text: /*
      FreeRTOS V6.0.2 - Copyright (C) 2010 Real Time Engineers Ltd.
  
      ***************************************************************************
      *                                                                         *
      * If you are:                                                             *
      *                                                                         *
      *    + New to FreeRTOS,                                                   *
      *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
      *    + Looking for basic training,                                        *
      *    + Wanting to improve your FreeRTOS skills and productivity           *
      *                                                                         *
      * then take a look at the FreeRTOS eBook                                  *
      *                                                                         *
      *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
      *                  http://www.FreeRTOS.org/Documentation                  *
      *                                                                         *
      * A pdf reference manual is also available.  Both are usually delivered   *
      * to your inbox within 20 minutes to two hours when purchased between 8am *
      * and 8pm GMT (although please allow up to 24 hours in case of            *
      * exceptional circumstances).  Thank you for your support!                *
      *                                                                         *
      ***************************************************************************
  
      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 exception 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.  See the GNU General Public License for
      more details. You should have received a copy of the GNU General Public 
      License and the FreeRTOS license exception along with FreeRTOS; if not it 
      can be viewed here: http://www.freertos.org/a00114.html and also obtained 
      by writing to Richard Barry, contact details for whom are available on the
      FreeRTOS WEB site.
  
      1 tab == 4 spaces!
  
      http://www.FreeRTOS.org - Documentation, latest information, license and
      contact details.
  
      http://www.SafeRTOS.com - A version that is certified for use in safety
      critical systems.
  
      http://www.OpenRTOS.com - Commercial support, development, porting,
      licensing and training services.
  */
  
  
  /* 
   * 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 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 portLONG ulLoopCounter = 0;
  static volatile unsigned portLONG ulLoopCounter2 = 0;
  
  /* The variable that is guarded by the mutex in the mutex demo tasks. */
  static volatile unsigned portLONG ulGuardedVariable = 0;
  
  /* Handles used in the mutext test to suspend and resume the high and medium
  priority mutex test tasks. */
  static xTaskHandle xHighPriorityMutexTask, xMediumPriorityMutexTask;
  
  /*-----------------------------------------------------------*/
  
  void vStartGenericQueueTasks( unsigned portBASE_TYPE uxPriority )
  {
  xQueueHandle xQueue;
  xSemaphoreHandle xMutex;
  
  	/* Create the queue that we are going to use for the
  	prvSendFrontAndBackTest demo. */
  	xQueue = xQueueCreate( genqQUEUE_LENGTH, sizeof( unsigned portLONG ) );
  
  	/* 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, ( signed portCHAR * ) "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, ( signed portCHAR * )"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( ( xQueueHandle ) xMutex, ( signed portCHAR * ) "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, ( signed portCHAR * )"MuLow", configMINIMAL_STACK_SIZE, ( void * ) xMutex, genqMUTEX_LOW_PRIORITY, NULL );
  	xTaskCreate( prvMediumPriorityMutexTask, ( signed portCHAR * )"MuMed", configMINIMAL_STACK_SIZE, NULL, genqMUTEX_MEDIUM_PRIORITY, &xMediumPriorityMutexTask );
  	xTaskCreate( prvHighPriorityMutexTask, ( signed portCHAR * )"MuHigh", configMINIMAL_STACK_SIZE, ( void * ) xMutex, genqMUTEX_HIGH_PRIORITY, &xHighPriorityMutexTask );
  }
  /*-----------------------------------------------------------*/
  
  static void prvSendFrontAndBackTest( void *pvParameters )
  {
  unsigned portLONG ulData, ulData2;
  xQueueHandle xQueue;
  
  	#ifdef USE_STDIO
  	void vPrintDisplayMessage( const portCHAR * const * ppcMessageToSend );
  	
  		const portCHAR * 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 = ( xQueueHandle ) 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 )
  {
  xSemaphoreHandle xMutex = ( xSemaphoreHandle ) pvParameters;
  
  	#ifdef USE_STDIO
  	void vPrintDisplayMessage( const portCHAR * const * ppcMessageToSend );
  	
  		const portCHAR * 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 );
  
  		/* 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;
  		}
  
  		/* 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 )
  {
  xSemaphoreHandle xMutex = ( xSemaphoreHandle ) 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 portLONG 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 !xErrorDetected;
  }
  
  
  