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/*
FreeRTOS V7.4.2 - 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.
*/
/*
* Basic task to demonstrate the xQueueOverwrite() function. See the comments
* in the function itself.
*/
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
/* Demo program include files. */
#include "QueueOverwrite.h"
/* A block time of 0 just means "don't block". */
#define qoDONT_BLOCK 0
/* Number of times to overwrite the value in the queue. */
#define qoLOOPS 5
/* The task that uses the queue. */
static void prvQueueOverwriteTask( void *pvParameters );
/* Variable that is incremented on each loop of prvQueueOverwriteTask() provided
prvQueueOverwriteTask() has not found any errors. */
static unsigned long ulLoopCounter = 0;
/* Set to pdFALSE if an error is discovered by the
vQueueOverwritePeriodicISRDemo() function. */
static portBASE_TYPE xISRTestStatus = pdPASS;
/* The queue that is accessed from the ISR. The queue accessed by the task is
created inside the task itself. */
static xQueueHandle xISRQueue = NULL;
/*-----------------------------------------------------------*/
void vStartQueueOverwriteTask( unsigned portBASE_TYPE uxPriority )
{
const unsigned portBASE_TYPE uxQueueLength = 1;
/* Create the queue used by the ISR. xQueueOverwriteFromISR() should only
be used on queues that have a length of 1. */
xISRQueue = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( unsigned long ) );
/* Create the test task. The queue used by the test task is created inside
the task itself. */
xTaskCreate( prvQueueOverwriteTask, ( signed char * ) "QOver", configMINIMAL_STACK_SIZE, NULL, uxPriority, ( xTaskHandle * ) NULL );
}
/*-----------------------------------------------------------*/
static void prvQueueOverwriteTask( void *pvParameters )
{
xQueueHandle xTaskQueue;
const unsigned portBASE_TYPE uxQueueLength = 1;
unsigned long ulValue, ulStatus = pdPASS, x;
/* The parameter is not used. */
( void ) pvParameters;
/* Create the queue. xQueueOverwrite() should only be used on queues that
have a length of 1. */
xTaskQueue = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( unsigned long ) );
configASSERT( xTaskQueue );
for( ;; )
{
/* The queue is empty. Writing to the queue then reading from the queue
should return the item written. */
ulValue = 10;
xQueueOverwrite( xTaskQueue, &ulValue );
ulValue = 0;
xQueueReceive( xTaskQueue, &ulValue, qoDONT_BLOCK );
if( ulValue != 10 )
{
ulStatus = pdFAIL;
}
/* Now try writing to the queue several times. Each time the value
in the queue should get overwritten. */
for( x = 0; x < qoLOOPS; x++ )
{
/* Write to the queue. */
xQueueOverwrite( xTaskQueue, &x );
/* Check the value in the queue is that written, even though the
queue was not necessarily empty. */
xQueuePeek( xTaskQueue, &ulValue, qoDONT_BLOCK );
if( ulValue != x )
{
ulStatus = pdFAIL;
}
/* There should always be one item in the queue. */
if( uxQueueMessagesWaiting( xTaskQueue ) != uxQueueLength )
{
ulStatus = pdFAIL;
}
}
/* Empty the queue again. */
xQueueReceive( xTaskQueue, &ulValue, qoDONT_BLOCK );
if( uxQueueMessagesWaiting( xTaskQueue ) != 0 )
{
ulStatus = pdFAIL;
}
if( ulStatus != pdFAIL )
{
/* Increment a counter to show this task is still running without
error. */
ulLoopCounter++;
}
}
}
/*-----------------------------------------------------------*/
portBASE_TYPE xIsQueueOverwriteTaskStillRunning( void )
{
portBASE_TYPE xReturn;
if( xISRTestStatus != pdPASS )
{
xReturn = pdFAIL;
}
else if( ulLoopCounter > 0 )
{
xReturn = pdPASS;
}
else
{
/* The task has either stalled of discovered an error. */
xReturn = pdFAIL;
}
ulLoopCounter = 0;
return xReturn;
}
/*-----------------------------------------------------------*/
void vQueueOverwritePeriodicISRDemo( void )
{
static unsigned long ulCallCount = 0;
const unsigned long ulTx1 = 10UL, ulTx2 = 20UL, ulNumberOfSwitchCases = 3UL;
unsigned long ulRx;
/* This function should be called from an interrupt, such as the tick hook
function vApplicationTickHook(). */
configASSERT( xISRQueue );
switch( ulCallCount )
{
case 0:
/* The queue is empty. Write ulTx1 to the queue. In this demo the
last parameter is not used because there are no tasks blocked on
this queue. */
xQueueOverwriteFromISR( xISRQueue, &ulTx1, NULL );
break;
case 1:
/* The queue already holds ulTx1. Overwrite the value in the queue
with ulTx2. */
xQueueOverwriteFromISR( xISRQueue, &ulTx2, NULL );
break;
case 2:
/* Read from the queue to empty the queue again. The value read
should be ulTx2. */
xQueueReceiveFromISR( xISRQueue, &ulRx, NULL );
if( ulRx != ulTx2 )
{
xISRTestStatus = pdFAIL;
}
break;
}
/* Run the next case in the switch statement above next time this function
is called. */
ulCallCount++;
if( ulCallCount >= ulNumberOfSwitchCases )
{
/* Go back to the start. */
ulCallCount = 0;
}
}
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