/*
 * FreeRTOS Kernel V10.3.0
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * http://www.FreeRTOS.org
 * http://aws.amazon.com/freertos
 *
 * 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;
}