/* | |
FreeRTOS V7.0.0 - Copyright (C) 2011 Real Time Engineers Ltd. | |
*************************************************************************** | |
* * | |
* 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 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; | |
} | |