/*
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.
*/
/*
* 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 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 ( ( 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 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, ( signed char * ) "Poll_Test_Queue" );
/* Spawn the producer and consumer. */
xTaskCreate( vPolledQueueConsumer, ( signed char * ) "QConsNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( xTaskHandle * ) NULL );
xTaskCreate( vPolledQueueProducer, ( signed char * ) "QProdNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( xTaskHandle * ) 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( *( ( 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 short usData, usExpectedValue = ( unsigned short ) 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;
}