/*
 * 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.
 *
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 * 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
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 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * http://www.FreeRTOS.org
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 * 1 tab == 4 spaces!
 */

/*
 * Basic task to demonstrate the xQueueOverwrite() function.  See the comments
 * in the function itself.
 */

/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

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

/* A block time of 0 just means "don't block". */
#define qoDONT_BLOCK 0

/* Number of times to overwrite the value in the queue. */
#define qoLOOPS 5

/* The task that uses the queue. */
static void prvQueueOverwriteTask(void *pvParameters);

/* Variable that is incremented on each loop of prvQueueOverwriteTask() provided
prvQueueOverwriteTask() has not found any errors. */
static uint32_t ulLoopCounter = 0;

/* Set to pdFALSE if an error is discovered by the
vQueueOverwritePeriodicISRDemo() function. */
static BaseType_t xISRTestStatus = pdPASS;

/* The queue that is accessed from the ISR.  The queue accessed by the task is
created inside the task itself. */
static QueueHandle_t xISRQueue = NULL;

/*-----------------------------------------------------------*/

void vStartQueueOverwriteTask(UBaseType_t uxPriority)
{
	const UBaseType_t uxQueueLength = 1;

	/* Create the queue used by the ISR.  xQueueOverwriteFromISR() should only
	be used on queues that have a length of 1. */
	xISRQueue = xQueueCreate(uxQueueLength, (UBaseType_t)sizeof(uint32_t));

	/* Create the test task.  The queue used by the test task is created inside
	the task itself. */
	xTaskCreate(prvQueueOverwriteTask, "QOver", configMINIMAL_STACK_SIZE,
		    NULL, uxPriority, (TaskHandle_t *)NULL);
}
/*-----------------------------------------------------------*/

static void prvQueueOverwriteTask(void *pvParameters)
{
	QueueHandle_t xTaskQueue;
	const UBaseType_t uxQueueLength = 1;
	uint32_t ulValue, ulStatus = pdPASS, x;

	/* The parameter is not used. */
	(void)pvParameters;

	/* Create the queue.  xQueueOverwrite() should only be used on queues that
	have a length of 1. */
	xTaskQueue = xQueueCreate(uxQueueLength, (UBaseType_t)sizeof(uint32_t));
	configASSERT(xTaskQueue);

	for (;;) {
		/* The queue is empty.  Writing to the queue then reading from the queue
		should return the item written. */
		ulValue = 10;
		xQueueOverwrite(xTaskQueue, &ulValue);

		ulValue = 0;
		xQueueReceive(xTaskQueue, &ulValue, qoDONT_BLOCK);

		if (ulValue != 10) {
			ulStatus = pdFAIL;
		}

		/* Now try writing to the queue several times.  Each time the value
		in the queue should get overwritten. */
		for (x = 0; x < qoLOOPS; x++) {
			/* Write to the queue. */
			xQueueOverwrite(xTaskQueue, &x);

			/* Check the value in the queue is that written, even though the
			queue was not necessarily empty. */
			xQueuePeek(xTaskQueue, &ulValue, qoDONT_BLOCK);
			if (ulValue != x) {
				ulStatus = pdFAIL;
			}

			/* There should always be one item in the queue. */
			if (uxQueueMessagesWaiting(xTaskQueue) !=
			    uxQueueLength) {
				ulStatus = pdFAIL;
			}
		}

		/* Empty the queue again. */
		xQueueReceive(xTaskQueue, &ulValue, qoDONT_BLOCK);

		if (uxQueueMessagesWaiting(xTaskQueue) != 0) {
			ulStatus = pdFAIL;
		}

		if (ulStatus != pdFAIL) {
			/* Increment a counter to show this task is still running without
			error. */
			ulLoopCounter++;
		}

#if (configUSE_PREEMPTION == 0)
		taskYIELD();
#endif
	}
}
/*-----------------------------------------------------------*/

BaseType_t xIsQueueOverwriteTaskStillRunning(void)
{
	BaseType_t xReturn;

	if (xISRTestStatus != pdPASS) {
		xReturn = pdFAIL;
	} else if (ulLoopCounter > 0) {
		xReturn = pdPASS;
	} else {
		/* The task has either stalled of discovered an error. */
		xReturn = pdFAIL;
	}

	ulLoopCounter = 0;

	return xReturn;
}
/*-----------------------------------------------------------*/

void vQueueOverwritePeriodicISRDemo(void)
{
	static uint32_t ulCallCount = 0;
	const uint32_t ulTx1 = 10UL, ulTx2 = 20UL, ulNumberOfSwitchCases = 3UL;
	uint32_t ulRx;

	/* This function should be called from an interrupt, such as the tick hook
	function vApplicationTickHook(). */

	configASSERT(xISRQueue);

	switch (ulCallCount) {
	case 0:
		/* The queue is empty.  Write ulTx1 to the queue.  In this demo the
			last parameter is not used because there are no tasks blocked on
			this queue. */
		xQueueOverwriteFromISR(xISRQueue, &ulTx1, NULL);

		/* Peek the queue to check it holds the expected value. */
		xQueuePeekFromISR(xISRQueue, &ulRx);
		if (ulRx != ulTx1) {
			xISRTestStatus = pdFAIL;
		}
		break;

	case 1:
		/* The queue already holds ulTx1.  Overwrite the value in the queue
			with ulTx2. */
		xQueueOverwriteFromISR(xISRQueue, &ulTx2, NULL);
		break;

	case 2:
		/* Read from the queue to empty the queue again.  The value read
			should be ulTx2. */
		xQueueReceiveFromISR(xISRQueue, &ulRx, NULL);

		if (ulRx != ulTx2) {
			xISRTestStatus = pdFAIL;
		}
		break;
	}

	/* Run the next case in the switch statement above next time this function
	is called. */
	ulCallCount++;

	if (ulCallCount >= ulNumberOfSwitchCases) {
		/* Go back to the start. */
		ulCallCount = 0;
	}
}