2 FreeRTOS.org V4.1.0 - Copyright (C) 2003-2006 Richard Barry.
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4 This file is part of the FreeRTOS.org distribution.
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6 FreeRTOS.org is free software; you can redistribute it and/or modify
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7 it under the terms of the GNU General Public License as published by
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8 the Free Software Foundation; either version 2 of the License, or
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9 (at your option) any later version.
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11 FreeRTOS.org is distributed in the hope that it will be useful,
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12 but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 GNU General Public License for more details.
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16 You should have received a copy of the GNU General Public License
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17 along with FreeRTOS.org; if not, write to the Free Software
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18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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20 A special exception to the GPL can be applied should you wish to distribute
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21 a combined work that includes FreeRTOS.org, without being obliged to provide
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22 the source code for any proprietary components. See the licensing section
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23 of http://www.FreeRTOS.org for full details of how and when the exception
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26 ***************************************************************************
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27 See http://www.FreeRTOS.org for documentation, latest information, license
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28 and contact details. Please ensure to read the configuration and relevant
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29 port sections of the online documentation.
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30 ***************************************************************************
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36 #include "portable.h"
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39 /*-----------------------------------------------------------
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40 * MACROS AND DEFINITIONS
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41 *----------------------------------------------------------*/
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43 #define tskKERNEL_VERSION_NUMBER "V4.1.0"
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48 * Type by which tasks are referenced. For example, a call to xTaskCreate
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49 * returns (via a pointer parameter) an xTaskHandle variable that can then
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50 * be used as a parameter to vTaskDelete to delete the task.
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52 * \page xTaskHandle xTaskHandle
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55 typedef void * xTaskHandle;
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58 * Used internally only.
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60 typedef struct xTIME_OUT
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62 portBASE_TYPE xOverflowCount;
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63 portTickType xTimeOnEntering;
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67 * Defines the priority used by the idle task. This must not be modified.
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69 * \ingroup TaskUtils
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71 #define tskIDLE_PRIORITY ( ( unsigned portBASE_TYPE ) 0 )
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76 * Macro for forcing a context switch.
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78 * \page taskYIELD taskYIELD
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79 * \ingroup SchedulerControl
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81 #define taskYIELD() portYIELD()
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86 * Macro to mark the start of a critical code region. Preemptive context
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87 * switches cannot occur when in a critical region.
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89 * NOTE: This may alter the stack (depending on the portable implementation)
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90 * so must be used with care!
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92 * \page taskENTER_CRITICAL taskENTER_CRITICAL
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93 * \ingroup SchedulerControl
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95 #define taskENTER_CRITICAL() portENTER_CRITICAL()
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100 * Macro to mark the end of a critical code region. Preemptive context
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101 * switches cannot occur when in a critical region.
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103 * NOTE: This may alter the stack (depending on the portable implementation)
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104 * so must be used with care!
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106 * \page taskEXIT_CRITICAL taskEXIT_CRITICAL
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107 * \ingroup SchedulerControl
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109 #define taskEXIT_CRITICAL() portEXIT_CRITICAL()
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114 * Macro to disable all maskable interrupts.
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116 * \page taskDISABLE_INTERRUPTS taskDISABLE_INTERRUPTS
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117 * \ingroup SchedulerControl
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119 #define taskDISABLE_INTERRUPTS() portDISABLE_INTERRUPTS()
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124 * Macro to enable microcontroller interrupts.
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126 * \page taskENABLE_INTERRUPTS taskENABLE_INTERRUPTS
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127 * \ingroup SchedulerControl
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129 #define taskENABLE_INTERRUPTS() portENABLE_INTERRUPTS()
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132 /*-----------------------------------------------------------
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133 * TASK CREATION API
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134 *----------------------------------------------------------*/
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139 portBASE_TYPE xTaskCreate(
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140 pdTASK_CODE pvTaskCode,
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141 const portCHAR * const pcName,
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142 unsigned portSHORT usStackDepth,
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143 void *pvParameters,
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144 unsigned portBASE_TYPE uxPriority,
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145 xTaskHandle *pvCreatedTask
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148 * Create a new task and add it to the list of tasks that are ready to run.
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150 * @param pvTaskCode Pointer to the task entry function. Tasks
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151 * must be implemented to never return (i.e. continuous loop).
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153 * @param pcName A descriptive name for the task. This is mainly used to
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154 * facilitate debugging. Max length defined by tskMAX_TASK_NAME_LEN - default
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157 * @param usStackDepth The size of the task stack specified as the number of
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158 * variables the stack can hold - not the number of bytes. For example, if
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159 * the stack is 16 bits wide and usStackDepth is defined as 100, 200 bytes
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160 * will be allocated for stack storage.
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162 * @param pvParameters Pointer that will be used as the parameter for the task
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165 * @param uxPriority The priority at which the task should run.
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167 * @param pvCreatedTask Used to pass back a handle by which the created task
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168 * can be referenced.
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170 * @return pdPASS if the task was successfully created and added to a ready
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171 * list, otherwise an error code defined in the file errors. h
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175 // Task to be created.
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176 void vTaskCode( void * pvParameters )
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180 // Task code goes here.
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184 // Function that creates a task.
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185 void vOtherFunction( void )
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187 unsigned char ucParameterToPass;
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188 xTaskHandle xHandle;
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190 // Create the task, storing the handle.
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191 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle );
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193 // Use the handle to delete the task.
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194 vTaskDelete( xHandle );
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197 * \defgroup xTaskCreate xTaskCreate
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200 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pvCreatedTask );
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204 * <pre>void vTaskDelete( xTaskHandle pxTask );</pre>
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206 * INCLUDE_vTaskDelete must be defined as 1 for this function to be available.
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207 * See the configuration section for more information.
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209 * Remove a task from the RTOS real time kernels management. The task being
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210 * deleted will be removed from all ready, blocked, suspended and event lists.
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212 * NOTE: The idle task is responsible for freeing the kernel allocated
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213 * memory from tasks that have been deleted. It is therefore important that
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214 * the idle task is not starved of microcontroller processing time if your
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215 * application makes any calls to vTaskDelete (). Memory allocated by the
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216 * task code is not automatically freed, and should be freed before the task
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219 * See the demo application file death.c for sample code that utilises
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222 * @param pxTask The handle of the task to be deleted. Passing NULL will
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223 * cause the calling task to be deleted.
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227 void vOtherFunction( void )
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229 xTaskHandle xHandle;
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231 // Create the task, storing the handle.
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232 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
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234 // Use the handle to delete the task.
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235 vTaskDelete( xHandle );
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238 * \defgroup vTaskDelete vTaskDelete
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241 void vTaskDelete( xTaskHandle pxTask );
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244 /*-----------------------------------------------------------
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246 *----------------------------------------------------------*/
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250 * <pre>void vTaskDelay( portTickType xTicksToDelay );</pre>
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252 * Delay a task for a given number of ticks. The actual time that the
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253 * task remains blocked depends on the tick rate. The constant
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254 * portTICK_RATE_MS can be used to calculate real time from the tick
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255 * rate - with the resolution of one tick period.
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257 * INCLUDE_vTaskDelay must be defined as 1 for this function to be available.
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258 * See the configuration section for more information.
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260 * @param xTicksToDelay The amount of time, in tick periods, that
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261 * the calling task should block.
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265 // Wait 10 ticks before performing an action.
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267 // This is for demonstration only and would be better achieved
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268 // using vTaskDelayUntil ().
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269 void vTaskFunction( void * pvParameters )
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271 portTickType xDelay, xNextTime;
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273 // Calc the time at which we want to perform the action
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275 xNextTime = xTaskGetTickCount () + ( portTickType ) 10;
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279 xDelay = xNextTime - xTaskGetTickCount ();
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280 xNextTime += ( portTickType ) 10;
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282 // Guard against overflow
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283 if( xDelay <= ( portTickType ) 10 )
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285 vTaskDelay( xDelay );
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288 // Perform action here.
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292 * \defgroup vTaskDelay vTaskDelay
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293 * \ingroup TaskCtrl
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295 void vTaskDelay( portTickType xTicksToDelay );
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299 * <pre>void vTaskDelayUntil( portTickType *pxPreviousWakeTime, portTickType xTimeIncrement );</pre>
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301 * INCLUDE_vTaskDelayUntil must be defined as 1 for this function to be available.
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302 * See the configuration section for more information.
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304 * Delay a task until a specified time. This function can be used by cyclical
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305 * tasks to ensure a constant execution frequency.
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307 * This function differs from vTaskDelay () in one important aspect: vTaskDelay () will
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308 * cause a task to block for the specified number of ticks from the time vTaskDelay () is
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309 * called. It is therefore difficult to use vTaskDelay () by itself to generate a fixed
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310 * execution frequency as the time between a task starting to execute and that task
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311 * calling vTaskDelay () may not be fixed [the task may take a different path though the
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312 * code between calls, or may get interrupted or preempted a different number of times
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313 * each time it executes].
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315 * Whereas vTaskDelay () specifies a wake time relative to the time at which the function
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316 * is called, vTaskDelayUntil () specifies the absolute (exact) time at which it wishes to
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319 * The constant portTICK_RATE_MS can be used to calculate real time from the tick
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320 * rate - with the resolution of one tick period.
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322 * @param pxPreviousWakeTime Pointer to a variable that holds the time at which the
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323 * task was last unblocked. The variable must be initialised with the current time
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324 * prior to its first use (see the example below). Following this the variable is
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325 * automatically updated within vTaskDelayUntil ().
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327 * @param xTimeIncrement The cycle time period. The task will be unblocked at
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328 * time *pxPreviousWakeTime + xTimeIncrement. Calling vTaskDelayUntil with the
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329 * same xTimeIncrement parameter value will cause the task to execute with
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330 * a fixed interface period.
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334 // Perform an action every 10 ticks.
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335 void vTaskFunction( void * pvParameters )
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337 portTickType xLastWakeTime;
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338 const portTickType xFrequency = 10;
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340 // Initialise the xLastWakeTime variable with the current time.
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341 xLastWakeTime = xTaskGetTickCount ();
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344 // Wait for the next cycle.
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345 vTaskDelayUntil( &xLastWakeTime, xFrequency );
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347 // Perform action here.
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351 * \defgroup vTaskDelayUntil vTaskDelayUntil
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352 * \ingroup TaskCtrl
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354 void vTaskDelayUntil( portTickType *pxPreviousWakeTime, portTickType xTimeIncrement );
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358 * <pre>unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask );</pre>
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360 * INCLUDE_xTaskPriorityGet must be defined as 1 for this function to be available.
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361 * See the configuration section for more information.
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363 * Obtain the priority of any task.
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365 * @param pxTask Handle of the task to be queried. Passing a NULL
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366 * handle results in the priority of the calling task being returned.
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368 * @return The priority of pxTask.
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372 void vAFunction( void )
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374 xTaskHandle xHandle;
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376 // Create a task, storing the handle.
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377 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
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381 // Use the handle to obtain the priority of the created task.
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382 // It was created with tskIDLE_PRIORITY, but may have changed
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384 if( uxTaskPriorityGet( xHandle ) != tskIDLE_PRIORITY )
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386 // The task has changed it's priority.
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391 // Is our priority higher than the created task?
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392 if( uxTaskPriorityGet( xHandle ) < uxTaskPriorityGet( NULL ) )
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394 // Our priority (obtained using NULL handle) is higher.
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398 * \defgroup uxTaskPriorityGet uxTaskPriorityGet
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399 * \ingroup TaskCtrl
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401 unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask );
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405 * <pre>void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority );</pre>
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407 * INCLUDE_vTaskPrioritySet must be defined as 1 for this function to be available.
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408 * See the configuration section for more information.
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410 * Set the priority of any task.
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412 * A context switch will occur before the function returns if the priority
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413 * being set is higher than the currently executing task.
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415 * @param pxTask Handle to the task for which the priority is being set.
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416 * Passing a NULL handle results in the priority of the calling task being set.
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418 * @param uxNewPriority The priority to which the task will be set.
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422 void vAFunction( void )
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424 xTaskHandle xHandle;
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426 // Create a task, storing the handle.
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427 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
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431 // Use the handle to raise the priority of the created task.
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432 vTaskPrioritySet( xHandle, tskIDLE_PRIORITY + 1 );
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436 // Use a NULL handle to raise our priority to the same value.
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437 vTaskPrioritySet( NULL, tskIDLE_PRIORITY + 1 );
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440 * \defgroup vTaskPrioritySet vTaskPrioritySet
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441 * \ingroup TaskCtrl
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443 void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority );
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447 * <pre>void vTaskSuspend( xTaskHandle pxTaskToSuspend );</pre>
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449 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
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450 * See the configuration section for more information.
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452 * Suspend any task. When suspended a task will never get any microcontroller
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453 * processing time, no matter what its priority.
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455 * Calls to vTaskSuspend are not accumulative -
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456 * i.e. calling vTaskSuspend () twice on the same task still only requires one
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457 * call to vTaskResume () to ready the suspended task.
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459 * @param pxTaskToSuspend Handle to the task being suspended. Passing a NULL
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460 * handle will cause the calling task to be suspended.
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464 void vAFunction( void )
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466 xTaskHandle xHandle;
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468 // Create a task, storing the handle.
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469 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
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473 // Use the handle to suspend the created task.
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474 vTaskSuspend( xHandle );
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478 // The created task will not run during this period, unless
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479 // another task calls vTaskResume( xHandle ).
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484 // Suspend ourselves.
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485 vTaskSuspend( NULL );
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487 // We cannot get here unless another task calls vTaskResume
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488 // with our handle as the parameter.
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491 * \defgroup vTaskSuspend vTaskSuspend
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492 * \ingroup TaskCtrl
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494 void vTaskSuspend( xTaskHandle pxTaskToSuspend );
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498 * <pre>void vTaskResume( xTaskHandle pxTaskToResume );</pre>
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500 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
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501 * See the configuration section for more information.
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503 * Resumes a suspended task.
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505 * A task that has been suspended by one of more calls to vTaskSuspend ()
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506 * will be made available for running again by a single call to
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509 * @param pxTaskToResume Handle to the task being readied.
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513 void vAFunction( void )
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515 xTaskHandle xHandle;
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517 // Create a task, storing the handle.
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518 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
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522 // Use the handle to suspend the created task.
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523 vTaskSuspend( xHandle );
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527 // The created task will not run during this period, unless
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528 // another task calls vTaskResume( xHandle ).
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533 // Resume the suspended task ourselves.
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534 vTaskResume( xHandle );
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536 // The created task will once again get microcontroller processing
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537 // time in accordance with it priority within the system.
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540 * \defgroup vTaskResume vTaskResume
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541 * \ingroup TaskCtrl
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543 void vTaskResume( xTaskHandle pxTaskToResume );
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547 * <pre>void xTaskResumeFromISR( xTaskHandle pxTaskToResume );</pre>
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549 * INCLUDE_xTaskResumeFromISR must be defined as 1 for this function to be
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550 * available. See the configuration section for more information.
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552 * An implementation of vTaskResume() that can be called from within an ISR.
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554 * A task that has been suspended by one of more calls to vTaskSuspend ()
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555 * will be made available for running again by a single call to
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556 * xTaskResumeFromISR ().
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558 * @param pxTaskToResume Handle to the task being readied.
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560 * \defgroup vTaskResumeFromISR vTaskResumeFromISR
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561 * \ingroup TaskCtrl
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563 portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume );
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565 /*-----------------------------------------------------------
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566 * SCHEDULER CONTROL
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567 *----------------------------------------------------------*/
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571 * <pre>void vTaskStartScheduler( void );</pre>
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573 * Starts the real time kernel tick processing. After calling the kernel
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574 * has control over which tasks are executed and when. This function
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575 * does not return until an executing task calls vTaskEndScheduler ().
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577 * At least one task should be created via a call to xTaskCreate ()
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578 * before calling vTaskStartScheduler (). The idle task is created
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579 * automatically when the first application task is created.
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581 * See the demo application file main.c for an example of creating
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582 * tasks and starting the kernel.
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586 void vAFunction( void )
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588 // Create at least one task before starting the kernel.
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589 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
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591 // Start the real time kernel with preemption.
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592 vTaskStartScheduler ();
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594 // Will not get here unless a task calls vTaskEndScheduler ()
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598 * \defgroup vTaskStartScheduler vTaskStartScheduler
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599 * \ingroup SchedulerControl
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601 void vTaskStartScheduler( void );
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605 * <pre>void vTaskEndScheduler( void );</pre>
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607 * Stops the real time kernel tick. All created tasks will be automatically
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608 * deleted and multitasking (either preemptive or cooperative) will
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609 * stop. Execution then resumes from the point where vTaskStartScheduler ()
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610 * was called, as if vTaskStartScheduler () had just returned.
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612 * See the demo application file main. c in the demo/PC directory for an
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613 * example that uses vTaskEndScheduler ().
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615 * vTaskEndScheduler () requires an exit function to be defined within the
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616 * portable layer (see vPortEndScheduler () in port. c for the PC port). This
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617 * performs hardware specific operations such as stopping the kernel tick.
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619 * vTaskEndScheduler () will cause all of the resources allocated by the
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620 * kernel to be freed - but will not free resources allocated by application
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625 void vTaskCode( void * pvParameters )
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629 // Task code goes here.
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631 // At some point we want to end the real time kernel processing
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633 vTaskEndScheduler ();
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637 void vAFunction( void )
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639 // Create at least one task before starting the kernel.
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640 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
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642 // Start the real time kernel with preemption.
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643 vTaskStartScheduler ();
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645 // Will only get here when the vTaskCode () task has called
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646 // vTaskEndScheduler (). When we get here we are back to single task
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651 * \defgroup vTaskEndScheduler vTaskEndScheduler
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652 * \ingroup SchedulerControl
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654 void vTaskEndScheduler( void );
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658 * <pre>void vTaskSuspendAll( void );</pre>
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660 * Suspends all real time kernel activity while keeping interrupts (including the
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661 * kernel tick) enabled.
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663 * After calling vTaskSuspendAll () the calling task will continue to execute
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664 * without risk of being swapped out until a call to xTaskResumeAll () has been
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669 void vTask1( void * pvParameters )
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673 // Task code goes here.
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677 // At some point the task wants to perform a long operation during
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678 // which it does not want to get swapped out. It cannot use
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679 // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
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680 // operation may cause interrupts to be missed - including the
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683 // Prevent the real time kernel swapping out the task.
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684 vTaskSuspendAll ();
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686 // Perform the operation here. There is no need to use critical
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687 // sections as we have all the microcontroller processing time.
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688 // During this time interrupts will still operate and the kernel
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689 // tick count will be maintained.
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693 // The operation is complete. Restart the kernel.
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698 * \defgroup vTaskSuspendAll vTaskSuspendAll
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699 * \ingroup SchedulerControl
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701 void vTaskSuspendAll( void );
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705 * <pre>portCHAR xTaskResumeAll( void );</pre>
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707 * Resumes real time kernel activity following a call to vTaskSuspendAll ().
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708 * After a call to vTaskSuspendAll () the kernel will take control of which
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709 * task is executing at any time.
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711 * @return If resuming the scheduler caused a context switch then pdTRUE is
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712 * returned, otherwise pdFALSE is returned.
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716 void vTask1( void * pvParameters )
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720 // Task code goes here.
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724 // At some point the task wants to perform a long operation during
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725 // which it does not want to get swapped out. It cannot use
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726 // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
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727 // operation may cause interrupts to be missed - including the
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730 // Prevent the real time kernel swapping out the task.
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731 vTaskSuspendAll ();
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733 // Perform the operation here. There is no need to use critical
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734 // sections as we have all the microcontroller processing time.
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735 // During this time interrupts will still operate and the real
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736 // time kernel tick count will be maintained.
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740 // The operation is complete. Restart the kernel. We want to force
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741 // a context switch - but there is no point if resuming the scheduler
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742 // caused a context switch already.
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743 if( !xTaskResumeAll () )
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750 * \defgroup xTaskResumeAll xTaskResumeAll
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751 * \ingroup SchedulerControl
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753 signed portBASE_TYPE xTaskResumeAll( void );
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756 /*-----------------------------------------------------------
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758 *----------------------------------------------------------*/
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762 * <PRE>volatile portTickType xTaskGetTickCount( void );</PRE>
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764 * @return The count of ticks since vTaskStartScheduler was called.
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766 * \page xTaskGetTickCount xTaskGetTickCount
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767 * \ingroup TaskUtils
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769 portTickType xTaskGetTickCount( void );
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773 * <PRE>unsigned portSHORT uxTaskGetNumberOfTasks( void );</PRE>
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775 * @return The number of tasks that the real time kernel is currently managing.
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776 * This includes all ready, blocked and suspended tasks. A task that
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777 * has been deleted but not yet freed by the idle task will also be
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778 * included in the count.
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780 * \page uxTaskGetNumberOfTasks uxTaskGetNumberOfTasks
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781 * \ingroup TaskUtils
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783 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void );
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787 * <PRE>void vTaskList( portCHAR *pcWriteBuffer );</PRE>
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789 * configUSE_TRACE_FACILITY, INCLUDE_vTaskDelete and INCLUDE_vTaskSuspend
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790 * must all be defined as 1 for this function to be available.
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791 * See the configuration section for more information.
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793 * NOTE: This function will disable interrupts for its duration. It is
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794 * not intended for normal application runtime use but as a debug aid.
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796 * Lists all the current tasks, along with their current state and stack
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797 * usage high water mark.
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799 * Tasks are reported as blocked ('B'), ready ('R'), deleted ('D') or
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802 * @param pcWriteBuffer A buffer into which the above mentioned details
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803 * will be written, in ascii form. This buffer is assumed to be large
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804 * enough to contain the generated report. Approximately 40 bytes per
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805 * task should be sufficient.
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807 * \page vTaskList vTaskList
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808 * \ingroup TaskUtils
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810 void vTaskList( signed portCHAR *pcWriteBuffer );
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814 * <PRE>void vTaskStartTrace( portCHAR * pcBuffer, unsigned portBASE_TYPE uxBufferSize );</PRE>
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816 * Starts a real time kernel activity trace. The trace logs the identity of
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817 * which task is running when.
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819 * The trace file is stored in binary format. A separate DOS utility called
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820 * convtrce.exe is used to convert this into a tab delimited text file which
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821 * can be viewed and plotted in a spread sheet.
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823 * @param pcBuffer The buffer into which the trace will be written.
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825 * @param ulBufferSize The size of pcBuffer in bytes. The trace will continue
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826 * until either the buffer in full, or ulTaskEndTrace () is called.
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828 * \page vTaskStartTrace vTaskStartTrace
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829 * \ingroup TaskUtils
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831 void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize );
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835 * <PRE>unsigned portLONG ulTaskEndTrace( void );</PRE>
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837 * Stops a kernel activity trace. See vTaskStartTrace ().
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839 * @return The number of bytes that have been written into the trace buffer.
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841 * \page usTaskEndTrace usTaskEndTrace
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842 * \ingroup TaskUtils
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844 unsigned portLONG ulTaskEndTrace( void );
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847 /*-----------------------------------------------------------
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848 * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES
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849 *----------------------------------------------------------*/
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852 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY
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853 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
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854 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
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856 * Called from the real time kernel tick (either preemptive or cooperative),
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857 * this increments the tick count and checks if any tasks that are blocked
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858 * for a finite period required removing from a blocked list and placing on
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861 inline void vTaskIncrementTick( void );
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864 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
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865 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
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867 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
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869 * Removes the calling task from the ready list and places it both
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870 * on the list of tasks waiting for a particular event, and the
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871 * list of delayed tasks. The task will be removed from both lists
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872 * and replaced on the ready list should either the event occur (and
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873 * there be no higher priority tasks waiting on the same event) or
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874 * the delay period expires.
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876 * @param pxEventList The list containing tasks that are blocked waiting
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877 * for the event to occur.
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879 * @param xTicksToWait The maximum amount of time that the task should wait
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880 * for the event to occur. This is specified in kernel ticks,the constant
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881 * portTICK_RATE_MS can be used to convert kernel ticks into a real time
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884 void vTaskPlaceOnEventList( xList *pxEventList, portTickType xTicksToWait );
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887 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
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888 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
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890 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
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892 * Removes a task from both the specified event list and the list of blocked
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893 * tasks, and places it on a ready queue.
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895 * xTaskRemoveFromEventList () will be called if either an event occurs to
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896 * unblock a task, or the block timeout period expires.
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898 * @return pdTRUE if the task being removed has a higher priority than the task
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899 * making the call, otherwise pdFALSE.
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901 signed portBASE_TYPE xTaskRemoveFromEventList( const xList *pxEventList );
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904 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
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905 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
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907 * INCLUDE_vTaskCleanUpResources and INCLUDE_vTaskSuspend must be defined as 1
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908 * for this function to be available.
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909 * See the configuration section for more information.
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911 * Empties the ready and delayed queues of task control blocks, freeing the
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912 * memory allocated for the task control block and task stacks as it goes.
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914 void vTaskCleanUpResources( void );
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917 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY
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918 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
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919 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
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921 * Sets the pointer to the current TCB to the TCB of the highest priority task
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922 * that is ready to run.
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924 inline void vTaskSwitchContext( void );
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927 * Return the handle of the calling task.
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929 xTaskHandle xTaskGetCurrentTaskHandle( void );
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932 * Capture the current time status for future reference.
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934 void vTaskSetTimeOutState( xTimeOutType *pxTimeOut );
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937 * Compare the time status now with that previously captured to see if the
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938 * timeout has expired.
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940 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType *pxTimeOut, portTickType *pxTicksToWait );
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943 * Shortcut used by the queue implementation to prevent unnecessary call to
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946 void vTaskMissedYield( void );
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948 #endif /* TASK_H */
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