FreeRTOS/Demo/SuperH_SH7216_Renesas/RTOSDemo/flop.c - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
     FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.

     FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME.  PLEASE VISIT
     http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

     ***************************************************************************
      *                                                                       *
      *    FreeRTOS tutorial books are available in pdf and paperback.        *
      *    Complete, revised, and edited pdf reference manuals are also       *
      *    available.                                                         *
      *                                                                       *
      *    Purchasing FreeRTOS documentation will not only help you, by       *
      *    ensuring you get running as quickly as possible and with an        *
      *    in-depth knowledge of how to use FreeRTOS, it will also help       *
      *    the FreeRTOS project to continue with its mission of providing     *
      *    professional grade, cross platform, de facto standard solutions    *
      *    for microcontrollers - completely free of charge!                  *
      *                                                                       *
      *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
      *                                                                       *
      *    Thank you for using FreeRTOS, and 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 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.  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 Real Time Engineers Ltd., contact details for whom are available
     on the FreeRTOS WEB site.

     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, and our new
     fully thread aware and reentrant UDP/IP stack.

     http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
     Integrity Systems, who sell the code with commercial support,
     indemnification and middleware, under the OpenRTOS brand.

     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.
 */

 /*
  * Creates eight tasks, each of which loops continuously performing a floating
  * point calculation and in so doing test the floating point context switching.
  * This file also demonstrates the use of the xPortUsesFloatingPoint() function
  * which informs the kernel that the task requires its floating point context
  * saved on each switch.
  *
  * All the tasks run at the idle priority and never block or yield.  This causes
  * all eight tasks to time slice with the idle task.  Running at the idle
  * priority means that these tasks will get pre-empted any time another task is
  * ready to run or a time slice occurs.  More often than not the pre-emption
  * will occur mid calculation, creating a good test of the schedulers context
  * switch mechanism - a calculation producing an unexpected result could be a
  * symptom of a corruption in the context of a task.
  */

 #include <stdlib.h>
 #include <math.h>

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

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

 #define mathSTACK_SIZE		configMINIMAL_STACK_SIZE
 #define mathNUMBER_OF_TASKS  ( 8 )

 /* Four tasks, each of which performs a different floating point calculation.
 Each of the four is created twice. */
 static void vCompetingMathTask1( void *pvParameters );
 static void vCompetingMathTask2( void *pvParameters );
 static void vCompetingMathTask3( void *pvParameters );
 static void vCompetingMathTask4( void *pvParameters );

 /* These variables are used to check that all the tasks are still running.  If a
 task gets a calculation wrong it will stop incrementing its check variable,
 otherwise the check variable will get incremented on each iteration of the
 tasks execution. */
 static volatile unsigned short usTaskCheck[ mathNUMBER_OF_TASKS ] = { ( unsigned short ) 0 };

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

 void vStartMathTasks( unsigned portBASE_TYPE uxPriority )
 {
 xTaskHandle xCreatedTask;

 	/* Create one of the floating point tasks... */
 	xTaskCreate( vCompetingMathTask1, ( signed char * ) "Math1", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 0 ] ), uxPriority, &xCreatedTask );

 	/* ... then enable floating point support for the created task so its flop
 	flop registers are maintained in a consistent state. */
 	xPortUsesFloatingPoint( xCreatedTask );

 	xTaskCreate( vCompetingMathTask2, ( signed char * ) "Math2", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 1 ] ), uxPriority, &xCreatedTask );
 	xPortUsesFloatingPoint( xCreatedTask );

 	xTaskCreate( vCompetingMathTask3, ( signed char * ) "Math3", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 2 ] ), uxPriority, &xCreatedTask );
 	xPortUsesFloatingPoint( xCreatedTask );

 	xTaskCreate( vCompetingMathTask4, ( signed char * ) "Math4", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 3 ] ), uxPriority, &xCreatedTask );
 	xPortUsesFloatingPoint( xCreatedTask );

 	xTaskCreate( vCompetingMathTask1, ( signed char * ) "Math5", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 4 ] ), uxPriority, &xCreatedTask );
 	xPortUsesFloatingPoint( xCreatedTask );

 	xTaskCreate( vCompetingMathTask2, ( signed char * ) "Math6", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 5 ] ), uxPriority, &xCreatedTask );
 	xPortUsesFloatingPoint( xCreatedTask );

 	xTaskCreate( vCompetingMathTask3, ( signed char * ) "Math7", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 6 ] ), uxPriority, &xCreatedTask );
 	xPortUsesFloatingPoint( xCreatedTask );

 	xTaskCreate( vCompetingMathTask4, ( signed char * ) "Math8", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 7 ] ), uxPriority, &xCreatedTask );
 	xPortUsesFloatingPoint( xCreatedTask );
 }
 /*-----------------------------------------------------------*/

 static void vCompetingMathTask1( void *pvParameters )
 {
 volatile double d1, d2, d3, d4;
 volatile unsigned short *pusTaskCheckVariable;
 volatile double dAnswer;
 short sError = pdFALSE;

 	d1 = 123.4567;
 	d2 = 2345.6789;
 	d3 = -918.222;

 	/* Calculate the expected answer. */
 	dAnswer = ( d1 + d2 ) * d3;

 	/* The variable this task increments to show it is still running is passed in
 	as the parameter. */
 	pusTaskCheckVariable = ( unsigned short * ) pvParameters;

 	/* Keep performing a calculation and checking the result against a constant. */
 	for(;;)
 	{
 		/* Perform the calculation. */
 		d1 = 123.4567;
 		d2 = 2345.6789;
 		d3 = -918.222;

 		d4 = ( d1 + d2 ) * d3;

 		/* If the calculation does not match the expected constant, stop the
 		increment of the check variable. */
 		if( fabs( d4 - dAnswer ) > 0.001 )
 		{
 			sError = pdTRUE;
 		}

 		if( sError == pdFALSE )
 		{
 			/* If the calculation has always been correct, increment the check
 			variable so we know this task is still running okay. */
 			( *pusTaskCheckVariable )++;
 		}
 	}
 }
 /*-----------------------------------------------------------*/

 static void vCompetingMathTask2( void *pvParameters )
 {
 volatile double d1, d2, d3, d4;
 volatile unsigned short *pusTaskCheckVariable;
 volatile double dAnswer;
 short sError = pdFALSE;

 	d1 = -389.38;
 	d2 = 32498.2;
 	d3 = -2.0001;

 	/* Calculate the expected answer. */
 	dAnswer = ( d1 / d2 ) * d3;


 	/* The variable this task increments to show it is still running is passed in
 	as the parameter. */
 	pusTaskCheckVariable = ( unsigned short * ) pvParameters;

 	/* Keep performing a calculation and checking the result against a constant. */
 	for( ;; )
 	{
 		/* Perform the calculation. */
 		d1 = -389.38;
 		d2 = 32498.2;
 		d3 = -2.0001;

 		d4 = ( d1 / d2 ) * d3;

 		/* If the calculation does not match the expected constant, stop the
 		increment of the check variable. */
 		if( fabs( d4 - dAnswer ) > 0.001 )
 		{
 			sError = pdTRUE;
 		}

 		if( sError == pdFALSE )
 		{
 			/* If the calculation has always been correct, increment the check
 			variable so we know
 			this task is still running okay. */
 			( *pusTaskCheckVariable )++;
 		}
 	}
 }
 /*-----------------------------------------------------------*/

 static void vCompetingMathTask3( void *pvParameters )
 {
 volatile double *pdArray, dTotal1, dTotal2, dDifference;
 volatile unsigned short *pusTaskCheckVariable;
 const size_t xArraySize = 10;
 size_t xPosition;
 short sError = pdFALSE;

 	/* The variable this task increments to show it is still running is passed
 	in as the parameter. */
 	pusTaskCheckVariable = ( unsigned short * ) pvParameters;

 	/* Allocate memory for use as an array. */
 	pdArray = ( double * ) pvPortMalloc( xArraySize * sizeof( double ) );

 	/* Keep filling an array, keeping a running total of the values placed in
 	the array.  Then run through the array adding up all the values.  If the two
 	totals do not match, stop the check variable from incrementing. */
 	for( ;; )
 	{
 		dTotal1 = 0.0;
 		dTotal2 = 0.0;

 		for( xPosition = 0; xPosition < xArraySize; xPosition++ )
 		{
 			pdArray[ xPosition ] = ( double ) xPosition + 5.5;
 			dTotal1 += ( double ) xPosition + 5.5;
 		}

 		for( xPosition = 0; xPosition < xArraySize; xPosition++ )
 		{
 			dTotal2 += pdArray[ xPosition ];
 		}

 		dDifference = dTotal1 - dTotal2;
 		if( fabs( dDifference ) > 0.001 )
 		{
 			sError = pdTRUE;
 		}

 		if( sError == pdFALSE )
 		{
 			/* If the calculation has always been correct, increment the check
 			variable so we know	this task is still running okay. */
 			( *pusTaskCheckVariable )++;
 		}
 	}
 }
 /*-----------------------------------------------------------*/

 static void vCompetingMathTask4( void *pvParameters )
 {
 volatile double *pdArray, dTotal1, dTotal2, dDifference;
 volatile unsigned short *pusTaskCheckVariable;
 const size_t xArraySize = 10;
 size_t xPosition;
 short sError = pdFALSE;

 	/* The variable this task increments to show it is still running is passed in
 	as the parameter. */
 	pusTaskCheckVariable = ( unsigned short * ) pvParameters;

 	/* Allocate RAM for use as an array. */
 	pdArray = ( double * ) pvPortMalloc( xArraySize * sizeof( double ) );

 	/* Keep filling an array, keeping a running total of the values placed in the
 	array.  Then run through the array adding up all the values.  If the two totals
 	do not match, stop the check variable from incrementing. */
 	for( ;; )
 	{
 		dTotal1 = 0.0;
 		dTotal2 = 0.0;

 		for( xPosition = 0; xPosition < xArraySize; xPosition++ )
 		{
 			pdArray[ xPosition ] = ( double ) xPosition * 12.123;
 			dTotal1 += ( double ) xPosition * 12.123;
 		}

 		for( xPosition = 0; xPosition < xArraySize; xPosition++ )
 		{
 			dTotal2 += pdArray[ xPosition ];
 		}

 		dDifference = dTotal1 - dTotal2;
 		if( fabs( dDifference ) > 0.001 )
 		{
 			sError = pdTRUE;
 		}

 		if( sError == pdFALSE )
 		{
 			/* If the calculation has always been correct, increment the check
 			variable so we know	this task is still running okay. */
 			( *pusTaskCheckVariable )++;
 		}
 	}
 }
 /*-----------------------------------------------------------*/

 /* This is called to check that all the created tasks are still running. */
 portBASE_TYPE xAreMathsTaskStillRunning( void )
 {
 /* Keep a history of the check variables so we know if they have been
 incremented since the last call. */
 static unsigned short usLastTaskCheck[ mathNUMBER_OF_TASKS ] = { ( unsigned short ) 0 };
 portBASE_TYPE xReturn = pdTRUE, xTask;

 	/* Check the maths tasks are still running by ensuring their check variables
 	are still incrementing. */
 	for( xTask = 0; xTask < mathNUMBER_OF_TASKS; xTask++ )
 	{
 		if( usTaskCheck[ xTask ] == usLastTaskCheck[ xTask ] )
 		{
 			/* The check has not incremented so an error exists. */
 			xReturn = pdFALSE;
 		}

 		usLastTaskCheck[ xTask ] = usTaskCheck[ xTask ];
 	}

 	return xReturn;
 }
	/*
	FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.

	FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
	http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

	***************************************************************************
	* *
	* FreeRTOS tutorial books are available in pdf and paperback. *
	* Complete, revised, and edited pdf reference manuals are also *
	* available. *
	* *
	* Purchasing FreeRTOS documentation will not only help you, by *
	* ensuring you get running as quickly as possible and with an *
	* in-depth knowledge of how to use FreeRTOS, it will also help *
	* the FreeRTOS project to continue with its mission of providing *
	* professional grade, cross platform, de facto standard solutions *
	* for microcontrollers - completely free of charge! *
	* *
	* >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
	* *
	* Thank you for using FreeRTOS, and 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 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. 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 Real Time Engineers Ltd., contact details for whom are available
	on the FreeRTOS WEB site.

	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, and our new
	fully thread aware and reentrant UDP/IP stack.

	http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
	Integrity Systems, who sell the code with commercial support,
	indemnification and middleware, under the OpenRTOS brand.

	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.
	*/

	/*
	* Creates eight tasks, each of which loops continuously performing a floating
	* point calculation and in so doing test the floating point context switching.
	* This file also demonstrates the use of the xPortUsesFloatingPoint() function
	* which informs the kernel that the task requires its floating point context
	* saved on each switch.
	*
	* All the tasks run at the idle priority and never block or yield. This causes
	* all eight tasks to time slice with the idle task. Running at the idle
	* priority means that these tasks will get pre-empted any time another task is
	* ready to run or a time slice occurs. More often than not the pre-emption
	* will occur mid calculation, creating a good test of the schedulers context
	* switch mechanism - a calculation producing an unexpected result could be a
	* symptom of a corruption in the context of a task.
	*/

	#include <stdlib.h>
	#include <math.h>

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

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

	#define mathSTACK_SIZE configMINIMAL_STACK_SIZE
	#define mathNUMBER_OF_TASKS ( 8 )

	/* Four tasks, each of which performs a different floating point calculation.
	Each of the four is created twice. */
	static void vCompetingMathTask1( void *pvParameters );
	static void vCompetingMathTask2( void *pvParameters );
	static void vCompetingMathTask3( void *pvParameters );
	static void vCompetingMathTask4( void *pvParameters );

	/* These variables are used to check that all the tasks are still running. If a
	task gets a calculation wrong it will stop incrementing its check variable,
	otherwise the check variable will get incremented on each iteration of the
	tasks execution. */
	static volatile unsigned short usTaskCheck[ mathNUMBER_OF_TASKS ] = { ( unsigned short ) 0 };

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

	void vStartMathTasks( unsigned portBASE_TYPE uxPriority )
	{
	xTaskHandle xCreatedTask;

	/* Create one of the floating point tasks... */
	xTaskCreate( vCompetingMathTask1, ( signed char * ) "Math1", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 0 ] ), uxPriority, &xCreatedTask );

	/* ... then enable floating point support for the created task so its flop
	flop registers are maintained in a consistent state. */
	xPortUsesFloatingPoint( xCreatedTask );

	xTaskCreate( vCompetingMathTask2, ( signed char * ) "Math2", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 1 ] ), uxPriority, &xCreatedTask );
	xPortUsesFloatingPoint( xCreatedTask );

	xTaskCreate( vCompetingMathTask3, ( signed char * ) "Math3", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 2 ] ), uxPriority, &xCreatedTask );
	xPortUsesFloatingPoint( xCreatedTask );

	xTaskCreate( vCompetingMathTask4, ( signed char * ) "Math4", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 3 ] ), uxPriority, &xCreatedTask );
	xPortUsesFloatingPoint( xCreatedTask );

	xTaskCreate( vCompetingMathTask1, ( signed char * ) "Math5", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 4 ] ), uxPriority, &xCreatedTask );
	xPortUsesFloatingPoint( xCreatedTask );

	xTaskCreate( vCompetingMathTask2, ( signed char * ) "Math6", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 5 ] ), uxPriority, &xCreatedTask );
	xPortUsesFloatingPoint( xCreatedTask );

	xTaskCreate( vCompetingMathTask3, ( signed char * ) "Math7", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 6 ] ), uxPriority, &xCreatedTask );
	xPortUsesFloatingPoint( xCreatedTask );

	xTaskCreate( vCompetingMathTask4, ( signed char * ) "Math8", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 7 ] ), uxPriority, &xCreatedTask );
	xPortUsesFloatingPoint( xCreatedTask );
	}
	/-----------------------------------------------------------/

	static void vCompetingMathTask1( void *pvParameters )
	{
	volatile double d1, d2, d3, d4;
	volatile unsigned short *pusTaskCheckVariable;
	volatile double dAnswer;
	short sError = pdFALSE;

	d1 = 123.4567;
	d2 = 2345.6789;
	d3 = -918.222;

	/* Calculate the expected answer. */
	dAnswer = ( d1 + d2 ) * d3;

	/* The variable this task increments to show it is still running is passed in
	as the parameter. */
	pusTaskCheckVariable = ( unsigned short * ) pvParameters;

	/* Keep performing a calculation and checking the result against a constant. */
	for(;;)
	{
	/* Perform the calculation. */
	d1 = 123.4567;
	d2 = 2345.6789;
	d3 = -918.222;

	d4 = ( d1 + d2 ) * d3;

	/* If the calculation does not match the expected constant, stop the
	increment of the check variable. */
	if( fabs( d4 - dAnswer ) > 0.001 )
	{
	sError = pdTRUE;
	}

	if( sError == pdFALSE )
	{
	/* If the calculation has always been correct, increment the check
	variable so we know this task is still running okay. */
	( *pusTaskCheckVariable )++;
	}
	}
	}
	/-----------------------------------------------------------/

	static void vCompetingMathTask2( void *pvParameters )
	{
	volatile double d1, d2, d3, d4;
	volatile unsigned short *pusTaskCheckVariable;
	volatile double dAnswer;
	short sError = pdFALSE;

	d1 = -389.38;
	d2 = 32498.2;
	d3 = -2.0001;

	/* Calculate the expected answer. */
	dAnswer = ( d1 / d2 ) * d3;


	/* The variable this task increments to show it is still running is passed in
	as the parameter. */
	pusTaskCheckVariable = ( unsigned short * ) pvParameters;

	/* Keep performing a calculation and checking the result against a constant. */
	for( ;; )
	{
	/* Perform the calculation. */
	d1 = -389.38;
	d2 = 32498.2;
	d3 = -2.0001;

	d4 = ( d1 / d2 ) * d3;

	/* If the calculation does not match the expected constant, stop the
	increment of the check variable. */
	if( fabs( d4 - dAnswer ) > 0.001 )
	{
	sError = pdTRUE;
	}

	if( sError == pdFALSE )
	{
	/* If the calculation has always been correct, increment the check
	variable so we know
	this task is still running okay. */
	( *pusTaskCheckVariable )++;
	}
	}
	}
	/-----------------------------------------------------------/

	static void vCompetingMathTask3( void *pvParameters )
	{
	volatile double *pdArray, dTotal1, dTotal2, dDifference;
	volatile unsigned short *pusTaskCheckVariable;
	const size_t xArraySize = 10;
	size_t xPosition;
	short sError = pdFALSE;

	/* The variable this task increments to show it is still running is passed
	in as the parameter. */
	pusTaskCheckVariable = ( unsigned short * ) pvParameters;

	/* Allocate memory for use as an array. */
	pdArray = ( double * ) pvPortMalloc( xArraySize * sizeof( double ) );

	/* Keep filling an array, keeping a running total of the values placed in
	the array. Then run through the array adding up all the values. If the two
	totals do not match, stop the check variable from incrementing. */
	for( ;; )
	{
	dTotal1 = 0.0;
	dTotal2 = 0.0;

	for( xPosition = 0; xPosition < xArraySize; xPosition++ )
	{
	pdArray[ xPosition ] = ( double ) xPosition + 5.5;
	dTotal1 += ( double ) xPosition + 5.5;
	}

	for( xPosition = 0; xPosition < xArraySize; xPosition++ )
	{
	dTotal2 += pdArray[ xPosition ];
	}

	dDifference = dTotal1 - dTotal2;
	if( fabs( dDifference ) > 0.001 )
	{
	sError = pdTRUE;
	}

	if( sError == pdFALSE )
	{
	/* If the calculation has always been correct, increment the check
	variable so we know this task is still running okay. */
	( *pusTaskCheckVariable )++;
	}
	}
	}
	/-----------------------------------------------------------/

	static void vCompetingMathTask4( void *pvParameters )
	{
	volatile double *pdArray, dTotal1, dTotal2, dDifference;
	volatile unsigned short *pusTaskCheckVariable;
	const size_t xArraySize = 10;
	size_t xPosition;
	short sError = pdFALSE;

	/* The variable this task increments to show it is still running is passed in
	as the parameter. */
	pusTaskCheckVariable = ( unsigned short * ) pvParameters;

	/* Allocate RAM for use as an array. */
	pdArray = ( double * ) pvPortMalloc( xArraySize * sizeof( double ) );

	/* Keep filling an array, keeping a running total of the values placed in the
	array. Then run through the array adding up all the values. If the two totals
	do not match, stop the check variable from incrementing. */
	for( ;; )
	{
	dTotal1 = 0.0;
	dTotal2 = 0.0;

	for( xPosition = 0; xPosition < xArraySize; xPosition++ )
	{
	pdArray[ xPosition ] = ( double ) xPosition * 12.123;
	dTotal1 += ( double ) xPosition * 12.123;
	}

	for( xPosition = 0; xPosition < xArraySize; xPosition++ )
	{
	dTotal2 += pdArray[ xPosition ];
	}

	dDifference = dTotal1 - dTotal2;
	if( fabs( dDifference ) > 0.001 )
	{
	sError = pdTRUE;
	}

	if( sError == pdFALSE )
	{
	/* If the calculation has always been correct, increment the check
	variable so we know this task is still running okay. */
	( *pusTaskCheckVariable )++;
	}
	}
	}
	/-----------------------------------------------------------/

	/* This is called to check that all the created tasks are still running. */
	portBASE_TYPE xAreMathsTaskStillRunning( void )
	{
	/* Keep a history of the check variables so we know if they have been
	incremented since the last call. */
	static unsigned short usLastTaskCheck[ mathNUMBER_OF_TASKS ] = { ( unsigned short ) 0 };
	portBASE_TYPE xReturn = pdTRUE, xTask;

	/* Check the maths tasks are still running by ensuring their check variables
	are still incrementing. */
	for( xTask = 0; xTask < mathNUMBER_OF_TASKS; xTask++ )
	{
	if( usTaskCheck[ xTask ] == usLastTaskCheck[ xTask ] )
	{
	/* The check has not incremented so an error exists. */
	xReturn = pdFALSE;
	}

	usLastTaskCheck[ xTask ] = usTaskCheck[ xTask ];
	}

	return xReturn;
	}