2 FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.
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4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
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5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS tutorial books are available in pdf and paperback. *
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10 * Complete, revised, and edited pdf reference manuals are also *
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13 * Purchasing FreeRTOS documentation will not only help you, by *
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14 * ensuring you get running as quickly as possible and with an *
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15 * in-depth knowledge of how to use FreeRTOS, it will also help *
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16 * the FreeRTOS project to continue with its mission of providing *
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17 * professional grade, cross platform, de facto standard solutions *
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18 * for microcontrollers - completely free of charge! *
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20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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22 * Thank you for using FreeRTOS, and thank you for your support! *
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24 ***************************************************************************
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27 This file is part of the FreeRTOS distribution.
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29 FreeRTOS is free software; you can redistribute it and/or modify it under
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30 the terms of the GNU General Public License (version 2) as published by the
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31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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32 >>>NOTE<<< The modification to the GPL is included to allow you to
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33 distribute a combined work that includes FreeRTOS without being obliged to
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34 provide the source code for proprietary components outside of the FreeRTOS
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35 kernel. FreeRTOS is distributed in the hope that it will be useful, but
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36 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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37 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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38 more details. You should have received a copy of the GNU General Public
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39 License and the FreeRTOS license exception along with FreeRTOS; if not it
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40 can be viewed here: http://www.freertos.org/a00114.html and also obtained
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41 by writing to Richard Barry, contact details for whom are available on the
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46 ***************************************************************************
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48 * Having a problem? Start by reading the FAQ "My application does *
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49 * not run, what could be wrong?" *
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51 * http://www.FreeRTOS.org/FAQHelp.html *
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53 ***************************************************************************
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56 http://www.FreeRTOS.org - Documentation, training, latest versions, license
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57 and contact details.
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59 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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60 including FreeRTOS+Trace - an indispensable productivity tool.
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62 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
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63 the code with commercial support, indemnification, and middleware, under
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64 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
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65 provide a safety engineered and independently SIL3 certified version under
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66 the SafeRTOS brand: http://www.SafeRTOS.com.
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73 #ifndef INC_FREERTOS_H
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74 #error "include FreeRTOS.h" must appear in source files before "include queue.h"
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82 #include "mpu_wrappers.h"
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85 * Type by which queues are referenced. For example, a call to xQueueCreate()
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86 * returns an xQueueHandle variable that can then be used as a parameter to
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87 * xQueueSend(), xQueueReceive(), etc.
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89 typedef void * xQueueHandle;
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92 * Type by which queue sets are referenced. For example, a call to
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93 * xQueueSetCreate() returns an xQueueSet variable that can then be used as a
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94 * parameter to xQueueReadMultiple(), xQueueAddToQueueSet(), etc.
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96 typedef void * xQueueSetHandle;
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98 /* For internal use only. */
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99 #define queueSEND_TO_BACK ( 0 )
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100 #define queueSEND_TO_FRONT ( 1 )
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102 /* For internal use only. These definitions *must* match those in queue.c. */
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103 #define queueQUEUE_TYPE_BASE ( 0U )
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104 #define queueQUEUE_TYPE_MUTEX ( 1U )
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105 #define queueQUEUE_TYPE_COUNTING_SEMAPHORE ( 2U )
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106 #define queueQUEUE_TYPE_BINARY_SEMAPHORE ( 3U )
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107 #define queueQUEUE_TYPE_RECURSIVE_MUTEX ( 4U )
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112 xQueueHandle xQueueCreate(
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113 unsigned portBASE_TYPE uxQueueLength,
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114 unsigned portBASE_TYPE uxItemSize
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118 * Creates a new queue instance. This allocates the storage required by the
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119 * new queue and returns a handle for the queue.
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121 * @param uxQueueLength The maximum number of items that the queue can contain.
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123 * @param uxItemSize The number of bytes each item in the queue will require.
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124 * Items are queued by copy, not by reference, so this is the number of bytes
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125 * that will be copied for each posted item. Each item on the queue must be
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128 * @return If the queue is successfully create then a handle to the newly
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129 * created queue is returned. If the queue cannot be created then 0 is
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140 void vATask( void *pvParameters )
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142 xQueueHandle xQueue1, xQueue2;
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144 // Create a queue capable of containing 10 unsigned long values.
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145 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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148 // Queue was not created and must not be used.
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151 // Create a queue capable of containing 10 pointers to AMessage structures.
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152 // These should be passed by pointer as they contain a lot of data.
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153 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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156 // Queue was not created and must not be used.
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159 // ... Rest of task code.
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162 * \defgroup xQueueCreate xQueueCreate
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163 * \ingroup QueueManagement
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165 #define xQueueCreate( uxQueueLength, uxItemSize ) xQueueGenericCreate( uxQueueLength, uxItemSize, queueQUEUE_TYPE_BASE )
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170 portBASE_TYPE xQueueSendToToFront(
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171 xQueueHandle xQueue,
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172 const void * pvItemToQueue,
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173 portTickType xTicksToWait
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177 * This is a macro that calls xQueueGenericSend().
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179 * Post an item to the front of a queue. The item is queued by copy, not by
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180 * reference. This function must not be called from an interrupt service
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181 * routine. See xQueueSendFromISR () for an alternative which may be used
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184 * @param xQueue The handle to the queue on which the item is to be posted.
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186 * @param pvItemToQueue A pointer to the item that is to be placed on the
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187 * queue. The size of the items the queue will hold was defined when the
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188 * queue was created, so this many bytes will be copied from pvItemToQueue
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189 * into the queue storage area.
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191 * @param xTicksToWait The maximum amount of time the task should block
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192 * waiting for space to become available on the queue, should it already
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193 * be full. The call will return immediately if this is set to 0 and the
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194 * queue is full. The time is defined in tick periods so the constant
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195 * portTICK_RATE_MS should be used to convert to real time if this is required.
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197 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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207 unsigned long ulVar = 10UL;
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209 void vATask( void *pvParameters )
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211 xQueueHandle xQueue1, xQueue2;
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212 struct AMessage *pxMessage;
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214 // Create a queue capable of containing 10 unsigned long values.
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215 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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217 // Create a queue capable of containing 10 pointers to AMessage structures.
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218 // These should be passed by pointer as they contain a lot of data.
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219 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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225 // Send an unsigned long. Wait for 10 ticks for space to become
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226 // available if necessary.
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227 if( xQueueSendToFront( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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229 // Failed to post the message, even after 10 ticks.
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235 // Send a pointer to a struct AMessage object. Don't block if the
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236 // queue is already full.
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237 pxMessage = & xMessage;
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238 xQueueSendToFront( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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241 // ... Rest of task code.
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244 * \defgroup xQueueSend xQueueSend
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245 * \ingroup QueueManagement
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247 #define xQueueSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
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252 portBASE_TYPE xQueueSendToBack(
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253 xQueueHandle xQueue,
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254 const void * pvItemToQueue,
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255 portTickType xTicksToWait
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259 * This is a macro that calls xQueueGenericSend().
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261 * Post an item to the back of a queue. The item is queued by copy, not by
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262 * reference. This function must not be called from an interrupt service
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263 * routine. See xQueueSendFromISR () for an alternative which may be used
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266 * @param xQueue The handle to the queue on which the item is to be posted.
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268 * @param pvItemToQueue A pointer to the item that is to be placed on the
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269 * queue. The size of the items the queue will hold was defined when the
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270 * queue was created, so this many bytes will be copied from pvItemToQueue
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271 * into the queue storage area.
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273 * @param xTicksToWait The maximum amount of time the task should block
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274 * waiting for space to become available on the queue, should it already
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275 * be full. The call will return immediately if this is set to 0 and the queue
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276 * is full. The time is defined in tick periods so the constant
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277 * portTICK_RATE_MS should be used to convert to real time if this is required.
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279 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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289 unsigned long ulVar = 10UL;
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291 void vATask( void *pvParameters )
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293 xQueueHandle xQueue1, xQueue2;
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294 struct AMessage *pxMessage;
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296 // Create a queue capable of containing 10 unsigned long values.
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297 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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299 // Create a queue capable of containing 10 pointers to AMessage structures.
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300 // These should be passed by pointer as they contain a lot of data.
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301 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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307 // Send an unsigned long. Wait for 10 ticks for space to become
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308 // available if necessary.
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309 if( xQueueSendToBack( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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311 // Failed to post the message, even after 10 ticks.
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317 // Send a pointer to a struct AMessage object. Don't block if the
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318 // queue is already full.
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319 pxMessage = & xMessage;
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320 xQueueSendToBack( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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323 // ... Rest of task code.
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326 * \defgroup xQueueSend xQueueSend
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327 * \ingroup QueueManagement
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329 #define xQueueSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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334 portBASE_TYPE xQueueSend(
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335 xQueueHandle xQueue,
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336 const void * pvItemToQueue,
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337 portTickType xTicksToWait
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341 * This is a macro that calls xQueueGenericSend(). It is included for
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342 * backward compatibility with versions of FreeRTOS.org that did not
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343 * include the xQueueSendToFront() and xQueueSendToBack() macros. It is
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344 * equivalent to xQueueSendToBack().
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346 * Post an item on a queue. The item is queued by copy, not by reference.
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347 * This function must not be called from an interrupt service routine.
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348 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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350 * @param xQueue The handle to the queue on which the item is to be posted.
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352 * @param pvItemToQueue A pointer to the item that is to be placed on the
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353 * queue. The size of the items the queue will hold was defined when the
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354 * queue was created, so this many bytes will be copied from pvItemToQueue
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355 * into the queue storage area.
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357 * @param xTicksToWait The maximum amount of time the task should block
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358 * waiting for space to become available on the queue, should it already
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359 * be full. The call will return immediately if this is set to 0 and the
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360 * queue is full. The time is defined in tick periods so the constant
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361 * portTICK_RATE_MS should be used to convert to real time if this is required.
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363 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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373 unsigned long ulVar = 10UL;
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375 void vATask( void *pvParameters )
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377 xQueueHandle xQueue1, xQueue2;
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378 struct AMessage *pxMessage;
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380 // Create a queue capable of containing 10 unsigned long values.
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381 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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383 // Create a queue capable of containing 10 pointers to AMessage structures.
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384 // These should be passed by pointer as they contain a lot of data.
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385 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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391 // Send an unsigned long. Wait for 10 ticks for space to become
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392 // available if necessary.
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393 if( xQueueSend( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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395 // Failed to post the message, even after 10 ticks.
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401 // Send a pointer to a struct AMessage object. Don't block if the
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402 // queue is already full.
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403 pxMessage = & xMessage;
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404 xQueueSend( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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407 // ... Rest of task code.
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410 * \defgroup xQueueSend xQueueSend
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411 * \ingroup QueueManagement
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413 #define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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419 portBASE_TYPE xQueueGenericSend(
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420 xQueueHandle xQueue,
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421 const void * pvItemToQueue,
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422 portTickType xTicksToWait
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423 portBASE_TYPE xCopyPosition
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427 * It is preferred that the macros xQueueSend(), xQueueSendToFront() and
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428 * xQueueSendToBack() are used in place of calling this function directly.
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430 * Post an item on a queue. The item is queued by copy, not by reference.
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431 * This function must not be called from an interrupt service routine.
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432 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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434 * @param xQueue The handle to the queue on which the item is to be posted.
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436 * @param pvItemToQueue A pointer to the item that is to be placed on the
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437 * queue. The size of the items the queue will hold was defined when the
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438 * queue was created, so this many bytes will be copied from pvItemToQueue
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439 * into the queue storage area.
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441 * @param xTicksToWait The maximum amount of time the task should block
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442 * waiting for space to become available on the queue, should it already
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443 * be full. The call will return immediately if this is set to 0 and the
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444 * queue is full. The time is defined in tick periods so the constant
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445 * portTICK_RATE_MS should be used to convert to real time if this is required.
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447 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
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448 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
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449 * at the front of the queue (for high priority messages).
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451 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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461 unsigned long ulVar = 10UL;
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463 void vATask( void *pvParameters )
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465 xQueueHandle xQueue1, xQueue2;
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466 struct AMessage *pxMessage;
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468 // Create a queue capable of containing 10 unsigned long values.
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469 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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471 // Create a queue capable of containing 10 pointers to AMessage structures.
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472 // These should be passed by pointer as they contain a lot of data.
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473 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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479 // Send an unsigned long. Wait for 10 ticks for space to become
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480 // available if necessary.
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481 if( xQueueGenericSend( xQueue1, ( void * ) &ulVar, ( portTickType ) 10, queueSEND_TO_BACK ) != pdPASS )
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483 // Failed to post the message, even after 10 ticks.
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489 // Send a pointer to a struct AMessage object. Don't block if the
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490 // queue is already full.
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491 pxMessage = & xMessage;
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492 xQueueGenericSend( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0, queueSEND_TO_BACK );
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495 // ... Rest of task code.
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498 * \defgroup xQueueSend xQueueSend
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499 * \ingroup QueueManagement
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501 signed portBASE_TYPE xQueueGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );
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506 portBASE_TYPE xQueuePeek(
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507 xQueueHandle xQueue,
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509 portTickType xTicksToWait
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512 * This is a macro that calls the xQueueGenericReceive() function.
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514 * Receive an item from a queue without removing the item from the queue.
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515 * The item is received by copy so a buffer of adequate size must be
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516 * provided. The number of bytes copied into the buffer was defined when
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517 * the queue was created.
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519 * Successfully received items remain on the queue so will be returned again
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520 * by the next call, or a call to xQueueReceive().
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522 * This macro must not be used in an interrupt service routine.
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524 * @param pxQueue The handle to the queue from which the item is to be
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527 * @param pvBuffer Pointer to the buffer into which the received item will
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530 * @param xTicksToWait The maximum amount of time the task should block
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531 * waiting for an item to receive should the queue be empty at the time
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532 * of the call. The time is defined in tick periods so the constant
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533 * portTICK_RATE_MS should be used to convert to real time if this is required.
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534 * xQueuePeek() will return immediately if xTicksToWait is 0 and the queue
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537 * @return pdTRUE if an item was successfully received from the queue,
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538 * otherwise pdFALSE.
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548 xQueueHandle xQueue;
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550 // Task to create a queue and post a value.
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551 void vATask( void *pvParameters )
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553 struct AMessage *pxMessage;
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555 // Create a queue capable of containing 10 pointers to AMessage structures.
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556 // These should be passed by pointer as they contain a lot of data.
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557 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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560 // Failed to create the queue.
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565 // Send a pointer to a struct AMessage object. Don't block if the
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566 // queue is already full.
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567 pxMessage = & xMessage;
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568 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
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570 // ... Rest of task code.
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573 // Task to peek the data from the queue.
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574 void vADifferentTask( void *pvParameters )
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576 struct AMessage *pxRxedMessage;
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580 // Peek a message on the created queue. Block for 10 ticks if a
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581 // message is not immediately available.
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582 if( xQueuePeek( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
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584 // pcRxedMessage now points to the struct AMessage variable posted
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585 // by vATask, but the item still remains on the queue.
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589 // ... Rest of task code.
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592 * \defgroup xQueueReceive xQueueReceive
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593 * \ingroup QueueManagement
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595 #define xQueuePeek( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )
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600 portBASE_TYPE xQueueReceive(
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601 xQueueHandle xQueue,
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603 portTickType xTicksToWait
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606 * This is a macro that calls the xQueueGenericReceive() function.
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608 * Receive an item from a queue. The item is received by copy so a buffer of
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609 * adequate size must be provided. The number of bytes copied into the buffer
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610 * was defined when the queue was created.
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612 * Successfully received items are removed from the queue.
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614 * This function must not be used in an interrupt service routine. See
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615 * xQueueReceiveFromISR for an alternative that can.
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617 * @param pxQueue The handle to the queue from which the item is to be
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620 * @param pvBuffer Pointer to the buffer into which the received item will
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623 * @param xTicksToWait The maximum amount of time the task should block
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624 * waiting for an item to receive should the queue be empty at the time
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625 * of the call. xQueueReceive() will return immediately if xTicksToWait
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626 * is zero and the queue is empty. The time is defined in tick periods so the
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627 * constant portTICK_RATE_MS should be used to convert to real time if this is
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630 * @return pdTRUE if an item was successfully received from the queue,
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631 * otherwise pdFALSE.
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641 xQueueHandle xQueue;
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643 // Task to create a queue and post a value.
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644 void vATask( void *pvParameters )
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646 struct AMessage *pxMessage;
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648 // Create a queue capable of containing 10 pointers to AMessage structures.
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649 // These should be passed by pointer as they contain a lot of data.
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650 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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653 // Failed to create the queue.
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658 // Send a pointer to a struct AMessage object. Don't block if the
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659 // queue is already full.
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660 pxMessage = & xMessage;
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661 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
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663 // ... Rest of task code.
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666 // Task to receive from the queue.
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667 void vADifferentTask( void *pvParameters )
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669 struct AMessage *pxRxedMessage;
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673 // Receive a message on the created queue. Block for 10 ticks if a
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674 // message is not immediately available.
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675 if( xQueueReceive( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
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677 // pcRxedMessage now points to the struct AMessage variable posted
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682 // ... Rest of task code.
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685 * \defgroup xQueueReceive xQueueReceive
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686 * \ingroup QueueManagement
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688 #define xQueueReceive( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
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694 portBASE_TYPE xQueueGenericReceive(
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695 xQueueHandle xQueue,
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697 portTickType xTicksToWait
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698 portBASE_TYPE xJustPeek
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701 * It is preferred that the macro xQueueReceive() be used rather than calling
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702 * this function directly.
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704 * Receive an item from a queue. The item is received by copy so a buffer of
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705 * adequate size must be provided. The number of bytes copied into the buffer
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706 * was defined when the queue was created.
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708 * This function must not be used in an interrupt service routine. See
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709 * xQueueReceiveFromISR for an alternative that can.
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711 * @param pxQueue The handle to the queue from which the item is to be
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714 * @param pvBuffer Pointer to the buffer into which the received item will
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717 * @param xTicksToWait The maximum amount of time the task should block
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718 * waiting for an item to receive should the queue be empty at the time
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719 * of the call. The time is defined in tick periods so the constant
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720 * portTICK_RATE_MS should be used to convert to real time if this is required.
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721 * xQueueGenericReceive() will return immediately if the queue is empty and
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722 * xTicksToWait is 0.
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724 * @param xJustPeek When set to true, the item received from the queue is not
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725 * actually removed from the queue - meaning a subsequent call to
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726 * xQueueReceive() will return the same item. When set to false, the item
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727 * being received from the queue is also removed from the queue.
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729 * @return pdTRUE if an item was successfully received from the queue,
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730 * otherwise pdFALSE.
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740 xQueueHandle xQueue;
\r
742 // Task to create a queue and post a value.
\r
743 void vATask( void *pvParameters )
\r
745 struct AMessage *pxMessage;
\r
747 // Create a queue capable of containing 10 pointers to AMessage structures.
\r
748 // These should be passed by pointer as they contain a lot of data.
\r
749 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
\r
752 // Failed to create the queue.
\r
757 // Send a pointer to a struct AMessage object. Don't block if the
\r
758 // queue is already full.
\r
759 pxMessage = & xMessage;
\r
760 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
\r
762 // ... Rest of task code.
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765 // Task to receive from the queue.
\r
766 void vADifferentTask( void *pvParameters )
\r
768 struct AMessage *pxRxedMessage;
\r
772 // Receive a message on the created queue. Block for 10 ticks if a
\r
773 // message is not immediately available.
\r
774 if( xQueueGenericReceive( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
\r
776 // pcRxedMessage now points to the struct AMessage variable posted
\r
781 // ... Rest of task code.
\r
784 * \defgroup xQueueReceive xQueueReceive
\r
785 * \ingroup QueueManagement
\r
787 signed portBASE_TYPE xQueueGenericReceive( xQueueHandle xQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeek );
\r
791 * <pre>unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle xQueue );</pre>
\r
793 * Return the number of messages stored in a queue.
\r
795 * @param xQueue A handle to the queue being queried.
\r
797 * @return The number of messages available in the queue.
\r
799 * \page uxQueueMessagesWaiting uxQueueMessagesWaiting
\r
800 * \ingroup QueueManagement
\r
802 unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle xQueue );
\r
806 * <pre>void vQueueDelete( xQueueHandle xQueue );</pre>
\r
808 * Delete a queue - freeing all the memory allocated for storing of items
\r
809 * placed on the queue.
\r
811 * @param xQueue A handle to the queue to be deleted.
\r
813 * \page vQueueDelete vQueueDelete
\r
814 * \ingroup QueueManagement
\r
816 void vQueueDelete( xQueueHandle pxQueue );
\r
821 portBASE_TYPE xQueueSendToFrontFromISR(
\r
822 xQueueHandle pxQueue,
\r
823 const void *pvItemToQueue,
\r
824 portBASE_TYPE *pxHigherPriorityTaskWoken
\r
828 * This is a macro that calls xQueueGenericSendFromISR().
\r
830 * Post an item to the front of a queue. It is safe to use this macro from
\r
831 * within an interrupt service routine.
\r
833 * Items are queued by copy not reference so it is preferable to only
\r
834 * queue small items, especially when called from an ISR. In most cases
\r
835 * it would be preferable to store a pointer to the item being queued.
\r
837 * @param xQueue The handle to the queue on which the item is to be posted.
\r
839 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
840 * queue. The size of the items the queue will hold was defined when the
\r
841 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
842 * into the queue storage area.
\r
844 * @param pxHigherPriorityTaskWoken xQueueSendToFrontFromISR() will set
\r
845 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
846 * to unblock, and the unblocked task has a priority higher than the currently
\r
847 * running task. If xQueueSendToFromFromISR() sets this value to pdTRUE then
\r
848 * a context switch should be requested before the interrupt is exited.
\r
850 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
853 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
856 void vBufferISR( void )
\r
859 portBASE_TYPE xHigherPrioritTaskWoken;
\r
861 // We have not woken a task at the start of the ISR.
\r
862 xHigherPriorityTaskWoken = pdFALSE;
\r
864 // Loop until the buffer is empty.
\r
867 // Obtain a byte from the buffer.
\r
868 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
871 xQueueSendToFrontFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
873 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
875 // Now the buffer is empty we can switch context if necessary.
\r
876 if( xHigherPriorityTaskWoken )
\r
883 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
884 * \ingroup QueueManagement
\r
886 #define xQueueSendToFrontFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( pxQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_FRONT )
\r
892 portBASE_TYPE xQueueSendToBackFromISR(
\r
893 xQueueHandle pxQueue,
\r
894 const void *pvItemToQueue,
\r
895 portBASE_TYPE *pxHigherPriorityTaskWoken
\r
899 * This is a macro that calls xQueueGenericSendFromISR().
\r
901 * Post an item to the back of a queue. It is safe to use this macro from
\r
902 * within an interrupt service routine.
\r
904 * Items are queued by copy not reference so it is preferable to only
\r
905 * queue small items, especially when called from an ISR. In most cases
\r
906 * it would be preferable to store a pointer to the item being queued.
\r
908 * @param xQueue The handle to the queue on which the item is to be posted.
\r
910 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
911 * queue. The size of the items the queue will hold was defined when the
\r
912 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
913 * into the queue storage area.
\r
915 * @param pxHigherPriorityTaskWoken xQueueSendToBackFromISR() will set
\r
916 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
917 * to unblock, and the unblocked task has a priority higher than the currently
\r
918 * running task. If xQueueSendToBackFromISR() sets this value to pdTRUE then
\r
919 * a context switch should be requested before the interrupt is exited.
\r
921 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
924 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
927 void vBufferISR( void )
\r
930 portBASE_TYPE xHigherPriorityTaskWoken;
\r
932 // We have not woken a task at the start of the ISR.
\r
933 xHigherPriorityTaskWoken = pdFALSE;
\r
935 // Loop until the buffer is empty.
\r
938 // Obtain a byte from the buffer.
\r
939 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
942 xQueueSendToBackFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
944 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
946 // Now the buffer is empty we can switch context if necessary.
\r
947 if( xHigherPriorityTaskWoken )
\r
954 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
955 * \ingroup QueueManagement
\r
957 #define xQueueSendToBackFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( pxQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
\r
962 portBASE_TYPE xQueueSendFromISR(
\r
963 xQueueHandle pxQueue,
\r
964 const void *pvItemToQueue,
\r
965 portBASE_TYPE *pxHigherPriorityTaskWoken
\r
969 * This is a macro that calls xQueueGenericSendFromISR(). It is included
\r
970 * for backward compatibility with versions of FreeRTOS.org that did not
\r
971 * include the xQueueSendToBackFromISR() and xQueueSendToFrontFromISR()
\r
974 * Post an item to the back of a queue. It is safe to use this function from
\r
975 * within an interrupt service routine.
\r
977 * Items are queued by copy not reference so it is preferable to only
\r
978 * queue small items, especially when called from an ISR. In most cases
\r
979 * it would be preferable to store a pointer to the item being queued.
\r
981 * @param xQueue The handle to the queue on which the item is to be posted.
\r
983 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
984 * queue. The size of the items the queue will hold was defined when the
\r
985 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
986 * into the queue storage area.
\r
988 * @param pxHigherPriorityTaskWoken xQueueSendFromISR() will set
\r
989 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
990 * to unblock, and the unblocked task has a priority higher than the currently
\r
991 * running task. If xQueueSendFromISR() sets this value to pdTRUE then
\r
992 * a context switch should be requested before the interrupt is exited.
\r
994 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
997 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1000 void vBufferISR( void )
\r
1003 portBASE_TYPE xHigherPriorityTaskWoken;
\r
1005 // We have not woken a task at the start of the ISR.
\r
1006 xHigherPriorityTaskWoken = pdFALSE;
\r
1008 // Loop until the buffer is empty.
\r
1011 // Obtain a byte from the buffer.
\r
1012 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1015 xQueueSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
1017 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1019 // Now the buffer is empty we can switch context if necessary.
\r
1020 if( xHigherPriorityTaskWoken )
\r
1022 // Actual macro used here is port specific.
\r
1023 taskYIELD_FROM_ISR ();
\r
1028 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1029 * \ingroup QueueManagement
\r
1031 #define xQueueSendFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( pxQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
\r
1036 portBASE_TYPE xQueueGenericSendFromISR(
\r
1037 xQueueHandle pxQueue,
\r
1038 const void *pvItemToQueue,
\r
1039 portBASE_TYPE *pxHigherPriorityTaskWoken,
\r
1040 portBASE_TYPE xCopyPosition
\r
1044 * It is preferred that the macros xQueueSendFromISR(),
\r
1045 * xQueueSendToFrontFromISR() and xQueueSendToBackFromISR() be used in place
\r
1046 * of calling this function directly.
\r
1048 * Post an item on a queue. It is safe to use this function from within an
\r
1049 * 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 xQueueGenericSendFromISR() 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 xQueueGenericSendFromISR() sets this value to pdTRUE then
\r
1066 * a context switch should be requested before the interrupt is exited.
\r
1068 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
\r
1069 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
\r
1070 * at the front of the queue (for high priority messages).
\r
1072 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1075 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1078 void vBufferISR( void )
\r
1081 portBASE_TYPE xHigherPriorityTaskWokenByPost;
\r
1083 // We have not woken a task at the start of the ISR.
\r
1084 xHigherPriorityTaskWokenByPost = pdFALSE;
\r
1086 // Loop until the buffer is empty.
\r
1089 // Obtain a byte from the buffer.
\r
1090 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1092 // Post each byte.
\r
1093 xQueueGenericSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWokenByPost, queueSEND_TO_BACK );
\r
1095 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1097 // Now the buffer is empty we can switch context if necessary. Note that the
\r
1098 // name of the yield function required is port specific.
\r
1099 if( xHigherPriorityTaskWokenByPost )
\r
1101 taskYIELD_YIELD_FROM_ISR();
\r
1106 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1107 * \ingroup QueueManagement
\r
1109 signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE *pxHigherPriorityTaskWoken, portBASE_TYPE xCopyPosition );
\r
1114 portBASE_TYPE xQueueReceiveFromISR(
\r
1115 xQueueHandle pxQueue,
\r
1117 portBASE_TYPE *pxTaskWoken
\r
1121 * Receive an item from a queue. It is safe to use this function from within an
\r
1122 * interrupt service routine.
\r
1124 * @param pxQueue The handle to the queue from which the item is to be
\r
1127 * @param pvBuffer Pointer to the buffer into which the received item will
\r
1130 * @param pxTaskWoken A task may be blocked waiting for space to become
\r
1131 * available on the queue. If xQueueReceiveFromISR causes such a task to
\r
1132 * unblock *pxTaskWoken will get set to pdTRUE, otherwise *pxTaskWoken will
\r
1133 * remain unchanged.
\r
1135 * @return pdTRUE if an item was successfully received from the queue,
\r
1136 * otherwise pdFALSE.
\r
1141 xQueueHandle xQueue;
\r
1143 // Function to create a queue and post some values.
\r
1144 void vAFunction( void *pvParameters )
\r
1146 char cValueToPost;
\r
1147 const portTickType xBlockTime = ( portTickType )0xff;
\r
1149 // Create a queue capable of containing 10 characters.
\r
1150 xQueue = xQueueCreate( 10, sizeof( char ) );
\r
1153 // Failed to create the queue.
\r
1158 // Post some characters that will be used within an ISR. If the queue
\r
1159 // is full then this task will block for xBlockTime ticks.
\r
1160 cValueToPost = 'a';
\r
1161 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1162 cValueToPost = 'b';
\r
1163 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1165 // ... keep posting characters ... this task may block when the queue
\r
1168 cValueToPost = 'c';
\r
1169 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1172 // ISR that outputs all the characters received on the queue.
\r
1173 void vISR_Routine( void )
\r
1175 portBASE_TYPE xTaskWokenByReceive = pdFALSE;
\r
1178 while( xQueueReceiveFromISR( xQueue, ( void * ) &cRxedChar, &xTaskWokenByReceive) )
\r
1180 // A character was received. Output the character now.
\r
1181 vOutputCharacter( cRxedChar );
\r
1183 // If removing the character from the queue woke the task that was
\r
1184 // posting onto the queue cTaskWokenByReceive will have been set to
\r
1185 // pdTRUE. No matter how many times this loop iterates only one
\r
1186 // task will be woken.
\r
1189 if( cTaskWokenByPost != ( char ) pdFALSE;
\r
1195 * \defgroup xQueueReceiveFromISR xQueueReceiveFromISR
\r
1196 * \ingroup QueueManagement
\r
1198 signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void * const pvBuffer, signed portBASE_TYPE *pxHigherPriorityTaskWoken );
\r
1201 * Utilities to query queues that are safe to use from an ISR. These utilities
\r
1202 * should be used only from witin an ISR, or within a critical section.
\r
1204 signed portBASE_TYPE xQueueIsQueueEmptyFromISR( const xQueueHandle pxQueue );
\r
1205 signed portBASE_TYPE xQueueIsQueueFullFromISR( const xQueueHandle pxQueue );
\r
1206 unsigned portBASE_TYPE uxQueueMessagesWaitingFromISR( const xQueueHandle pxQueue );
\r
1210 * xQueueAltGenericSend() is an alternative version of xQueueGenericSend().
\r
1211 * Likewise xQueueAltGenericReceive() is an alternative version of
\r
1212 * xQueueGenericReceive().
\r
1214 * The source code that implements the alternative (Alt) API is much
\r
1215 * simpler because it executes everything from within a critical section.
\r
1216 * This is the approach taken by many other RTOSes, but FreeRTOS.org has the
\r
1217 * preferred fully featured API too. The fully featured API has more
\r
1218 * complex code that takes longer to execute, but makes much less use of
\r
1219 * critical sections. Therefore the alternative API sacrifices interrupt
\r
1220 * responsiveness to gain execution speed, whereas the fully featured API
\r
1221 * sacrifices execution speed to ensure better interrupt responsiveness.
\r
1223 signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );
\r
1224 signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking );
\r
1225 #define xQueueAltSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
\r
1226 #define xQueueAltSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
\r
1227 #define xQueueAltReceive( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
\r
1228 #define xQueueAltPeek( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )
\r
1231 * The functions defined above are for passing data to and from tasks. The
\r
1232 * functions below are the equivalents for passing data to and from
\r
1235 * These functions are called from the co-routine macro implementation and
\r
1236 * should not be called directly from application code. Instead use the macro
\r
1237 * wrappers defined within croutine.h.
\r
1239 signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken );
\r
1240 signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken );
\r
1241 signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait );
\r
1242 signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait );
\r
1245 * For internal use only. Use xSemaphoreCreateMutex(),
\r
1246 * xSemaphoreCreateCounting() or xSemaphoreGetMutexHolder() instead of calling
\r
1247 * these functions directly.
\r
1249 xQueueHandle xQueueCreateMutex( unsigned char ucQueueType );
\r
1250 xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount );
\r
1251 void* xQueueGetMutexHolder( xQueueHandle xSemaphore );
\r
1254 * For internal use only. Use xSemaphoreTakeMutexRecursive() or
\r
1255 * xSemaphoreGiveMutexRecursive() instead of calling these functions directly.
\r
1257 portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle pxMutex, portTickType xBlockTime );
\r
1258 portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle pxMutex );
\r
1261 * Reset a queue back to its original empty state. pdPASS is returned if the
\r
1262 * queue is successfully reset. pdFAIL is returned if the queue could not be
\r
1263 * reset because there are tasks blocked on the queue waiting to either
\r
1264 * receive from the queue or send to the queue.
\r
1266 #define xQueueReset( pxQueue ) xQueueGenericReset( pxQueue, pdFALSE )
\r
1269 * The registry is provided as a means for kernel aware debuggers to
\r
1270 * locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
\r
1271 * a queue, semaphore or mutex handle to the registry if you want the handle
\r
1272 * to be available to a kernel aware debugger. If you are not using a kernel
\r
1273 * aware debugger then this function can be ignored.
\r
1275 * configQUEUE_REGISTRY_SIZE defines the maximum number of handles the
\r
1276 * registry can hold. configQUEUE_REGISTRY_SIZE must be greater than 0
\r
1277 * within FreeRTOSConfig.h for the registry to be available. Its value
\r
1278 * does not effect the number of queues, semaphores and mutexes that can be
\r
1279 * created - just the number that the registry can hold.
\r
1281 * @param xQueue The handle of the queue being added to the registry. This
\r
1282 * is the handle returned by a call to xQueueCreate(). Semaphore and mutex
\r
1283 * handles can also be passed in here.
\r
1285 * @param pcName The name to be associated with the handle. This is the
\r
1286 * name that the kernel aware debugger will display.
\r
1288 #if configQUEUE_REGISTRY_SIZE > 0U
\r
1289 void vQueueAddToRegistry( xQueueHandle xQueue, signed char *pcName );
\r
1293 * Generic version of the queue creation function, which is in turn called by
\r
1294 * any queue, semaphore or mutex creation function or macro.
\r
1296 xQueueHandle xQueueGenericCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize, unsigned char ucQueueType );
\r
1299 * Queue sets provide a mechanism to allow a task to block (pend) on a read
\r
1300 * operation from multiple queues or semaphores simultaneously.
\r
1302 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1305 * A queue set must be explicitly created using a call to xQueueSetCreate()
\r
1306 * before it can be used. Once created, standard FreeRTOS queues and semaphores
\r
1307 * can be added to the set using calls to xQueueAddToQueueSet().
\r
1308 * xQueueReadMultiple() is then used to determine which, if any, of the queues
\r
1309 * or semaphores contained in the set is in a state where a queue read or
\r
1310 * semaphore take operation would be successful.
\r
1312 * Note 1: See the documentation on http://wwwFreeRTOS.org for reasons why
\r
1313 * queue sets are very rarely needed in practice as there are simpler
\r
1314 * alternatives. Queue sets are provided to allow FreeRTOS to be integrated
\r
1315 * with legacy third party driver code.
\r
1317 * Note 2: Blocking on a queue set that contains a mutex will not cause the
\r
1318 * mutex holder to inherit the priority of the blocked task.
\r
1320 * Note 3: An additional 4 bytes of RAM is required for each space in a every
\r
1321 * queue added to a queue set. Therefore counting semaphores with large maximum
\r
1322 * counts should not be added to queue sets.
\r
1324 * @param uxEventQueueLength Queue sets themselves queue events that occur on
\r
1325 * the queues and semaphores contained in the set. uxEventQueueLength specifies
\r
1326 * the maximum number of events that can be queued at once. To be absolutely
\r
1327 * certain that events are not lost uxEventQueueLength should be set to the
\r
1328 * total sum of the length of the queues added to the set, where binary
\r
1329 * semaphores and mutexes have a length of 1, and counting semaphores have a
\r
1330 * length set by their maximum count value. Examples:
\r
1331 * + If a queue set is to hold a queue of length 5, another queue of length 12,
\r
1332 * and a binary semaphore, then uxEventQueueLength should be set to
\r
1333 * (5 + 12 + 1), or 18.
\r
1334 * + If a queue set is to hold three binary semaphores then uxEventQueueLength
\r
1335 * should be set to (1 + 1 + 1 ), or 3.
\r
1336 * + If a queue set is to hold a counting semaphore that has a maximum count of
\r
1337 * 5, and a counting semaphore that has a maximum count of 3, then
\r
1338 * uxEventQueueLength should be set to (5 + 3), or 8.
\r
1340 * @return If the queue set is created successfully then a handle to the created
\r
1341 * queue set is returned. Otherwise NULL is returned.
\r
1343 xQueueSetHandle xQueueSetCreate( unsigned portBASE_TYPE uxEventQueueLength );
\r
1346 * Adds a queue or semaphore to a queue set that was previously created by a
\r
1347 * call to xQueueSetCreate().
\r
1349 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1352 * @param xQueue The handle of the queue or semaphore being added to the
\r
1353 * queue set. Variables of type xSemaphoreHandle can be safely added to a
\r
1354 * queue set but may require casting to an xQueueHandle type to avoid compiler
\r
1357 * @param xQueueSet The handle of the queue set to which the queue or semaphore
\r
1360 * @return If the queue or semaphore was successfully added to the queue set
\r
1361 * then pdPASS is returned. If the queue could not be successfully added to the
\r
1362 * queue set because it is already a member of a different queue set then pdFAIL
\r
1365 portBASE_TYPE xQueueAddToQueueSet( xQueueHandle xQueue, xQueueSetHandle xQueueSet );
\r
1368 * Removes a queue or semaphore from a queue set.
\r
1370 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
\r
1373 * @param xQueue The handle of the queue or semaphore being removed from the
\r
1374 * queue set. Variables of type xSemaphoreHandle can be safely used but may
\r
1375 * require casting to an xQueueHandle type to avoid compiler warnings.
\r
1377 * @param xQueueSet The handle of the queue set in which the queue or semaphore
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1380 * @return If the queue or semaphore was successfully removed from the queue set
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1381 * then pdPASS is returned. If the queue was not in the queue set then pdFAIL
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1384 portBASE_TYPE xQueueRemoveFromQueueSet( xQueueSetHandle xQueueSet, xQueueHandle xQueue );
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1387 * xQueueReadMultiple() allows a task to block (pend) on a read operation on
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1388 * all the queues and semaphores in a queue set simultaneously.
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1390 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
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1393 * Note 1: See the documentation on http://wwwFreeRTOS.org for reasons why
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1394 * queue sets are very rarely needed in practice as there are simpler
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1395 * alternatives. Queue sets are provided to allow FreeRTOS to be integrated
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1396 * with legacy third party driver code.
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1398 * Note 2: Blocking on a queue set that contains a mutex will not cause the
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1399 * mutex holder to inherit the priority of the blocked task.
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1401 * @param xQueueSet The queue set on which the task will (potentially) block.
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1403 * @param xBlockTimeTicks The maximum time, in ticks, that the calling task will
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1404 * remain in the Blocked state (with other tasks executing) to wait for a member
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1405 * of the queue set to be ready for a successful queue read or semaphore take
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1408 * @return xQueueReadMultiple() will return the handle of a queue contained
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1409 * in the queue set that contains data, or the handle of a semaphore contained
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1410 * in the queue set that is available, or NULL if no such queue or semaphore
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1411 * exists before before the specified block time expires.
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1413 xQueueHandle xQueueReadMultiple( xQueueSetHandle xQueueSet, portTickType xBlockTimeTicks );
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1415 /* Not public API functions. */
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1416 void vQueueWaitForMessageRestricted( xQueueHandle pxQueue, portTickType xTicksToWait );
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1417 portBASE_TYPE xQueueGenericReset( xQueueHandle pxQueue, portBASE_TYPE xNewQueue );
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1420 #ifdef __cplusplus
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1424 #endif /* QUEUE_H */
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projects / freertos / blob