/*
    FreeRTOS V9.0.0 - Copyright (C) 2016 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,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that is more than just the market leader, it     *
     *    is the industry's de facto standard.                               *
     *                                                                       *
     *    Help yourself get started quickly while simultaneously helping     *
     *    to support the FreeRTOS project by purchasing a FreeRTOS           *
     *    tutorial book, reference manual, or both:                          *
     *    http://www.FreeRTOS.org/Documentation                              *
     *                                                                       *
    ***************************************************************************

    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()?

    http://www.FreeRTOS.org/support - In return for receiving this top quality
    embedded software for free we request you assist our global community by
    participating in the support forum.

    http://www.FreeRTOS.org/training - Investing in training allows your team to
    be as productive as possible as early as possible.  Now you can receive
    FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
    Ltd, and the world's leading authority on the world's leading RTOS.

    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.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.

    http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and commercial 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 uint32_t.
*/

#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		( pdMS_TO_TICKS( ( TickType_t ) 200 ) )
#define pollqCONSUMER_DELAY		( pollqPRODUCER_DELAY - ( TickType_t ) ( 20 / portTICK_PERIOD_MS ) )
#define pollqNO_DELAY			( ( TickType_t ) 0 )
#define pollqVALUES_TO_PRODUCE	( ( BaseType_t ) 3 )
#define pollqINITIAL_VALUE		( ( BaseType_t ) 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 BaseType_t xPollingConsumerCount = pollqINITIAL_VALUE, xPollingProducerCount = pollqINITIAL_VALUE;

/*-----------------------------------------------------------*/

void vStartPolledQueueTasks( UBaseType_t uxPriority )
{
static QueueHandle_t xPolledQueue;

	/* Create the queue used by the producer and consumer. */
	xPolledQueue = xQueueCreate( pollqQUEUE_SIZE, ( UBaseType_t ) sizeof( uint16_t ) );

	if( xPolledQueue != NULL )
	{
		/* 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 )
{
uint16_t usValue = ( uint16_t ) 0;
BaseType_t 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 )
{
uint16_t usData, usExpectedValue = ( uint16_t ) 0;
BaseType_t 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. */
BaseType_t xArePollingQueuesStillRunning( void )
{
BaseType_t 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;
}