2 FreeRTOS V8.2.3 - 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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74 #ifndef INC_FREERTOS_H
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75 #error "include FreeRTOS.h" must appear in source files before "include queue.h"
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84 * Type by which queues are referenced. For example, a call to xQueueCreate()
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85 * returns an QueueHandle_t variable that can then be used as a parameter to
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86 * xQueueSend(), xQueueReceive(), etc.
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88 typedef void * QueueHandle_t;
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91 * Type by which queue sets are referenced. For example, a call to
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92 * xQueueCreateSet() returns an xQueueSet variable that can then be used as a
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93 * parameter to xQueueSelectFromSet(), xQueueAddToSet(), etc.
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95 typedef void * QueueSetHandle_t;
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98 * Queue sets can contain both queues and semaphores, so the
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99 * QueueSetMemberHandle_t is defined as a type to be used where a parameter or
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100 * return value can be either an QueueHandle_t or an SemaphoreHandle_t.
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102 typedef void * QueueSetMemberHandle_t;
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104 /* For internal use only. */
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105 #define queueSEND_TO_BACK ( ( BaseType_t ) 0 )
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106 #define queueSEND_TO_FRONT ( ( BaseType_t ) 1 )
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107 #define queueOVERWRITE ( ( BaseType_t ) 2 )
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109 /* For internal use only. These definitions *must* match those in queue.c. */
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110 #define queueQUEUE_TYPE_BASE ( ( uint8_t ) 0U )
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111 #define queueQUEUE_TYPE_SET ( ( uint8_t ) 0U )
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112 #define queueQUEUE_TYPE_MUTEX ( ( uint8_t ) 1U )
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113 #define queueQUEUE_TYPE_COUNTING_SEMAPHORE ( ( uint8_t ) 2U )
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114 #define queueQUEUE_TYPE_BINARY_SEMAPHORE ( ( uint8_t ) 3U )
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115 #define queueQUEUE_TYPE_RECURSIVE_MUTEX ( ( uint8_t ) 4U )
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120 QueueHandle_t xQueueCreate(
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121 UBaseType_t uxQueueLength,
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122 UBaseType_t uxItemSize
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126 * Creates a new queue instance. This allocates the storage required by the
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127 * new queue and returns a handle for the queue.
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129 * @param uxQueueLength The maximum number of items that the queue can contain.
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131 * @param uxItemSize The number of bytes each item in the queue will require.
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132 * Items are queued by copy, not by reference, so this is the number of bytes
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133 * that will be copied for each posted item. Each item on the queue must be
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136 * @return If the queue is successfully create then a handle to the newly
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137 * created queue is returned. If the queue cannot be created then 0 is
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148 void vATask( void *pvParameters )
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150 QueueHandle_t xQueue1, xQueue2;
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152 // Create a queue capable of containing 10 uint32_t values.
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153 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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156 // Queue was not created and must not be used.
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159 // Create a queue capable of containing 10 pointers to AMessage structures.
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160 // These should be passed by pointer as they contain a lot of data.
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161 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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164 // Queue was not created and must not be used.
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167 // ... Rest of task code.
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170 * \defgroup xQueueCreate xQueueCreate
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171 * \ingroup QueueManagement
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173 #define xQueueCreate( uxQueueLength, uxItemSize ) xQueueGenericCreate( uxQueueLength, uxItemSize, NULL, NULL, queueQUEUE_TYPE_BASE )
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175 #if( configSUPPORT_STATIC_ALLOCATION == 1 )
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176 #define xQueueCreateStatic( uxQueueLength, uxItemSize, pucQueueStorage, pxStaticQueue ) xQueueGenericCreate( uxQueueLength, uxItemSize, pucQueueStorage, pxStaticQueue, queueQUEUE_TYPE_BASE )
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182 BaseType_t xQueueSendToToFront(
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183 QueueHandle_t xQueue,
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184 const void *pvItemToQueue,
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185 TickType_t xTicksToWait
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189 * This is a macro that calls xQueueGenericSend().
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191 * Post an item to the front of a queue. The item is queued by copy, not by
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192 * reference. This function must not be called from an interrupt service
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193 * routine. See xQueueSendFromISR () for an alternative which may be used
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196 * @param xQueue The handle to the queue on which the item is to be posted.
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198 * @param pvItemToQueue A pointer to the item that is to be placed on the
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199 * queue. The size of the items the queue will hold was defined when the
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200 * queue was created, so this many bytes will be copied from pvItemToQueue
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201 * into the queue storage area.
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203 * @param xTicksToWait The maximum amount of time the task should block
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204 * waiting for space to become available on the queue, should it already
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205 * be full. The call will return immediately if this is set to 0 and the
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206 * queue is full. The time is defined in tick periods so the constant
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207 * portTICK_PERIOD_MS should be used to convert to real time if this is required.
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209 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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219 uint32_t ulVar = 10UL;
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221 void vATask( void *pvParameters )
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223 QueueHandle_t xQueue1, xQueue2;
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224 struct AMessage *pxMessage;
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226 // Create a queue capable of containing 10 uint32_t values.
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227 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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229 // Create a queue capable of containing 10 pointers to AMessage structures.
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230 // These should be passed by pointer as they contain a lot of data.
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231 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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237 // Send an uint32_t. Wait for 10 ticks for space to become
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238 // available if necessary.
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239 if( xQueueSendToFront( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
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241 // Failed to post the message, even after 10 ticks.
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247 // Send a pointer to a struct AMessage object. Don't block if the
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248 // queue is already full.
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249 pxMessage = & xMessage;
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250 xQueueSendToFront( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
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253 // ... Rest of task code.
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256 * \defgroup xQueueSend xQueueSend
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257 * \ingroup QueueManagement
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259 #define xQueueSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
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264 BaseType_t xQueueSendToBack(
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265 QueueHandle_t xQueue,
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266 const void *pvItemToQueue,
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267 TickType_t xTicksToWait
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271 * This is a macro that calls xQueueGenericSend().
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273 * Post an item to the back of a queue. The item is queued by copy, not by
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274 * reference. This function must not be called from an interrupt service
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275 * routine. See xQueueSendFromISR () for an alternative which may be used
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278 * @param xQueue The handle to the queue on which the item is to be posted.
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280 * @param pvItemToQueue A pointer to the item that is to be placed on the
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281 * queue. The size of the items the queue will hold was defined when the
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282 * queue was created, so this many bytes will be copied from pvItemToQueue
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283 * into the queue storage area.
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285 * @param xTicksToWait The maximum amount of time the task should block
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286 * waiting for space to become available on the queue, should it already
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287 * be full. The call will return immediately if this is set to 0 and the queue
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288 * is full. The time is defined in tick periods so the constant
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289 * portTICK_PERIOD_MS should be used to convert to real time if this is required.
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291 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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301 uint32_t ulVar = 10UL;
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303 void vATask( void *pvParameters )
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305 QueueHandle_t xQueue1, xQueue2;
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306 struct AMessage *pxMessage;
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308 // Create a queue capable of containing 10 uint32_t values.
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309 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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311 // Create a queue capable of containing 10 pointers to AMessage structures.
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312 // These should be passed by pointer as they contain a lot of data.
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313 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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319 // Send an uint32_t. Wait for 10 ticks for space to become
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320 // available if necessary.
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321 if( xQueueSendToBack( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
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323 // Failed to post the message, even after 10 ticks.
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329 // Send a pointer to a struct AMessage object. Don't block if the
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330 // queue is already full.
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331 pxMessage = & xMessage;
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332 xQueueSendToBack( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
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335 // ... Rest of task code.
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338 * \defgroup xQueueSend xQueueSend
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339 * \ingroup QueueManagement
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341 #define xQueueSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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346 BaseType_t xQueueSend(
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347 QueueHandle_t xQueue,
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348 const void * pvItemToQueue,
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349 TickType_t xTicksToWait
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353 * This is a macro that calls xQueueGenericSend(). It is included for
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354 * backward compatibility with versions of FreeRTOS.org that did not
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355 * include the xQueueSendToFront() and xQueueSendToBack() macros. It is
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356 * equivalent to xQueueSendToBack().
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358 * Post an item on a queue. The item is queued by copy, not by reference.
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359 * This function must not be called from an interrupt service routine.
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360 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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362 * @param xQueue The handle to the queue on which the item is to be posted.
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364 * @param pvItemToQueue A pointer to the item that is to be placed on the
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365 * queue. The size of the items the queue will hold was defined when the
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366 * queue was created, so this many bytes will be copied from pvItemToQueue
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367 * into the queue storage area.
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369 * @param xTicksToWait The maximum amount of time the task should block
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370 * waiting for space to become available on the queue, should it already
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371 * be full. The call will return immediately if this is set to 0 and the
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372 * queue is full. The time is defined in tick periods so the constant
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373 * portTICK_PERIOD_MS should be used to convert to real time if this is required.
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375 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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385 uint32_t ulVar = 10UL;
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387 void vATask( void *pvParameters )
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389 QueueHandle_t xQueue1, xQueue2;
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390 struct AMessage *pxMessage;
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392 // Create a queue capable of containing 10 uint32_t values.
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393 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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395 // Create a queue capable of containing 10 pointers to AMessage structures.
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396 // These should be passed by pointer as they contain a lot of data.
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397 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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403 // Send an uint32_t. Wait for 10 ticks for space to become
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404 // available if necessary.
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405 if( xQueueSend( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
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407 // Failed to post the message, even after 10 ticks.
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413 // Send a pointer to a struct AMessage object. Don't block if the
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414 // queue is already full.
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415 pxMessage = & xMessage;
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416 xQueueSend( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
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419 // ... Rest of task code.
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422 * \defgroup xQueueSend xQueueSend
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423 * \ingroup QueueManagement
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425 #define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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430 BaseType_t xQueueOverwrite(
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431 QueueHandle_t xQueue,
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432 const void * pvItemToQueue
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436 * Only for use with queues that have a length of one - so the queue is either
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439 * Post an item on a queue. If the queue is already full then overwrite the
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440 * value held in the queue. The item is queued by copy, not by reference.
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442 * This function must not be called from an interrupt service routine.
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443 * See xQueueOverwriteFromISR () for an alternative which may be used in an ISR.
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445 * @param xQueue The handle of the queue to which the data is being sent.
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447 * @param pvItemToQueue A pointer to the item that is to be placed on the
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448 * queue. The size of the items the queue will hold was defined when the
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449 * queue was created, so this many bytes will be copied from pvItemToQueue
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450 * into the queue storage area.
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452 * @return xQueueOverwrite() is a macro that calls xQueueGenericSend(), and
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453 * therefore has the same return values as xQueueSendToFront(). However, pdPASS
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454 * is the only value that can be returned because xQueueOverwrite() will write
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455 * to the queue even when the queue is already full.
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460 void vFunction( void *pvParameters )
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462 QueueHandle_t xQueue;
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463 uint32_t ulVarToSend, ulValReceived;
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465 // Create a queue to hold one uint32_t value. It is strongly
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466 // recommended *not* to use xQueueOverwrite() on queues that can
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467 // contain more than one value, and doing so will trigger an assertion
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468 // if configASSERT() is defined.
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469 xQueue = xQueueCreate( 1, sizeof( uint32_t ) );
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471 // Write the value 10 to the queue using xQueueOverwrite().
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473 xQueueOverwrite( xQueue, &ulVarToSend );
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475 // Peeking the queue should now return 10, but leave the value 10 in
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476 // the queue. A block time of zero is used as it is known that the
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477 // queue holds a value.
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479 xQueuePeek( xQueue, &ulValReceived, 0 );
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481 if( ulValReceived != 10 )
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483 // Error unless the item was removed by a different task.
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486 // The queue is still full. Use xQueueOverwrite() to overwrite the
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487 // value held in the queue with 100.
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489 xQueueOverwrite( xQueue, &ulVarToSend );
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491 // This time read from the queue, leaving the queue empty once more.
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492 // A block time of 0 is used again.
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493 xQueueReceive( xQueue, &ulValReceived, 0 );
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495 // The value read should be the last value written, even though the
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496 // queue was already full when the value was written.
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497 if( ulValReceived != 100 )
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505 * \defgroup xQueueOverwrite xQueueOverwrite
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506 * \ingroup QueueManagement
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508 #define xQueueOverwrite( xQueue, pvItemToQueue ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), 0, queueOVERWRITE )
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514 BaseType_t xQueueGenericSend(
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515 QueueHandle_t xQueue,
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516 const void * pvItemToQueue,
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517 TickType_t xTicksToWait
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518 BaseType_t xCopyPosition
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522 * It is preferred that the macros xQueueSend(), xQueueSendToFront() and
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523 * xQueueSendToBack() are used in place of calling this function directly.
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525 * Post an item on a queue. The item is queued by copy, not by reference.
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526 * This function must not be called from an interrupt service routine.
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527 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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529 * @param xQueue The handle to the queue on which the item is to be posted.
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531 * @param pvItemToQueue A pointer to the item that is to be placed on the
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532 * queue. The size of the items the queue will hold was defined when the
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533 * queue was created, so this many bytes will be copied from pvItemToQueue
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534 * into the queue storage area.
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536 * @param xTicksToWait The maximum amount of time the task should block
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537 * waiting for space to become available on the queue, should it already
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538 * be full. The call will return immediately if this is set to 0 and the
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539 * queue is full. The time is defined in tick periods so the constant
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540 * portTICK_PERIOD_MS should be used to convert to real time if this is required.
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542 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
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543 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
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544 * at the front of the queue (for high priority messages).
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546 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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556 uint32_t ulVar = 10UL;
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558 void vATask( void *pvParameters )
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560 QueueHandle_t xQueue1, xQueue2;
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561 struct AMessage *pxMessage;
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563 // Create a queue capable of containing 10 uint32_t values.
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564 xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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566 // Create a queue capable of containing 10 pointers to AMessage structures.
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567 // These should be passed by pointer as they contain a lot of data.
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568 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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574 // Send an uint32_t. Wait for 10 ticks for space to become
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575 // available if necessary.
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576 if( xQueueGenericSend( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10, queueSEND_TO_BACK ) != pdPASS )
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578 // Failed to post the message, even after 10 ticks.
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584 // Send a pointer to a struct AMessage object. Don't block if the
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585 // queue is already full.
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586 pxMessage = & xMessage;
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587 xQueueGenericSend( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0, queueSEND_TO_BACK );
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590 // ... Rest of task code.
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593 * \defgroup xQueueSend xQueueSend
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594 * \ingroup QueueManagement
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596 BaseType_t xQueueGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, TickType_t xTicksToWait, const BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
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601 BaseType_t xQueuePeek(
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602 QueueHandle_t xQueue,
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604 TickType_t xTicksToWait
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607 * This is a macro that calls the xQueueGenericReceive() function.
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609 * Receive an item from a queue without removing the item from the queue.
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610 * The item is received by copy so a buffer of adequate size must be
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611 * provided. The number of bytes copied into the buffer was defined when
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612 * the queue was created.
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614 * Successfully received items remain on the queue so will be returned again
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615 * by the next call, or a call to xQueueReceive().
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617 * This macro must not be used in an interrupt service routine. See
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618 * xQueuePeekFromISR() for an alternative that can be called from an interrupt
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621 * @param xQueue The handle to the queue from which the item is to be
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624 * @param pvBuffer Pointer to the buffer into which the received item will
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627 * @param xTicksToWait The maximum amount of time the task should block
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628 * waiting for an item to receive should the queue be empty at the time
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629 * of the call. The time is defined in tick periods so the constant
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630 * portTICK_PERIOD_MS should be used to convert to real time if this is required.
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631 * xQueuePeek() will return immediately if xTicksToWait is 0 and the queue
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634 * @return pdTRUE if an item was successfully received from the queue,
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635 * otherwise pdFALSE.
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645 QueueHandle_t xQueue;
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647 // Task to create a queue and post a value.
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648 void vATask( void *pvParameters )
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650 struct AMessage *pxMessage;
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652 // Create a queue capable of containing 10 pointers to AMessage structures.
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653 // These should be passed by pointer as they contain a lot of data.
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654 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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657 // Failed to create the queue.
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662 // Send a pointer to a struct AMessage object. Don't block if the
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663 // queue is already full.
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664 pxMessage = & xMessage;
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665 xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );
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667 // ... Rest of task code.
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670 // Task to peek the data from the queue.
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671 void vADifferentTask( void *pvParameters )
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673 struct AMessage *pxRxedMessage;
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677 // Peek a message on the created queue. Block for 10 ticks if a
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678 // message is not immediately available.
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679 if( xQueuePeek( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
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681 // pcRxedMessage now points to the struct AMessage variable posted
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682 // by vATask, but the item still remains on the queue.
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686 // ... Rest of task code.
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689 * \defgroup xQueueReceive xQueueReceive
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690 * \ingroup QueueManagement
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692 #define xQueuePeek( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )
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697 BaseType_t xQueuePeekFromISR(
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698 QueueHandle_t xQueue,
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702 * A version of xQueuePeek() that can be called from an interrupt service
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705 * Receive an item from a queue without removing the item from the queue.
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706 * The item is received by copy so a buffer of adequate size must be
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707 * provided. The number of bytes copied into the buffer was defined when
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708 * the queue was created.
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710 * Successfully received items remain on the queue so will be returned again
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711 * by the next call, or a call to xQueueReceive().
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713 * @param xQueue The handle to the queue from which the item is to be
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716 * @param pvBuffer Pointer to the buffer into which the received item will
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719 * @return pdTRUE if an item was successfully received from the queue,
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720 * otherwise pdFALSE.
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722 * \defgroup xQueuePeekFromISR xQueuePeekFromISR
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723 * \ingroup QueueManagement
\r
725 BaseType_t xQueuePeekFromISR( QueueHandle_t xQueue, void * const pvBuffer ) PRIVILEGED_FUNCTION;
\r
730 BaseType_t xQueueReceive(
\r
731 QueueHandle_t xQueue,
\r
733 TickType_t xTicksToWait
\r
736 * This is a macro that calls the xQueueGenericReceive() function.
\r
738 * Receive an item from a queue. The item is received by copy so a buffer of
\r
739 * adequate size must be provided. The number of bytes copied into the buffer
\r
740 * was defined when the queue was created.
\r
742 * Successfully received items are removed from the queue.
\r
744 * This function must not be used in an interrupt service routine. See
\r
745 * xQueueReceiveFromISR for an alternative that can.
\r
747 * @param xQueue The handle to the queue from which the item is to be
\r
750 * @param pvBuffer Pointer to the buffer into which the received item will
\r
753 * @param xTicksToWait The maximum amount of time the task should block
\r
754 * waiting for an item to receive should the queue be empty at the time
\r
755 * of the call. xQueueReceive() will return immediately if xTicksToWait
\r
756 * is zero and the queue is empty. The time is defined in tick periods so the
\r
757 * constant portTICK_PERIOD_MS should be used to convert to real time if this is
\r
760 * @return pdTRUE if an item was successfully received from the queue,
\r
761 * otherwise pdFALSE.
\r
771 QueueHandle_t xQueue;
\r
773 // Task to create a queue and post a value.
\r
774 void vATask( void *pvParameters )
\r
776 struct AMessage *pxMessage;
\r
778 // Create a queue capable of containing 10 pointers to AMessage structures.
\r
779 // These should be passed by pointer as they contain a lot of data.
\r
780 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
\r
783 // Failed to create the queue.
\r
788 // Send a pointer to a struct AMessage object. Don't block if the
\r
789 // queue is already full.
\r
790 pxMessage = & xMessage;
\r
791 xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );
\r
793 // ... Rest of task code.
\r
796 // Task to receive from the queue.
\r
797 void vADifferentTask( void *pvParameters )
\r
799 struct AMessage *pxRxedMessage;
\r
803 // Receive a message on the created queue. Block for 10 ticks if a
\r
804 // message is not immediately available.
\r
805 if( xQueueReceive( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
\r
807 // pcRxedMessage now points to the struct AMessage variable posted
\r
812 // ... Rest of task code.
\r
815 * \defgroup xQueueReceive xQueueReceive
\r
816 * \ingroup QueueManagement
\r
818 #define xQueueReceive( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
\r
824 BaseType_t xQueueGenericReceive(
\r
825 QueueHandle_t xQueue,
\r
827 TickType_t xTicksToWait
\r
828 BaseType_t xJustPeek
\r
831 * It is preferred that the macro xQueueReceive() be used rather than calling
\r
832 * this function directly.
\r
834 * Receive an item from a queue. The item is received by copy so a buffer of
\r
835 * adequate size must be provided. The number of bytes copied into the buffer
\r
836 * was defined when the queue was created.
\r
838 * This function must not be used in an interrupt service routine. See
\r
839 * xQueueReceiveFromISR for an alternative that can.
\r
841 * @param xQueue The handle to the queue from which the item is to be
\r
844 * @param pvBuffer Pointer to the buffer into which the received item will
\r
847 * @param xTicksToWait The maximum amount of time the task should block
\r
848 * waiting for an item to receive should the queue be empty at the time
\r
849 * of the call. The time is defined in tick periods so the constant
\r
850 * portTICK_PERIOD_MS should be used to convert to real time if this is required.
\r
851 * xQueueGenericReceive() will return immediately if the queue is empty and
\r
852 * xTicksToWait is 0.
\r
854 * @param xJustPeek When set to true, the item received from the queue is not
\r
855 * actually removed from the queue - meaning a subsequent call to
\r
856 * xQueueReceive() will return the same item. When set to false, the item
\r
857 * being received from the queue is also removed from the queue.
\r
859 * @return pdTRUE if an item was successfully received from the queue,
\r
860 * otherwise pdFALSE.
\r
870 QueueHandle_t xQueue;
\r
872 // Task to create a queue and post a value.
\r
873 void vATask( void *pvParameters )
\r
875 struct AMessage *pxMessage;
\r
877 // Create a queue capable of containing 10 pointers to AMessage structures.
\r
878 // These should be passed by pointer as they contain a lot of data.
\r
879 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
\r
882 // Failed to create the queue.
\r
887 // Send a pointer to a struct AMessage object. Don't block if the
\r
888 // queue is already full.
\r
889 pxMessage = & xMessage;
\r
890 xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );
\r
892 // ... Rest of task code.
\r
895 // Task to receive from the queue.
\r
896 void vADifferentTask( void *pvParameters )
\r
898 struct AMessage *pxRxedMessage;
\r
902 // Receive a message on the created queue. Block for 10 ticks if a
\r
903 // message is not immediately available.
\r
904 if( xQueueGenericReceive( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
\r
906 // pcRxedMessage now points to the struct AMessage variable posted
\r
911 // ... Rest of task code.
\r
914 * \defgroup xQueueReceive xQueueReceive
\r
915 * \ingroup QueueManagement
\r
917 BaseType_t xQueueGenericReceive( QueueHandle_t xQueue, void * const pvBuffer, TickType_t xTicksToWait, const BaseType_t xJustPeek ) PRIVILEGED_FUNCTION;
\r
921 * <pre>UBaseType_t uxQueueMessagesWaiting( const QueueHandle_t xQueue );</pre>
\r
923 * Return the number of messages stored in a queue.
\r
925 * @param xQueue A handle to the queue being queried.
\r
927 * @return The number of messages available in the queue.
\r
929 * \defgroup uxQueueMessagesWaiting uxQueueMessagesWaiting
\r
930 * \ingroup QueueManagement
\r
932 UBaseType_t uxQueueMessagesWaiting( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
936 * <pre>UBaseType_t uxQueueSpacesAvailable( const QueueHandle_t xQueue );</pre>
\r
938 * Return the number of free spaces available in a queue. This is equal to the
\r
939 * number of items that can be sent to the queue before the queue becomes full
\r
940 * if no items are removed.
\r
942 * @param xQueue A handle to the queue being queried.
\r
944 * @return The number of spaces available in the queue.
\r
946 * \defgroup uxQueueMessagesWaiting uxQueueMessagesWaiting
\r
947 * \ingroup QueueManagement
\r
949 UBaseType_t uxQueueSpacesAvailable( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
953 * <pre>void vQueueDelete( QueueHandle_t xQueue );</pre>
\r
955 * Delete a queue - freeing all the memory allocated for storing of items
\r
956 * placed on the queue.
\r
958 * @param xQueue A handle to the queue to be deleted.
\r
960 * \defgroup vQueueDelete vQueueDelete
\r
961 * \ingroup QueueManagement
\r
963 void vQueueDelete( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
968 BaseType_t xQueueSendToFrontFromISR(
\r
969 QueueHandle_t xQueue,
\r
970 const void *pvItemToQueue,
\r
971 BaseType_t *pxHigherPriorityTaskWoken
\r
975 * This is a macro that calls xQueueGenericSendFromISR().
\r
977 * Post an item to the front of a queue. It is safe to use this macro from
\r
978 * within an interrupt service routine.
\r
980 * Items are queued by copy not reference so it is preferable to only
\r
981 * queue small items, especially when called from an ISR. In most cases
\r
982 * it would be preferable to store a pointer to the item being queued.
\r
984 * @param xQueue The handle to the queue on which the item is to be posted.
\r
986 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
987 * queue. The size of the items the queue will hold was defined when the
\r
988 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
989 * into the queue storage area.
\r
991 * @param pxHigherPriorityTaskWoken xQueueSendToFrontFromISR() will set
\r
992 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
993 * to unblock, and the unblocked task has a priority higher than the currently
\r
994 * running task. If xQueueSendToFromFromISR() sets this value to pdTRUE then
\r
995 * a context switch should be requested before the interrupt is exited.
\r
997 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1000 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1003 void vBufferISR( void )
\r
1006 BaseType_t xHigherPrioritTaskWoken;
\r
1008 // We have not woken a task at the start of the ISR.
\r
1009 xHigherPriorityTaskWoken = pdFALSE;
\r
1011 // Loop until the buffer is empty.
\r
1014 // Obtain a byte from the buffer.
\r
1015 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1018 xQueueSendToFrontFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
1020 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1022 // Now the buffer is empty we can switch context if necessary.
\r
1023 if( xHigherPriorityTaskWoken )
\r
1030 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1031 * \ingroup QueueManagement
\r
1033 #define xQueueSendToFrontFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_FRONT )
\r
1039 BaseType_t xQueueSendToBackFromISR(
\r
1040 QueueHandle_t xQueue,
\r
1041 const void *pvItemToQueue,
\r
1042 BaseType_t *pxHigherPriorityTaskWoken
\r
1046 * This is a macro that calls xQueueGenericSendFromISR().
\r
1048 * Post an item to the back of a queue. It is safe to use this macro from
\r
1049 * within an interrupt service routine.
\r
1051 * Items are queued by copy not reference so it is preferable to only
\r
1052 * queue small items, especially when called from an ISR. In most cases
\r
1053 * it would be preferable to store a pointer to the item being queued.
\r
1055 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1057 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1058 * queue. The size of the items the queue will hold was defined when the
\r
1059 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1060 * into the queue storage area.
\r
1062 * @param pxHigherPriorityTaskWoken xQueueSendToBackFromISR() will set
\r
1063 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1064 * to unblock, and the unblocked task has a priority higher than the currently
\r
1065 * running task. If xQueueSendToBackFromISR() sets this value to pdTRUE then
\r
1066 * a context switch should be requested before the interrupt is exited.
\r
1068 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1071 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1074 void vBufferISR( void )
\r
1077 BaseType_t xHigherPriorityTaskWoken;
\r
1079 // We have not woken a task at the start of the ISR.
\r
1080 xHigherPriorityTaskWoken = pdFALSE;
\r
1082 // Loop until the buffer is empty.
\r
1085 // Obtain a byte from the buffer.
\r
1086 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1089 xQueueSendToBackFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
1091 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1093 // Now the buffer is empty we can switch context if necessary.
\r
1094 if( xHigherPriorityTaskWoken )
\r
1101 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1102 * \ingroup QueueManagement
\r
1104 #define xQueueSendToBackFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
\r
1109 BaseType_t xQueueOverwriteFromISR(
\r
1110 QueueHandle_t xQueue,
\r
1111 const void * pvItemToQueue,
\r
1112 BaseType_t *pxHigherPriorityTaskWoken
\r
1116 * A version of xQueueOverwrite() that can be used in an interrupt service
\r
1119 * Only for use with queues that can hold a single item - so the queue is either
\r
1122 * Post an item on a queue. If the queue is already full then overwrite the
\r
1123 * value held in the queue. The item is queued by copy, not by reference.
\r
1125 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1127 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1128 * queue. The size of the items the queue will hold was defined when the
\r
1129 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1130 * into the queue storage area.
\r
1132 * @param pxHigherPriorityTaskWoken xQueueOverwriteFromISR() will set
\r
1133 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1134 * to unblock, and the unblocked task has a priority higher than the currently
\r
1135 * running task. If xQueueOverwriteFromISR() sets this value to pdTRUE then
\r
1136 * a context switch should be requested before the interrupt is exited.
\r
1138 * @return xQueueOverwriteFromISR() is a macro that calls
\r
1139 * xQueueGenericSendFromISR(), and therefore has the same return values as
\r
1140 * xQueueSendToFrontFromISR(). However, pdPASS is the only value that can be
\r
1141 * returned because xQueueOverwriteFromISR() will write to the queue even when
\r
1142 * the queue is already full.
\r
1147 QueueHandle_t xQueue;
\r
1149 void vFunction( void *pvParameters )
\r
1151 // Create a queue to hold one uint32_t value. It is strongly
\r
1152 // recommended *not* to use xQueueOverwriteFromISR() on queues that can
\r
1153 // contain more than one value, and doing so will trigger an assertion
\r
1154 // if configASSERT() is defined.
\r
1155 xQueue = xQueueCreate( 1, sizeof( uint32_t ) );
\r
1158 void vAnInterruptHandler( void )
\r
1160 // xHigherPriorityTaskWoken must be set to pdFALSE before it is used.
\r
1161 BaseType_t xHigherPriorityTaskWoken = pdFALSE;
\r
1162 uint32_t ulVarToSend, ulValReceived;
\r
1164 // Write the value 10 to the queue using xQueueOverwriteFromISR().
\r
1166 xQueueOverwriteFromISR( xQueue, &ulVarToSend, &xHigherPriorityTaskWoken );
\r
1168 // The queue is full, but calling xQueueOverwriteFromISR() again will still
\r
1169 // pass because the value held in the queue will be overwritten with the
\r
1171 ulVarToSend = 100;
\r
1172 xQueueOverwriteFromISR( xQueue, &ulVarToSend, &xHigherPriorityTaskWoken );
\r
1174 // Reading from the queue will now return 100.
\r
1178 if( xHigherPrioritytaskWoken == pdTRUE )
\r
1180 // Writing to the queue caused a task to unblock and the unblocked task
\r
1181 // has a priority higher than or equal to the priority of the currently
\r
1182 // executing task (the task this interrupt interrupted). Perform a context
\r
1183 // switch so this interrupt returns directly to the unblocked task.
\r
1184 portYIELD_FROM_ISR(); // or portEND_SWITCHING_ISR() depending on the port.
\r
1188 * \defgroup xQueueOverwriteFromISR xQueueOverwriteFromISR
\r
1189 * \ingroup QueueManagement
\r
1191 #define xQueueOverwriteFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueOVERWRITE )
\r
1196 BaseType_t xQueueSendFromISR(
\r
1197 QueueHandle_t xQueue,
\r
1198 const void *pvItemToQueue,
\r
1199 BaseType_t *pxHigherPriorityTaskWoken
\r
1203 * This is a macro that calls xQueueGenericSendFromISR(). It is included
\r
1204 * for backward compatibility with versions of FreeRTOS.org that did not
\r
1205 * include the xQueueSendToBackFromISR() and xQueueSendToFrontFromISR()
\r
1208 * Post an item to the back of a queue. It is safe to use this function from
\r
1209 * within an interrupt service routine.
\r
1211 * Items are queued by copy not reference so it is preferable to only
\r
1212 * queue small items, especially when called from an ISR. In most cases
\r
1213 * it would be preferable to store a pointer to the item being queued.
\r
1215 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1217 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1218 * queue. The size of the items the queue will hold was defined when the
\r
1219 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1220 * into the queue storage area.
\r
1222 * @param pxHigherPriorityTaskWoken xQueueSendFromISR() will set
\r
1223 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1224 * to unblock, and the unblocked task has a priority higher than the currently
\r
1225 * running task. If xQueueSendFromISR() sets this value to pdTRUE then
\r
1226 * a context switch should be requested before the interrupt is exited.
\r
1228 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1231 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1234 void vBufferISR( void )
\r
1237 BaseType_t xHigherPriorityTaskWoken;
\r
1239 // We have not woken a task at the start of the ISR.
\r
1240 xHigherPriorityTaskWoken = pdFALSE;
\r
1242 // Loop until the buffer is empty.
\r
1245 // Obtain a byte from the buffer.
\r
1246 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1249 xQueueSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
1251 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1253 // Now the buffer is empty we can switch context if necessary.
\r
1254 if( xHigherPriorityTaskWoken )
\r
1256 // Actual macro used here is port specific.
\r
1257 portYIELD_FROM_ISR ();
\r
1262 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1263 * \ingroup QueueManagement
\r
1265 #define xQueueSendFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
\r
1270 BaseType_t xQueueGenericSendFromISR(
\r
1271 QueueHandle_t xQueue,
\r
1272 const void *pvItemToQueue,
\r
1273 BaseType_t *pxHigherPriorityTaskWoken,
\r
1274 BaseType_t xCopyPosition
\r
1278 * It is preferred that the macros xQueueSendFromISR(),
\r
1279 * xQueueSendToFrontFromISR() and xQueueSendToBackFromISR() be used in place
\r
1280 * of calling this function directly. xQueueGiveFromISR() is an
\r
1281 * equivalent for use by semaphores that don't actually copy any data.
\r
1283 * Post an item on a queue. It is safe to use this function from within an
\r
1284 * interrupt service routine.
\r
1286 * Items are queued by copy not reference so it is preferable to only
\r
1287 * queue small items, especially when called from an ISR. In most cases
\r
1288 * it would be preferable to store a pointer to the item being queued.
\r
1290 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1292 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1293 * queue. The size of the items the queue will hold was defined when the
\r
1294 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1295 * into the queue storage area.
\r
1297 * @param pxHigherPriorityTaskWoken xQueueGenericSendFromISR() will set
\r
1298 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1299 * to unblock, and the unblocked task has a priority higher than the currently
\r
1300 * running task. If xQueueGenericSendFromISR() sets this value to pdTRUE then
\r
1301 * a context switch should be requested before the interrupt is exited.
\r
1303 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
\r
1304 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
\r
1305 * at the front of the queue (for high priority messages).
\r
1307 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1310 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1313 void vBufferISR( void )
\r
1316 BaseType_t xHigherPriorityTaskWokenByPost;
\r
1318 // We have not woken a task at the start of the ISR.
\r
1319 xHigherPriorityTaskWokenByPost = pdFALSE;
\r
1321 // Loop until the buffer is empty.
\r
1324 // Obtain a byte from the buffer.
\r
1325 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1327 // Post each byte.
\r
1328 xQueueGenericSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWokenByPost, queueSEND_TO_BACK );
\r
1330 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1332 // Now the buffer is empty we can switch context if necessary. Note that the
\r
1333 // name of the yield function required is port specific.
\r
1334 if( xHigherPriorityTaskWokenByPost )
\r
1336 taskYIELD_YIELD_FROM_ISR();
\r
1341 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1342 * \ingroup QueueManagement
\r
1344 BaseType_t xQueueGenericSendFromISR( QueueHandle_t xQueue, const void * const pvItemToQueue, BaseType_t * const pxHigherPriorityTaskWoken, const BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
\r
1345 BaseType_t xQueueGiveFromISR( QueueHandle_t xQueue, BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
\r
1350 BaseType_t xQueueReceiveFromISR(
\r
1351 QueueHandle_t xQueue,
\r
1353 BaseType_t *pxTaskWoken
\r
1357 * Receive an item from a queue. It is safe to use this function from within an
\r
1358 * interrupt service routine.
\r
1360 * @param xQueue The handle to the queue from which the item is to be
\r
1363 * @param pvBuffer Pointer to the buffer into which the received item will
\r
1366 * @param pxTaskWoken A task may be blocked waiting for space to become
\r
1367 * available on the queue. If xQueueReceiveFromISR causes such a task to
\r
1368 * unblock *pxTaskWoken will get set to pdTRUE, otherwise *pxTaskWoken will
\r
1369 * remain unchanged.
\r
1371 * @return pdTRUE if an item was successfully received from the queue,
\r
1372 * otherwise pdFALSE.
\r
1377 QueueHandle_t xQueue;
\r
1379 // Function to create a queue and post some values.
\r
1380 void vAFunction( void *pvParameters )
\r
1382 char cValueToPost;
\r
1383 const TickType_t xTicksToWait = ( TickType_t )0xff;
\r
1385 // Create a queue capable of containing 10 characters.
\r
1386 xQueue = xQueueCreate( 10, sizeof( char ) );
\r
1389 // Failed to create the queue.
\r
1394 // Post some characters that will be used within an ISR. If the queue
\r
1395 // is full then this task will block for xTicksToWait ticks.
\r
1396 cValueToPost = 'a';
\r
1397 xQueueSend( xQueue, ( void * ) &cValueToPost, xTicksToWait );
\r
1398 cValueToPost = 'b';
\r
1399 xQueueSend( xQueue, ( void * ) &cValueToPost, xTicksToWait );
\r
1401 // ... keep posting characters ... this task may block when the queue
\r
1404 cValueToPost = 'c';
\r
1405 xQueueSend( xQueue, ( void * ) &cValueToPost, xTicksToWait );
\r
1408 // ISR that outputs all the characters received on the queue.
\r
1409 void vISR_Routine( void )
\r
1411 BaseType_t xTaskWokenByReceive = pdFALSE;
\r
1414 while( xQueueReceiveFromISR( xQueue, ( void * ) &cRxedChar, &xTaskWokenByReceive) )
\r
1416 // A character was received. Output the character now.
\r
1417 vOutputCharacter( cRxedChar );
\r
1419 // If removing the character from the queue woke the task that was
\r
1420 // posting onto the queue cTaskWokenByReceive will have been set to
\r
1421 // pdTRUE. No matter how many times this loop iterates only one
\r
1422 // task will be woken.
\r
1425 if( cTaskWokenByPost != ( char ) pdFALSE;
\r
1431 * \defgroup xQueueReceiveFromISR xQueueReceiveFromISR
\r
1432 * \ingroup QueueManagement
\r
1434 BaseType_t xQueueReceiveFromISR( QueueHandle_t xQueue, void * const pvBuffer, BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
\r
1437 * Utilities to query queues that are safe to use from an ISR. These utilities
\r
1438 * should be used only from witin an ISR, or within a critical section.
\r
1440 BaseType_t xQueueIsQueueEmptyFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1441 BaseType_t xQueueIsQueueFullFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1442 UBaseType_t uxQueueMessagesWaitingFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1446 * xQueueAltGenericSend() is an alternative version of xQueueGenericSend().
\r
1447 * Likewise xQueueAltGenericReceive() is an alternative version of
\r
1448 * xQueueGenericReceive().
\r
1450 * The source code that implements the alternative (Alt) API is much
\r
1451 * simpler because it executes everything from within a critical section.
\r
1452 * This is the approach taken by many other RTOSes, but FreeRTOS.org has the
\r
1453 * preferred fully featured API too. The fully featured API has more
\r
1454 * complex code that takes longer to execute, but makes much less use of
\r
1455 * critical sections. Therefore the alternative API sacrifices interrupt
\r
1456 * responsiveness to gain execution speed, whereas the fully featured API
\r
1457 * sacrifices execution speed to ensure better interrupt responsiveness.
\r
1459 BaseType_t xQueueAltGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, TickType_t xTicksToWait, BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
\r
1460 BaseType_t xQueueAltGenericReceive( QueueHandle_t xQueue, void * const pvBuffer, TickType_t xTicksToWait, BaseType_t xJustPeeking ) PRIVILEGED_FUNCTION;
\r
1461 #define xQueueAltSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
\r
1462 #define xQueueAltSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
\r
1463 #define xQueueAltReceive( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
\r
1464 #define xQueueAltPeek( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )
\r
1467 * The functions defined above are for passing data to and from tasks. The
\r
1468 * functions below are the equivalents for passing data to and from
\r
1471 * These functions are called from the co-routine macro implementation and
\r
1472 * should not be called directly from application code. Instead use the macro
\r
1473 * wrappers defined within croutine.h.
\r
1475 BaseType_t xQueueCRSendFromISR( QueueHandle_t xQueue, const void *pvItemToQueue, BaseType_t xCoRoutinePreviouslyWoken );
\r
1476 BaseType_t xQueueCRReceiveFromISR( QueueHandle_t xQueue, void *pvBuffer, BaseType_t *pxTaskWoken );
\r
1477 BaseType_t xQueueCRSend( QueueHandle_t xQueue, const void *pvItemToQueue, TickType_t xTicksToWait );
\r
1478 BaseType_t xQueueCRReceive( QueueHandle_t xQueue, void *pvBuffer, TickType_t xTicksToWait );
\r
1481 * For internal use only. Use xSemaphoreCreateMutex(),
\r
1482 * xSemaphoreCreateCounting() or xSemaphoreGetMutexHolder() instead of calling
\r
1483 * these functions directly.
\r
1485 QueueHandle_t xQueueCreateMutex( const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;
\r
1486 QueueHandle_t xQueueCreateCountingSemaphore( const UBaseType_t uxMaxCount, const UBaseType_t uxInitialCount ) PRIVILEGED_FUNCTION;
\r
1487 void* xQueueGetMutexHolder( QueueHandle_t xSemaphore ) PRIVILEGED_FUNCTION;
\r
1490 * For internal use only. Use xSemaphoreTakeMutexRecursive() or
\r
1491 * xSemaphoreGiveMutexRecursive() instead of calling these functions directly.
\r
1493 BaseType_t xQueueTakeMutexRecursive( QueueHandle_t xMutex, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
\r
1494 BaseType_t xQueueGiveMutexRecursive( QueueHandle_t pxMutex ) PRIVILEGED_FUNCTION;
\r
1497 * Reset a queue back to its original empty state. The return value is now
\r
1498 * obsolete and is always set to pdPASS.
\r
1500 #define xQueueReset( xQueue ) xQueueGenericReset( xQueue, pdFALSE )
\r
1503 * The registry is provided as a means for kernel aware debuggers to
\r
1504 * locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
\r
1505 * a queue, semaphore or mutex handle to the registry if you want the handle
\r
1506 * to be available to a kernel aware debugger. If you are not using a kernel
\r
1507 * aware debugger then this function can be ignored.
\r
1509 * configQUEUE_REGISTRY_SIZE defines the maximum number of handles the
\r
1510 * registry can hold. configQUEUE_REGISTRY_SIZE must be greater than 0
\r
1511 * within FreeRTOSConfig.h for the registry to be available. Its value
\r
1512 * does not effect the number of queues, semaphores and mutexes that can be
\r
1513 * created - just the number that the registry can hold.
\r
1515 * @param xQueue The handle of the queue being added to the registry. This
\r
1516 * is the handle returned by a call to xQueueCreate(). Semaphore and mutex
\r
1517 * handles can also be passed in here.
\r
1519 * @param pcName The name to be associated with the handle. This is the
\r
1520 * name that the kernel aware debugger will display. The queue registry only
\r
1521 * stores a pointer to the string - so the string must be persistent (global or
\r
1522 * preferably in ROM/Flash), not on the stack.
\r
1524 #if( configQUEUE_REGISTRY_SIZE > 0 )
\r
1525 void vQueueAddToRegistry( QueueHandle_t xQueue, const char *pcName ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
\r
1529 * The registry is provided as a means for kernel aware debuggers to
\r
1530 * locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
\r
1531 * a queue, semaphore or mutex handle to the registry if you want the handle
\r
1532 * to be available to a kernel aware debugger, and vQueueUnregisterQueue() to
\r
1533 * remove the queue, semaphore or mutex from the register. If you are not using
\r
1534 * a kernel aware debugger then this function can be ignored.
\r
1536 * @param xQueue The handle of the queue being removed from the registry.
\r
1538 #if( configQUEUE_REGISTRY_SIZE > 0 )
\r
1539 void vQueueUnregisterQueue( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1543 * The registry is provided as a means for kernel aware debuggers to
\r
1544 * locate queues, semaphores and mutexes. Call pcQueueGetQueueName() to look
\r
1545 * up and return the name of a queue in the queue registry from the queue's
\r
1548 * @param xQueue The handle of the queue the name of which will be returned.
\r
1549 * @return If the queue is in the registry then a pointer to the name of the
\r
1550 * queue is returned. If the queue is not in the registry then NULL is
\r
1553 #if( configQUEUE_REGISTRY_SIZE > 0 )
\r
1554 const char *pcQueueGetQueueName( QueueHandle_t xQueue );
\r
1558 * Generic version of the queue creation function, which is in turn called by
\r
1559 * any queue, semaphore or mutex creation function or macro.
\r
1561 QueueHandle_t xQueueGenericCreate( const UBaseType_t uxQueueLength, const UBaseType_t uxItemSize, uint8_t *pucQueueStorage, StaticQueue_t *pxStaticQueue, const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;
\r
1564 * Queue sets provide a mechanism to allow a task to block (pend) on a read
\r
1565 * operation from multiple queues or semaphores simultaneously.
\r
1567 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1570 * A queue set must be explicitly created using a call to xQueueCreateSet()
\r
1571 * before it can be used. Once created, standard FreeRTOS queues and semaphores
\r
1572 * can be added to the set using calls to xQueueAddToSet().
\r
1573 * xQueueSelectFromSet() is then used to determine which, if any, of the queues
\r
1574 * or semaphores contained in the set is in a state where a queue read or
\r
1575 * semaphore take operation would be successful.
\r
1577 * Note 1: See the documentation on http://wwwFreeRTOS.org/RTOS-queue-sets.html
\r
1578 * for reasons why queue sets are very rarely needed in practice as there are
\r
1579 * simpler methods of blocking on multiple objects.
\r
1581 * Note 2: Blocking on a queue set that contains a mutex will not cause the
\r
1582 * mutex holder to inherit the priority of the blocked task.
\r
1584 * Note 3: An additional 4 bytes of RAM is required for each space in a every
\r
1585 * queue added to a queue set. Therefore counting semaphores that have a high
\r
1586 * maximum count value should not be added to a queue set.
\r
1588 * Note 4: A receive (in the case of a queue) or take (in the case of a
\r
1589 * semaphore) operation must not be performed on a member of a queue set unless
\r
1590 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
\r
1592 * @param uxEventQueueLength Queue sets store events that occur on
\r
1593 * the queues and semaphores contained in the set. uxEventQueueLength specifies
\r
1594 * the maximum number of events that can be queued at once. To be absolutely
\r
1595 * certain that events are not lost uxEventQueueLength should be set to the
\r
1596 * total sum of the length of the queues added to the set, where binary
\r
1597 * semaphores and mutexes have a length of 1, and counting semaphores have a
\r
1598 * length set by their maximum count value. Examples:
\r
1599 * + If a queue set is to hold a queue of length 5, another queue of length 12,
\r
1600 * and a binary semaphore, then uxEventQueueLength should be set to
\r
1601 * (5 + 12 + 1), or 18.
\r
1602 * + If a queue set is to hold three binary semaphores then uxEventQueueLength
\r
1603 * should be set to (1 + 1 + 1 ), or 3.
\r
1604 * + If a queue set is to hold a counting semaphore that has a maximum count of
\r
1605 * 5, and a counting semaphore that has a maximum count of 3, then
\r
1606 * uxEventQueueLength should be set to (5 + 3), or 8.
\r
1608 * @return If the queue set is created successfully then a handle to the created
\r
1609 * queue set is returned. Otherwise NULL is returned.
\r
1611 QueueSetHandle_t xQueueCreateSet( const UBaseType_t uxEventQueueLength ) PRIVILEGED_FUNCTION;
\r
1614 * Adds a queue or semaphore to a queue set that was previously created by a
\r
1615 * call to xQueueCreateSet().
\r
1617 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1620 * Note 1: A receive (in the case of a queue) or take (in the case of a
\r
1621 * semaphore) operation must not be performed on a member of a queue set unless
\r
1622 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
\r
1624 * @param xQueueOrSemaphore The handle of the queue or semaphore being added to
\r
1625 * the queue set (cast to an QueueSetMemberHandle_t type).
\r
1627 * @param xQueueSet The handle of the queue set to which the queue or semaphore
\r
1630 * @return If the queue or semaphore was successfully added to the queue set
\r
1631 * then pdPASS is returned. If the queue could not be successfully added to the
\r
1632 * queue set because it is already a member of a different queue set then pdFAIL
\r
1635 BaseType_t xQueueAddToSet( QueueSetMemberHandle_t xQueueOrSemaphore, QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
\r
1638 * Removes a queue or semaphore from a queue set. A queue or semaphore can only
\r
1639 * be removed from a set if the queue or semaphore is empty.
\r
1641 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1644 * @param xQueueOrSemaphore The handle of the queue or semaphore being removed
\r
1645 * from the queue set (cast to an QueueSetMemberHandle_t type).
\r
1647 * @param xQueueSet The handle of the queue set in which the queue or semaphore
\r
1650 * @return If the queue or semaphore was successfully removed from the queue set
\r
1651 * then pdPASS is returned. If the queue was not in the queue set, or the
\r
1652 * queue (or semaphore) was not empty, then pdFAIL is returned.
\r
1654 BaseType_t xQueueRemoveFromSet( QueueSetMemberHandle_t xQueueOrSemaphore, QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
\r
1657 * xQueueSelectFromSet() selects from the members of a queue set a queue or
\r
1658 * semaphore that either contains data (in the case of a queue) or is available
\r
1659 * to take (in the case of a semaphore). xQueueSelectFromSet() effectively
\r
1660 * allows a task to block (pend) on a read operation on all the queues and
\r
1661 * semaphores in a queue set simultaneously.
\r
1663 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1666 * Note 1: See the documentation on http://wwwFreeRTOS.org/RTOS-queue-sets.html
\r
1667 * for reasons why queue sets are very rarely needed in practice as there are
\r
1668 * simpler methods of blocking on multiple objects.
\r
1670 * Note 2: Blocking on a queue set that contains a mutex will not cause the
\r
1671 * mutex holder to inherit the priority of the blocked task.
\r
1673 * Note 3: A receive (in the case of a queue) or take (in the case of a
\r
1674 * semaphore) operation must not be performed on a member of a queue set unless
\r
1675 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
\r
1677 * @param xQueueSet The queue set on which the task will (potentially) block.
\r
1679 * @param xTicksToWait The maximum time, in ticks, that the calling task will
\r
1680 * remain in the Blocked state (with other tasks executing) to wait for a member
\r
1681 * of the queue set to be ready for a successful queue read or semaphore take
\r
1684 * @return xQueueSelectFromSet() will return the handle of a queue (cast to
\r
1685 * a QueueSetMemberHandle_t type) contained in the queue set that contains data,
\r
1686 * or the handle of a semaphore (cast to a QueueSetMemberHandle_t type) contained
\r
1687 * in the queue set that is available, or NULL if no such queue or semaphore
\r
1688 * exists before before the specified block time expires.
\r
1690 QueueSetMemberHandle_t xQueueSelectFromSet( QueueSetHandle_t xQueueSet, const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
\r
1693 * A version of xQueueSelectFromSet() that can be used from an ISR.
\r
1695 QueueSetMemberHandle_t xQueueSelectFromSetFromISR( QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
\r
1697 /* Not public API functions. */
\r
1698 void vQueueWaitForMessageRestricted( QueueHandle_t xQueue, TickType_t xTicksToWait, const BaseType_t xWaitIndefinitely ) PRIVILEGED_FUNCTION;
\r
1699 BaseType_t xQueueGenericReset( QueueHandle_t xQueue, BaseType_t xNewQueue ) PRIVILEGED_FUNCTION;
\r
1700 void vQueueSetQueueNumber( QueueHandle_t xQueue, UBaseType_t uxQueueNumber ) PRIVILEGED_FUNCTION;
\r
1701 UBaseType_t uxQueueGetQueueNumber( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1702 uint8_t ucQueueGetQueueType( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
\r
1705 #ifdef __cplusplus
\r
1709 #endif /* QUEUE_H */
\r