2 FreeRTOS V7.6.0 - Copyright (C) 2013 Real Time Engineers Ltd.
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5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS provides completely free yet professionally developed, *
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10 * robust, strictly quality controlled, supported, and cross *
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11 * platform software that has become a de facto standard. *
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13 * Help yourself get started quickly and support the FreeRTOS *
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14 * project by purchasing a FreeRTOS tutorial book, reference *
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15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
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19 ***************************************************************************
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21 This file is part of the FreeRTOS distribution.
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23 FreeRTOS is free software; you can redistribute it and/or modify it under
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24 the terms of the GNU General Public License (version 2) as published by the
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25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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27 >>! NOTE: The modification to the GPL is included to allow you to distribute
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28 >>! a combined work that includes FreeRTOS without being obliged to provide
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29 >>! the source code for proprietary components outside of the FreeRTOS
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32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
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35 link: http://www.freertos.org/a00114.html
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39 ***************************************************************************
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41 * Having a problem? Start by reading the FAQ "My application does *
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42 * not run, what could be wrong?" *
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44 * http://www.FreeRTOS.org/FAQHelp.html *
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46 ***************************************************************************
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48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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49 license and Real Time Engineers Ltd. contact details.
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51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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57 licenses offer ticketed support, indemnification and middleware.
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59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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60 engineered and independently SIL3 certified version for use in safety and
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61 mission critical applications that require provable dependability.
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66 /* Standard includes. */
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69 /* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
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70 all the API functions to use the MPU wrappers. That should only be done when
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71 task.h is included from an application file. */
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72 #define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
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74 /* FreeRTOS includes. */
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75 #include "FreeRTOS.h"
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78 #include "event_groups.h"
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80 /* Lint e961 and e750 are suppressed as a MISRA exception justified because the
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81 MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be defined for the
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82 header files above, but not in this file, in order to generate the correct
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83 privileged Vs unprivileged linkage and placement. */
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84 #undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*lint !e961 !e750. */
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86 #if ( INCLUDE_xEventGroupSetBitFromISR == 1 ) && ( configUSE_TIMERS == 0 )
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87 #error configUSE_TIMERS must be set to 1 to make the xEventGroupSetBitFromISR() function available.
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90 #if ( INCLUDE_xEventGroupSetBitFromISR == 1 ) && ( INCLUDE_xTimerPendCallbackFromISR == 0 )
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91 #error INCLUDE_xTimerPendCallbackFromISR must also be set to one to make the xEventGroupSetBitFromISR() function available.
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95 #if configUSE_16_BIT_TICKS == 1
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96 #define taskCLEAR_EVENTS_ON_EXIT_BIT 0x0100U
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97 #define taskUNBLOCKED_DUE_TO_BIT_SET_BIT 0x0200U
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98 #define taskWAIT_FOR_ALL_BITS 0x0400U
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99 #define taskEVENT_BITS_CONTROL_BYTES 0xff00U
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101 #define taskCLEAR_EVENTS_ON_EXIT_BIT 0x01000000UL
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102 #define taskUNBLOCKED_DUE_TO_BIT_SET_BIT 0x02000000UL
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103 #define taskWAIT_FOR_ALL_BITS 0x04000000UL
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104 #define taskEVENT_BITS_CONTROL_BYTES 0xff000000UL
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107 typedef struct EventBitsDefinition
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109 xEventBitsType uxEventBits;
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110 xList xTasksWaitingForBits; /*< List of tasks waiting for a bit to be set. */
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113 /* Used internally only. */
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114 typedef struct EVENT_GROUP_CALLBACK_PARAMTERS
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116 xEventGroupHandle xTargetEventGroup;
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117 xEventBitsType xBitsToSet;
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118 } xEventGroupCallbackParameters;
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120 /*-----------------------------------------------------------*/
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122 xEventGroupHandle xEventGroupCreate( void )
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124 xEVENT_BITS *pxEventBits;
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126 pxEventBits = pvPortMalloc( sizeof( xEVENT_BITS ) );
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127 if( pxEventBits != NULL )
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129 pxEventBits->uxEventBits = 0;
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130 vListInitialise( &( pxEventBits->xTasksWaitingForBits ) );
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133 return ( xEventGroupHandle ) pxEventBits;
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135 /*-----------------------------------------------------------*/
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137 xEventBitsType xEventGroupSync( xEventGroupHandle xEventGroup, xEventBitsType uxBitsToSet, xEventBitsType uxBitsToWaitFor, portTickType xBlockTime )
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139 xEventBitsType uxOriginalBitValue, uxReturn;
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140 xEVENT_BITS *pxEventBits = ( xEVENT_BITS * ) xEventGroup;
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141 portBASE_TYPE xYieldedAlready;
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145 uxOriginalBitValue = pxEventBits->uxEventBits;
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147 ( void ) xEventGroupSetBits( xEventGroup, uxBitsToSet );
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149 if( ( ( uxOriginalBitValue | uxBitsToSet ) & uxBitsToWaitFor ) == uxBitsToWaitFor )
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151 /* All the rendezvous bits will have been set once this task set
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152 its bits - no need to block. */
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153 uxReturn = ( uxOriginalBitValue | uxBitsToSet );
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155 /* Rendezvous always clear the bits. They will have been cleared
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156 already unless this is the only task in the rendezvous. */
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157 pxEventBits->uxEventBits &= uxBitsToWaitFor;
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163 if( xBlockTime != ( portTickType ) 0 )
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165 /* Store the bits that the calling task is waiting for in the
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166 task's event list item so the kernel knows when a match is
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167 found. Then enter the blocked state. */
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168 vTaskPlaceOnUnorderedEventList( &( pxEventBits->xTasksWaitingForBits ), ( uxBitsToWaitFor | taskCLEAR_EVENTS_ON_EXIT_BIT | taskWAIT_FOR_ALL_BITS ), xBlockTime );
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172 /* The rendezvous bits were not set, but no block time was
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173 specified - just return the current event bit value. */
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174 uxReturn = pxEventBits->uxEventBits;
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178 xYieldedAlready = xTaskResumeAll();
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180 if( xBlockTime != ( portTickType ) 0 )
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182 if( xYieldedAlready == pdFALSE )
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184 portYIELD_WITHIN_API();
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187 /* The task blocked to wait for its required bits to be set - at this
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188 point either the required bits were set or the block time expired. If
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189 the required bits were set they will have been stored in the task's
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190 event list item, and they should now be retrieved then cleared. */
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191 uxReturn = uxTaskResetEventItemValue();
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193 if( ( uxReturn & taskUNBLOCKED_DUE_TO_BIT_SET_BIT ) == ( xEventBitsType ) 0 )
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195 /* The task timed out, just return the current event bit value. */
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196 uxReturn = pxEventBits->uxEventBits;
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200 /* The task unblocked because the bits were set. Clear the control
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201 bits before returning the value. */
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202 uxReturn &= ~taskEVENT_BITS_CONTROL_BYTES;
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208 /*-----------------------------------------------------------*/
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210 xEventBitsType xEventGroupWaitBits( xEventGroupHandle xEventGroup, xEventBitsType uxBitsToWaitFor, portBASE_TYPE xClearOnExit, portBASE_TYPE xWaitForAllBits, portTickType xBlockTime )
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212 xEVENT_BITS *pxEventBits = ( xEVENT_BITS * ) xEventGroup;
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213 const xEventBitsType uxCurrentEventBits = pxEventBits->uxEventBits;
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214 xEventBitsType uxReturn, uxControlBits = 0;
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216 /* Check the user is not attempting to wait on the bits used by the kernel
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217 itself, and that at least one bit is being requested. */
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218 configASSERT( ( uxBitsToWaitFor & taskEVENT_BITS_CONTROL_BYTES ) == 0 );
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219 configASSERT( uxBitsToWaitFor != 0 );
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221 taskENTER_CRITICAL();
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223 if( xWaitForAllBits == pdFALSE )
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225 /* Task only has to wait for one bit within uxBitsToWaitFor to be set. Is
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226 one already set? */
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227 if( ( uxCurrentEventBits & uxBitsToWaitFor ) != ( xEventBitsType ) 0 )
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229 /* At least one of the bits was set. No need to block. */
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235 /* Task has to wait for all the bits in uxBitsToWaitFor to be set. Are they
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237 if( ( uxCurrentEventBits & uxBitsToWaitFor ) == uxBitsToWaitFor )
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239 /* All the bits were set, no need to block. */
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244 /* The task can return now if either its wait condition is already met
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245 or the requested block time is 0. */
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246 if( xBlockTime == ( portTickType ) 0 )
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248 /* No need to block, just set the return value. */
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249 uxReturn = uxCurrentEventBits;
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251 if( xClearOnExit != pdFALSE )
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253 /* The user requested the bits be cleared again prior to exiting
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255 pxEventBits->uxEventBits &= ~uxBitsToWaitFor;
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260 /* The task is going to block to wait for its required bits to be
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261 set. uxControlBits are used to remember the specified behaviour of
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262 this call to xEventGroupWaitBits() - for use when the event bits
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263 unblock the task. */
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264 if( xClearOnExit != pdFALSE )
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266 uxControlBits |= taskCLEAR_EVENTS_ON_EXIT_BIT;
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269 if( xWaitForAllBits != pdFALSE )
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271 uxControlBits |= taskWAIT_FOR_ALL_BITS;
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274 /* Store the bits that the calling task is waiting for in the
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275 task's event list item so the kernel knows when a match is
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276 found. Then enter the blocked state. */
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277 vTaskPlaceOnUnorderedEventList( &( pxEventBits->xTasksWaitingForBits ), ( uxBitsToWaitFor | uxControlBits ), xBlockTime );
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278 portYIELD_WITHIN_API();
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281 taskEXIT_CRITICAL();
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283 if( xBlockTime != ( portTickType ) 0 )
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285 /* The task blocked to wait for its required bits to be set - at this
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286 point either the required bits were set or the block time expired. If
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287 the required bits were set they will have been stored in the task's
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288 event list item, and they should now be retrieved then cleared. */
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289 uxReturn = uxTaskResetEventItemValue();
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291 if( ( uxReturn & taskUNBLOCKED_DUE_TO_BIT_SET_BIT ) == ( xEventBitsType ) 0 )
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293 /* The task timed out, just return the current event bit value. */
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294 uxReturn = pxEventBits->uxEventBits;
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298 /* The task unblocked because the bits were set. Clear the control
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299 bits before returning the value. */
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300 uxReturn &= ~taskEVENT_BITS_CONTROL_BYTES;
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306 /*-----------------------------------------------------------*/
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308 xEventBitsType xEventGroupClearBits( xEventGroupHandle xEventGroup, xEventBitsType uxBitsToClear )
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310 xEVENT_BITS *pxEventBits = ( xEVENT_BITS * ) xEventGroup;
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311 xEventBitsType uxReturn;
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313 /* Check the user is not attempting to clear the bits used by the kernel
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315 configASSERT( ( uxBitsToClear & taskEVENT_BITS_CONTROL_BYTES ) == 0 );
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317 uxBitsToClear = ~uxBitsToClear;
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318 taskENTER_CRITICAL();
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320 /* The value returned is the event group value prior to the bits being
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322 uxReturn = pxEventBits->uxEventBits;
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324 /* Clear the bits. */
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325 pxEventBits->uxEventBits &= uxBitsToClear;
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327 taskEXIT_CRITICAL();
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331 /*-----------------------------------------------------------*/
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333 xEventBitsType xEventGroupSetBits( xEventGroupHandle xEventGroup, xEventBitsType uxBitsToSet )
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335 xListItem *pxListItem, *pxNext;
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336 xListItem const *pxListEnd;
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338 xEventBitsType uxBitsToClear = 0, uxBitsWaitedFor, uxControlBits;
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339 xEVENT_BITS *pxEventBits = ( xEVENT_BITS * ) xEventGroup;
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340 portBASE_TYPE xMatchFound = pdFALSE;
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342 /* Check the user is not attempting to set the bits used by the kernel
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344 configASSERT( ( uxBitsToSet & taskEVENT_BITS_CONTROL_BYTES ) == 0 );
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346 pxList = &( pxEventBits->xTasksWaitingForBits );
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347 pxListEnd = listGET_END_MARKER( pxList ); /*lint !e826 !e740 The mini list structure is used as the list end to save RAM. This is checked and valid. */
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348 pxListItem = listGET_HEAD_ENTRY( pxList );
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351 /* Set the bits. */
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352 pxEventBits->uxEventBits |= uxBitsToSet;
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354 /* See if the new bit value should unblock any tasks. */
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355 while( pxListItem != pxListEnd )
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357 pxNext = listGET_NEXT( pxListItem );
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358 uxBitsWaitedFor = listGET_LIST_ITEM_VALUE( pxListItem );
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360 /* Split the bits waited for from the control bits. */
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361 uxControlBits = uxBitsWaitedFor & taskEVENT_BITS_CONTROL_BYTES;
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362 uxBitsWaitedFor &= ~taskEVENT_BITS_CONTROL_BYTES;
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364 if( ( uxControlBits & taskWAIT_FOR_ALL_BITS ) == ( xEventBitsType ) 0 )
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366 /* Just looking for single bit being set. */
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367 if( ( uxBitsWaitedFor & pxEventBits->uxEventBits ) != ( xEventBitsType ) 0 )
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369 xMatchFound = pdTRUE;
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372 else if( ( uxBitsWaitedFor & pxEventBits->uxEventBits ) == uxBitsWaitedFor )
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374 /* All bits are set. */
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375 xMatchFound = pdTRUE;
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379 /* Need all bits to be set, but not all the bits were set. */
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382 if( xMatchFound != pdFALSE )
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384 /* The bits match. Should the bits be cleared on exit? */
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385 if( ( uxControlBits & taskCLEAR_EVENTS_ON_EXIT_BIT ) != ( xEventBitsType ) 0 )
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387 uxBitsToClear |= uxBitsWaitedFor;
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390 /* Store the actual event flag value in the task's event list
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391 item before removing the task from the event list. The
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392 taskUNBLOCKED_DUE_TO_BIT_SET_BIT bit is set so the task knows
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393 that is was unblocked due to its required bits matching, rather
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394 than because it timed out. */
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395 ( void ) xTaskRemoveFromUnorderedEventList( pxListItem, pxEventBits->uxEventBits | taskUNBLOCKED_DUE_TO_BIT_SET_BIT );
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398 /* Move onto the next list item. Note pxListItem->pxNext is not
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399 used here as the list item may have been removed from the event list
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400 and inserted into the ready/pending reading list. */
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401 pxListItem = pxNext;
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404 /* Clear any bits that matched when the taskCLEAR_EVENTS_ON_EXIT_BIT
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405 bit was set in the control word. */
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406 pxEventBits->uxEventBits &= ~uxBitsToClear;
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408 ( void ) xTaskResumeAll();
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410 return pxEventBits->uxEventBits;
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412 /*-----------------------------------------------------------*/
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414 void vEventGroupDelete( xEventGroupHandle xEventGroup )
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416 xEVENT_BITS *pxEventBits = ( xEVENT_BITS * ) xEventGroup;
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417 const xList *pxTasksWaitingForBits = &( pxEventBits->xTasksWaitingForBits );
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421 while( listCURRENT_LIST_LENGTH( pxTasksWaitingForBits ) > ( unsigned portBASE_TYPE ) 0 )
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423 /* Unblock the task, returning 0 as the event list is being deleted
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424 and cannot therefore have any bits set. */
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425 configASSERT( pxTasksWaitingForBits->xListEnd.pxNext != ( xListItem * ) &( pxTasksWaitingForBits->xListEnd ) );
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426 ( void ) xTaskRemoveFromUnorderedEventList( pxTasksWaitingForBits->xListEnd.pxNext, ( portTickType ) 0 );
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429 vPortFree( pxEventBits );
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431 ( void ) xTaskResumeAll();
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433 /*-----------------------------------------------------------*/
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435 /* For internal use only - execute a 'set bits' command that was pended from
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437 void vEventGroupSetBitsCallback( void *pvEventGroup, unsigned long ulBitsToSet )
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439 ( void ) xEventGroupSetBits( pvEventGroup, ( xEventBitsType ) ulBitsToSet );
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