2 FreeRTOS V8.0.0:rc1 - Copyright (C) 2014 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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70 #ifndef INC_FREERTOS_H
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71 #error "include FreeRTOS.h" must appear in source files before "include queue.h"
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80 * Type by which queues are referenced. For example, a call to xQueueCreate()
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81 * returns an QueueHandle_t variable that can then be used as a parameter to
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82 * xQueueSend(), xQueueReceive(), etc.
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84 typedef void * QueueHandle_t;
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87 * Type by which queue sets are referenced. For example, a call to
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88 * xQueueCreateSet() returns an xQueueSet variable that can then be used as a
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89 * parameter to xQueueSelectFromSet(), xQueueAddToSet(), etc.
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91 typedef void * QueueSetHandle_t;
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94 * Queue sets can contain both queues and semaphores, so the
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95 * QueueSetMemberHandle_t is defined as a type to be used where a parameter or
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96 * return value can be either an QueueHandle_t or an SemaphoreHandle_t.
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98 typedef void * QueueSetMemberHandle_t;
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100 /* For internal use only. */
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101 #define queueSEND_TO_BACK ( ( BaseType_t ) 0 )
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102 #define queueSEND_TO_FRONT ( ( BaseType_t ) 1 )
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103 #define queueOVERWRITE ( ( BaseType_t ) 2 )
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105 /* For internal use only. These definitions *must* match those in queue.c. */
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106 #define queueQUEUE_TYPE_BASE ( ( uint8_t ) 0U )
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107 #define queueQUEUE_TYPE_SET ( ( uint8_t ) 0U )
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108 #define queueQUEUE_TYPE_MUTEX ( ( uint8_t ) 1U )
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109 #define queueQUEUE_TYPE_COUNTING_SEMAPHORE ( ( uint8_t ) 2U )
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110 #define queueQUEUE_TYPE_BINARY_SEMAPHORE ( ( uint8_t ) 3U )
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111 #define queueQUEUE_TYPE_RECURSIVE_MUTEX ( ( uint8_t ) 4U )
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116 QueueHandle_t xQueueCreate(
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117 UBaseType_t uxQueueLength,
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118 UBaseType_t uxItemSize
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122 * Creates a new queue instance. This allocates the storage required by the
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123 * new queue and returns a handle for the queue.
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125 * @param uxQueueLength The maximum number of items that the queue can contain.
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127 * @param uxItemSize The number of bytes each item in the queue will require.
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128 * Items are queued by copy, not by reference, so this is the number of bytes
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129 * that will be copied for each posted item. Each item on the queue must be
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132 * @return If the queue is successfully create then a handle to the newly
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133 * created queue is returned. If the queue cannot be created then 0 is
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144 void vATask( void *pvParameters )
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146 QueueHandle_t xQueue1, xQueue2;
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148 // Create a queue capable of containing 10 uint32_t values.
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149 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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152 // Queue was not created and must not be used.
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155 // Create a queue capable of containing 10 pointers to AMessage structures.
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156 // These should be passed by pointer as they contain a lot of data.
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157 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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160 // Queue was not created and must not be used.
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163 // ... Rest of task code.
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166 * \defgroup xQueueCreate xQueueCreate
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167 * \ingroup QueueManagement
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169 #define xQueueCreate( uxQueueLength, uxItemSize ) xQueueGenericCreate( uxQueueLength, uxItemSize, queueQUEUE_TYPE_BASE )
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174 BaseType_t xQueueSendToToFront(
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175 QueueHandle_t xQueue,
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176 const void * pvItemToQueue,
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177 TickType_t xTicksToWait
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181 * This is a macro that calls xQueueGenericSend().
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183 * Post an item to the front of a queue. The item is queued by copy, not by
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184 * reference. This function must not be called from an interrupt service
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185 * routine. See xQueueSendFromISR () for an alternative which may be used
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188 * @param xQueue The handle to the queue on which the item is to be posted.
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190 * @param pvItemToQueue A pointer to the item that is to be placed on the
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191 * queue. The size of the items the queue will hold was defined when the
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192 * queue was created, so this many bytes will be copied from pvItemToQueue
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193 * into the queue storage area.
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195 * @param xTicksToWait The maximum amount of time the task should block
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196 * waiting for space to become available on the queue, should it already
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197 * be full. The call will return immediately if this is set to 0 and the
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198 * queue is full. The time is defined in tick periods so the constant
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199 * portTICK_RATE_MS should be used to convert to real time if this is required.
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201 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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211 uint32_t ulVar = 10UL;
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213 void vATask( void *pvParameters )
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215 QueueHandle_t xQueue1, xQueue2;
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216 struct AMessage *pxMessage;
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218 // Create a queue capable of containing 10 uint32_t values.
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219 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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221 // Create a queue capable of containing 10 pointers to AMessage structures.
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222 // These should be passed by pointer as they contain a lot of data.
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223 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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229 // Send an uint32_t. Wait for 10 ticks for space to become
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230 // available if necessary.
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231 if( xQueueSendToFront( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
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233 // Failed to post the message, even after 10 ticks.
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239 // Send a pointer to a struct AMessage object. Don't block if the
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240 // queue is already full.
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241 pxMessage = & xMessage;
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242 xQueueSendToFront( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
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245 // ... Rest of task code.
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248 * \defgroup xQueueSend xQueueSend
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249 * \ingroup QueueManagement
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251 #define xQueueSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
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256 BaseType_t xQueueSendToBack(
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257 QueueHandle_t xQueue,
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258 const void *pvItemToQueue,
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259 TickType_t xTicksToWait
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263 * This is a macro that calls xQueueGenericSend().
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265 * Post an item to the back of a queue. The item is queued by copy, not by
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266 * reference. This function must not be called from an interrupt service
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267 * routine. See xQueueSendFromISR () for an alternative which may be used
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270 * @param xQueue The handle to the queue on which the item is to be posted.
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272 * @param pvItemToQueue A pointer to the item that is to be placed on the
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273 * queue. The size of the items the queue will hold was defined when the
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274 * queue was created, so this many bytes will be copied from pvItemToQueue
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275 * into the queue storage area.
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277 * @param xTicksToWait The maximum amount of time the task should block
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278 * waiting for space to become available on the queue, should it already
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279 * be full. The call will return immediately if this is set to 0 and the queue
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280 * is full. The time is defined in tick periods so the constant
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281 * portTICK_RATE_MS should be used to convert to real time if this is required.
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283 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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293 uint32_t ulVar = 10UL;
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295 void vATask( void *pvParameters )
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297 QueueHandle_t xQueue1, xQueue2;
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298 struct AMessage *pxMessage;
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300 // Create a queue capable of containing 10 uint32_t values.
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301 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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303 // Create a queue capable of containing 10 pointers to AMessage structures.
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304 // These should be passed by pointer as they contain a lot of data.
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305 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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311 // Send an uint32_t. Wait for 10 ticks for space to become
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312 // available if necessary.
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313 if( xQueueSendToBack( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
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315 // Failed to post the message, even after 10 ticks.
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321 // Send a pointer to a struct AMessage object. Don't block if the
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322 // queue is already full.
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323 pxMessage = & xMessage;
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324 xQueueSendToBack( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
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327 // ... Rest of task code.
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330 * \defgroup xQueueSend xQueueSend
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331 * \ingroup QueueManagement
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333 #define xQueueSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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338 BaseType_t xQueueSend(
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339 QueueHandle_t xQueue,
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340 const void * pvItemToQueue,
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341 TickType_t xTicksToWait
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345 * This is a macro that calls xQueueGenericSend(). It is included for
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346 * backward compatibility with versions of FreeRTOS.org that did not
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347 * include the xQueueSendToFront() and xQueueSendToBack() macros. It is
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348 * equivalent to xQueueSendToBack().
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350 * Post an item on a queue. The item is queued by copy, not by reference.
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351 * This function must not be called from an interrupt service routine.
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352 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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354 * @param xQueue The handle to the queue on which the item is to be posted.
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356 * @param pvItemToQueue A pointer to the item that is to be placed on the
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357 * queue. The size of the items the queue will hold was defined when the
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358 * queue was created, so this many bytes will be copied from pvItemToQueue
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359 * into the queue storage area.
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361 * @param xTicksToWait The maximum amount of time the task should block
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362 * waiting for space to become available on the queue, should it already
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363 * be full. The call will return immediately if this is set to 0 and the
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364 * queue is full. The time is defined in tick periods so the constant
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365 * portTICK_RATE_MS should be used to convert to real time if this is required.
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367 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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377 uint32_t ulVar = 10UL;
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379 void vATask( void *pvParameters )
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381 QueueHandle_t xQueue1, xQueue2;
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382 struct AMessage *pxMessage;
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384 // Create a queue capable of containing 10 uint32_t values.
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385 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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387 // Create a queue capable of containing 10 pointers to AMessage structures.
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388 // These should be passed by pointer as they contain a lot of data.
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389 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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395 // Send an uint32_t. Wait for 10 ticks for space to become
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396 // available if necessary.
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397 if( xQueueSend( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
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399 // Failed to post the message, even after 10 ticks.
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405 // Send a pointer to a struct AMessage object. Don't block if the
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406 // queue is already full.
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407 pxMessage = & xMessage;
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408 xQueueSend( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
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411 // ... Rest of task code.
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414 * \defgroup xQueueSend xQueueSend
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415 * \ingroup QueueManagement
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417 #define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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422 BaseType_t xQueueOverwrite(
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423 QueueHandle_t xQueue,
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424 const void * pvItemToQueue
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428 * Only for use with queues that have a length of one - so the queue is either
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431 * Post an item on a queue. If the queue is already full then overwrite the
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432 * value held in the queue. The item is queued by copy, not by reference.
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434 * This function must not be called from an interrupt service routine.
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435 * See xQueueOverwriteFromISR () for an alternative which may be used in an ISR.
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437 * @param xQueue The handle of the queue to which the data is being sent.
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439 * @param pvItemToQueue A pointer to the item that is to be placed on the
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440 * queue. The size of the items the queue will hold was defined when the
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441 * queue was created, so this many bytes will be copied from pvItemToQueue
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442 * into the queue storage area.
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444 * @return xQueueOverwrite() is a macro that calls xQueueGenericSend(), and
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445 * therefore has the same return values as xQueueSendToFront(). However, pdPASS
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446 * is the only value that can be returned because xQueueOverwrite() will write
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447 * to the queue even when the queue is already full.
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452 void vFunction( void *pvParameters )
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454 QueueHandle_t xQueue;
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455 uint32_t ulVarToSend, ulValReceived;
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457 // Create a queue to hold one uint32_t value. It is strongly
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458 // recommended *not* to use xQueueOverwrite() on queues that can
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459 // contain more than one value, and doing so will trigger an assertion
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460 // if configASSERT() is defined.
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461 xQueue = xQueueCreate( 1, sizeof( uint32_t ) );
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463 // Write the value 10 to the queue using xQueueOverwrite().
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465 xQueueOverwrite( xQueue, &ulVarToSend );
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467 // Peeking the queue should now return 10, but leave the value 10 in
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468 // the queue. A block time of zero is used as it is known that the
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469 // queue holds a value.
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471 xQueuePeek( xQueue, &ulValReceived, 0 );
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473 if( ulValReceived != 10 )
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475 // Error unless the item was removed by a different task.
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478 // The queue is still full. Use xQueueOverwrite() to overwrite the
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479 // value held in the queue with 100.
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481 xQueueOverwrite( xQueue, &ulVarToSend );
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483 // This time read from the queue, leaving the queue empty once more.
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484 // A block time of 0 is used again.
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485 xQueueReceive( xQueue, &ulValReceived, 0 );
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487 // The value read should be the last value written, even though the
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488 // queue was already full when the value was written.
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489 if( ulValReceived != 100 )
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497 * \defgroup xQueueOverwrite xQueueOverwrite
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498 * \ingroup QueueManagement
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500 #define xQueueOverwrite( xQueue, pvItemToQueue ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), 0, queueOVERWRITE )
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506 BaseType_t xQueueGenericSend(
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507 QueueHandle_t xQueue,
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508 const void * pvItemToQueue,
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509 TickType_t xTicksToWait
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510 BaseType_t xCopyPosition
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514 * It is preferred that the macros xQueueSend(), xQueueSendToFront() and
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515 * xQueueSendToBack() are used in place of calling this function directly.
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517 * Post an item on a queue. The item is queued by copy, not by reference.
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518 * This function must not be called from an interrupt service routine.
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519 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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521 * @param xQueue The handle to the queue on which the item is to be posted.
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523 * @param pvItemToQueue A pointer to the item that is to be placed on the
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524 * queue. The size of the items the queue will hold was defined when the
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525 * queue was created, so this many bytes will be copied from pvItemToQueue
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526 * into the queue storage area.
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528 * @param xTicksToWait The maximum amount of time the task should block
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529 * waiting for space to become available on the queue, should it already
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530 * be full. The call will return immediately if this is set to 0 and the
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531 * queue is full. The time is defined in tick periods so the constant
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532 * portTICK_RATE_MS should be used to convert to real time if this is required.
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534 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
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535 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
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536 * at the front of the queue (for high priority messages).
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538 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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548 uint32_t ulVar = 10UL;
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550 void vATask( void *pvParameters )
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552 QueueHandle_t xQueue1, xQueue2;
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553 struct AMessage *pxMessage;
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555 // Create a queue capable of containing 10 uint32_t values.
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556 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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558 // Create a queue capable of containing 10 pointers to AMessage structures.
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559 // These should be passed by pointer as they contain a lot of data.
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560 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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566 // Send an uint32_t. Wait for 10 ticks for space to become
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567 // available if necessary.
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568 if( xQueueGenericSend( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10, queueSEND_TO_BACK ) != pdPASS )
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570 // Failed to post the message, even after 10 ticks.
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576 // Send a pointer to a struct AMessage object. Don't block if the
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577 // queue is already full.
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578 pxMessage = & xMessage;
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579 xQueueGenericSend( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0, queueSEND_TO_BACK );
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582 // ... Rest of task code.
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585 * \defgroup xQueueSend xQueueSend
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586 * \ingroup QueueManagement
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588 BaseType_t xQueueGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, TickType_t xTicksToWait, const BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
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593 BaseType_t xQueuePeek(
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594 QueueHandle_t xQueue,
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596 TickType_t xTicksToWait
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599 * This is a macro that calls the xQueueGenericReceive() function.
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601 * Receive an item from a queue without removing the item from the queue.
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602 * The item is received by copy so a buffer of adequate size must be
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603 * provided. The number of bytes copied into the buffer was defined when
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604 * the queue was created.
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606 * Successfully received items remain on the queue so will be returned again
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607 * by the next call, or a call to xQueueReceive().
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609 * This macro must not be used in an interrupt service routine. See
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610 * xQueuePeekFromISR() for an alternative that can be called from an interrupt
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613 * @param xQueue The handle to the queue from which the item is to be
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616 * @param pvBuffer Pointer to the buffer into which the received item will
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619 * @param xTicksToWait The maximum amount of time the task should block
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620 * waiting for an item to receive should the queue be empty at the time
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621 * of the call. The time is defined in tick periods so the constant
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622 * portTICK_RATE_MS should be used to convert to real time if this is required.
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623 * xQueuePeek() will return immediately if xTicksToWait is 0 and the queue
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626 * @return pdTRUE if an item was successfully received from the queue,
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627 * otherwise pdFALSE.
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637 QueueHandle_t xQueue;
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639 // Task to create a queue and post a value.
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640 void vATask( void *pvParameters )
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642 struct AMessage *pxMessage;
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644 // Create a queue capable of containing 10 pointers to AMessage structures.
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645 // These should be passed by pointer as they contain a lot of data.
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646 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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649 // Failed to create the queue.
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654 // Send a pointer to a struct AMessage object. Don't block if the
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655 // queue is already full.
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656 pxMessage = & xMessage;
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657 xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );
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659 // ... Rest of task code.
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662 // Task to peek the data from the queue.
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663 void vADifferentTask( void *pvParameters )
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665 struct AMessage *pxRxedMessage;
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669 // Peek a message on the created queue. Block for 10 ticks if a
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670 // message is not immediately available.
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671 if( xQueuePeek( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
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673 // pcRxedMessage now points to the struct AMessage variable posted
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674 // by vATask, but the item still remains on the queue.
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678 // ... Rest of task code.
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681 * \defgroup xQueueReceive xQueueReceive
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682 * \ingroup QueueManagement
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684 #define xQueuePeek( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )
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689 BaseType_t xQueuePeekFromISR(
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690 QueueHandle_t xQueue,
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694 * A version of xQueuePeek() that can be called from an interrupt service
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697 * Receive an item from a queue without removing the item from the queue.
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698 * The item is received by copy so a buffer of adequate size must be
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699 * provided. The number of bytes copied into the buffer was defined when
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700 * the queue was created.
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702 * Successfully received items remain on the queue so will be returned again
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703 * by the next call, or a call to xQueueReceive().
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705 * @param xQueue The handle to the queue from which the item is to be
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708 * @param pvBuffer Pointer to the buffer into which the received item will
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711 * @return pdTRUE if an item was successfully received from the queue,
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712 * otherwise pdFALSE.
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714 * \defgroup xQueuePeekFromISR xQueuePeekFromISR
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715 * \ingroup QueueManagement
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717 BaseType_t xQueuePeekFromISR( QueueHandle_t xQueue, void * const pvBuffer ) PRIVILEGED_FUNCTION;
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722 BaseType_t xQueueReceive(
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723 QueueHandle_t xQueue,
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725 TickType_t xTicksToWait
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728 * This is a macro that calls the xQueueGenericReceive() function.
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730 * Receive an item from a queue. The item is received by copy so a buffer of
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731 * adequate size must be provided. The number of bytes copied into the buffer
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732 * was defined when the queue was created.
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734 * Successfully received items are removed from the queue.
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736 * This function must not be used in an interrupt service routine. See
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737 * xQueueReceiveFromISR for an alternative that can.
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739 * @param xQueue The handle to the queue from which the item is to be
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742 * @param pvBuffer Pointer to the buffer into which the received item will
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745 * @param xTicksToWait The maximum amount of time the task should block
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746 * waiting for an item to receive should the queue be empty at the time
\r
747 * of the call. xQueueReceive() will return immediately if xTicksToWait
\r
748 * is zero and the queue is empty. The time is defined in tick periods so the
\r
749 * constant portTICK_RATE_MS should be used to convert to real time if this is
\r
752 * @return pdTRUE if an item was successfully received from the queue,
\r
753 * otherwise pdFALSE.
\r
763 QueueHandle_t xQueue;
\r
765 // Task to create a queue and post a value.
\r
766 void vATask( void *pvParameters )
\r
768 struct AMessage *pxMessage;
\r
770 // Create a queue capable of containing 10 pointers to AMessage structures.
\r
771 // These should be passed by pointer as they contain a lot of data.
\r
772 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
\r
775 // Failed to create the queue.
\r
780 // Send a pointer to a struct AMessage object. Don't block if the
\r
781 // queue is already full.
\r
782 pxMessage = & xMessage;
\r
783 xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );
\r
785 // ... Rest of task code.
\r
788 // Task to receive from the queue.
\r
789 void vADifferentTask( void *pvParameters )
\r
791 struct AMessage *pxRxedMessage;
\r
795 // Receive a message on the created queue. Block for 10 ticks if a
\r
796 // message is not immediately available.
\r
797 if( xQueueReceive( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
\r
799 // pcRxedMessage now points to the struct AMessage variable posted
\r
804 // ... Rest of task code.
\r
807 * \defgroup xQueueReceive xQueueReceive
\r
808 * \ingroup QueueManagement
\r
810 #define xQueueReceive( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
\r
816 BaseType_t xQueueGenericReceive(
\r
817 QueueHandle_t xQueue,
\r
819 TickType_t xTicksToWait
\r
820 BaseType_t xJustPeek
\r
823 * It is preferred that the macro xQueueReceive() be used rather than calling
\r
824 * this function directly.
\r
826 * Receive an item from a queue. The item is received by copy so a buffer of
\r
827 * adequate size must be provided. The number of bytes copied into the buffer
\r
828 * was defined when the queue was created.
\r
830 * This function must not be used in an interrupt service routine. See
\r
831 * xQueueReceiveFromISR for an alternative that can.
\r
833 * @param xQueue The handle to the queue from which the item is to be
\r
836 * @param pvBuffer Pointer to the buffer into which the received item will
\r
839 * @param xTicksToWait The maximum amount of time the task should block
\r
840 * waiting for an item to receive should the queue be empty at the time
\r
841 * of the call. The time is defined in tick periods so the constant
\r
842 * portTICK_RATE_MS should be used to convert to real time if this is required.
\r
843 * xQueueGenericReceive() will return immediately if the queue is empty and
\r
844 * xTicksToWait is 0.
\r
846 * @param xJustPeek When set to true, the item received from the queue is not
\r
847 * actually removed from the queue - meaning a subsequent call to
\r
848 * xQueueReceive() will return the same item. When set to false, the item
\r
849 * being received from the queue is also removed from the queue.
\r
851 * @return pdTRUE if an item was successfully received from the queue,
\r
852 * otherwise pdFALSE.
\r
862 QueueHandle_t xQueue;
\r
864 // Task to create a queue and post a value.
\r
865 void vATask( void *pvParameters )
\r
867 struct AMessage *pxMessage;
\r
869 // Create a queue capable of containing 10 pointers to AMessage structures.
\r
870 // These should be passed by pointer as they contain a lot of data.
\r
871 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
\r
874 // Failed to create the queue.
\r
879 // Send a pointer to a struct AMessage object. Don't block if the
\r
880 // queue is already full.
\r
881 pxMessage = & xMessage;
\r
882 xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );
\r
884 // ... Rest of task code.
\r
887 // Task to receive from the queue.
\r
888 void vADifferentTask( void *pvParameters )
\r
890 struct AMessage *pxRxedMessage;
\r
894 // Receive a message on the created queue. Block for 10 ticks if a
\r
895 // message is not immediately available.
\r
896 if( xQueueGenericReceive( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
\r
898 // pcRxedMessage now points to the struct AMessage variable posted
\r
903 // ... Rest of task code.
\r
906 * \defgroup xQueueReceive xQueueReceive
\r
907 * \ingroup QueueManagement
\r
909 BaseType_t xQueueGenericReceive( QueueHandle_t xQueue, void * const pvBuffer, TickType_t xTicksToWait, const BaseType_t xJustPeek ) PRIVILEGED_FUNCTION;
\r
913 * <pre>UBaseType_t uxQueueMessagesWaiting( const QueueHandle_t xQueue );</pre>
\r
915 * Return the number of messages stored in a queue.
\r
917 * @param xQueue A handle to the queue being queried.
\r
919 * @return The number of messages available in the queue.
\r
921 * \defgroup uxQueueMessagesWaiting uxQueueMessagesWaiting
\r
922 * \ingroup QueueManagement
\r
924 UBaseType_t uxQueueMessagesWaiting( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
928 * <pre>UBaseType_t uxQueueSpacesAvailable( const QueueHandle_t xQueue );</pre>
\r
930 * Return the number of free spaces available in a queue. This is equal to the
\r
931 * number of items that can be sent to the queue before the queue becomes full
\r
932 * if no items are removed.
\r
934 * @param xQueue A handle to the queue being queried.
\r
936 * @return The number of spaces available in the queue.
\r
938 * \defgroup uxQueueMessagesWaiting uxQueueMessagesWaiting
\r
939 * \ingroup QueueManagement
\r
941 UBaseType_t uxQueueSpacesAvailable( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
945 * <pre>void vQueueDelete( QueueHandle_t xQueue );</pre>
\r
947 * Delete a queue - freeing all the memory allocated for storing of items
\r
948 * placed on the queue.
\r
950 * @param xQueue A handle to the queue to be deleted.
\r
952 * \defgroup vQueueDelete vQueueDelete
\r
953 * \ingroup QueueManagement
\r
955 void vQueueDelete( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
960 BaseType_t xQueueSendToFrontFromISR(
\r
961 QueueHandle_t xQueue,
\r
962 const void *pvItemToQueue,
\r
963 BaseType_t *pxHigherPriorityTaskWoken
\r
967 * This is a macro that calls xQueueGenericSendFromISR().
\r
969 * Post an item to the front of a queue. It is safe to use this macro from
\r
970 * within an interrupt service routine.
\r
972 * Items are queued by copy not reference so it is preferable to only
\r
973 * queue small items, especially when called from an ISR. In most cases
\r
974 * it would be preferable to store a pointer to the item being queued.
\r
976 * @param xQueue The handle to the queue on which the item is to be posted.
\r
978 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
979 * queue. The size of the items the queue will hold was defined when the
\r
980 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
981 * into the queue storage area.
\r
983 * @param pxHigherPriorityTaskWoken xQueueSendToFrontFromISR() will set
\r
984 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
985 * to unblock, and the unblocked task has a priority higher than the currently
\r
986 * running task. If xQueueSendToFromFromISR() sets this value to pdTRUE then
\r
987 * a context switch should be requested before the interrupt is exited.
\r
989 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
992 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
995 void vBufferISR( void )
\r
998 BaseType_t xHigherPrioritTaskWoken;
\r
1000 // We have not woken a task at the start of the ISR.
\r
1001 xHigherPriorityTaskWoken = pdFALSE;
\r
1003 // Loop until the buffer is empty.
\r
1006 // Obtain a byte from the buffer.
\r
1007 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1010 xQueueSendToFrontFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
1012 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1014 // Now the buffer is empty we can switch context if necessary.
\r
1015 if( xHigherPriorityTaskWoken )
\r
1022 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1023 * \ingroup QueueManagement
\r
1025 #define xQueueSendToFrontFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_FRONT )
\r
1031 BaseType_t xQueueSendToBackFromISR(
\r
1032 QueueHandle_t xQueue,
\r
1033 const void *pvItemToQueue,
\r
1034 BaseType_t *pxHigherPriorityTaskWoken
\r
1038 * This is a macro that calls xQueueGenericSendFromISR().
\r
1040 * Post an item to the back of a queue. It is safe to use this macro from
\r
1041 * within an interrupt service routine.
\r
1043 * Items are queued by copy not reference so it is preferable to only
\r
1044 * queue small items, especially when called from an ISR. In most cases
\r
1045 * it would be preferable to store a pointer to the item being queued.
\r
1047 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1049 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1050 * queue. The size of the items the queue will hold was defined when the
\r
1051 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1052 * into the queue storage area.
\r
1054 * @param pxHigherPriorityTaskWoken xQueueSendToBackFromISR() will set
\r
1055 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1056 * to unblock, and the unblocked task has a priority higher than the currently
\r
1057 * running task. If xQueueSendToBackFromISR() sets this value to pdTRUE then
\r
1058 * a context switch should be requested before the interrupt is exited.
\r
1060 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1063 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1066 void vBufferISR( void )
\r
1069 BaseType_t xHigherPriorityTaskWoken;
\r
1071 // We have not woken a task at the start of the ISR.
\r
1072 xHigherPriorityTaskWoken = pdFALSE;
\r
1074 // Loop until the buffer is empty.
\r
1077 // Obtain a byte from the buffer.
\r
1078 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1081 xQueueSendToBackFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
1083 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1085 // Now the buffer is empty we can switch context if necessary.
\r
1086 if( xHigherPriorityTaskWoken )
\r
1093 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1094 * \ingroup QueueManagement
\r
1096 #define xQueueSendToBackFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
\r
1101 BaseType_t xQueueOverwriteFromISR(
\r
1102 QueueHandle_t xQueue,
\r
1103 const void * pvItemToQueue,
\r
1104 BaseType_t *pxHigherPriorityTaskWoken
\r
1108 * A version of xQueueOverwrite() that can be used in an interrupt service
\r
1111 * Only for use with queues that can hold a single item - so the queue is either
\r
1114 * Post an item on a queue. If the queue is already full then overwrite the
\r
1115 * value held in the queue. The item is queued by copy, not by reference.
\r
1117 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1119 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1120 * queue. The size of the items the queue will hold was defined when the
\r
1121 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1122 * into the queue storage area.
\r
1124 * @param pxHigherPriorityTaskWoken xQueueOverwriteFromISR() will set
\r
1125 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1126 * to unblock, and the unblocked task has a priority higher than the currently
\r
1127 * running task. If xQueueOverwriteFromISR() sets this value to pdTRUE then
\r
1128 * a context switch should be requested before the interrupt is exited.
\r
1130 * @return xQueueOverwriteFromISR() is a macro that calls
\r
1131 * xQueueGenericSendFromISR(), and therefore has the same return values as
\r
1132 * xQueueSendToFrontFromISR(). However, pdPASS is the only value that can be
\r
1133 * returned because xQueueOverwriteFromISR() will write to the queue even when
\r
1134 * the queue is already full.
\r
1139 QueueHandle_t xQueue;
\r
1141 void vFunction( void *pvParameters )
\r
1143 // Create a queue to hold one uint32_t value. It is strongly
\r
1144 // recommended *not* to use xQueueOverwriteFromISR() on queues that can
\r
1145 // contain more than one value, and doing so will trigger an assertion
\r
1146 // if configASSERT() is defined.
\r
1147 xQueue = xQueueCreate( 1, sizeof( uint32_t ) );
\r
1150 void vAnInterruptHandler( void )
\r
1152 // xHigherPriorityTaskWoken must be set to pdFALSE before it is used.
\r
1153 BaseType_t xHigherPriorityTaskWoken = pdFALSE;
\r
1154 uint32_t ulVarToSend, ulValReceived;
\r
1156 // Write the value 10 to the queue using xQueueOverwriteFromISR().
\r
1158 xQueueOverwriteFromISR( xQueue, &ulVarToSend, &xHigherPriorityTaskWoken );
\r
1160 // The queue is full, but calling xQueueOverwriteFromISR() again will still
\r
1161 // pass because the value held in the queue will be overwritten with the
\r
1163 ulVarToSend = 100;
\r
1164 xQueueOverwriteFromISR( xQueue, &ulVarToSend, &xHigherPriorityTaskWoken );
\r
1166 // Reading from the queue will now return 100.
\r
1170 if( xHigherPrioritytaskWoken == pdTRUE )
\r
1172 // Writing to the queue caused a task to unblock and the unblocked task
\r
1173 // has a priority higher than or equal to the priority of the currently
\r
1174 // executing task (the task this interrupt interrupted). Perform a context
\r
1175 // switch so this interrupt returns directly to the unblocked task.
\r
1176 portYIELD_FROM_ISR(); // or portEND_SWITCHING_ISR() depending on the port.
\r
1180 * \defgroup xQueueOverwriteFromISR xQueueOverwriteFromISR
\r
1181 * \ingroup QueueManagement
\r
1183 #define xQueueOverwriteFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueOVERWRITE )
\r
1188 BaseType_t xQueueSendFromISR(
\r
1189 QueueHandle_t xQueue,
\r
1190 const void *pvItemToQueue,
\r
1191 BaseType_t *pxHigherPriorityTaskWoken
\r
1195 * This is a macro that calls xQueueGenericSendFromISR(). It is included
\r
1196 * for backward compatibility with versions of FreeRTOS.org that did not
\r
1197 * include the xQueueSendToBackFromISR() and xQueueSendToFrontFromISR()
\r
1200 * Post an item to the back of a queue. It is safe to use this function from
\r
1201 * within an interrupt service routine.
\r
1203 * Items are queued by copy not reference so it is preferable to only
\r
1204 * queue small items, especially when called from an ISR. In most cases
\r
1205 * it would be preferable to store a pointer to the item being queued.
\r
1207 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1209 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1210 * queue. The size of the items the queue will hold was defined when the
\r
1211 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1212 * into the queue storage area.
\r
1214 * @param pxHigherPriorityTaskWoken xQueueSendFromISR() will set
\r
1215 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1216 * to unblock, and the unblocked task has a priority higher than the currently
\r
1217 * running task. If xQueueSendFromISR() sets this value to pdTRUE then
\r
1218 * a context switch should be requested before the interrupt is exited.
\r
1220 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1223 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1226 void vBufferISR( void )
\r
1229 BaseType_t xHigherPriorityTaskWoken;
\r
1231 // We have not woken a task at the start of the ISR.
\r
1232 xHigherPriorityTaskWoken = pdFALSE;
\r
1234 // Loop until the buffer is empty.
\r
1237 // Obtain a byte from the buffer.
\r
1238 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1241 xQueueSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
1243 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1245 // Now the buffer is empty we can switch context if necessary.
\r
1246 if( xHigherPriorityTaskWoken )
\r
1248 // Actual macro used here is port specific.
\r
1249 portYIELD_FROM_ISR ();
\r
1254 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1255 * \ingroup QueueManagement
\r
1257 #define xQueueSendFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
\r
1262 BaseType_t xQueueGenericSendFromISR(
\r
1263 QueueHandle_t xQueue,
\r
1264 const void *pvItemToQueue,
\r
1265 BaseType_t *pxHigherPriorityTaskWoken,
\r
1266 BaseType_t xCopyPosition
\r
1270 * It is preferred that the macros xQueueSendFromISR(),
\r
1271 * xQueueSendToFrontFromISR() and xQueueSendToBackFromISR() be used in place
\r
1272 * of calling this function directly.
\r
1274 * Post an item on a queue. It is safe to use this function from within an
\r
1275 * interrupt service routine.
\r
1277 * Items are queued by copy not reference so it is preferable to only
\r
1278 * queue small items, especially when called from an ISR. In most cases
\r
1279 * it would be preferable to store a pointer to the item being queued.
\r
1281 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1283 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1284 * queue. The size of the items the queue will hold was defined when the
\r
1285 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1286 * into the queue storage area.
\r
1288 * @param pxHigherPriorityTaskWoken xQueueGenericSendFromISR() will set
\r
1289 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1290 * to unblock, and the unblocked task has a priority higher than the currently
\r
1291 * running task. If xQueueGenericSendFromISR() sets this value to pdTRUE then
\r
1292 * a context switch should be requested before the interrupt is exited.
\r
1294 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
\r
1295 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
\r
1296 * at the front of the queue (for high priority messages).
\r
1298 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1301 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1304 void vBufferISR( void )
\r
1307 BaseType_t xHigherPriorityTaskWokenByPost;
\r
1309 // We have not woken a task at the start of the ISR.
\r
1310 xHigherPriorityTaskWokenByPost = pdFALSE;
\r
1312 // Loop until the buffer is empty.
\r
1315 // Obtain a byte from the buffer.
\r
1316 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1318 // Post each byte.
\r
1319 xQueueGenericSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWokenByPost, queueSEND_TO_BACK );
\r
1321 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1323 // Now the buffer is empty we can switch context if necessary. Note that the
\r
1324 // name of the yield function required is port specific.
\r
1325 if( xHigherPriorityTaskWokenByPost )
\r
1327 taskYIELD_YIELD_FROM_ISR();
\r
1332 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1333 * \ingroup QueueManagement
\r
1335 BaseType_t xQueueGenericSendFromISR( QueueHandle_t xQueue, const void * const pvItemToQueue, BaseType_t * const pxHigherPriorityTaskWoken, const BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
\r
1340 BaseType_t xQueueReceiveFromISR(
\r
1341 QueueHandle_t xQueue,
\r
1343 BaseType_t *pxTaskWoken
\r
1347 * Receive an item from a queue. It is safe to use this function from within an
\r
1348 * interrupt service routine.
\r
1350 * @param xQueue The handle to the queue from which the item is to be
\r
1353 * @param pvBuffer Pointer to the buffer into which the received item will
\r
1356 * @param pxTaskWoken A task may be blocked waiting for space to become
\r
1357 * available on the queue. If xQueueReceiveFromISR causes such a task to
\r
1358 * unblock *pxTaskWoken will get set to pdTRUE, otherwise *pxTaskWoken will
\r
1359 * remain unchanged.
\r
1361 * @return pdTRUE if an item was successfully received from the queue,
\r
1362 * otherwise pdFALSE.
\r
1367 QueueHandle_t xQueue;
\r
1369 // Function to create a queue and post some values.
\r
1370 void vAFunction( void *pvParameters )
\r
1372 char cValueToPost;
\r
1373 const TickType_t xBlockTime = ( TickType_t )0xff;
\r
1375 // Create a queue capable of containing 10 characters.
\r
1376 xQueue = xQueueCreate( 10, sizeof( char ) );
\r
1379 // Failed to create the queue.
\r
1384 // Post some characters that will be used within an ISR. If the queue
\r
1385 // is full then this task will block for xBlockTime ticks.
\r
1386 cValueToPost = 'a';
\r
1387 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1388 cValueToPost = 'b';
\r
1389 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1391 // ... keep posting characters ... this task may block when the queue
\r
1394 cValueToPost = 'c';
\r
1395 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1398 // ISR that outputs all the characters received on the queue.
\r
1399 void vISR_Routine( void )
\r
1401 BaseType_t xTaskWokenByReceive = pdFALSE;
\r
1404 while( xQueueReceiveFromISR( xQueue, ( void * ) &cRxedChar, &xTaskWokenByReceive) )
\r
1406 // A character was received. Output the character now.
\r
1407 vOutputCharacter( cRxedChar );
\r
1409 // If removing the character from the queue woke the task that was
\r
1410 // posting onto the queue cTaskWokenByReceive will have been set to
\r
1411 // pdTRUE. No matter how many times this loop iterates only one
\r
1412 // task will be woken.
\r
1415 if( cTaskWokenByPost != ( char ) pdFALSE;
\r
1421 * \defgroup xQueueReceiveFromISR xQueueReceiveFromISR
\r
1422 * \ingroup QueueManagement
\r
1424 BaseType_t xQueueReceiveFromISR( QueueHandle_t xQueue, void * const pvBuffer, BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
\r
1427 * Utilities to query queues that are safe to use from an ISR. These utilities
\r
1428 * should be used only from witin an ISR, or within a critical section.
\r
1430 BaseType_t xQueueIsQueueEmptyFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1431 BaseType_t xQueueIsQueueFullFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1432 UBaseType_t uxQueueMessagesWaitingFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
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1436 * xQueueAltGenericSend() is an alternative version of xQueueGenericSend().
\r
1437 * Likewise xQueueAltGenericReceive() is an alternative version of
\r
1438 * xQueueGenericReceive().
\r
1440 * The source code that implements the alternative (Alt) API is much
\r
1441 * simpler because it executes everything from within a critical section.
\r
1442 * This is the approach taken by many other RTOSes, but FreeRTOS.org has the
\r
1443 * preferred fully featured API too. The fully featured API has more
\r
1444 * complex code that takes longer to execute, but makes much less use of
\r
1445 * critical sections. Therefore the alternative API sacrifices interrupt
\r
1446 * responsiveness to gain execution speed, whereas the fully featured API
\r
1447 * sacrifices execution speed to ensure better interrupt responsiveness.
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1449 BaseType_t xQueueAltGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, TickType_t xTicksToWait, BaseType_t xCopyPosition );
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1450 BaseType_t xQueueAltGenericReceive( QueueHandle_t xQueue, void * const pvBuffer, TickType_t xTicksToWait, BaseType_t xJustPeeking );
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1451 #define xQueueAltSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
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1452 #define xQueueAltSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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1453 #define xQueueAltReceive( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
\r
1454 #define xQueueAltPeek( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )
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1457 * The functions defined above are for passing data to and from tasks. The
\r
1458 * functions below are the equivalents for passing data to and from
\r
1461 * These functions are called from the co-routine macro implementation and
\r
1462 * should not be called directly from application code. Instead use the macro
\r
1463 * wrappers defined within croutine.h.
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1465 BaseType_t xQueueCRSendFromISR( QueueHandle_t xQueue, const void *pvItemToQueue, BaseType_t xCoRoutinePreviouslyWoken );
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1466 BaseType_t xQueueCRReceiveFromISR( QueueHandle_t xQueue, void *pvBuffer, BaseType_t *pxTaskWoken );
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1467 BaseType_t xQueueCRSend( QueueHandle_t xQueue, const void *pvItemToQueue, TickType_t xTicksToWait );
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1468 BaseType_t xQueueCRReceive( QueueHandle_t xQueue, void *pvBuffer, TickType_t xTicksToWait );
\r
1471 * For internal use only. Use xSemaphoreCreateMutex(),
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1472 * xSemaphoreCreateCounting() or xSemaphoreGetMutexHolder() instead of calling
\r
1473 * these functions directly.
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1475 QueueHandle_t xQueueCreateMutex( const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;
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1476 QueueHandle_t xQueueCreateCountingSemaphore( const UBaseType_t uxMaxCount, const UBaseType_t uxInitialCount ) PRIVILEGED_FUNCTION;
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1477 void* xQueueGetMutexHolder( QueueHandle_t xSemaphore ) PRIVILEGED_FUNCTION;
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1480 * For internal use only. Use xSemaphoreTakeMutexRecursive() or
\r
1481 * xSemaphoreGiveMutexRecursive() instead of calling these functions directly.
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1483 BaseType_t xQueueTakeMutexRecursive( QueueHandle_t xMutex, TickType_t xBlockTime ) PRIVILEGED_FUNCTION;
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1484 BaseType_t xQueueGiveMutexRecursive( QueueHandle_t pxMutex ) PRIVILEGED_FUNCTION;
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1487 * Reset a queue back to its original empty state. pdPASS is returned if the
\r
1488 * queue is successfully reset. pdFAIL is returned if the queue could not be
\r
1489 * reset because there are tasks blocked on the queue waiting to either
\r
1490 * receive from the queue or send to the queue.
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1492 #define xQueueReset( xQueue ) xQueueGenericReset( xQueue, pdFALSE )
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1495 * The registry is provided as a means for kernel aware debuggers to
\r
1496 * locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
\r
1497 * a queue, semaphore or mutex handle to the registry if you want the handle
\r
1498 * to be available to a kernel aware debugger. If you are not using a kernel
\r
1499 * aware debugger then this function can be ignored.
\r
1501 * configQUEUE_REGISTRY_SIZE defines the maximum number of handles the
\r
1502 * registry can hold. configQUEUE_REGISTRY_SIZE must be greater than 0
\r
1503 * within FreeRTOSConfig.h for the registry to be available. Its value
\r
1504 * does not effect the number of queues, semaphores and mutexes that can be
\r
1505 * created - just the number that the registry can hold.
\r
1507 * @param xQueue The handle of the queue being added to the registry. This
\r
1508 * is the handle returned by a call to xQueueCreate(). Semaphore and mutex
\r
1509 * handles can also be passed in here.
\r
1511 * @param pcName The name to be associated with the handle. This is the
\r
1512 * name that the kernel aware debugger will display. The queue registry only
\r
1513 * stores a pointer to the string - so the string must be persistent (global or
\r
1514 * preferably in ROM/Flash), not on the stack.
\r
1516 #if configQUEUE_REGISTRY_SIZE > 0
\r
1517 void vQueueAddToRegistry( QueueHandle_t xQueue, char *pcName ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
\r
1521 * The registry is provided as a means for kernel aware debuggers to
\r
1522 * locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
\r
1523 * a queue, semaphore or mutex handle to the registry if you want the handle
\r
1524 * to be available to a kernel aware debugger, and vQueueUnregisterQueue() to
\r
1525 * remove the queue, semaphore or mutex from the register. If you are not using
\r
1526 * a kernel aware debugger then this function can be ignored.
\r
1528 * @param xQueue The handle of the queue being removed from the registry.
\r
1530 #if configQUEUE_REGISTRY_SIZE > 0
\r
1531 void vQueueUnregisterQueue( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1535 * Generic version of the queue creation function, which is in turn called by
\r
1536 * any queue, semaphore or mutex creation function or macro.
\r
1538 QueueHandle_t xQueueGenericCreate( const UBaseType_t uxQueueLength, const UBaseType_t uxItemSize, const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;
\r
1541 * Queue sets provide a mechanism to allow a task to block (pend) on a read
\r
1542 * operation from multiple queues or semaphores simultaneously.
\r
1544 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1547 * A queue set must be explicitly created using a call to xQueueCreateSet()
\r
1548 * before it can be used. Once created, standard FreeRTOS queues and semaphores
\r
1549 * can be added to the set using calls to xQueueAddToSet().
\r
1550 * xQueueSelectFromSet() is then used to determine which, if any, of the queues
\r
1551 * or semaphores contained in the set is in a state where a queue read or
\r
1552 * semaphore take operation would be successful.
\r
1554 * Note 1: See the documentation on http://wwwFreeRTOS.org/RTOS-queue-sets.html
\r
1555 * for reasons why queue sets are very rarely needed in practice as there are
\r
1556 * simpler methods of blocking on multiple objects.
\r
1558 * Note 2: Blocking on a queue set that contains a mutex will not cause the
\r
1559 * mutex holder to inherit the priority of the blocked task.
\r
1561 * Note 3: An additional 4 bytes of RAM is required for each space in a every
\r
1562 * queue added to a queue set. Therefore counting semaphores that have a high
\r
1563 * maximum count value should not be added to a queue set.
\r
1565 * Note 4: A receive (in the case of a queue) or take (in the case of a
\r
1566 * semaphore) operation must not be performed on a member of a queue set unless
\r
1567 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
\r
1569 * @param uxEventQueueLength Queue sets store events that occur on
\r
1570 * the queues and semaphores contained in the set. uxEventQueueLength specifies
\r
1571 * the maximum number of events that can be queued at once. To be absolutely
\r
1572 * certain that events are not lost uxEventQueueLength should be set to the
\r
1573 * total sum of the length of the queues added to the set, where binary
\r
1574 * semaphores and mutexes have a length of 1, and counting semaphores have a
\r
1575 * length set by their maximum count value. Examples:
\r
1576 * + If a queue set is to hold a queue of length 5, another queue of length 12,
\r
1577 * and a binary semaphore, then uxEventQueueLength should be set to
\r
1578 * (5 + 12 + 1), or 18.
\r
1579 * + If a queue set is to hold three binary semaphores then uxEventQueueLength
\r
1580 * should be set to (1 + 1 + 1 ), or 3.
\r
1581 * + If a queue set is to hold a counting semaphore that has a maximum count of
\r
1582 * 5, and a counting semaphore that has a maximum count of 3, then
\r
1583 * uxEventQueueLength should be set to (5 + 3), or 8.
\r
1585 * @return If the queue set is created successfully then a handle to the created
\r
1586 * queue set is returned. Otherwise NULL is returned.
\r
1588 QueueSetHandle_t xQueueCreateSet( const UBaseType_t uxEventQueueLength ) PRIVILEGED_FUNCTION;
\r
1591 * Adds a queue or semaphore to a queue set that was previously created by a
\r
1592 * call to xQueueCreateSet().
\r
1594 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1597 * Note 1: A receive (in the case of a queue) or take (in the case of a
\r
1598 * semaphore) operation must not be performed on a member of a queue set unless
\r
1599 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
\r
1601 * @param xQueueOrSemaphore The handle of the queue or semaphore being added to
\r
1602 * the queue set (cast to an QueueSetMemberHandle_t type).
\r
1604 * @param xQueueSet The handle of the queue set to which the queue or semaphore
\r
1607 * @return If the queue or semaphore was successfully added to the queue set
\r
1608 * then pdPASS is returned. If the queue could not be successfully added to the
\r
1609 * queue set because it is already a member of a different queue set then pdFAIL
\r
1612 BaseType_t xQueueAddToSet( QueueSetMemberHandle_t xQueueOrSemaphore, QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
\r
1615 * Removes a queue or semaphore from a queue set. A queue or semaphore can only
\r
1616 * be removed from a set if the queue or semaphore is empty.
\r
1618 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1621 * @param xQueueOrSemaphore The handle of the queue or semaphore being removed
\r
1622 * from the queue set (cast to an QueueSetMemberHandle_t type).
\r
1624 * @param xQueueSet The handle of the queue set in which the queue or semaphore
\r
1627 * @return If the queue or semaphore was successfully removed from the queue set
\r
1628 * then pdPASS is returned. If the queue was not in the queue set, or the
\r
1629 * queue (or semaphore) was not empty, then pdFAIL is returned.
\r
1631 BaseType_t xQueueRemoveFromSet( QueueSetMemberHandle_t xQueueOrSemaphore, QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
\r
1634 * xQueueSelectFromSet() selects from the members of a queue set a queue or
\r
1635 * semaphore that either contains data (in the case of a queue) or is available
\r
1636 * to take (in the case of a semaphore). xQueueSelectFromSet() effectively
\r
1637 * allows a task to block (pend) on a read operation on all the queues and
\r
1638 * semaphores in a queue set simultaneously.
\r
1640 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1643 * Note 1: See the documentation on http://wwwFreeRTOS.org/RTOS-queue-sets.html
\r
1644 * for reasons why queue sets are very rarely needed in practice as there are
\r
1645 * simpler methods of blocking on multiple objects.
\r
1647 * Note 2: Blocking on a queue set that contains a mutex will not cause the
\r
1648 * mutex holder to inherit the priority of the blocked task.
\r
1650 * Note 3: A receive (in the case of a queue) or take (in the case of a
\r
1651 * semaphore) operation must not be performed on a member of a queue set unless
\r
1652 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
\r
1654 * @param xQueueSet The queue set on which the task will (potentially) block.
\r
1656 * @param xBlockTimeTicks The maximum time, in ticks, that the calling task will
\r
1657 * remain in the Blocked state (with other tasks executing) to wait for a member
\r
1658 * of the queue set to be ready for a successful queue read or semaphore take
\r
1661 * @return xQueueSelectFromSet() will return the handle of a queue (cast to
\r
1662 * a QueueSetMemberHandle_t type) contained in the queue set that contains data,
\r
1663 * or the handle of a semaphore (cast to a QueueSetMemberHandle_t type) contained
\r
1664 * in the queue set that is available, or NULL if no such queue or semaphore
\r
1665 * exists before before the specified block time expires.
\r
1667 QueueSetMemberHandle_t xQueueSelectFromSet( QueueSetHandle_t xQueueSet, const TickType_t xBlockTimeTicks ) PRIVILEGED_FUNCTION;
\r
1670 * A version of xQueueSelectFromSet() that can be used from an ISR.
\r
1672 QueueSetMemberHandle_t xQueueSelectFromSetFromISR( QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
\r
1674 /* Not public API functions. */
\r
1675 void vQueueWaitForMessageRestricted( QueueHandle_t xQueue, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
\r
1676 BaseType_t xQueueGenericReset( QueueHandle_t xQueue, BaseType_t xNewQueue ) PRIVILEGED_FUNCTION;
\r
1677 void vQueueSetQueueNumber( QueueHandle_t xQueue, UBaseType_t uxQueueNumber ) PRIVILEGED_FUNCTION;
\r
1678 UBaseType_t uxQueueGetQueueNumber( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1679 uint8_t ucQueueGetQueueType( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1682 #ifdef __cplusplus
\r
1686 #endif /* QUEUE_H */
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