2 FreeRTOS V7.6.0 - Copyright (C) 2013 Real Time Engineers Ltd.
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5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS provides completely free yet professionally developed, *
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10 * robust, strictly quality controlled, supported, and cross *
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11 * platform software that has become a de facto standard. *
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13 * Help yourself get started quickly and support the FreeRTOS *
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14 * project by purchasing a FreeRTOS tutorial book, reference *
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15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
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19 ***************************************************************************
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21 This file is part of the FreeRTOS distribution.
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23 FreeRTOS is free software; you can redistribute it and/or modify it under
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24 the terms of the GNU General Public License (version 2) as published by the
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25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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27 >>! NOTE: The modification to the GPL is included to allow you to distribute
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28 >>! a combined work that includes FreeRTOS without being obliged to provide
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29 >>! the source code for proprietary components outside of the FreeRTOS
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32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
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35 link: http://www.freertos.org/a00114.html
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39 ***************************************************************************
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41 * Having a problem? Start by reading the FAQ "My application does *
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42 * not run, what could be wrong?" *
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44 * http://www.FreeRTOS.org/FAQHelp.html *
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46 ***************************************************************************
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48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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49 license and Real Time Engineers Ltd. contact details.
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51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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57 licenses offer ticketed support, indemnification and middleware.
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59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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60 engineered and independently SIL3 certified version for use in safety and
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61 mission critical applications that require provable dependability.
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67 * Creates six tasks that operate on three queues as follows:
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69 * The first two tasks send and receive an incrementing number to/from a queue.
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70 * One task acts as a producer and the other as the consumer. The consumer is a
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71 * higher priority than the producer and is set to block on queue reads. The queue
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72 * only has space for one item - as soon as the producer posts a message on the
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73 * queue the consumer will unblock, pre-empt the producer, and remove the item.
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75 * The second two tasks work the other way around. Again the queue used only has
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76 * enough space for one item. This time the consumer has a lower priority than the
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77 * producer. The producer will try to post on the queue blocking when the queue is
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78 * full. When the consumer wakes it will remove the item from the queue, causing
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79 * the producer to unblock, pre-empt the consumer, and immediately re-fill the
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82 * The last two tasks use the same queue producer and consumer functions. This time the queue has
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83 * enough space for lots of items and the tasks operate at the same priority. The
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84 * producer will execute, placing items into the queue. The consumer will start
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85 * executing when either the queue becomes full (causing the producer to block) or
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86 * a context switch occurs (tasks of the same priority will time slice).
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92 /* Scheduler include files. */
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93 #include "FreeRTOS.h"
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97 /* Demo program include files. */
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100 #define blckqSTACK_SIZE configMINIMAL_STACK_SIZE
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101 #define blckqNUM_TASK_SETS ( 3 )
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103 /* Structure used to pass parameters to the blocking queue tasks. */
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104 typedef struct BLOCKING_QUEUE_PARAMETERS
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106 xQueueHandle xQueue; /*< The queue to be used by the task. */
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107 portTickType xBlockTime; /*< The block time to use on queue reads/writes. */
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108 volatile short *psCheckVariable; /*< Incremented on each successful cycle to check the task is still running. */
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109 } xBlockingQueueParameters;
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111 /* Task function that creates an incrementing number and posts it on a queue. */
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112 static portTASK_FUNCTION_PROTO( vBlockingQueueProducer, pvParameters );
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114 /* Task function that removes the incrementing number from a queue and checks that
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115 it is the expected number. */
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116 static portTASK_FUNCTION_PROTO( vBlockingQueueConsumer, pvParameters );
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118 /* Variables which are incremented each time an item is removed from a queue, and
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119 found to be the expected value.
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120 These are used to check that the tasks are still running. */
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121 static volatile short sBlockingConsumerCount[ blckqNUM_TASK_SETS ] = { ( unsigned short ) 0, ( unsigned short ) 0, ( unsigned short ) 0 };
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123 /* Variable which are incremented each time an item is posted on a queue. These
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124 are used to check that the tasks are still running. */
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125 static volatile short sBlockingProducerCount[ blckqNUM_TASK_SETS ] = { ( unsigned short ) 0, ( unsigned short ) 0, ( unsigned short ) 0 };
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127 /*-----------------------------------------------------------*/
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129 void vStartBlockingQueueTasks( unsigned portBASE_TYPE uxPriority )
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131 xBlockingQueueParameters *pxQueueParameters1, *pxQueueParameters2;
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132 xBlockingQueueParameters *pxQueueParameters3, *pxQueueParameters4;
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133 xBlockingQueueParameters *pxQueueParameters5, *pxQueueParameters6;
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134 const unsigned portBASE_TYPE uxQueueSize1 = 1, uxQueueSize5 = 5;
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135 const portTickType xBlockTime = ( portTickType ) 1000 / portTICK_RATE_MS;
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136 const portTickType xDontBlock = ( portTickType ) 0;
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138 /* Create the first two tasks as described at the top of the file. */
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140 /* First create the structure used to pass parameters to the consumer tasks. */
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141 pxQueueParameters1 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
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143 /* Create the queue used by the first two tasks to pass the incrementing number.
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144 Pass a pointer to the queue in the parameter structure. */
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145 pxQueueParameters1->xQueue = xQueueCreate( uxQueueSize1, ( unsigned portBASE_TYPE ) sizeof( unsigned short ) );
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147 /* The consumer is created first so gets a block time as described above. */
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148 pxQueueParameters1->xBlockTime = xBlockTime;
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150 /* Pass in the variable that this task is going to increment so we can check it
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151 is still running. */
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152 pxQueueParameters1->psCheckVariable = &( sBlockingConsumerCount[ 0 ] );
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154 /* Create the structure used to pass parameters to the producer task. */
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155 pxQueueParameters2 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
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157 /* Pass the queue to this task also, using the parameter structure. */
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158 pxQueueParameters2->xQueue = pxQueueParameters1->xQueue;
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160 /* The producer is not going to block - as soon as it posts the consumer will
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161 wake and remove the item so the producer should always have room to post. */
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162 pxQueueParameters2->xBlockTime = xDontBlock;
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164 /* Pass in the variable that this task is going to increment so we can check
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165 it is still running. */
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166 pxQueueParameters2->psCheckVariable = &( sBlockingProducerCount[ 0 ] );
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169 /* Note the producer has a lower priority than the consumer when the tasks are
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171 xTaskCreate( vBlockingQueueConsumer, "QConsB1", blckqSTACK_SIZE, ( void * ) pxQueueParameters1, uxPriority, NULL );
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172 xTaskCreate( vBlockingQueueProducer, "QProdB2", blckqSTACK_SIZE, ( void * ) pxQueueParameters2, tskIDLE_PRIORITY, NULL );
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176 /* Create the second two tasks as described at the top of the file. This uses
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177 the same mechanism but reverses the task priorities. */
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179 pxQueueParameters3 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
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180 pxQueueParameters3->xQueue = xQueueCreate( uxQueueSize1, ( unsigned portBASE_TYPE ) sizeof( unsigned short ) );
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181 pxQueueParameters3->xBlockTime = xDontBlock;
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182 pxQueueParameters3->psCheckVariable = &( sBlockingProducerCount[ 1 ] );
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184 pxQueueParameters4 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
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185 pxQueueParameters4->xQueue = pxQueueParameters3->xQueue;
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186 pxQueueParameters4->xBlockTime = xBlockTime;
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187 pxQueueParameters4->psCheckVariable = &( sBlockingConsumerCount[ 1 ] );
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189 xTaskCreate( vBlockingQueueConsumer, "QConsB3", blckqSTACK_SIZE, ( void * ) pxQueueParameters3, tskIDLE_PRIORITY, NULL );
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190 xTaskCreate( vBlockingQueueProducer, "QProdB4", blckqSTACK_SIZE, ( void * ) pxQueueParameters4, uxPriority, NULL );
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194 /* Create the last two tasks as described above. The mechanism is again just
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195 the same. This time both parameter structures are given a block time. */
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196 pxQueueParameters5 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
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197 pxQueueParameters5->xQueue = xQueueCreate( uxQueueSize5, ( unsigned portBASE_TYPE ) sizeof( unsigned short ) );
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198 pxQueueParameters5->xBlockTime = xBlockTime;
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199 pxQueueParameters5->psCheckVariable = &( sBlockingProducerCount[ 2 ] );
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201 pxQueueParameters6 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
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202 pxQueueParameters6->xQueue = pxQueueParameters5->xQueue;
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203 pxQueueParameters6->xBlockTime = xBlockTime;
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204 pxQueueParameters6->psCheckVariable = &( sBlockingConsumerCount[ 2 ] );
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206 xTaskCreate( vBlockingQueueProducer, "QProdB5", blckqSTACK_SIZE, ( void * ) pxQueueParameters5, tskIDLE_PRIORITY, NULL );
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207 xTaskCreate( vBlockingQueueConsumer, "QConsB6", blckqSTACK_SIZE, ( void * ) pxQueueParameters6, tskIDLE_PRIORITY, NULL );
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209 /*-----------------------------------------------------------*/
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211 static portTASK_FUNCTION( vBlockingQueueProducer, pvParameters )
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213 unsigned short usValue = 0;
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214 xBlockingQueueParameters *pxQueueParameters;
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215 short sErrorEverOccurred = pdFALSE;
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217 pxQueueParameters = ( xBlockingQueueParameters * ) pvParameters;
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221 if( xQueueSend( pxQueueParameters->xQueue, ( void * ) &usValue, pxQueueParameters->xBlockTime ) != pdPASS )
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223 sErrorEverOccurred = pdTRUE;
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227 /* We have successfully posted a message, so increment the variable
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228 used to check we are still running. */
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229 if( sErrorEverOccurred == pdFALSE )
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231 ( *pxQueueParameters->psCheckVariable )++;
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234 /* Increment the variable we are going to post next time round. The
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235 consumer will expect the numbers to follow in numerical order. */
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238 #if configUSE_PREEMPTION == 0
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244 /*-----------------------------------------------------------*/
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246 static portTASK_FUNCTION( vBlockingQueueConsumer, pvParameters )
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248 unsigned short usData, usExpectedValue = 0;
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249 xBlockingQueueParameters *pxQueueParameters;
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250 short sErrorEverOccurred = pdFALSE;
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252 pxQueueParameters = ( xBlockingQueueParameters * ) pvParameters;
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256 if( xQueueReceive( pxQueueParameters->xQueue, &usData, pxQueueParameters->xBlockTime ) == pdPASS )
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258 if( usData != usExpectedValue )
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261 usExpectedValue = usData;
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263 sErrorEverOccurred = pdTRUE;
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267 /* We have successfully received a message, so increment the
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268 variable used to check we are still running. */
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269 if( sErrorEverOccurred == pdFALSE )
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271 ( *pxQueueParameters->psCheckVariable )++;
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274 /* Increment the value we expect to remove from the queue next time
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279 #if configUSE_PREEMPTION == 0
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281 if( pxQueueParameters->xBlockTime == 0 )
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290 /*-----------------------------------------------------------*/
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292 /* This is called to check that all the created tasks are still running. */
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293 portBASE_TYPE xAreBlockingQueuesStillRunning( void )
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295 static short sLastBlockingConsumerCount[ blckqNUM_TASK_SETS ] = { ( unsigned short ) 0, ( unsigned short ) 0, ( unsigned short ) 0 };
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296 static short sLastBlockingProducerCount[ blckqNUM_TASK_SETS ] = { ( unsigned short ) 0, ( unsigned short ) 0, ( unsigned short ) 0 };
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297 portBASE_TYPE xReturn = pdPASS, xTasks;
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299 /* Not too worried about mutual exclusion on these variables as they are 16
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300 bits and we are only reading them. We also only care to see if they have
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303 Loop through each check variable to and return pdFALSE if any are found not
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304 to have changed since the last call. */
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306 for( xTasks = 0; xTasks < blckqNUM_TASK_SETS; xTasks++ )
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308 if( sBlockingConsumerCount[ xTasks ] == sLastBlockingConsumerCount[ xTasks ] )
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312 sLastBlockingConsumerCount[ xTasks ] = sBlockingConsumerCount[ xTasks ];
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315 if( sBlockingProducerCount[ xTasks ] == sLastBlockingProducerCount[ xTasks ] )
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319 sLastBlockingProducerCount[ xTasks ] = sBlockingProducerCount[ xTasks ];
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