Subversion Repositories openrisc_2011-10-31

/*

    FreeRTOS V6.1.1 - Copyright (C) 2011 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 books - available as PDF or paperback  *

    *                                                                         *

    *        "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.

*/

/*

 * This version of integer. c is for use on systems that have limited stack

 * space and no display facilities.  The complete version can be found in

 * the Demo/Common/Full directory.

 *

 * As with the full version, the tasks created in this file are a good test

 * of the scheduler context switch mechanism.  The processor has to access

 * 32bit variables in two or four chunks (depending on the processor).  The low

 * priority of these tasks means there is a high probability that a context

 * switch will occur mid calculation.  See flop. c documentation for

 * more information.

 *

 */

/*

Changes from V1.2.1

        + The constants used in the calculations are larger to ensure the

          optimiser does not truncate them to 16 bits.

Changes from V1.2.3

        + uxTaskCheck is now just used as a boolean.  Instead of incrementing

          the variable each cycle of the task, the variable is simply set to

          true.  sAreIntegerMathsTaskStillRunning() sets it back to false and

          expects it to have been set back to true by the time it is called

          again.

        + A division has been included in the calculation.

*/

#include <stdlib.h>

/* Scheduler include files. */

#include "FreeRTOS.h"

#include "task.h"

/* Demo program include files. */

#include "integer.h"

/* The constants used in the calculation. */

#define intgCONST1                              ( ( long ) 123 )

#define intgCONST2                              ( ( long ) 234567 )

#define intgCONST3                              ( ( long ) -3 )

#define intgCONST4                              ( ( long ) 7 )

#define intgEXPECTED_ANSWER             ( ( ( intgCONST1 + intgCONST2 ) * intgCONST3 ) / intgCONST4 )

#define intgSTACK_SIZE                  configMINIMAL_STACK_SIZE

/* As this is the minimal version, we will only create one task. */

#define intgNUMBER_OF_TASKS             ( 1 )

/* The task function.  Repeatedly performs a 32 bit calculation, checking the

result against the expected result.  If the result is incorrect then the

context switch must have caused some corruption. */

static portTASK_FUNCTION_PROTO( vCompeteingIntMathTask, pvParameters );

/* Variables that are set to true within the calculation task to indicate

that the task is still executing.  The check task sets the variable back to

false, flagging an error if the variable is still false the next time it

is called. */

static volatile signed portBASE_TYPE xTaskCheck[ intgNUMBER_OF_TASKS ] = { ( signed portBASE_TYPE ) pdFALSE };

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

void vStartIntegerMathTasks( unsigned portBASE_TYPE uxPriority )

{

short sTask;

        for( sTask = 0; sTask < intgNUMBER_OF_TASKS; sTask++ )

        {

                xTaskCreate( vCompeteingIntMathTask, ( signed char * ) "IntMath", intgSTACK_SIZE, ( void * ) &( xTaskCheck[ sTask ] ), uxPriority, ( xTaskHandle * ) NULL );

        }

}

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

static portTASK_FUNCTION( vCompeteingIntMathTask, pvParameters )

{

/* These variables are all effectively set to constants so they are volatile to

ensure the compiler does not just get rid of them. */

volatile long lValue;

short sError = pdFALSE;

volatile signed portBASE_TYPE *pxTaskHasExecuted;

        /* Set a pointer to the variable we are going to set to true each

        iteration.  This is also a good test of the parameter passing mechanism

        within each port. */

        pxTaskHasExecuted = ( volatile signed portBASE_TYPE * ) pvParameters;

        /* Keep performing a calculation and checking the result against a constant. */

        for( ;; )

        {

                /* Perform the calculation.  This will store partial value in

                registers, resulting in a good test of the context switch mechanism. */

                lValue = intgCONST1;

                lValue += intgCONST2;

                /* Yield in case cooperative scheduling is being used. */

                #if configUSE_PREEMPTION == 0

                {

                        taskYIELD();

                }

                #endif

                /* Finish off the calculation. */

                lValue *= intgCONST3;

                lValue /= intgCONST4;

                /* If the calculation is found to be incorrect we stop setting the

                TaskHasExecuted variable so the check task can see an error has

                occurred. */

                if( lValue != intgEXPECTED_ANSWER ) /*lint !e774 volatile used to prevent this being optimised out. */

                {

                        sError = pdTRUE;

                }

                if( sError == pdFALSE )

                {

                        /* We have not encountered any errors, so set the flag that show

                        we are still executing.  This will be periodically cleared by

                        the check task. */

                        portENTER_CRITICAL();

                                *pxTaskHasExecuted = pdTRUE;

                        portEXIT_CRITICAL();

                }

                /* Yield in case cooperative scheduling is being used. */

                #if configUSE_PREEMPTION == 0

                {

                        taskYIELD();

                }

                #endif

        }

}

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

/* This is called to check that all the created tasks are still running. */

portBASE_TYPE xAreIntegerMathsTaskStillRunning( void )

{

portBASE_TYPE xReturn = pdTRUE;

short sTask;

        /* Check the maths tasks are still running by ensuring their check variables

        are still being set to true. */

        for( sTask = 0; sTask < intgNUMBER_OF_TASKS; sTask++ )

        {

                if( xTaskCheck[ sTask ] == pdFALSE )

                {

                        /* The check has not incremented so an error exists. */

                        xReturn = pdFALSE;

                }

                /* Reset the check variable so we can tell if it has been set by

                the next time around. */

                xTaskCheck[ sTask ] = pdFALSE;

        }

        return xReturn;

}