root/webserver/example/freeRTOSexample/EnergyMeters/Common/Minimal/flop.c

/*
        FreeRTOS V5.4.1 - Copyright (C) 2009 Real Time Engineers Ltd.

        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.  
        Alternative commercial license and support terms are also available upon 
        request.  See the licensing section of http://www.FreeRTOS.org for full 
        license details.

        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 along
        with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
        Temple Place, Suite 330, Boston, MA  02111-1307  USA.


        ***************************************************************************
        *                                                                         *
        * Looking for a quick start?  Then check out the FreeRTOS eBook!          *
        * See http://www.FreeRTOS.org/Documentation for details                   *
        *                                                                         *
        ***************************************************************************

        1 tab == 4 spaces!

        Please ensure to read the configuration and relevant port sections of the
        online documentation.

        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.

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        licensing and training services.
*/

/*
 * Creates eight tasks, each of which loops continuously performing an (emulated) 
 * floating point calculation.
 *
 * 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 portTASK_FUNCTION_PROTO( vCompetingMathTask1, pvParameters );
static portTASK_FUNCTION_PROTO( vCompetingMathTask2, pvParameters );
static portTASK_FUNCTION_PROTO( vCompetingMathTask3, pvParameters );
static portTASK_FUNCTION_PROTO( vCompetingMathTask4, 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. */
static volatile unsigned portSHORT usTaskCheck[ mathNUMBER_OF_TASKS ] = { ( unsigned portSHORT ) 0 };

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

void vStartMathTasks( unsigned portBASE_TYPE uxPriority )
{
        xTaskCreate( vCompetingMathTask1, ( signed portCHAR * ) "Math1", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 0 ] ), uxPriority, NULL );
        xTaskCreate( vCompetingMathTask2, ( signed portCHAR * ) "Math2", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 1 ] ), uxPriority, NULL );
        xTaskCreate( vCompetingMathTask3, ( signed portCHAR * ) "Math3", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 2 ] ), uxPriority, NULL );
        xTaskCreate( vCompetingMathTask4, ( signed portCHAR * ) "Math4", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 3 ] ), uxPriority, NULL );
        xTaskCreate( vCompetingMathTask1, ( signed portCHAR * ) "Math5", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 4 ] ), uxPriority, NULL );
        xTaskCreate( vCompetingMathTask2, ( signed portCHAR * ) "Math6", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 5 ] ), uxPriority, NULL );
        xTaskCreate( vCompetingMathTask3, ( signed portCHAR * ) "Math7", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 6 ] ), uxPriority, NULL );
        xTaskCreate( vCompetingMathTask4, ( signed portCHAR * ) "Math8", mathSTACK_SIZE, ( void * ) &( usTaskCheck[ 7 ] ), uxPriority, NULL );
}
/*-----------------------------------------------------------*/

static portTASK_FUNCTION( vCompetingMathTask1, pvParameters )
{
volatile portDOUBLE d1, d2, d3, d4;
volatile unsigned portSHORT *pusTaskCheckVariable;
volatile portDOUBLE dAnswer;
portSHORT sError = pdFALSE;

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

        dAnswer = ( d1 + d2 ) * d3;

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

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

                d4 = ( d1 + d2 ) * d3;

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

                /* 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 )++;
                }

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

        }
}
/*-----------------------------------------------------------*/

static portTASK_FUNCTION( vCompetingMathTask2, pvParameters )
{
volatile portDOUBLE d1, d2, d3, d4;
volatile unsigned portSHORT *pusTaskCheckVariable;
volatile portDOUBLE dAnswer;
portSHORT sError = pdFALSE;

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

        dAnswer = ( d1 / d2 ) * d3;


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

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

                d4 = ( d1 / d2 ) * d3;

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

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

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

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

        pdArray = ( portDOUBLE * ) pvPortMalloc( xArraySize * sizeof( portDOUBLE ) );

        /* 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 ] = ( portDOUBLE ) xPosition + 5.5;
                        dTotal1 += ( portDOUBLE ) xPosition + 5.5;      
                }

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

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

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

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

                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 portTASK_FUNCTION( vCompetingMathTask4, pvParameters )
{
volatile portDOUBLE *pdArray, dTotal1, dTotal2, dDifference;
volatile unsigned portSHORT *pusTaskCheckVariable;
const size_t xArraySize = 10;
size_t xPosition;
portSHORT sError = pdFALSE;

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

        pdArray = ( portDOUBLE * ) pvPortMalloc( xArraySize * sizeof( portDOUBLE ) );

        /* 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 ] = ( portDOUBLE ) xPosition * 12.123;
                        dTotal1 += ( portDOUBLE ) xPosition * 12.123;   
                }

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

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

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

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

                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 portSHORT usLastTaskCheck[ mathNUMBER_OF_TASKS ] = { ( unsigned portSHORT ) 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;
}