2 FreeRTOS V5.4.2 - Copyright (C) 2009 Real Time Engineers Ltd.
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4 This file is part of the FreeRTOS distribution.
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6 FreeRTOS is free software; you can redistribute it and/or modify it under
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7 the terms of the GNU General Public License (version 2) as published by the
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8 Free Software Foundation and modified by the FreeRTOS exception.
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9 **NOTE** The exception to the GPL is included to allow you to distribute a
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10 combined work that includes FreeRTOS without being obliged to provide the
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11 source code for proprietary components outside of the FreeRTOS kernel.
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12 Alternative commercial license and support terms are also available upon
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13 request. See the licensing section of http://www.FreeRTOS.org for full
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16 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
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17 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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18 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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21 You should have received a copy of the GNU General Public License along
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22 with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
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23 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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26 ***************************************************************************
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28 * Looking for a quick start? Then check out the FreeRTOS eBook! *
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29 * See http://www.FreeRTOS.org/Documentation for details *
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31 ***************************************************************************
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35 Please ensure to read the configuration and relevant port sections of the
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36 online documentation.
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38 http://www.FreeRTOS.org - Documentation, latest information, license and
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41 http://www.SafeRTOS.com - A version that is certified for use in safety
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44 http://www.OpenRTOS.com - Commercial support, development, porting,
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45 licensing and training services.
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48 #ifndef INC_FREERTOS_H
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49 #error "#include FreeRTOS.h" must appear in source files before "#include queue.h"
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63 #include "mpu_wrappers.h"
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66 typedef void * xQueueHandle;
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69 /* For internal use only. */
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70 #define queueSEND_TO_BACK ( 0 )
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71 #define queueSEND_TO_FRONT ( 1 )
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77 xQueueHandle xQueueCreate(
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78 unsigned portBASE_TYPE uxQueueLength,
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79 unsigned portBASE_TYPE uxItemSize
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83 * Creates a new queue instance. This allocates the storage required by the
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84 * new queue and returns a handle for the queue.
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86 * @param uxQueueLength The maximum number of items that the queue can contain.
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88 * @param uxItemSize The number of bytes each item in the queue will require.
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89 * Items are queued by copy, not by reference, so this is the number of bytes
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90 * that will be copied for each posted item. Each item on the queue must be
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93 * @return If the queue is successfully create then a handle to the newly
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94 * created queue is returned. If the queue cannot be created then 0 is
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101 portCHAR ucMessageID;
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102 portCHAR ucData[ 20 ];
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105 void vATask( void *pvParameters )
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107 xQueueHandle xQueue1, xQueue2;
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109 // Create a queue capable of containing 10 unsigned long values.
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110 xQueue1 = xQueueCreate( 10, sizeof( unsigned portLONG ) );
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113 // Queue was not created and must not be used.
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116 // Create a queue capable of containing 10 pointers to AMessage structures.
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117 // These should be passed by pointer as they contain a lot of data.
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118 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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121 // Queue was not created and must not be used.
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124 // ... Rest of task code.
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127 * \defgroup xQueueCreate xQueueCreate
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128 * \ingroup QueueManagement
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130 xQueueHandle xQueueCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize );
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135 portBASE_TYPE xQueueSendToToFront(
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136 xQueueHandle xQueue,
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137 const void * pvItemToQueue,
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138 portTickType xTicksToWait
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142 * This is a macro that calls xQueueGenericSend().
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144 * Post an item to the front of a queue. The item is queued by copy, not by
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145 * reference. This function must not be called from an interrupt service
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146 * routine. See xQueueSendFromISR () for an alternative which may be used
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149 * @param xQueue The handle to the queue on which the item is to be posted.
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151 * @param pvItemToQueue A pointer to the item that is to be placed on the
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152 * queue. The size of the items the queue will hold was defined when the
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153 * queue was created, so this many bytes will be copied from pvItemToQueue
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154 * into the queue storage area.
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156 * @param xTicksToWait The maximum amount of time the task should block
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157 * waiting for space to become available on the queue, should it already
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158 * be full. The call will return immediately if this is set to 0 and the
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159 * queue is full. The time is defined in tick periods so the constant
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160 * portTICK_RATE_MS should be used to convert to real time if this is required.
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162 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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168 portCHAR ucMessageID;
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169 portCHAR ucData[ 20 ];
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172 unsigned portLONG ulVar = 10UL;
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174 void vATask( void *pvParameters )
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176 xQueueHandle xQueue1, xQueue2;
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177 struct AMessage *pxMessage;
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179 // Create a queue capable of containing 10 unsigned long values.
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180 xQueue1 = xQueueCreate( 10, sizeof( unsigned portLONG ) );
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182 // Create a queue capable of containing 10 pointers to AMessage structures.
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183 // These should be passed by pointer as they contain a lot of data.
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184 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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190 // Send an unsigned long. Wait for 10 ticks for space to become
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191 // available if necessary.
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192 if( xQueueSendToFront( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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194 // Failed to post the message, even after 10 ticks.
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200 // Send a pointer to a struct AMessage object. Don't block if the
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201 // queue is already full.
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202 pxMessage = & xMessage;
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203 xQueueSendToFront( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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206 // ... Rest of task code.
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209 * \defgroup xQueueSend xQueueSend
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210 * \ingroup QueueManagement
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212 #define xQueueSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( xQueue, pvItemToQueue, xTicksToWait, queueSEND_TO_FRONT )
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217 portBASE_TYPE xQueueSendToBack(
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218 xQueueHandle xQueue,
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219 const void * pvItemToQueue,
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220 portTickType xTicksToWait
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224 * This is a macro that calls xQueueGenericSend().
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226 * Post an item to the back of a queue. The item is queued by copy, not by
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227 * reference. This function must not be called from an interrupt service
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228 * routine. See xQueueSendFromISR () for an alternative which may be used
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231 * @param xQueue The handle to the queue on which the item is to be posted.
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233 * @param pvItemToQueue A pointer to the item that is to be placed on the
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234 * queue. The size of the items the queue will hold was defined when the
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235 * queue was created, so this many bytes will be copied from pvItemToQueue
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236 * into the queue storage area.
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238 * @param xTicksToWait The maximum amount of time the task should block
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239 * waiting for space to become available on the queue, should it already
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240 * be full. The call will return immediately if this is set to 0 and the queue
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241 * is full. The time is defined in tick periods so the constant
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242 * portTICK_RATE_MS should be used to convert to real time if this is required.
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244 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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250 portCHAR ucMessageID;
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251 portCHAR ucData[ 20 ];
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254 unsigned portLONG ulVar = 10UL;
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256 void vATask( void *pvParameters )
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258 xQueueHandle xQueue1, xQueue2;
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259 struct AMessage *pxMessage;
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261 // Create a queue capable of containing 10 unsigned long values.
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262 xQueue1 = xQueueCreate( 10, sizeof( unsigned portLONG ) );
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264 // Create a queue capable of containing 10 pointers to AMessage structures.
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265 // These should be passed by pointer as they contain a lot of data.
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266 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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272 // Send an unsigned long. Wait for 10 ticks for space to become
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273 // available if necessary.
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274 if( xQueueSendToBack( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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276 // Failed to post the message, even after 10 ticks.
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282 // Send a pointer to a struct AMessage object. Don't block if the
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283 // queue is already full.
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284 pxMessage = & xMessage;
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285 xQueueSendToBack( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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288 // ... Rest of task code.
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291 * \defgroup xQueueSend xQueueSend
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292 * \ingroup QueueManagement
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294 #define xQueueSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( xQueue, pvItemToQueue, xTicksToWait, queueSEND_TO_BACK )
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299 portBASE_TYPE xQueueSend(
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300 xQueueHandle xQueue,
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301 const void * pvItemToQueue,
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302 portTickType xTicksToWait
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306 * This is a macro that calls xQueueGenericSend(). It is included for
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307 * backward compatibility with versions of FreeRTOS.org that did not
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308 * include the xQueueSendToFront() and xQueueSendToBack() macros. It is
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309 * equivalent to xQueueSendToBack().
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311 * Post an item on a queue. The item is queued by copy, not by reference.
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312 * This function must not be called from an interrupt service routine.
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313 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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315 * @param xQueue The handle to the queue on which the item is to be posted.
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317 * @param pvItemToQueue A pointer to the item that is to be placed on the
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318 * queue. The size of the items the queue will hold was defined when the
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319 * queue was created, so this many bytes will be copied from pvItemToQueue
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320 * into the queue storage area.
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322 * @param xTicksToWait The maximum amount of time the task should block
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323 * waiting for space to become available on the queue, should it already
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324 * be full. The call will return immediately if this is set to 0 and the
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325 * queue is full. The time is defined in tick periods so the constant
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326 * portTICK_RATE_MS should be used to convert to real time if this is required.
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328 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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334 portCHAR ucMessageID;
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335 portCHAR ucData[ 20 ];
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338 unsigned portLONG ulVar = 10UL;
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340 void vATask( void *pvParameters )
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342 xQueueHandle xQueue1, xQueue2;
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343 struct AMessage *pxMessage;
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345 // Create a queue capable of containing 10 unsigned long values.
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346 xQueue1 = xQueueCreate( 10, sizeof( unsigned portLONG ) );
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348 // Create a queue capable of containing 10 pointers to AMessage structures.
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349 // These should be passed by pointer as they contain a lot of data.
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350 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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356 // Send an unsigned long. Wait for 10 ticks for space to become
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357 // available if necessary.
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358 if( xQueueSend( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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360 // Failed to post the message, even after 10 ticks.
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366 // Send a pointer to a struct AMessage object. Don't block if the
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367 // queue is already full.
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368 pxMessage = & xMessage;
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369 xQueueSend( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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372 // ... Rest of task code.
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375 * \defgroup xQueueSend xQueueSend
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376 * \ingroup QueueManagement
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378 #define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( xQueue, pvItemToQueue, xTicksToWait, queueSEND_TO_BACK )
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384 portBASE_TYPE xQueueGenericSend(
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385 xQueueHandle xQueue,
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386 const void * pvItemToQueue,
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387 portTickType xTicksToWait
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388 portBASE_TYPE xCopyPosition
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392 * It is preferred that the macros xQueueSend(), xQueueSendToFront() and
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393 * xQueueSendToBack() are used in place of calling this function directly.
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395 * Post an item on a queue. The item is queued by copy, not by reference.
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396 * This function must not be called from an interrupt service routine.
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397 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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399 * @param xQueue The handle to the queue on which the item is to be posted.
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401 * @param pvItemToQueue A pointer to the item that is to be placed on the
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402 * queue. The size of the items the queue will hold was defined when the
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403 * queue was created, so this many bytes will be copied from pvItemToQueue
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404 * into the queue storage area.
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406 * @param xTicksToWait The maximum amount of time the task should block
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407 * waiting for space to become available on the queue, should it already
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408 * be full. The call will return immediately if this is set to 0 and the
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409 * queue is full. The time is defined in tick periods so the constant
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410 * portTICK_RATE_MS should be used to convert to real time if this is required.
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412 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
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413 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
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414 * at the front of the queue (for high priority messages).
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416 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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422 portCHAR ucMessageID;
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423 portCHAR ucData[ 20 ];
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426 unsigned portLONG ulVar = 10UL;
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428 void vATask( void *pvParameters )
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430 xQueueHandle xQueue1, xQueue2;
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431 struct AMessage *pxMessage;
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433 // Create a queue capable of containing 10 unsigned long values.
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434 xQueue1 = xQueueCreate( 10, sizeof( unsigned portLONG ) );
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436 // Create a queue capable of containing 10 pointers to AMessage structures.
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437 // These should be passed by pointer as they contain a lot of data.
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438 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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444 // Send an unsigned long. Wait for 10 ticks for space to become
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445 // available if necessary.
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446 if( xQueueGenericSend( xQueue1, ( void * ) &ulVar, ( portTickType ) 10, queueSEND_TO_BACK ) != pdPASS )
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448 // Failed to post the message, even after 10 ticks.
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454 // Send a pointer to a struct AMessage object. Don't block if the
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455 // queue is already full.
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456 pxMessage = & xMessage;
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457 xQueueGenericSend( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0, queueSEND_TO_BACK );
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460 // ... Rest of task code.
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463 * \defgroup xQueueSend xQueueSend
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464 * \ingroup QueueManagement
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466 signed portBASE_TYPE xQueueGenericSend( xQueueHandle xQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );
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471 portBASE_TYPE xQueuePeek(
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472 xQueueHandle xQueue,
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474 portTickType xTicksToWait
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477 * This is a macro that calls the xQueueGenericReceive() function.
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479 * Receive an item from a queue without removing the item from the queue.
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480 * The item is received by copy so a buffer of adequate size must be
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481 * provided. The number of bytes copied into the buffer was defined when
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482 * the queue was created.
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484 * Successfully received items remain on the queue so will be returned again
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485 * by the next call, or a call to xQueueReceive().
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487 * This macro must not be used in an interrupt service routine.
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489 * @param pxQueue The handle to the queue from which the item is to be
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492 * @param pvBuffer Pointer to the buffer into which the received item will
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495 * @param xTicksToWait The maximum amount of time the task should block
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496 * waiting for an item to receive should the queue be empty at the time
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497 * of the call. The time is defined in tick periods so the constant
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498 * portTICK_RATE_MS should be used to convert to real time if this is required.
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499 * xQueuePeek() will return immediately if xTicksToWait is 0 and the queue
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502 * @return pdTRUE if an item was successfully received from the queue,
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503 * otherwise pdFALSE.
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509 portCHAR ucMessageID;
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510 portCHAR ucData[ 20 ];
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513 xQueueHandle xQueue;
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515 // Task to create a queue and post a value.
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516 void vATask( void *pvParameters )
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518 struct AMessage *pxMessage;
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520 // Create a queue capable of containing 10 pointers to AMessage structures.
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521 // These should be passed by pointer as they contain a lot of data.
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522 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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525 // Failed to create the queue.
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530 // Send a pointer to a struct AMessage object. Don't block if the
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531 // queue is already full.
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532 pxMessage = & xMessage;
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533 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
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535 // ... Rest of task code.
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538 // Task to peek the data from the queue.
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539 void vADifferentTask( void *pvParameters )
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541 struct AMessage *pxRxedMessage;
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545 // Peek a message on the created queue. Block for 10 ticks if a
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546 // message is not immediately available.
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547 if( xQueuePeek( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
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549 // pcRxedMessage now points to the struct AMessage variable posted
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550 // by vATask, but the item still remains on the queue.
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554 // ... Rest of task code.
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557 * \defgroup xQueueReceive xQueueReceive
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558 * \ingroup QueueManagement
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560 #define xQueuePeek( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( xQueue, pvBuffer, xTicksToWait, pdTRUE )
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565 portBASE_TYPE xQueueReceive(
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566 xQueueHandle xQueue,
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568 portTickType xTicksToWait
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571 * This is a macro that calls the xQueueGenericReceive() function.
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573 * Receive an item from a queue. The item is received by copy so a buffer of
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574 * adequate size must be provided. The number of bytes copied into the buffer
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575 * was defined when the queue was created.
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577 * Successfully received items are removed from the queue.
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579 * This function must not be used in an interrupt service routine. See
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580 * xQueueReceiveFromISR for an alternative that can.
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582 * @param pxQueue The handle to the queue from which the item is to be
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585 * @param pvBuffer Pointer to the buffer into which the received item will
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588 * @param xTicksToWait The maximum amount of time the task should block
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589 * waiting for an item to receive should the queue be empty at the time
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590 * of the call. xQueueReceive() will return immediately if xTicksToWait
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591 * is zero and the queue is empty. The time is defined in tick periods so the
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592 * constant portTICK_RATE_MS should be used to convert to real time if this is
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595 * @return pdTRUE if an item was successfully received from the queue,
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596 * otherwise pdFALSE.
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602 portCHAR ucMessageID;
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603 portCHAR ucData[ 20 ];
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606 xQueueHandle xQueue;
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608 // Task to create a queue and post a value.
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609 void vATask( void *pvParameters )
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611 struct AMessage *pxMessage;
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613 // Create a queue capable of containing 10 pointers to AMessage structures.
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614 // These should be passed by pointer as they contain a lot of data.
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615 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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618 // Failed to create the queue.
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623 // Send a pointer to a struct AMessage object. Don't block if the
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624 // queue is already full.
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625 pxMessage = & xMessage;
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626 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
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628 // ... Rest of task code.
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631 // Task to receive from the queue.
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632 void vADifferentTask( void *pvParameters )
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634 struct AMessage *pxRxedMessage;
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638 // Receive a message on the created queue. Block for 10 ticks if a
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639 // message is not immediately available.
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640 if( xQueueReceive( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
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642 // pcRxedMessage now points to the struct AMessage variable posted
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647 // ... Rest of task code.
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650 * \defgroup xQueueReceive xQueueReceive
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651 * \ingroup QueueManagement
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653 #define xQueueReceive( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( xQueue, pvBuffer, xTicksToWait, pdFALSE )
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659 portBASE_TYPE xQueueGenericReceive(
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660 xQueueHandle xQueue,
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662 portTickType xTicksToWait
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663 portBASE_TYPE xJustPeek
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666 * It is preferred that the macro xQueueReceive() be used rather than calling
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667 * this function directly.
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669 * Receive an item from a queue. The item is received by copy so a buffer of
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670 * adequate size must be provided. The number of bytes copied into the buffer
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671 * was defined when the queue was created.
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673 * This function must not be used in an interrupt service routine. See
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674 * xQueueReceiveFromISR for an alternative that can.
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676 * @param pxQueue The handle to the queue from which the item is to be
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679 * @param pvBuffer Pointer to the buffer into which the received item will
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682 * @param xTicksToWait The maximum amount of time the task should block
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683 * waiting for an item to receive should the queue be empty at the time
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684 * of the call. The time is defined in tick periods so the constant
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685 * portTICK_RATE_MS should be used to convert to real time if this is required.
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686 * xQueueGenericReceive() will return immediately if the queue is empty and
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687 * xTicksToWait is 0.
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689 * @param xJustPeek When set to true, the item received from the queue is not
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690 * actually removed from the queue - meaning a subsequent call to
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691 * xQueueReceive() will return the same item. When set to false, the item
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692 * being received from the queue is also removed from the queue.
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694 * @return pdTRUE if an item was successfully received from the queue,
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695 * otherwise pdFALSE.
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701 portCHAR ucMessageID;
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702 portCHAR ucData[ 20 ];
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705 xQueueHandle xQueue;
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707 // Task to create a queue and post a value.
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708 void vATask( void *pvParameters )
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710 struct AMessage *pxMessage;
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712 // Create a queue capable of containing 10 pointers to AMessage structures.
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713 // These should be passed by pointer as they contain a lot of data.
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714 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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717 // Failed to create the queue.
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722 // Send a pointer to a struct AMessage object. Don't block if the
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723 // queue is already full.
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724 pxMessage = & xMessage;
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725 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
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727 // ... Rest of task code.
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730 // Task to receive from the queue.
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731 void vADifferentTask( void *pvParameters )
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733 struct AMessage *pxRxedMessage;
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737 // Receive a message on the created queue. Block for 10 ticks if a
\r
738 // message is not immediately available.
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739 if( xQueueGenericReceive( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
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741 // pcRxedMessage now points to the struct AMessage variable posted
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746 // ... Rest of task code.
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749 * \defgroup xQueueReceive xQueueReceive
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750 * \ingroup QueueManagement
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752 signed portBASE_TYPE xQueueGenericReceive( xQueueHandle xQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeek );
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756 * <pre>unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle xQueue );</pre>
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758 * Return the number of messages stored in a queue.
\r
760 * @param xQueue A handle to the queue being queried.
\r
762 * @return The number of messages available in the queue.
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764 * \page uxQueueMessagesWaiting uxQueueMessagesWaiting
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765 * \ingroup QueueManagement
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767 unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle xQueue );
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771 * <pre>void vQueueDelete( xQueueHandle xQueue );</pre>
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773 * Delete a queue - freeing all the memory allocated for storing of items
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774 * placed on the queue.
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776 * @param xQueue A handle to the queue to be deleted.
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778 * \page vQueueDelete vQueueDelete
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779 * \ingroup QueueManagement
\r
781 void vQueueDelete( xQueueHandle xQueue );
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786 portBASE_TYPE xQueueSendToFrontFromISR(
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787 xQueueHandle pxQueue,
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788 const void *pvItemToQueue,
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789 portBASE_TYPE *pxHigherPriorityTaskWoken
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793 * This is a macro that calls xQueueGenericSendFromISR().
\r
795 * Post an item to the front of a queue. It is safe to use this macro from
\r
796 * within an interrupt service routine.
\r
798 * Items are queued by copy not reference so it is preferable to only
\r
799 * queue small items, especially when called from an ISR. In most cases
\r
800 * it would be preferable to store a pointer to the item being queued.
\r
802 * @param xQueue The handle to the queue on which the item is to be posted.
\r
804 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
805 * queue. The size of the items the queue will hold was defined when the
\r
806 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
807 * into the queue storage area.
\r
809 * @param pxHigherPriorityTaskWoken xQueueSendToFrontFromISR() will set
\r
810 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
811 * to unblock, and the unblocked task has a priority higher than the currently
\r
812 * running task. If xQueueSendToFromFromISR() sets this value to pdTRUE then
\r
813 * a context switch should be requested before the interrupt is exited.
\r
815 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
818 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
821 void vBufferISR( void )
\r
824 portBASE_TYPE xHigherPrioritTaskWoken;
\r
826 // We have not woken a task at the start of the ISR.
\r
827 xHigherPriorityTaskWoken = pdFALSE;
\r
829 // Loop until the buffer is empty.
\r
832 // Obtain a byte from the buffer.
\r
833 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
836 xQueueSendToFrontFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
838 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
840 // Now the buffer is empty we can switch context if necessary.
\r
841 if( xHigherPriorityTaskWoken )
\r
848 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
849 * \ingroup QueueManagement
\r
851 #define xQueueSendToFrontFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken, queueSEND_TO_FRONT )
\r
857 portBASE_TYPE xQueueSendToBackFromISR(
\r
858 xQueueHandle pxQueue,
\r
859 const void *pvItemToQueue,
\r
860 portBASE_TYPE *pxHigherPriorityTaskWoken
\r
864 * This is a macro that calls xQueueGenericSendFromISR().
\r
866 * Post an item to the back of a queue. It is safe to use this macro from
\r
867 * within an interrupt service routine.
\r
869 * Items are queued by copy not reference so it is preferable to only
\r
870 * queue small items, especially when called from an ISR. In most cases
\r
871 * it would be preferable to store a pointer to the item being queued.
\r
873 * @param xQueue The handle to the queue on which the item is to be posted.
\r
875 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
876 * queue. The size of the items the queue will hold was defined when the
\r
877 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
878 * into the queue storage area.
\r
880 * @param pxHigherPriorityTaskWoken xQueueSendToBackFromISR() will set
\r
881 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
882 * to unblock, and the unblocked task has a priority higher than the currently
\r
883 * running task. If xQueueSendToBackFromISR() sets this value to pdTRUE then
\r
884 * a context switch should be requested before the interrupt is exited.
\r
886 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
889 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
892 void vBufferISR( void )
\r
895 portBASE_TYPE xHigherPriorityTaskWoken;
\r
897 // We have not woken a task at the start of the ISR.
\r
898 xHigherPriorityTaskWoken = pdFALSE;
\r
900 // Loop until the buffer is empty.
\r
903 // Obtain a byte from the buffer.
\r
904 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
907 xQueueSendToBackFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
909 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
911 // Now the buffer is empty we can switch context if necessary.
\r
912 if( xHigherPriorityTaskWoken )
\r
919 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
920 * \ingroup QueueManagement
\r
922 #define xQueueSendToBackFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken, queueSEND_TO_BACK )
\r
927 portBASE_TYPE xQueueSendFromISR(
\r
928 xQueueHandle pxQueue,
\r
929 const void *pvItemToQueue,
\r
930 portBASE_TYPE *pxHigherPriorityTaskWoken
\r
934 * This is a macro that calls xQueueGenericSendFromISR(). It is included
\r
935 * for backward compatibility with versions of FreeRTOS.org that did not
\r
936 * include the xQueueSendToBackFromISR() and xQueueSendToFrontFromISR()
\r
939 * Post an item to the back of a queue. It is safe to use this function from
\r
940 * within an interrupt service routine.
\r
942 * Items are queued by copy not reference so it is preferable to only
\r
943 * queue small items, especially when called from an ISR. In most cases
\r
944 * it would be preferable to store a pointer to the item being queued.
\r
946 * @param xQueue The handle to the queue on which the item is to be posted.
\r
948 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
949 * queue. The size of the items the queue will hold was defined when the
\r
950 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
951 * into the queue storage area.
\r
953 * @param pxHigherPriorityTaskWoken xQueueSendFromISR() will set
\r
954 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
955 * to unblock, and the unblocked task has a priority higher than the currently
\r
956 * running task. If xQueueSendFromISR() sets this value to pdTRUE then
\r
957 * a context switch should be requested before the interrupt is exited.
\r
959 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
962 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
965 void vBufferISR( void )
\r
968 portBASE_TYPE xHigherPriorityTaskWoken;
\r
970 // We have not woken a task at the start of the ISR.
\r
971 xHigherPriorityTaskWoken = pdFALSE;
\r
973 // Loop until the buffer is empty.
\r
976 // Obtain a byte from the buffer.
\r
977 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
980 xQueueSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
982 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
984 // Now the buffer is empty we can switch context if necessary.
\r
985 if( xHigherPriorityTaskWoken )
\r
987 // Actual macro used here is port specific.
\r
988 taskYIELD_FROM_ISR ();
\r
993 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
994 * \ingroup QueueManagement
\r
996 #define xQueueSendFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken, queueSEND_TO_BACK )
\r
1001 portBASE_TYPE xQueueGenericSendFromISR(
\r
1002 xQueueHandle pxQueue,
\r
1003 const void *pvItemToQueue,
\r
1004 portBASE_TYPE *pxHigherPriorityTaskWoken,
\r
1005 portBASE_TYPE xCopyPosition
\r
1009 * It is preferred that the macros xQueueSendFromISR(),
\r
1010 * xQueueSendToFrontFromISR() and xQueueSendToBackFromISR() be used in place
\r
1011 * of calling this function directly.
\r
1013 * Post an item on a queue. It is safe to use this function from within an
\r
1014 * interrupt service routine.
\r
1016 * Items are queued by copy not reference so it is preferable to only
\r
1017 * queue small items, especially when called from an ISR. In most cases
\r
1018 * it would be preferable to store a pointer to the item being queued.
\r
1020 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1022 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1023 * queue. The size of the items the queue will hold was defined when the
\r
1024 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1025 * into the queue storage area.
\r
1027 * @param pxHigherPriorityTaskWoken xQueueGenericSendFromISR() will set
\r
1028 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1029 * to unblock, and the unblocked task has a priority higher than the currently
\r
1030 * running task. If xQueueGenericSendFromISR() sets this value to pdTRUE then
\r
1031 * a context switch should be requested before the interrupt is exited.
\r
1033 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
\r
1034 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
\r
1035 * at the front of the queue (for high priority messages).
\r
1037 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1040 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1043 void vBufferISR( void )
\r
1046 portBASE_TYPE xHigherPriorityTaskWokenByPost;
\r
1048 // We have not woken a task at the start of the ISR.
\r
1049 xHigherPriorityTaskWokenByPost = pdFALSE;
\r
1051 // Loop until the buffer is empty.
\r
1054 // Obtain a byte from the buffer.
\r
1055 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1057 // Post each byte.
\r
1058 xQueueGenericSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWokenByPost, queueSEND_TO_BACK );
\r
1060 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1062 // Now the buffer is empty we can switch context if necessary. Note that the
\r
1063 // name of the yield function required is port specific.
\r
1064 if( xHigherPriorityTaskWokenByPost )
\r
1066 taskYIELD_YIELD_FROM_ISR();
\r
1071 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1072 * \ingroup QueueManagement
\r
1074 signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE *pxHigherPriorityTaskWoken, portBASE_TYPE xCopyPosition );
\r
1079 portBASE_TYPE xQueueReceiveFromISR(
\r
1080 xQueueHandle pxQueue,
\r
1082 portBASE_TYPE *pxTaskWoken
\r
1086 * Receive an item from a queue. It is safe to use this function from within an
\r
1087 * interrupt service routine.
\r
1089 * @param pxQueue The handle to the queue from which the item is to be
\r
1092 * @param pvBuffer Pointer to the buffer into which the received item will
\r
1095 * @param pxTaskWoken A task may be blocked waiting for space to become
\r
1096 * available on the queue. If xQueueReceiveFromISR causes such a task to
\r
1097 * unblock *pxTaskWoken will get set to pdTRUE, otherwise *pxTaskWoken will
\r
1098 * remain unchanged.
\r
1100 * @return pdTRUE if an item was successfully received from the queue,
\r
1101 * otherwise pdFALSE.
\r
1106 xQueueHandle xQueue;
\r
1108 // Function to create a queue and post some values.
\r
1109 void vAFunction( void *pvParameters )
\r
1111 portCHAR cValueToPost;
\r
1112 const portTickType xBlockTime = ( portTickType )0xff;
\r
1114 // Create a queue capable of containing 10 characters.
\r
1115 xQueue = xQueueCreate( 10, sizeof( portCHAR ) );
\r
1118 // Failed to create the queue.
\r
1123 // Post some characters that will be used within an ISR. If the queue
\r
1124 // is full then this task will block for xBlockTime ticks.
\r
1125 cValueToPost = 'a';
\r
1126 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1127 cValueToPost = 'b';
\r
1128 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1130 // ... keep posting characters ... this task may block when the queue
\r
1133 cValueToPost = 'c';
\r
1134 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1137 // ISR that outputs all the characters received on the queue.
\r
1138 void vISR_Routine( void )
\r
1140 portBASE_TYPE xTaskWokenByReceive = pdFALSE;
\r
1141 portCHAR cRxedChar;
\r
1143 while( xQueueReceiveFromISR( xQueue, ( void * ) &cRxedChar, &xTaskWokenByReceive) )
\r
1145 // A character was received. Output the character now.
\r
1146 vOutputCharacter( cRxedChar );
\r
1148 // If removing the character from the queue woke the task that was
\r
1149 // posting onto the queue cTaskWokenByReceive will have been set to
\r
1150 // pdTRUE. No matter how many times this loop iterates only one
\r
1151 // task will be woken.
\r
1154 if( cTaskWokenByPost != ( portCHAR ) pdFALSE;
\r
1160 * \defgroup xQueueReceiveFromISR xQueueReceiveFromISR
\r
1161 * \ingroup QueueManagement
\r
1163 signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken );
\r
1166 * Utilities to query queue that are safe to use from an ISR. These utilities
\r
1167 * should be used only from witin an ISR, or within a critical section.
\r
1169 signed portBASE_TYPE xQueueIsQueueEmptyFromISR( const xQueueHandle pxQueue );
\r
1170 signed portBASE_TYPE xQueueIsQueueFullFromISR( const xQueueHandle pxQueue );
\r
1171 unsigned portBASE_TYPE uxQueueMessagesWaitingFromISR( const xQueueHandle pxQueue );
\r
1175 * xQueueAltGenericSend() is an alternative version of xQueueGenericSend().
\r
1176 * Likewise xQueueAltGenericReceive() is an alternative version of
\r
1177 * xQueueGenericReceive().
\r
1179 * The source code that implements the alternative (Alt) API is much
\r
1180 * simpler because it executes everything from within a critical section.
\r
1181 * This is the approach taken by many other RTOSes, but FreeRTOS.org has the
\r
1182 * preferred fully featured API too. The fully featured API has more
\r
1183 * complex code that takes longer to execute, but makes much less use of
\r
1184 * critical sections. Therefore the alternative API sacrifices interrupt
\r
1185 * responsiveness to gain execution speed, whereas the fully featured API
\r
1186 * sacrifices execution speed to ensure better interrupt responsiveness.
\r
1188 signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );
\r
1189 signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking );
\r
1190 #define xQueueAltSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( xQueue, pvItemToQueue, xTicksToWait, queueSEND_TO_FRONT )
\r
1191 #define xQueueAltSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( xQueue, pvItemToQueue, xTicksToWait, queueSEND_TO_BACK )
\r
1192 #define xQueueAltReceive( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( xQueue, pvBuffer, xTicksToWait, pdFALSE )
\r
1193 #define xQueueAltPeek( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( xQueue, pvBuffer, xTicksToWait, pdTRUE )
\r
1196 * The functions defined above are for passing data to and from tasks. The
\r
1197 * functions below are the equivalents for passing data to and from
\r
1200 * These functions are called from the co-routine macro implementation and
\r
1201 * should not be called directly from application code. Instead use the macro
\r
1202 * wrappers defined within croutine.h.
\r
1204 signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken );
\r
1205 signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken );
\r
1206 signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait );
\r
1207 signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait );
\r
1210 * For internal use only. Use xSemaphoreCreateMutex() or
\r
1211 * xSemaphoreCreateCounting() instead of calling these functions directly.
\r
1213 xQueueHandle xQueueCreateMutex( void );
\r
1214 xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount );
\r
1217 * For internal use only. Use xSemaphoreTakeMutexRecursive() or
\r
1218 * xSemaphoreGiveMutexRecursive() instead of calling these functions directly.
\r
1220 portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle xMutex, portTickType xBlockTime );
\r
1221 portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle xMutex );
\r
1224 * The registry is provided as a means for kernel aware debuggers to
\r
1225 * locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
\r
1226 * a queue, semaphore or mutex handle to the registry if you want the handle
\r
1227 * to be available to a kernel aware debugger. If you are not using a kernel
\r
1228 * aware debugger then this function can be ignored.
\r
1230 * configQUEUE_REGISTRY_SIZE defines the maximum number of handles the
\r
1231 * registry can hold. configQUEUE_REGISTRY_SIZE must be greater than 0
\r
1232 * within FreeRTOSConfig.h for the registry to be available. Its value
\r
1233 * does not effect the number of queues, semaphores and mutexes that can be
\r
1234 * created - just the number that the registry can hold.
\r
1236 * @param xQueue The handle of the queue being added to the registry. This
\r
1237 * is the handle returned by a call to xQueueCreate(). Semaphore and mutex
\r
1238 * handles can also be passed in here.
\r
1240 * @param pcName The name to be associated with the handle. This is the
\r
1241 * name that the kernel aware debugger will display.
\r
1243 #if configQUEUE_REGISTRY_SIZE > 0
\r
1244 void vQueueAddToRegistry( xQueueHandle xQueue, signed portCHAR *pcName );
\r
1250 #ifdef __cplusplus
\r
1254 #endif /* QUEUE_H */
\r
projects / freertos / blob