2 FreeRTOS V8.2.1 - Copyright (C) 2015 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 This file is part of the FreeRTOS distribution.
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9 FreeRTOS is free software; you can redistribute it and/or modify it under
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10 the terms of the GNU General Public License (version 2) as published by the
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11 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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13 ***************************************************************************
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14 >>! NOTE: The modification to the GPL is included to allow you to !<<
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15 >>! distribute a combined work that includes FreeRTOS without being !<<
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16 >>! obliged to provide the source code for proprietary components !<<
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17 >>! outside of the FreeRTOS kernel. !<<
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18 ***************************************************************************
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20 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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21 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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22 FOR A PARTICULAR PURPOSE. Full license text is available on the following
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23 link: http://www.freertos.org/a00114.html
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25 ***************************************************************************
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27 * FreeRTOS provides completely free yet professionally developed, *
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28 * robust, strictly quality controlled, supported, and cross *
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29 * platform software that is more than just the market leader, it *
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30 * is the industry's de facto standard. *
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32 * Help yourself get started quickly while simultaneously helping *
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33 * to support the FreeRTOS project by purchasing a FreeRTOS *
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34 * tutorial book, reference manual, or both: *
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35 * http://www.FreeRTOS.org/Documentation *
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37 ***************************************************************************
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39 http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading
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40 the FAQ page "My application does not run, what could be wrong?". Have you
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41 defined configASSERT()?
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43 http://www.FreeRTOS.org/support - In return for receiving this top quality
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44 embedded software for free we request you assist our global community by
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45 participating in the support forum.
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47 http://www.FreeRTOS.org/training - Investing in training allows your team to
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48 be as productive as possible as early as possible. Now you can receive
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49 FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
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50 Ltd, and the world's leading authority on the world's leading RTOS.
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52 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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53 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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54 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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56 http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
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57 Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
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59 http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
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60 Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
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61 licenses offer ticketed support, indemnification and commercial middleware.
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63 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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64 engineered and independently SIL3 certified version for use in safety and
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65 mission critical applications that require provable dependability.
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71 * This is a version of PollQ.c that uses the alternative (Alt) API.
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73 * Creates two tasks that communicate over a single queue. One task acts as a
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74 * producer, the other a consumer.
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76 * The producer loops for three iteration, posting an incrementing number onto the
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77 * queue each cycle. It then delays for a fixed period before doing exactly the
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80 * The consumer loops emptying the queue. Each item removed from the queue is
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81 * checked to ensure it contains the expected value. When the queue is empty it
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82 * blocks for a fixed period, then does the same again.
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84 * All queue access is performed without blocking. The consumer completely empties
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85 * the queue each time it runs so the producer should never find the queue full.
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87 * An error is flagged if the consumer obtains an unexpected value or the producer
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88 * find the queue is full.
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94 + Delay periods are now specified using variables and constants of
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95 TickType_t rather than uint32_t.
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100 /* Scheduler include files. */
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101 #include "FreeRTOS.h"
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105 /* Demo program include files. */
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106 #include "AltPollQ.h"
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108 #define pollqSTACK_SIZE configMINIMAL_STACK_SIZE
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109 #define pollqQUEUE_SIZE ( 10 )
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110 #define pollqPRODUCER_DELAY ( ( TickType_t ) 200 / portTICK_PERIOD_MS )
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111 #define pollqCONSUMER_DELAY ( pollqPRODUCER_DELAY - ( TickType_t ) ( 20 / portTICK_PERIOD_MS ) )
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112 #define pollqNO_DELAY ( ( TickType_t ) 0 )
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113 #define pollqVALUES_TO_PRODUCE ( ( BaseType_t ) 3 )
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114 #define pollqINITIAL_VALUE ( ( BaseType_t ) 0 )
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116 /* The task that posts the incrementing number onto the queue. */
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117 static portTASK_FUNCTION_PROTO( vPolledQueueProducer, pvParameters );
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119 /* The task that empties the queue. */
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120 static portTASK_FUNCTION_PROTO( vPolledQueueConsumer, pvParameters );
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122 /* Variables that are used to check that the tasks are still running with no
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124 static volatile BaseType_t xPollingConsumerCount = pollqINITIAL_VALUE, xPollingProducerCount = pollqINITIAL_VALUE;
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126 /*-----------------------------------------------------------*/
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128 void vStartAltPolledQueueTasks( UBaseType_t uxPriority )
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130 static QueueHandle_t xPolledQueue;
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132 /* Create the queue used by the producer and consumer. */
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133 xPolledQueue = xQueueCreate( pollqQUEUE_SIZE, ( UBaseType_t ) sizeof( uint16_t ) );
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135 /* vQueueAddToRegistry() adds the queue to the queue registry, if one is
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136 in use. The queue registry is provided as a means for kernel aware
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137 debuggers to locate queues and has no purpose if a kernel aware debugger
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138 is not being used. The call to vQueueAddToRegistry() will be removed
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139 by the pre-processor if configQUEUE_REGISTRY_SIZE is not defined or is
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140 defined to be less than 1. */
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141 vQueueAddToRegistry( xPolledQueue, "AltPollQueue" );
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144 /* Spawn the producer and consumer. */
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145 xTaskCreate( vPolledQueueConsumer, "QConsNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( TaskHandle_t * ) NULL );
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146 xTaskCreate( vPolledQueueProducer, "QProdNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( TaskHandle_t * ) NULL );
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148 /*-----------------------------------------------------------*/
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150 static portTASK_FUNCTION( vPolledQueueProducer, pvParameters )
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152 uint16_t usValue = ( uint16_t ) 0;
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153 BaseType_t xError = pdFALSE, xLoop;
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156 void vPrintDisplayMessage( const char * const * ppcMessageToSend );
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158 const char * const pcTaskStartMsg = "Alt polling queue producer task started.\r\n";
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160 /* Queue a message for printing to say the task has started. */
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161 vPrintDisplayMessage( &pcTaskStartMsg );
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166 for( xLoop = 0; xLoop < pollqVALUES_TO_PRODUCE; xLoop++ )
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168 /* Send an incrementing number on the queue without blocking. */
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169 if( xQueueAltSendToBack( *( ( QueueHandle_t * ) pvParameters ), ( void * ) &usValue, pollqNO_DELAY ) != pdPASS )
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171 /* We should never find the queue full so if we get here there
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172 has been an error. */
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177 if( xError == pdFALSE )
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179 /* If an error has ever been recorded we stop incrementing the
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181 portENTER_CRITICAL();
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182 xPollingProducerCount++;
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183 portEXIT_CRITICAL();
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186 /* Update the value we are going to post next time around. */
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191 /* Wait before we start posting again to ensure the consumer runs and
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192 empties the queue. */
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193 vTaskDelay( pollqPRODUCER_DELAY );
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195 } /*lint !e818 Function prototype must conform to API. */
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196 /*-----------------------------------------------------------*/
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198 static portTASK_FUNCTION( vPolledQueueConsumer, pvParameters )
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200 uint16_t usData, usExpectedValue = ( uint16_t ) 0;
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201 BaseType_t xError = pdFALSE;
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204 void vPrintDisplayMessage( const char * const * ppcMessageToSend );
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206 const char * const pcTaskStartMsg = "Alt blocking queue consumer task started.\r\n";
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208 /* Queue a message for printing to say the task has started. */
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209 vPrintDisplayMessage( &pcTaskStartMsg );
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214 /* Loop until the queue is empty. */
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215 while( uxQueueMessagesWaiting( *( ( QueueHandle_t * ) pvParameters ) ) )
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217 if( xQueueAltReceive( *( ( QueueHandle_t * ) pvParameters ), &usData, pollqNO_DELAY ) == pdPASS )
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219 if( usData != usExpectedValue )
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221 /* This is not what we expected to receive so an error has
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225 /* Catch-up to the value we received so our next expected
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226 value should again be correct. */
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227 usExpectedValue = usData;
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231 if( xError == pdFALSE )
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233 /* Only increment the check variable if no errors have
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235 portENTER_CRITICAL();
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236 xPollingConsumerCount++;
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237 portEXIT_CRITICAL();
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241 /* Next time round we would expect the number to be one higher. */
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246 /* Now the queue is empty we block, allowing the producer to place more
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247 items in the queue. */
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248 vTaskDelay( pollqCONSUMER_DELAY );
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250 } /*lint !e818 Function prototype must conform to API. */
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251 /*-----------------------------------------------------------*/
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253 /* This is called to check that all the created tasks are still running with no errors. */
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254 BaseType_t xAreAltPollingQueuesStillRunning( void )
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256 BaseType_t xReturn;
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258 /* Check both the consumer and producer poll count to check they have both
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259 been changed since out last trip round. We do not need a critical section
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260 around the check variables as this is called from a higher priority than
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261 the other tasks that access the same variables. */
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262 if( ( xPollingConsumerCount == pollqINITIAL_VALUE ) ||
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263 ( xPollingProducerCount == pollqINITIAL_VALUE )
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273 /* Set the check variables back down so we know if they have been
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274 incremented the next time around. */
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275 xPollingConsumerCount = pollqINITIAL_VALUE;
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276 xPollingProducerCount = pollqINITIAL_VALUE;
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