/* | |
FreeRTOS V9.0.1 - Copyright (C) 2017 Real Time Engineers Ltd. | |
All rights reserved | |
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. | |
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. Full license text is available on the following | |
link: http://www.freertos.org/a00114.html | |
*************************************************************************** | |
* * | |
* FreeRTOS provides completely free yet professionally developed, * | |
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* * | |
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*************************************************************************** | |
http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading | |
the FAQ page "My application does not run, what could be wrong?". Have you | |
defined configASSERT()? | |
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mission critical applications that require provable dependability. | |
1 tab == 4 spaces! | |
*/ | |
/* | |
* 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 uint32_t ulLoopCounter = 0; | |
/* Set to pdFALSE if an error is discovered by the | |
vQueueOverwritePeriodicISRDemo() function. */ | |
static BaseType_t xISRTestStatus = pdPASS; | |
/* The queue that is accessed from the ISR. The queue accessed by the task is | |
created inside the task itself. */ | |
static QueueHandle_t xISRQueue = NULL; | |
/*-----------------------------------------------------------*/ | |
void vStartQueueOverwriteTask( UBaseType_t uxPriority ) | |
{ | |
const UBaseType_t 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, ( UBaseType_t ) sizeof( uint32_t ) ); | |
/* Create the test task. The queue used by the test task is created inside | |
the task itself. */ | |
xTaskCreate( prvQueueOverwriteTask, "QOver", configMINIMAL_STACK_SIZE, NULL, uxPriority, ( TaskHandle_t * ) NULL ); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvQueueOverwriteTask( void *pvParameters ) | |
{ | |
QueueHandle_t xTaskQueue; | |
const UBaseType_t uxQueueLength = 1; | |
uint32_t 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, ( UBaseType_t ) sizeof( uint32_t ) ); | |
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++; | |
} | |
#if( configUSE_PREEMPTION == 0 ) | |
taskYIELD(); | |
#endif | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
BaseType_t xIsQueueOverwriteTaskStillRunning( void ) | |
{ | |
BaseType_t 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 uint32_t ulCallCount = 0; | |
const uint32_t ulTx1 = 10UL, ulTx2 = 20UL, ulNumberOfSwitchCases = 3UL; | |
uint32_t 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 ); | |
/* Peek the queue to check it holds the expected value. */ | |
xQueuePeekFromISR( xISRQueue, &ulRx ); | |
if( ulRx != ulTx1 ) | |
{ | |
xISRTestStatus = pdFAIL; | |
} | |
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; | |
} | |
} | |