/*
FreeRTOS.org V5.0.3 - Copyright (C) 2003-2008 Richard Barry.
This file is part of the FreeRTOS.org distribution.
FreeRTOS.org is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FreeRTOS.org 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
along with FreeRTOS.org; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes FreeRTOS.org, without being obliged to provide
the source code for any proprietary components. See the licensing section
of http://www.FreeRTOS.org for full details of how and when the exception
can be applied.
***************************************************************************
***************************************************************************
* *
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* and even write all or part of your application on your behalf. *
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***************************************************************************
***************************************************************************
Please ensure to read the configuration and relevant port sections of the
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*/
/*
* 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
portTickType rather than unsigned portLONG.
*/
#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 ( ( portTickType ) 200 / portTICK_RATE_MS )
#define pollqCONSUMER_DELAY ( pollqPRODUCER_DELAY - ( portTickType ) ( 20 / portTICK_RATE_MS ) )
#define pollqNO_DELAY ( ( portTickType ) 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 xQueueHandle xPolledQueue;
/* Create the queue used by the producer and consumer. */
xPolledQueue = xQueueCreate( pollqQUEUE_SIZE, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );
/* 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, ( signed portCHAR * ) "Poll_Test_Queue" );
/* Spawn the producer and consumer. */
xTaskCreate( vPolledQueueConsumer, ( signed portCHAR * ) "QConsNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( xTaskHandle * ) NULL );
xTaskCreate( vPolledQueueProducer, ( signed portCHAR * ) "QProdNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( xTaskHandle * ) NULL );
}
/*-----------------------------------------------------------*/
static portTASK_FUNCTION( vPolledQueueProducer, pvParameters )
{
unsigned portSHORT usValue = ( unsigned portSHORT ) 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( *( ( xQueueHandle * ) 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 portSHORT usData, usExpectedValue = ( unsigned portSHORT ) 0;
signed portBASE_TYPE xError = pdFALSE;
for( ;; )
{
/* Loop until the queue is empty. */
while( uxQueueMessagesWaiting( *( ( xQueueHandle * ) pvParameters ) ) )
{
if( xQueueReceive( *( ( xQueueHandle * ) 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;
}