL, genqMUTEX_TEST_PRIORITY );
	if( uxTaskPriorityGet( NULL ) != genqMUTEX_HIGH_PRIORITY )
	{
	xErrorDetected = pdTRUE;
	}

	/* Now unsuspend the medium priority task. This should not run as our
	inherited priority is above that of the medium priority task. */
	vTaskResume( xMediumPriorityMutexTask );

	/* If the did run then it will have incremented our guarded variable. */
	if( ulGuardedVariable != 0 )
	{
	xErrorDetected = pdTRUE;
	}

	/* When we give back the semaphore our priority should be disinherited
	back to the priority to which we attempted to set ourselves. This means
	that when the high priority task next blocks, the medium priority task
	should execute and increment the guarded variable. When we next run
	both the high and medium priority tasks will have been suspended again. */
	if( xSemaphoreGive( xMutex ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	#if configUSE_PREEMPTION == 0
	taskYIELD();
	#endif

	/* Check that the guarded variable did indeed increment... */
	if( ulGuardedVariable != 1 )
	{
	xErrorDetected = pdTRUE;
	}

	/* ... and that our priority has been disinherited to
	genqMUTEX_TEST_PRIORITY. */
	if( uxTaskPriorityGet( NULL ) != genqMUTEX_TEST_PRIORITY )
	{
	xErrorDetected = pdTRUE;
	}

	/* Set our priority back to our original priority ready for the next
	loop around this test. */
	vTaskPrioritySet( NULL, genqMUTEX_LOW_PRIORITY );

	/* Just to show we are still running. */
	ulLoopCounter2++;

	#if configUSE_PREEMPTION == 0
	taskYIELD();
	#endif
	}
	}
	/-----------------------------------------------------------/

	static void prvMediumPriorityMutexTask( void *pvParameters )
	{
	( void ) pvParameters;

	for( ;; )
	{
	/* The medium priority task starts by suspending itself. The low
	priority task will unsuspend this task when required. */
	vTaskSuspend( NULL );

	/* When this task unsuspends all it does is increment the guarded
	variable, this is so the low priority task knows that it has
	executed. */
	ulGuardedVariable++;
	}
	}
	/-----------------------------------------------------------/

	static void prvHighPriorityMutexTask( void *pvParameters )
	{
	SemaphoreHandle_t xMutex = ( SemaphoreHandle_t ) pvParameters;

	for( ;; )
	{
	/* The high priority task starts by suspending itself. The low
	priority task will unsuspend this task when required. */
	vTaskSuspend( NULL );

	/* When this task unsuspends all it does is attempt to obtain
	the mutex. It should find the mutex is not available so a
	block time is specified. */
	if( xSemaphoreTake( xMutex, portMAX_DELAY ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}

	/* When we eventually obtain the mutex we just give it back then
	return to suspend ready for the next test. */
	if( xSemaphoreGive( xMutex ) != pdPASS )
	{
	xErrorDetected = pdTRUE;
	}
	}
	}
	/-----------------------------------------------------------/

	/* This is called to check that all the created tasks are still running. */
	portBASE_TYPE xAreGenericQueueTasksStillRunning( void )
	{
	static unsigned long ulLastLoopCounter = 0, ulLastLoopCounter2 = 0;

	/* If the demo task is still running then we expect the loopcounters to
	have incremented since this function was last called. */
	if( ulLastLoopCounter == ulLoopCounter )
	{
	xErrorDetected = pdTRUE;
	}

	if( ulLastLoopCounter2 == ulLoopCounter2 )
	{
	xErrorDetected = pdTRUE;
	}

	ulLastLoopCounter = ulLoopCounter;
	ulLastLoopCounter2 = ulLoopCounter2;

	/* Errors detected in the task itself will have latched xErrorDetected
	to true. */

	return ( portBASE_TYPE ) !xErrorDetected;
	}