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/*
FreeRTOS V8.0.0 - Copyright (C) 2014 Real Time Engineers Ltd.
All rights reserved
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
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 from the following
link: http://www.freertos.org/a00114.html
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, a DOS
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
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.
1 tab == 4 spaces!
*/
/*
* This version of PollQ. 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.
*
* Creates two tasks that communicate over a single queue. One task acts as a
* producer, the other a consumer.
*
* The producer loops for three iteration, posting an incrementing number onto the
* queue each cycle. It then delays for a fixed period before doing exactly the
* same again.
*
* The consumer loops emptying the queue. Each item removed from the queue is
* checked to ensure it contains the expected value. When the queue is empty it
* blocks for a fixed period, then does the same again.
*
* All queue access is performed without blocking. The consumer completely empties
* the queue each time it runs so the producer should never find the queue full.
*
* An error is flagged if the consumer obtains an unexpected value or the producer
* find the queue is full.
*/
/*
Changes from V2.0.0
+ Delay periods are now specified using variables and constants of
TickType_t rather than unsigned long.
*/
#include <stdlib.h>
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
/* Demo program include files. */
#include "PollQ.h"
#define pollqSTACK_SIZE configMINIMAL_STACK_SIZE
#define pollqQUEUE_SIZE ( 10 )
#define pollqPRODUCER_DELAY ( ( TickType_t ) 200 / portTICK_PERIOD_MS )
#define pollqCONSUMER_DELAY ( pollqPRODUCER_DELAY - ( TickType_t ) ( 20 / portTICK_PERIOD_MS ) )
#define pollqNO_DELAY ( ( TickType_t ) 0 )
#define pollqVALUES_TO_PRODUCE ( ( signed portBASE_TYPE ) 3 )
#define pollqINITIAL_VALUE ( ( signed portBASE_TYPE ) 0 )
/* The task that posts the incrementing number onto the queue. */
static portTASK_FUNCTION_PROTO( vPolledQueueProducer, pvParameters );
/* The task that empties the queue. */
static portTASK_FUNCTION_PROTO( vPolledQueueConsumer, pvParameters );
/* Variables that are used to check that the tasks are still running with no
errors. */
static volatile signed portBASE_TYPE xPollingConsumerCount = pollqINITIAL_VALUE, xPollingProducerCount = pollqINITIAL_VALUE;
/*-----------------------------------------------------------*/
void vStartPolledQueueTasks( unsigned portBASE_TYPE uxPriority )
{
static QueueHandle_t xPolledQueue;
/* Create the queue used by the producer and consumer. */
xPolledQueue = xQueueCreate( pollqQUEUE_SIZE, ( unsigned portBASE_TYPE ) sizeof( unsigned short ) );
/* vQueueAddToRegistry() adds the queue to the queue registry, if one is
in use. The queue registry is provided as a means for kernel aware
debuggers to locate queues and has no purpose if a kernel aware debugger
is not being used. The call to vQueueAddToRegistry() will be removed
by the pre-processor if configQUEUE_REGISTRY_SIZE is not defined or is
defined to be less than 1. */
vQueueAddToRegistry( xPolledQueue, "Poll_Test_Queue" );
/* Spawn the producer and consumer. */
xTaskCreate( vPolledQueueConsumer, "QConsNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( TaskHandle_t * ) NULL );
xTaskCreate( vPolledQueueProducer, "QProdNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( TaskHandle_t * ) NULL );
}
/*-----------------------------------------------------------*/
static portTASK_FUNCTION( vPolledQueueProducer, pvParameters )
{
unsigned short usValue = ( unsigned short ) 0;
signed portBASE_TYPE xError = pdFALSE, xLoop;
for( ;; )
{
for( xLoop = 0; xLoop < pollqVALUES_TO_PRODUCE; xLoop++ )
{
/* Send an incrementing number on the queue without blocking. */
if( xQueueSend( *( ( QueueHandle_t * ) pvParameters ), ( void * ) &usValue, pollqNO_DELAY ) != pdPASS )
{
/* We should never find the queue full so if we get here there
has been an error. */
xError = pdTRUE;
}
else
{
if( xError == pdFALSE )
{
/* If an error has ever been recorded we stop incrementing the
check variable. */
portENTER_CRITICAL();
xPollingProducerCount++;
portEXIT_CRITICAL();
}
/* Update the value we are going to post next time around. */
usValue++;
}
}
/* Wait before we start posting again to ensure the consumer runs and
empties the queue. */
vTaskDelay( pollqPRODUCER_DELAY );
}
} /*lint !e818 Function prototype must conform to API. */
/*-----------------------------------------------------------*/
static portTASK_FUNCTION( vPolledQueueConsumer, pvParameters )
{
unsigned short usData, usExpectedValue = ( unsigned short ) 0;
signed portBASE_TYPE xError = pdFALSE;
for( ;; )
{
/* Loop until the queue is empty. */
while( uxQueueMessagesWaiting( *( ( QueueHandle_t * ) pvParameters ) ) )
{
if( xQueueReceive( *( ( QueueHandle_t * ) pvParameters ), &usData, pollqNO_DELAY ) == pdPASS )
{
if( usData != usExpectedValue )
{
/* This is not what we expected to receive so an error has
occurred. */
xError = pdTRUE;
/* Catch-up to the value we received so our next expected
value should again be correct. */
usExpectedValue = usData;
}
else
{
if( xError == pdFALSE )
{
/* Only increment the check variable if no errors have
occurred. */
portENTER_CRITICAL();
xPollingConsumerCount++;
portEXIT_CRITICAL();
}
}
/* Next time round we would expect the number to be one higher. */
usExpectedValue++;
}
}
/* Now the queue is empty we block, allowing the producer to place more
items in the queue. */
vTaskDelay( pollqCONSUMER_DELAY );
}
} /*lint !e818 Function prototype must conform to API. */
/*-----------------------------------------------------------*/
/* This is called to check that all the created tasks are still running with no errors. */
portBASE_TYPE xArePollingQueuesStillRunning( void )
{
portBASE_TYPE xReturn;
/* Check both the consumer and producer poll count to check they have both
been changed since out last trip round. We do not need a critical section
around the check variables as this is called from a higher priority than
the other tasks that access the same variables. */
if( ( xPollingConsumerCount == pollqINITIAL_VALUE ) ||
( xPollingProducerCount == pollqINITIAL_VALUE )
)
{
xReturn = pdFALSE;
}
else
{
xReturn = pdTRUE;
}
/* Set the check variables back down so we know if they have been
incremented the next time around. */
xPollingConsumerCount = pollqINITIAL_VALUE;
xPollingProducerCount = pollqINITIAL_VALUE;
return xReturn;
}
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