Demo/Common/Minimal/integer.c - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
     FreeRTOS V6.0.4 - 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.
 */

 /*
  * 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;
 }
	/*
	FreeRTOS V6.0.4 - 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.
	*/

	/*
	* 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;
	}