/*
	FreeRTOS V5.4.1 - Copyright (C) 2009 Real Time Engineers Ltd.

	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 exception 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.  
	Alternative commercial license and support terms are also available upon 
	request.  See the licensing section of http://www.FreeRTOS.org for full 
	license details.

	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 along
	with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
	Temple Place, Suite 330, Boston, MA  02111-1307  USA.


	***************************************************************************
	*                                                                         *
	* Looking for a quick start?  Then check out the FreeRTOS eBook!          *
	* See http://www.FreeRTOS.org/Documentation for details                   *
	*                                                                         *
	***************************************************************************

	1 tab == 4 spaces!

	Please ensure to read the configuration and relevant port sections of the
	online documentation.

	http://www.FreeRTOS.org - Documentation, latest information, license and
	contact details.

	http://www.SafeRTOS.com - A version that is certified for use in safety
	critical systems.

	http://www.OpenRTOS.com - Commercial support, development, porting,
	licensing and training services.
*/


/**
 * This is a very simple queue test.  See the BlockQ. c documentation for a more 
 * comprehensive version.
 *
 * 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.
 *
 * \page PollQC pollQ.c
 * \ingroup DemoFiles
 * <HR>
 */

/*
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"
#include "print.h"

/* Demo program include files. */
#include "PollQ.h"

#define pollqSTACK_SIZE		( ( unsigned portSHORT ) configMINIMAL_STACK_SIZE )

/* The task that posts the incrementing number onto the queue. */
static void vPolledQueueProducer( void *pvParameters );

/* The task that empties the queue. */
static void vPolledQueueConsumer( void *pvParameters );

/* Variables that are used to check that the tasks are still running with no errors. */
static volatile portSHORT sPollingConsumerCount = 0, sPollingProducerCount = 0;
/*-----------------------------------------------------------*/

void vStartPolledQueueTasks( unsigned portBASE_TYPE uxPriority )
{
static xQueueHandle xPolledQueue;
const unsigned portBASE_TYPE uxQueueSize = 10;

	/* Create the queue used by the producer and consumer. */
	xPolledQueue = xQueueCreate( uxQueueSize, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );

	/* Spawn the producer and consumer. */
	xTaskCreate( vPolledQueueConsumer, "QConsNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, NULL );
	xTaskCreate( vPolledQueueProducer, "QProdNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, NULL );
}
/*-----------------------------------------------------------*/

static void vPolledQueueProducer( void *pvParameters )
{
unsigned portSHORT usValue = 0, usLoop;
xQueueHandle *pxQueue;
const portTickType xDelay = ( portTickType ) 200 / portTICK_RATE_MS;
const unsigned portSHORT usNumToProduce = 3;
const portCHAR * const pcTaskStartMsg = "Polled queue producer started.\r\n";
const portCHAR * const pcTaskErrorMsg = "Could not post on polled queue.\r\n";
portSHORT sError = pdFALSE;

	/* Queue a message for printing to say the task has started. */
	vPrintDisplayMessage( &pcTaskStartMsg );

	/* The queue being used is passed in as the parameter. */
	pxQueue = ( xQueueHandle * ) pvParameters;

	for( ;; )
	{		
		for( usLoop = 0; usLoop < usNumToProduce; ++usLoop )
		{
			/* Send an incrementing number on the queue without blocking. */
			if( xQueueSendToBack( *pxQueue, ( void * ) &usValue, ( portTickType ) 0 ) != pdPASS )
			{
				/* We should never find the queue full - this is an error. */
				vPrintDisplayMessage( &pcTaskErrorMsg );
				sError = pdTRUE;
			}
			else
			{
				if( sError == pdFALSE )
				{
					/* If an error has ever been recorded we stop incrementing the 
					check variable. */
					++sPollingProducerCount;
				}

				/* 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( xDelay );
	}
}
/*-----------------------------------------------------------*/

static void vPolledQueueConsumer( void *pvParameters )
{
unsigned portSHORT usData, usExpectedValue = 0;
xQueueHandle *pxQueue;
const portTickType xDelay = ( portTickType ) 200 / portTICK_RATE_MS;
const portCHAR * const pcTaskStartMsg = "Polled queue consumer started.\r\n";
const portCHAR * const pcTaskErrorMsg = "Incorrect value received on polled queue.\r\n";
portSHORT sError = pdFALSE;

	/* Queue a message for printing to say the task has started. */
	vPrintDisplayMessage( &pcTaskStartMsg );

	/* The queue being used is passed in as the parameter. */
	pxQueue = ( xQueueHandle * ) pvParameters;

	for( ;; )
	{		
		/* Loop until the queue is empty. */
		while( uxQueueMessagesWaiting( *pxQueue ) )
		{
			if( xQueueReceive( *pxQueue, &usData, ( portTickType ) 0 ) == pdPASS )
			{
				if( usData != usExpectedValue )
				{
					/* This is not what we expected to receive so an error has 
					occurred. */
					vPrintDisplayMessage( &pcTaskErrorMsg );
					sError = pdTRUE;
					/* Catch-up to the value we received so our next expected value 
					should again be correct. */
					usExpectedValue = usData;
				}
				else
				{
					if( sError == pdFALSE )
					{
						/* Only increment the check variable if no errors have 
						occurred. */
						++sPollingConsumerCount;
					}
				}
				++usExpectedValue;
			}
		}

		/* Now the queue is empty we block, allowing the producer to place more 
		items in the queue. */
		vTaskDelay( xDelay );
	}
}
/*-----------------------------------------------------------*/

/* This is called to check that all the created tasks are still running with no errors. */
portBASE_TYPE xArePollingQueuesStillRunning( void )
{
static portSHORT sLastPollingConsumerCount = 0, sLastPollingProducerCount = 0;
portBASE_TYPE xReturn;

	if( ( sLastPollingConsumerCount == sPollingConsumerCount ) ||
		( sLastPollingProducerCount == sPollingProducerCount ) 
	  )
	{
		xReturn = pdFALSE;
	}
	else
	{
		xReturn = pdTRUE;
	}

	sLastPollingConsumerCount = sPollingConsumerCount;
	sLastPollingProducerCount = sPollingProducerCount;

	return xReturn;
}