2 FreeRTOS V7.4.2 - Copyright (C) 2013 Real Time Engineers Ltd.
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4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
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5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS tutorial books are available in pdf and paperback. *
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10 * Complete, revised, and edited pdf reference manuals are also *
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13 * Purchasing FreeRTOS documentation will not only help you, by *
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14 * ensuring you get running as quickly as possible and with an *
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15 * in-depth knowledge of how to use FreeRTOS, it will also help *
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16 * the FreeRTOS project to continue with its mission of providing *
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17 * professional grade, cross platform, de facto standard solutions *
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18 * for microcontrollers - completely free of charge! *
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20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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22 * Thank you for using FreeRTOS, and thank you for your support! *
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24 ***************************************************************************
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27 This file is part of the FreeRTOS distribution.
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29 FreeRTOS is free software; you can redistribute it and/or modify it under
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30 the terms of the GNU General Public License (version 2) as published by the
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31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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33 >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
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34 distribute a combined work that includes FreeRTOS without being obliged to
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35 provide the source code for proprietary components outside of the FreeRTOS
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38 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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39 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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40 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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41 details. You should have received a copy of the GNU General Public License
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42 and the FreeRTOS license exception along with FreeRTOS; if not it can be
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43 viewed here: http://www.freertos.org/a00114.html and also obtained by
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44 writing to Real Time Engineers Ltd., contact details for whom are available
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45 on the FreeRTOS WEB site.
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49 ***************************************************************************
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51 * Having a problem? Start by reading the FAQ "My application does *
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52 * not run, what could be wrong?" *
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54 * http://www.FreeRTOS.org/FAQHelp.html *
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56 ***************************************************************************
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59 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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60 license and Real Time Engineers Ltd. contact details.
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62 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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63 including FreeRTOS+Trace - an indispensable productivity tool, and our new
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64 fully thread aware and reentrant UDP/IP stack.
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66 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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67 Integrity Systems, who sell the code with commercial support,
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68 indemnification and middleware, under the OpenRTOS brand.
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70 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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71 engineered and independently SIL3 certified version for use in safety and
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72 mission critical applications that require provable dependability.
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76 * Basic task to demonstrate the xQueueOverwrite() function. See the comments
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77 * in the function itself.
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80 /* Scheduler include files. */
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81 #include "FreeRTOS.h"
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85 /* Demo program include files. */
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86 #include "QueueOverwrite.h"
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88 /* A block time of 0 just means "don't block". */
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89 #define qoDONT_BLOCK 0
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91 /* Number of times to overwrite the value in the queue. */
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94 /* The task that uses the queue. */
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95 static void prvQueueOverwriteTask( void *pvParameters );
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97 /* Variable that is incremented on each loop of prvQueueOverwriteTask() provided
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98 prvQueueOverwriteTask() has not found any errors. */
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99 static unsigned long ulLoopCounter = 0;
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101 /*-----------------------------------------------------------*/
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103 void vStartQueueOverwriteTask( unsigned portBASE_TYPE uxPriority )
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105 /* Create the test task. */
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106 xTaskCreate( prvQueueOverwriteTask, ( signed char * ) "QOver", configMINIMAL_STACK_SIZE, NULL, uxPriority, ( xTaskHandle * ) NULL );
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108 /*-----------------------------------------------------------*/
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110 static void prvQueueOverwriteTask( void *pvParameters )
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112 xQueueHandle xQueue;
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113 const unsigned portBASE_TYPE uxQueueLength = 1;
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114 unsigned long ulValue, ulStatus = pdPASS, x;
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116 /* The parameter is not used. */
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117 ( void ) pvParameters;
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119 /* Create the queue. xQueueOverwrite() should only be used on queues that
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120 have a length of 1. */
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121 xQueue = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( unsigned long ) );
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122 configASSERT( xQueue );
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126 /* The queue is empty. Writing to the queue then reading from the queue
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127 should return the item written. */
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129 xQueueOverwrite( xQueue, &ulValue );
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132 xQueueReceive( xQueue, &ulValue, qoDONT_BLOCK );
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134 if( ulValue != 10 )
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139 /* Now try writing to the queue several times. Each time the value
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140 in the queue should get overwritten. */
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141 for( x = 0; x < qoLOOPS; x++ )
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143 /* Write to the queue. */
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144 xQueueOverwrite( xQueue, &x );
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146 /* Check the value in the queue is that written, even though the
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147 queue was not necessarily empty. */
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148 xQueuePeek( xQueue, &ulValue, qoDONT_BLOCK );
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154 /* There should always be one item in the queue. */
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155 if( uxQueueMessagesWaiting( xQueue ) != uxQueueLength )
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161 /* Empty the queue again. */
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162 xQueueReceive( xQueue, &ulValue, qoDONT_BLOCK );
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164 if( uxQueueMessagesWaiting( xQueue ) != 0 )
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169 if( ulStatus != pdFAIL )
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171 /* Increment a counter to show this task is still running without
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177 /*-----------------------------------------------------------*/
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179 portBASE_TYPE xIsQueueOverwriteTaskStillRunning( void )
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181 portBASE_TYPE xReturn;
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183 if( ulLoopCounter > 0 )
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189 /* The task has either stalled of discovered an error. */
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