2 FreeRTOS.org V5.0.4 - Copyright (C) 2003-2008 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 ***************************************************************************
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29 * SAVE TIME AND MONEY! We can port FreeRTOS.org to your own hardware, *
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30 * and even write all or part of your application on your behalf. *
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31 * See http://www.OpenRTOS.com for details of the services we provide to *
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32 * expedite your project. *
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34 ***************************************************************************
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35 ***************************************************************************
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37 Please ensure to read the configuration and relevant port sections of the
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38 online documentation.
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40 http://www.FreeRTOS.org - Documentation, latest information, license and
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43 http://www.SafeRTOS.com - A version that is certified for use in safety
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46 http://www.OpenRTOS.com - Commercial support, development, porting,
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47 licensing and training services.
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55 #include "FreeRTOS.h"
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57 #include "StackMacros.h"
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60 * Macro to define the amount of stack available to the idle task.
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62 #define tskIDLE_STACK_SIZE configMINIMAL_STACK_SIZE
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65 * Task control block. A task control block (TCB) is allocated to each task,
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66 * and stores the context of the task.
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68 typedef struct tskTaskControlBlock
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70 volatile portSTACK_TYPE *pxTopOfStack; /*< Points to the location of the last item placed on the tasks stack. THIS MUST BE THE FIRST MEMBER OF THE STRUCT. */
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71 xListItem xGenericListItem; /*< List item used to place the TCB in ready and blocked queues. */
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72 xListItem xEventListItem; /*< List item used to place the TCB in event lists. */
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73 unsigned portBASE_TYPE uxPriority; /*< The priority of the task where 0 is the lowest priority. */
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74 portSTACK_TYPE *pxStack; /*< Points to the start of the stack. */
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75 signed portCHAR pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created. Facilitates debugging only. */
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77 #if ( portSTACK_GROWTH > 0 )
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78 portSTACK_TYPE *pxEndOfStack; /*< Used for stack overflow checking on architectures where the stack grows up from low memory. */
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81 #if ( portCRITICAL_NESTING_IN_TCB == 1 )
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82 unsigned portBASE_TYPE uxCriticalNesting;
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85 #if ( configUSE_TRACE_FACILITY == 1 )
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86 unsigned portBASE_TYPE uxTCBNumber; /*< This is used for tracing the scheduler and making debugging easier only. */
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89 #if ( configUSE_MUTEXES == 1 )
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90 unsigned portBASE_TYPE uxBasePriority;
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93 #if ( configUSE_APPLICATION_TASK_TAG == 1 )
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94 pdTASK_HOOK_CODE pxTaskTag;
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100 * Some kernel aware debuggers require data to be viewed to be global, rather
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103 #ifdef portREMOVE_STATIC_QUALIFIER
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109 tskTCB * volatile pxCurrentTCB = NULL;
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111 /* Lists for ready and blocked tasks. --------------------*/
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113 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */
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114 static xList xDelayedTaskList1; /*< Delayed tasks. */
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115 static xList xDelayedTaskList2; /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */
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116 static xList * volatile pxDelayedTaskList; /*< Points to the delayed task list currently being used. */
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117 static xList * volatile pxOverflowDelayedTaskList; /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */
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118 static xList xPendingReadyList; /*< Tasks that have been readied while the scheduler was suspended. They will be moved to the ready queue when the scheduler is resumed. */
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120 #if ( INCLUDE_vTaskDelete == 1 )
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122 static volatile xList xTasksWaitingTermination; /*< Tasks that have been deleted - but the their memory not yet freed. */
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123 static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;
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127 #if ( INCLUDE_vTaskSuspend == 1 )
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129 static xList xSuspendedTaskList; /*< Tasks that are currently suspended. */
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133 /* File private variables. --------------------------------*/
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134 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks = ( unsigned portBASE_TYPE ) 0;
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135 static volatile portTickType xTickCount = ( portTickType ) 0;
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136 static unsigned portBASE_TYPE uxTopUsedPriority = tskIDLE_PRIORITY;
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137 static volatile unsigned portBASE_TYPE uxTopReadyPriority = tskIDLE_PRIORITY;
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138 static volatile signed portBASE_TYPE xSchedulerRunning = pdFALSE;
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139 static volatile unsigned portBASE_TYPE uxSchedulerSuspended = ( unsigned portBASE_TYPE ) pdFALSE;
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140 static volatile unsigned portBASE_TYPE uxMissedTicks = ( unsigned portBASE_TYPE ) 0;
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141 static volatile portBASE_TYPE xMissedYield = ( portBASE_TYPE ) pdFALSE;
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142 static volatile portBASE_TYPE xNumOfOverflows = ( portBASE_TYPE ) 0;
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143 #if ( configUSE_TRACE_FACILITY == 1 )
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144 static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */
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147 /* Debugging and trace facilities private variables and macros. ------------*/
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150 * The value used to fill the stack of a task when the task is created. This
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151 * is used purely for checking the high water mark for tasks.
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153 #define tskSTACK_FILL_BYTE ( 0xa5 )
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156 * Macros used by vListTask to indicate which state a task is in.
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158 #define tskBLOCKED_CHAR ( ( signed portCHAR ) 'B' )
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159 #define tskREADY_CHAR ( ( signed portCHAR ) 'R' )
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160 #define tskDELETED_CHAR ( ( signed portCHAR ) 'D' )
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161 #define tskSUSPENDED_CHAR ( ( signed portCHAR ) 'S' )
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164 * Macros and private variables used by the trace facility.
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166 #if ( configUSE_TRACE_FACILITY == 1 )
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168 #define tskSIZE_OF_EACH_TRACE_LINE ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )
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169 static volatile signed portCHAR * volatile pcTraceBuffer;
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170 static signed portCHAR *pcTraceBufferStart;
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171 static signed portCHAR *pcTraceBufferEnd;
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172 static signed portBASE_TYPE xTracing = pdFALSE;
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173 static unsigned portBASE_TYPE uxPreviousTask = 255;
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174 static portCHAR pcStatusString[ 50 ];
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177 /*-----------------------------------------------------------*/
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180 * Macro that writes a trace of scheduler activity to a buffer. This trace
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181 * shows which task is running when and is very useful as a debugging tool.
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182 * As this macro is called each context switch it is a good idea to undefine
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183 * it if not using the facility.
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185 #if ( configUSE_TRACE_FACILITY == 1 )
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187 #define vWriteTraceToBuffer() \
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191 if( uxPreviousTask != pxCurrentTCB->uxTCBNumber ) \
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193 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd ) \
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195 uxPreviousTask = pxCurrentTCB->uxTCBNumber; \
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196 *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount; \
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197 pcTraceBuffer += sizeof( unsigned portLONG ); \
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198 *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask; \
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199 pcTraceBuffer += sizeof( unsigned portLONG ); \
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203 xTracing = pdFALSE; \
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211 #define vWriteTraceToBuffer()
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214 /*-----------------------------------------------------------*/
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217 * Place the task represented by pxTCB into the appropriate ready queue for
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218 * the task. It is inserted at the end of the list. One quirk of this is
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219 * that if the task being inserted is at the same priority as the currently
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220 * executing task, then it will only be rescheduled after the currently
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221 * executing task has been rescheduled.
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223 #define prvAddTaskToReadyQueue( pxTCB ) \
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225 if( pxTCB->uxPriority > uxTopReadyPriority ) \
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227 uxTopReadyPriority = pxTCB->uxPriority; \
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229 vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ); \
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231 /*-----------------------------------------------------------*/
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234 * Macro that looks at the list of tasks that are currently delayed to see if
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235 * any require waking.
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237 * Tasks are stored in the queue in the order of their wake time - meaning
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238 * once one tasks has been found whose timer has not expired we need not look
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239 * any further down the list.
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241 #define prvCheckDelayedTasks() \
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243 register tskTCB *pxTCB; \
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245 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL ) \
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247 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) ) \
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251 vListRemove( &( pxTCB->xGenericListItem ) ); \
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252 /* Is the task waiting on an event also? */ \
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253 if( pxTCB->xEventListItem.pvContainer ) \
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255 vListRemove( &( pxTCB->xEventListItem ) ); \
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257 prvAddTaskToReadyQueue( pxTCB ); \
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260 /*-----------------------------------------------------------*/
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263 * Several functions take an xTaskHandle parameter that can optionally be NULL,
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264 * where NULL is used to indicate that the handle of the currently executing
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265 * task should be used in place of the parameter. This macro simply checks to
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266 * see if the parameter is NULL and returns a pointer to the appropriate TCB.
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268 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )
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271 /* File private functions. --------------------------------*/
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274 * Utility to ready a TCB for a given task. Mainly just copies the parameters
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275 * into the TCB structure.
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277 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );
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280 * Utility to ready all the lists used by the scheduler. This is called
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281 * automatically upon the creation of the first task.
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283 static void prvInitialiseTaskLists( void );
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286 * The idle task, which as all tasks is implemented as a never ending loop.
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287 * The idle task is automatically created and added to the ready lists upon
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288 * creation of the first user task.
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290 * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific
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291 * language extensions. The equivalent prototype for this function is:
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293 * void prvIdleTask( void *pvParameters );
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296 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );
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299 * Utility to free all memory allocated by the scheduler to hold a TCB,
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300 * including the stack pointed to by the TCB.
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302 * This does not free memory allocated by the task itself (i.e. memory
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303 * allocated by calls to pvPortMalloc from within the tasks application code).
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305 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )
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306 static void prvDeleteTCB( tskTCB *pxTCB );
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310 * Used only by the idle task. This checks to see if anything has been placed
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311 * in the list of tasks waiting to be deleted. If so the task is cleaned up
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312 * and its TCB deleted.
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314 static void prvCheckTasksWaitingTermination( void );
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317 * Allocates memory from the heap for a TCB and associated stack. Checks the
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318 * allocation was successful.
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320 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );
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323 * Called from vTaskList. vListTasks details all the tasks currently under
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324 * control of the scheduler. The tasks may be in one of a number of lists.
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325 * prvListTaskWithinSingleList accepts a list and details the tasks from
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326 * within just that list.
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328 * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM
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329 * NORMAL APPLICATION CODE.
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331 #if ( configUSE_TRACE_FACILITY == 1 )
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333 static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );
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338 * When a task is created, the stack of the task is filled with a known value.
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339 * This function determines the 'high water mark' of the task stack by
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340 * determining how much of the stack remains at the original preset value.
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342 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )
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344 unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );
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353 /*-----------------------------------------------------------
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354 * TASK CREATION API documented in task.h
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355 *----------------------------------------------------------*/
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357 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )
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359 signed portBASE_TYPE xReturn;
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362 /* Allocate the memory required by the TCB and stack for the new task.
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363 checking that the allocation was successful. */
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364 pxNewTCB = prvAllocateTCBAndStack( usStackDepth );
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366 if( pxNewTCB != NULL )
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368 portSTACK_TYPE *pxTopOfStack;
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370 /* Setup the newly allocated TCB with the initial state of the task. */
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371 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );
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373 /* Calculate the top of stack address. This depends on whether the
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374 stack grows from high memory to low (as per the 80x86) or visa versa.
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375 portSTACK_GROWTH is used to make the result positive or negative as
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376 required by the port. */
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377 #if portSTACK_GROWTH < 0
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379 pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );
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383 pxTopOfStack = pxNewTCB->pxStack;
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385 /* If we want to use stack checking on architectures that use
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386 a positive stack growth direction then we also need to store the
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387 other extreme of the stack space. */
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388 pxNewTCB->pxEndOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );
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392 /* Initialize the TCB stack to look as if the task was already running,
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393 but had been interrupted by the scheduler. The return address is set
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394 to the start of the task function. Once the stack has been initialised
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395 the top of stack variable is updated. */
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396 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );
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398 /* We are going to manipulate the task queues to add this task to a
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399 ready list, so must make sure no interrupts occur. */
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400 portENTER_CRITICAL();
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402 uxCurrentNumberOfTasks++;
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403 if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )
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405 /* As this is the first task it must also be the current task. */
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406 pxCurrentTCB = pxNewTCB;
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408 /* This is the first task to be created so do the preliminary
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409 initialisation required. We will not recover if this call
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410 fails, but we will report the failure. */
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411 prvInitialiseTaskLists();
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415 /* If the scheduler is not already running, make this task the
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416 current task if it is the highest priority task to be created
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418 if( xSchedulerRunning == pdFALSE )
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420 if( pxCurrentTCB->uxPriority <= uxPriority )
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422 pxCurrentTCB = pxNewTCB;
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427 /* Remember the top priority to make context switching faster. Use
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428 the priority in pxNewTCB as this has been capped to a valid value. */
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429 if( pxNewTCB->uxPriority > uxTopUsedPriority )
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431 uxTopUsedPriority = pxNewTCB->uxPriority;
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434 #if ( configUSE_TRACE_FACILITY == 1 )
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436 /* Add a counter into the TCB for tracing only. */
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437 pxNewTCB->uxTCBNumber = uxTaskNumber;
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442 prvAddTaskToReadyQueue( pxNewTCB );
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445 traceTASK_CREATE( pxNewTCB );
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447 portEXIT_CRITICAL();
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451 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;
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452 traceTASK_CREATE_FAILED( pxNewTCB );
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455 if( xReturn == pdPASS )
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457 if( ( void * ) pxCreatedTask != NULL )
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459 /* Pass the TCB out - in an anonymous way. The calling function/
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460 task can use this as a handle to delete the task later if
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462 *pxCreatedTask = ( xTaskHandle ) pxNewTCB;
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465 if( xSchedulerRunning != pdFALSE )
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467 /* If the created task is of a higher priority than the current task
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468 then it should run now. */
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469 if( pxCurrentTCB->uxPriority < uxPriority )
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478 /*-----------------------------------------------------------*/
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480 #if ( INCLUDE_vTaskDelete == 1 )
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482 void vTaskDelete( xTaskHandle pxTaskToDelete )
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486 taskENTER_CRITICAL();
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488 /* Ensure a yield is performed if the current task is being
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490 if( pxTaskToDelete == pxCurrentTCB )
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492 pxTaskToDelete = NULL;
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495 /* If null is passed in here then we are deleting ourselves. */
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496 pxTCB = prvGetTCBFromHandle( pxTaskToDelete );
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498 traceTASK_DELETE( pxTCB );
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500 /* Remove task from the ready list and place in the termination list.
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501 This will stop the task from be scheduled. The idle task will check
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502 the termination list and free up any memory allocated by the
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503 scheduler for the TCB and stack. */
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504 vListRemove( &( pxTCB->xGenericListItem ) );
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506 /* Is the task waiting on an event also? */
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507 if( pxTCB->xEventListItem.pvContainer )
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509 vListRemove( &( pxTCB->xEventListItem ) );
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512 vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );
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514 /* Increment the ucTasksDeleted variable so the idle task knows
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515 there is a task that has been deleted and that it should therefore
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516 check the xTasksWaitingTermination list. */
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519 taskEXIT_CRITICAL();
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521 /* Force a reschedule if we have just deleted the current task. */
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522 if( xSchedulerRunning != pdFALSE )
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524 if( ( void * ) pxTaskToDelete == NULL )
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538 /*-----------------------------------------------------------
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539 * TASK CONTROL API documented in task.h
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540 *----------------------------------------------------------*/
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542 #if ( INCLUDE_vTaskDelayUntil == 1 )
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544 void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )
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546 portTickType xTimeToWake;
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547 portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;
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551 /* Generate the tick time at which the task wants to wake. */
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552 xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;
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554 if( xTickCount < *pxPreviousWakeTime )
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556 /* The tick count has overflowed since this function was
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557 lasted called. In this case the only time we should ever
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558 actually delay is if the wake time has also overflowed,
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559 and the wake time is greater than the tick time. When this
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560 is the case it is as if neither time had overflowed. */
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561 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )
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563 xShouldDelay = pdTRUE;
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568 /* The tick time has not overflowed. In this case we will
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569 delay if either the wake time has overflowed, and/or the
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570 tick time is less than the wake time. */
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571 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )
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573 xShouldDelay = pdTRUE;
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577 /* Update the wake time ready for the next call. */
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578 *pxPreviousWakeTime = xTimeToWake;
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582 traceTASK_DELAY_UNTIL();
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584 /* We must remove ourselves from the ready list before adding
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585 ourselves to the blocked list as the same list item is used for
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587 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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589 /* The list item will be inserted in wake time order. */
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590 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );
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592 if( xTimeToWake < xTickCount )
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594 /* Wake time has overflowed. Place this item in the
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596 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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600 /* The wake time has not overflowed, so we can use the
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601 current block list. */
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602 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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606 xAlreadyYielded = xTaskResumeAll();
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608 /* Force a reschedule if xTaskResumeAll has not already done so, we may
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609 have put ourselves to sleep. */
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610 if( !xAlreadyYielded )
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617 /*-----------------------------------------------------------*/
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619 #if ( INCLUDE_vTaskDelay == 1 )
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621 void vTaskDelay( portTickType xTicksToDelay )
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623 portTickType xTimeToWake;
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624 signed portBASE_TYPE xAlreadyYielded = pdFALSE;
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626 /* A delay time of zero just forces a reschedule. */
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627 if( xTicksToDelay > ( portTickType ) 0 )
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633 /* A task that is removed from the event list while the
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634 scheduler is suspended will not get placed in the ready
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635 list or removed from the blocked list until the scheduler
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638 This task cannot be in an event list as it is the currently
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641 /* Calculate the time to wake - this may overflow but this is
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643 xTimeToWake = xTickCount + xTicksToDelay;
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645 /* We must remove ourselves from the ready list before adding
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646 ourselves to the blocked list as the same list item is used for
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648 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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650 /* The list item will be inserted in wake time order. */
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651 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );
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653 if( xTimeToWake < xTickCount )
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655 /* Wake time has overflowed. Place this item in the
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657 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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661 /* The wake time has not overflowed, so we can use the
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662 current block list. */
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663 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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666 xAlreadyYielded = xTaskResumeAll();
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669 /* Force a reschedule if xTaskResumeAll has not already done so, we may
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670 have put ourselves to sleep. */
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671 if( !xAlreadyYielded )
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678 /*-----------------------------------------------------------*/
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680 #if ( INCLUDE_uxTaskPriorityGet == 1 )
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682 unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )
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685 unsigned portBASE_TYPE uxReturn;
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687 taskENTER_CRITICAL();
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689 /* If null is passed in here then we are changing the
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690 priority of the calling function. */
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691 pxTCB = prvGetTCBFromHandle( pxTask );
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692 uxReturn = pxTCB->uxPriority;
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694 taskEXIT_CRITICAL();
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700 /*-----------------------------------------------------------*/
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702 #if ( INCLUDE_vTaskPrioritySet == 1 )
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704 void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )
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707 unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;
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709 /* Ensure the new priority is valid. */
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710 if( uxNewPriority >= configMAX_PRIORITIES )
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712 uxNewPriority = configMAX_PRIORITIES - 1;
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715 taskENTER_CRITICAL();
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717 if( pxTask == pxCurrentTCB )
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722 /* If null is passed in here then we are changing the
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723 priority of the calling function. */
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724 pxTCB = prvGetTCBFromHandle( pxTask );
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726 traceTASK_PRIORITY_SET( pxTask, uxNewPriority );
\r
728 #if ( configUSE_MUTEXES == 1 )
\r
730 uxCurrentPriority = pxTCB->uxBasePriority;
\r
734 uxCurrentPriority = pxTCB->uxPriority;
\r
738 if( uxCurrentPriority != uxNewPriority )
\r
740 /* The priority change may have readied a task of higher
\r
741 priority than the calling task. */
\r
742 if( uxNewPriority > uxCurrentPriority )
\r
744 if( pxTask != NULL )
\r
746 /* The priority of another task is being raised. If we
\r
747 were raising the priority of the currently running task
\r
748 there would be no need to switch as it must have already
\r
749 been the highest priority task. */
\r
750 xYieldRequired = pdTRUE;
\r
753 else if( pxTask == NULL )
\r
755 /* Setting our own priority down means there may now be another
\r
756 task of higher priority that is ready to execute. */
\r
757 xYieldRequired = pdTRUE;
\r
762 #if ( configUSE_MUTEXES == 1 )
\r
764 /* Only change the priority being used if the task is not
\r
765 currently using an inherited priority. */
\r
766 if( pxTCB->uxBasePriority == pxTCB->uxPriority )
\r
768 pxTCB->uxPriority = uxNewPriority;
\r
771 /* The base priority gets set whatever. */
\r
772 pxTCB->uxBasePriority = uxNewPriority;
\r
776 pxTCB->uxPriority = uxNewPriority;
\r
780 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );
\r
782 /* If the task is in the blocked or suspended list we need do
\r
783 nothing more than change it's priority variable. However, if
\r
784 the task is in a ready list it needs to be removed and placed
\r
785 in the queue appropriate to its new priority. */
\r
786 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )
\r
788 /* The task is currently in its ready list - remove before adding
\r
789 it to it's new ready list. As we are in a critical section we
\r
790 can do this even if the scheduler is suspended. */
\r
791 vListRemove( &( pxTCB->xGenericListItem ) );
\r
792 prvAddTaskToReadyQueue( pxTCB );
\r
795 if( xYieldRequired == pdTRUE )
\r
801 taskEXIT_CRITICAL();
\r
805 /*-----------------------------------------------------------*/
\r
807 #if ( INCLUDE_vTaskSuspend == 1 )
\r
809 void vTaskSuspend( xTaskHandle pxTaskToSuspend )
\r
813 taskENTER_CRITICAL();
\r
815 /* Ensure a yield is performed if the current task is being
\r
817 if( pxTaskToSuspend == pxCurrentTCB )
\r
819 pxTaskToSuspend = NULL;
\r
822 /* If null is passed in here then we are suspending ourselves. */
\r
823 pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );
\r
825 traceTASK_SUSPEND( pxTaskToSuspend );
\r
827 /* Remove task from the ready/delayed list and place in the suspended list. */
\r
828 vListRemove( &( pxTCB->xGenericListItem ) );
\r
830 /* Is the task waiting on an event also? */
\r
831 if( pxTCB->xEventListItem.pvContainer )
\r
833 vListRemove( &( pxTCB->xEventListItem ) );
\r
836 vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );
\r
838 taskEXIT_CRITICAL();
\r
840 /* We may have just suspended the current task. */
\r
841 if( ( void * ) pxTaskToSuspend == NULL )
\r
848 /*-----------------------------------------------------------*/
\r
850 #if ( INCLUDE_vTaskSuspend == 1 )
\r
852 signed portBASE_TYPE xTaskIsTaskSuspended( xTaskHandle xTask )
\r
854 portBASE_TYPE xReturn = pdFALSE;
\r
855 const tskTCB * const pxTCB = ( tskTCB * ) xTask;
\r
857 /* Is the task we are attempting to resume actually in the
\r
859 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )
\r
861 /* Has the task already been resumed from within an ISR? */
\r
862 if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )
\r
864 /* Is it in the suspended list because it is in the
\r
865 Suspended state? It is possible to be in the suspended
\r
866 list because it is blocked on a task with no timeout
\r
868 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )
\r
879 /*-----------------------------------------------------------*/
\r
881 #if ( INCLUDE_vTaskSuspend == 1 )
\r
883 void vTaskResume( xTaskHandle pxTaskToResume )
\r
887 /* Remove the task from whichever list it is currently in, and place
\r
888 it in the ready list. */
\r
889 pxTCB = ( tskTCB * ) pxTaskToResume;
\r
891 /* The parameter cannot be NULL as it is impossible to resume the
\r
892 currently executing task. */
\r
893 if( ( pxTCB != NULL ) && ( pxTCB != pxCurrentTCB ) )
\r
895 taskENTER_CRITICAL();
\r
897 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )
\r
899 traceTASK_RESUME( pxTCB );
\r
901 /* As we are in a critical section we can access the ready
\r
902 lists even if the scheduler is suspended. */
\r
903 vListRemove( &( pxTCB->xGenericListItem ) );
\r
904 prvAddTaskToReadyQueue( pxTCB );
\r
906 /* We may have just resumed a higher priority task. */
\r
907 if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )
\r
909 /* This yield may not cause the task just resumed to run, but
\r
910 will leave the lists in the correct state for the next yield. */
\r
915 taskEXIT_CRITICAL();
\r
921 /*-----------------------------------------------------------*/
\r
923 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )
\r
925 portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )
\r
927 portBASE_TYPE xYieldRequired = pdFALSE;
\r
930 pxTCB = ( tskTCB * ) pxTaskToResume;
\r
932 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )
\r
934 traceTASK_RESUME_FROM_ISR( pxTCB );
\r
936 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
938 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );
\r
939 vListRemove( &( pxTCB->xGenericListItem ) );
\r
940 prvAddTaskToReadyQueue( pxTCB );
\r
944 /* We cannot access the delayed or ready lists, so will hold this
\r
945 task pending until the scheduler is resumed, at which point a
\r
946 yield will be performed if necessary. */
\r
947 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );
\r
951 return xYieldRequired;
\r
959 /*-----------------------------------------------------------
\r
960 * PUBLIC SCHEDULER CONTROL documented in task.h
\r
961 *----------------------------------------------------------*/
\r
964 void vTaskStartScheduler( void )
\r
966 portBASE_TYPE xReturn;
\r
968 /* Add the idle task at the lowest priority. */
\r
969 xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );
\r
971 if( xReturn == pdPASS )
\r
973 /* Interrupts are turned off here, to ensure a tick does not occur
\r
974 before or during the call to xPortStartScheduler(). The stacks of
\r
975 the created tasks contain a status word with interrupts switched on
\r
976 so interrupts will automatically get re-enabled when the first task
\r
979 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE
\r
980 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */
\r
981 portDISABLE_INTERRUPTS();
\r
983 xSchedulerRunning = pdTRUE;
\r
984 xTickCount = ( portTickType ) 0;
\r
986 /* Setting up the timer tick is hardware specific and thus in the
\r
987 portable interface. */
\r
988 if( xPortStartScheduler() )
\r
990 /* Should not reach here as if the scheduler is running the
\r
991 function will not return. */
\r
995 /* Should only reach here if a task calls xTaskEndScheduler(). */
\r
999 /*-----------------------------------------------------------*/
\r
1001 void vTaskEndScheduler( void )
\r
1003 /* Stop the scheduler interrupts and call the portable scheduler end
\r
1004 routine so the original ISRs can be restored if necessary. The port
\r
1005 layer must ensure interrupts enable bit is left in the correct state. */
\r
1006 portDISABLE_INTERRUPTS();
\r
1007 xSchedulerRunning = pdFALSE;
\r
1008 vPortEndScheduler();
\r
1010 /*----------------------------------------------------------*/
\r
1012 void vTaskSuspendAll( void )
\r
1014 portENTER_CRITICAL();
\r
1015 ++uxSchedulerSuspended;
\r
1016 portEXIT_CRITICAL();
\r
1018 /*----------------------------------------------------------*/
\r
1020 signed portBASE_TYPE xTaskResumeAll( void )
\r
1022 register tskTCB *pxTCB;
\r
1023 signed portBASE_TYPE xAlreadyYielded = pdFALSE;
\r
1025 /* It is possible that an ISR caused a task to be removed from an event
\r
1026 list while the scheduler was suspended. If this was the case then the
\r
1027 removed task will have been added to the xPendingReadyList. Once the
\r
1028 scheduler has been resumed it is safe to move all the pending ready
\r
1029 tasks from this list into their appropriate ready list. */
\r
1030 portENTER_CRITICAL();
\r
1032 --uxSchedulerSuspended;
\r
1034 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
1036 if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )
\r
1038 portBASE_TYPE xYieldRequired = pdFALSE;
\r
1040 /* Move any readied tasks from the pending list into the
\r
1041 appropriate ready list. */
\r
1042 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xPendingReadyList ) ) ) != NULL )
\r
1044 vListRemove( &( pxTCB->xEventListItem ) );
\r
1045 vListRemove( &( pxTCB->xGenericListItem ) );
\r
1046 prvAddTaskToReadyQueue( pxTCB );
\r
1048 /* If we have moved a task that has a priority higher than
\r
1049 the current task then we should yield. */
\r
1050 if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )
\r
1052 xYieldRequired = pdTRUE;
\r
1056 /* If any ticks occurred while the scheduler was suspended then
\r
1057 they should be processed now. This ensures the tick count does not
\r
1058 slip, and that any delayed tasks are resumed at the correct time. */
\r
1059 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )
\r
1061 while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )
\r
1063 vTaskIncrementTick();
\r
1067 /* As we have processed some ticks it is appropriate to yield
\r
1068 to ensure the highest priority task that is ready to run is
\r
1069 the task actually running. */
\r
1070 #if configUSE_PREEMPTION == 1
\r
1072 xYieldRequired = pdTRUE;
\r
1077 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )
\r
1079 xAlreadyYielded = pdTRUE;
\r
1080 xMissedYield = pdFALSE;
\r
1086 portEXIT_CRITICAL();
\r
1088 return xAlreadyYielded;
\r
1096 /*-----------------------------------------------------------
\r
1097 * PUBLIC TASK UTILITIES documented in task.h
\r
1098 *----------------------------------------------------------*/
\r
1102 portTickType xTaskGetTickCount( void )
\r
1104 portTickType xTicks;
\r
1106 /* Critical section required if running on a 16 bit processor. */
\r
1107 taskENTER_CRITICAL();
\r
1109 xTicks = xTickCount;
\r
1111 taskEXIT_CRITICAL();
\r
1115 /*-----------------------------------------------------------*/
\r
1117 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )
\r
1119 unsigned portBASE_TYPE uxNumberOfTasks;
\r
1121 taskENTER_CRITICAL();
\r
1122 uxNumberOfTasks = uxCurrentNumberOfTasks;
\r
1123 taskEXIT_CRITICAL();
\r
1125 return uxNumberOfTasks;
\r
1127 /*-----------------------------------------------------------*/
\r
1129 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )
\r
1131 void vTaskList( signed portCHAR *pcWriteBuffer )
\r
1133 unsigned portBASE_TYPE uxQueue;
\r
1135 /* This is a VERY costly function that should be used for debug only.
\r
1136 It leaves interrupts disabled for a LONG time. */
\r
1138 vTaskSuspendAll();
\r
1140 /* Run through all the lists that could potentially contain a TCB and
\r
1141 report the task name, state and stack high water mark. */
\r
1143 pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;
\r
1144 strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );
\r
1146 uxQueue = uxTopUsedPriority + 1;
\r
1152 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )
\r
1154 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );
\r
1156 }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );
\r
1158 if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )
\r
1160 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );
\r
1163 if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )
\r
1165 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );
\r
1168 if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )
\r
1170 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );
\r
1173 if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )
\r
1175 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );
\r
1182 /*----------------------------------------------------------*/
\r
1184 #if ( configUSE_TRACE_FACILITY == 1 )
\r
1186 void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )
\r
1188 portENTER_CRITICAL();
\r
1190 pcTraceBuffer = ( signed portCHAR * )pcBuffer;
\r
1191 pcTraceBufferStart = pcBuffer;
\r
1192 pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );
\r
1193 xTracing = pdTRUE;
\r
1195 portEXIT_CRITICAL();
\r
1199 /*----------------------------------------------------------*/
\r
1201 #if ( configUSE_TRACE_FACILITY == 1 )
\r
1203 unsigned portLONG ulTaskEndTrace( void )
\r
1205 unsigned portLONG ulBufferLength;
\r
1207 portENTER_CRITICAL();
\r
1208 xTracing = pdFALSE;
\r
1209 portEXIT_CRITICAL();
\r
1211 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );
\r
1213 return ulBufferLength;
\r
1220 /*-----------------------------------------------------------
\r
1221 * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES
\r
1222 * documented in task.h
\r
1223 *----------------------------------------------------------*/
\r
1226 void vTaskIncrementTick( void )
\r
1228 /* Called by the portable layer each time a tick interrupt occurs.
\r
1229 Increments the tick then checks to see if the new tick value will cause any
\r
1230 tasks to be unblocked. */
\r
1231 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
1234 if( xTickCount == ( portTickType ) 0 )
\r
1238 /* Tick count has overflowed so we need to swap the delay lists.
\r
1239 If there are any items in pxDelayedTaskList here then there is
\r
1241 pxTemp = pxDelayedTaskList;
\r
1242 pxDelayedTaskList = pxOverflowDelayedTaskList;
\r
1243 pxOverflowDelayedTaskList = pxTemp;
\r
1244 xNumOfOverflows++;
\r
1247 /* See if this tick has made a timeout expire. */
\r
1248 prvCheckDelayedTasks();
\r
1254 /* The tick hook gets called at regular intervals, even if the
\r
1255 scheduler is locked. */
\r
1256 #if ( configUSE_TICK_HOOK == 1 )
\r
1258 extern void vApplicationTickHook( void );
\r
1260 vApplicationTickHook();
\r
1265 #if ( configUSE_TICK_HOOK == 1 )
\r
1267 extern void vApplicationTickHook( void );
\r
1269 /* Guard against the tick hook being called when the missed tick
\r
1270 count is being unwound (when the scheduler is being unlocked. */
\r
1271 if( uxMissedTicks == 0 )
\r
1273 vApplicationTickHook();
\r
1278 traceTASK_INCREMENT_TICK( xTickCount );
\r
1280 /*-----------------------------------------------------------*/
\r
1282 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )
\r
1284 void vTaskCleanUpResources( void )
\r
1286 unsigned portSHORT usQueue;
\r
1287 volatile tskTCB *pxTCB;
\r
1289 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;
\r
1291 /* Remove any TCB's from the ready queues. */
\r
1296 while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )
\r
1298 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );
\r
1299 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1301 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1303 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );
\r
1305 /* Remove any TCB's from the delayed queue. */
\r
1306 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )
\r
1308 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );
\r
1309 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1311 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1314 /* Remove any TCB's from the overflow delayed queue. */
\r
1315 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )
\r
1317 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );
\r
1318 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1320 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1323 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )
\r
1325 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );
\r
1326 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1328 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1333 /*-----------------------------------------------------------*/
\r
1335 #if ( configUSE_APPLICATION_TASK_TAG == 1 )
\r
1337 void vTaskSetApplicationTaskTag( xTaskHandle xTask, pdTASK_HOOK_CODE pxTagValue )
\r
1341 /* If xTask is NULL then we are setting our own task hook. */
\r
1342 if( xTask == NULL )
\r
1344 xTCB = ( tskTCB * ) pxCurrentTCB;
\r
1348 xTCB = ( tskTCB * ) xTask;
\r
1351 /* Save the hook function in the TCB. */
\r
1352 portENTER_CRITICAL();
\r
1353 xTCB->pxTaskTag = pxTagValue;
\r
1354 portEXIT_CRITICAL();
\r
1358 /*-----------------------------------------------------------*/
\r
1360 #if ( configUSE_APPLICATION_TASK_TAG == 1 )
\r
1362 portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, void *pvParameter )
\r
1365 portBASE_TYPE xReturn;
\r
1367 /* If xTask is NULL then we are calling our own task hook. */
\r
1368 if( xTask == NULL )
\r
1370 xTCB = ( tskTCB * ) pxCurrentTCB;
\r
1374 xTCB = ( tskTCB * ) xTask;
\r
1377 if( xTCB->pxTaskTag != NULL )
\r
1379 xReturn = xTCB->pxTaskTag( pvParameter );
\r
1390 /*-----------------------------------------------------------*/
\r
1392 void vTaskSwitchContext( void )
\r
1394 traceTASK_SWITCHED_OUT();
\r
1396 if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )
\r
1398 /* The scheduler is currently suspended - do not allow a context
\r
1400 xMissedYield = pdTRUE;
\r
1404 taskFIRST_CHECK_FOR_STACK_OVERFLOW();
\r
1405 taskSECOND_CHECK_FOR_STACK_OVERFLOW();
\r
1407 /* Find the highest priority queue that contains ready tasks. */
\r
1408 while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )
\r
1410 --uxTopReadyPriority;
\r
1413 /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the
\r
1414 same priority get an equal share of the processor time. */
\r
1415 listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );
\r
1417 traceTASK_SWITCHED_IN();
\r
1418 vWriteTraceToBuffer();
\r
1420 /*-----------------------------------------------------------*/
\r
1422 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )
\r
1424 portTickType xTimeToWake;
\r
1426 /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE
\r
1427 SCHEDULER SUSPENDED. */
\r
1429 /* Place the event list item of the TCB in the appropriate event list.
\r
1430 This is placed in the list in priority order so the highest priority task
\r
1431 is the first to be woken by the event. */
\r
1432 vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );
\r
1434 /* We must remove ourselves from the ready list before adding ourselves
\r
1435 to the blocked list as the same list item is used for both lists. We have
\r
1436 exclusive access to the ready lists as the scheduler is locked. */
\r
1437 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1440 #if ( INCLUDE_vTaskSuspend == 1 )
\r
1442 if( xTicksToWait == portMAX_DELAY )
\r
1444 /* Add ourselves to the suspended task list instead of a delayed task
\r
1445 list to ensure we are not woken by a timing event. We will block
\r
1447 vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1451 /* Calculate the time at which the task should be woken if the event does
\r
1452 not occur. This may overflow but this doesn't matter. */
\r
1453 xTimeToWake = xTickCount + xTicksToWait;
\r
1455 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );
\r
1457 if( xTimeToWake < xTickCount )
\r
1459 /* Wake time has overflowed. Place this item in the overflow list. */
\r
1460 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1464 /* The wake time has not overflowed, so we can use the current block list. */
\r
1465 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1471 /* Calculate the time at which the task should be woken if the event does
\r
1472 not occur. This may overflow but this doesn't matter. */
\r
1473 xTimeToWake = xTickCount + xTicksToWait;
\r
1475 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );
\r
1477 if( xTimeToWake < xTickCount )
\r
1479 /* Wake time has overflowed. Place this item in the overflow list. */
\r
1480 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1484 /* The wake time has not overflowed, so we can use the current block list. */
\r
1485 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1490 /*-----------------------------------------------------------*/
\r
1492 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )
\r
1494 tskTCB *pxUnblockedTCB;
\r
1495 portBASE_TYPE xReturn;
\r
1497 /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE
\r
1498 SCHEDULER SUSPENDED. It can also be called from within an ISR. */
\r
1500 /* The event list is sorted in priority order, so we can remove the
\r
1501 first in the list, remove the TCB from the delayed list, and add
\r
1502 it to the ready list.
\r
1504 If an event is for a queue that is locked then this function will never
\r
1505 get called - the lock count on the queue will get modified instead. This
\r
1506 means we can always expect exclusive access to the event list here. */
\r
1507 pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );
\r
1508 vListRemove( &( pxUnblockedTCB->xEventListItem ) );
\r
1510 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
1512 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );
\r
1513 prvAddTaskToReadyQueue( pxUnblockedTCB );
\r
1517 /* We cannot access the delayed or ready lists, so will hold this
\r
1518 task pending until the scheduler is resumed. */
\r
1519 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );
\r
1522 if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )
\r
1524 /* Return true if the task removed from the event list has
\r
1525 a higher priority than the calling task. This allows
\r
1526 the calling task to know if it should force a context
\r
1532 xReturn = pdFALSE;
\r
1537 /*-----------------------------------------------------------*/
\r
1539 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )
\r
1541 pxTimeOut->xOverflowCount = xNumOfOverflows;
\r
1542 pxTimeOut->xTimeOnEntering = xTickCount;
\r
1544 /*-----------------------------------------------------------*/
\r
1546 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )
\r
1548 portBASE_TYPE xReturn;
\r
1550 portENTER_CRITICAL();
\r
1552 #if ( INCLUDE_vTaskSuspend == 1 )
\r
1553 /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is
\r
1554 the maximum block time then the task should block indefinitely, and
\r
1555 therefore never time out. */
\r
1556 if( *pxTicksToWait == portMAX_DELAY )
\r
1558 xReturn = pdFALSE;
\r
1560 else /* We are not blocking indefinitely, perform the checks below. */
\r
1563 if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )
\r
1565 /* The tick count is greater than the time at which vTaskSetTimeout()
\r
1566 was called, but has also overflowed since vTaskSetTimeOut() was called.
\r
1567 It must have wrapped all the way around and gone past us again. This
\r
1568 passed since vTaskSetTimeout() was called. */
\r
1571 else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )
\r
1573 /* Not a genuine timeout. Adjust parameters for time remaining. */
\r
1574 *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );
\r
1575 vTaskSetTimeOutState( pxTimeOut );
\r
1576 xReturn = pdFALSE;
\r
1583 portEXIT_CRITICAL();
\r
1587 /*-----------------------------------------------------------*/
\r
1589 void vTaskMissedYield( void )
\r
1591 xMissedYield = pdTRUE;
\r
1595 * -----------------------------------------------------------
\r
1597 * ----------------------------------------------------------
\r
1599 * The portTASK_FUNCTION() macro is used to allow port/compiler specific
\r
1600 * language extensions. The equivalent prototype for this function is:
\r
1602 * void prvIdleTask( void *pvParameters );
\r
1605 static portTASK_FUNCTION( prvIdleTask, pvParameters )
\r
1607 /* Stop warnings. */
\r
1608 ( void ) pvParameters;
\r
1612 /* See if any tasks have been deleted. */
\r
1613 prvCheckTasksWaitingTermination();
\r
1615 #if ( configUSE_PREEMPTION == 0 )
\r
1617 /* If we are not using preemption we keep forcing a task switch to
\r
1618 see if any other task has become available. If we are using
\r
1619 preemption we don't need to do this as any task becoming available
\r
1620 will automatically get the processor anyway. */
\r
1625 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )
\r
1627 /* When using preemption tasks of equal priority will be
\r
1628 timesliced. If a task that is sharing the idle priority is ready
\r
1629 to run then the idle task should yield before the end of the
\r
1632 A critical region is not required here as we are just reading from
\r
1633 the list, and an occasional incorrect value will not matter. If
\r
1634 the ready list at the idle priority contains more than one task
\r
1635 then a task other than the idle task is ready to execute. */
\r
1636 if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )
\r
1643 #if ( configUSE_IDLE_HOOK == 1 )
\r
1645 extern void vApplicationIdleHook( void );
\r
1647 /* Call the user defined function from within the idle task. This
\r
1648 allows the application designer to add background functionality
\r
1649 without the overhead of a separate task.
\r
1650 NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,
\r
1651 CALL A FUNCTION THAT MIGHT BLOCK. */
\r
1652 vApplicationIdleHook();
\r
1656 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */
\r
1664 /*-----------------------------------------------------------
\r
1665 * File private functions documented at the top of the file.
\r
1666 *----------------------------------------------------------*/
\r
1670 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )
\r
1672 /* Store the function name in the TCB. */
\r
1673 strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );
\r
1674 pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';
\r
1676 /* This is used as an array index so must ensure it's not too large. */
\r
1677 if( uxPriority >= configMAX_PRIORITIES )
\r
1679 uxPriority = configMAX_PRIORITIES - 1;
\r
1682 pxTCB->uxPriority = uxPriority;
\r
1683 #if ( configUSE_MUTEXES == 1 )
\r
1685 pxTCB->uxBasePriority = uxPriority;
\r
1689 vListInitialiseItem( &( pxTCB->xGenericListItem ) );
\r
1690 vListInitialiseItem( &( pxTCB->xEventListItem ) );
\r
1692 /* Set the pxTCB as a link back from the xListItem. This is so we can get
\r
1693 back to the containing TCB from a generic item in a list. */
\r
1694 listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );
\r
1696 /* Event lists are always in priority order. */
\r
1697 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );
\r
1698 listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );
\r
1700 #if ( portCRITICAL_NESTING_IN_TCB == 1 )
\r
1702 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;
\r
1706 #if ( configUSE_APPLICATION_TASK_TAG == 1 )
\r
1708 pxTCB->pxTaskTag = NULL;
\r
1712 /*-----------------------------------------------------------*/
\r
1714 static void prvInitialiseTaskLists( void )
\r
1716 unsigned portBASE_TYPE uxPriority;
\r
1718 for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )
\r
1720 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );
\r
1723 vListInitialise( ( xList * ) &xDelayedTaskList1 );
\r
1724 vListInitialise( ( xList * ) &xDelayedTaskList2 );
\r
1725 vListInitialise( ( xList * ) &xPendingReadyList );
\r
1727 #if ( INCLUDE_vTaskDelete == 1 )
\r
1729 vListInitialise( ( xList * ) &xTasksWaitingTermination );
\r
1733 #if ( INCLUDE_vTaskSuspend == 1 )
\r
1735 vListInitialise( ( xList * ) &xSuspendedTaskList );
\r
1739 /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList
\r
1741 pxDelayedTaskList = &xDelayedTaskList1;
\r
1742 pxOverflowDelayedTaskList = &xDelayedTaskList2;
\r
1744 /*-----------------------------------------------------------*/
\r
1746 static void prvCheckTasksWaitingTermination( void )
\r
1748 #if ( INCLUDE_vTaskDelete == 1 )
\r
1750 portBASE_TYPE xListIsEmpty;
\r
1752 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called
\r
1753 too often in the idle task. */
\r
1754 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )
\r
1756 vTaskSuspendAll();
\r
1757 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );
\r
1760 if( !xListIsEmpty )
\r
1764 portENTER_CRITICAL();
\r
1766 pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );
\r
1767 vListRemove( &( pxTCB->xGenericListItem ) );
\r
1768 --uxCurrentNumberOfTasks;
\r
1771 portEXIT_CRITICAL();
\r
1773 prvDeleteTCB( pxTCB );
\r
1779 /*-----------------------------------------------------------*/
\r
1781 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )
\r
1785 /* Allocate space for the TCB. Where the memory comes from depends on
\r
1786 the implementation of the port malloc function. */
\r
1787 pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );
\r
1789 if( pxNewTCB != NULL )
\r
1791 /* Allocate space for the stack used by the task being created.
\r
1792 The base of the stack memory stored in the TCB so the task can
\r
1793 be deleted later if required. */
\r
1794 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );
\r
1796 if( pxNewTCB->pxStack == NULL )
\r
1798 /* Could not allocate the stack. Delete the allocated TCB. */
\r
1799 vPortFree( pxNewTCB );
\r
1804 /* Just to help debugging. */
\r
1805 memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );
\r
1811 /*-----------------------------------------------------------*/
\r
1813 #if ( configUSE_TRACE_FACILITY == 1 )
\r
1815 static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )
\r
1817 volatile tskTCB *pxNextTCB, *pxFirstTCB;
\r
1818 unsigned portSHORT usStackRemaining;
\r
1820 /* Write the details of all the TCB's in pxList into the buffer. */
\r
1821 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );
\r
1824 listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );
\r
1825 usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );
\r
1826 sprintf( pcStatusString, ( portCHAR * ) "%s\t\t%c\t%u\t%u\t%u\r\n", pxNextTCB->pcTaskName, cStatus, ( unsigned int ) pxNextTCB->uxPriority, usStackRemaining, ( unsigned int ) pxNextTCB->uxTCBNumber );
\r
1827 strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );
\r
1829 } while( pxNextTCB != pxFirstTCB );
\r
1833 /*-----------------------------------------------------------*/
\r
1835 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )
\r
1837 unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )
\r
1839 register unsigned portSHORT usCount = 0;
\r
1841 while( *pucStackByte == tskSTACK_FILL_BYTE )
\r
1843 pucStackByte -= portSTACK_GROWTH;
\r
1847 usCount /= sizeof( portSTACK_TYPE );
\r
1853 /*-----------------------------------------------------------*/
\r
1855 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )
\r
1857 unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask )
\r
1860 unsigned portCHAR *pcEndOfStack;
\r
1862 pxTCB = prvGetTCBFromHandle( xTask );
\r
1864 #if portSTACK_GROWTH < 0
\r
1866 pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxStack;
\r
1870 pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxEndOfStack;
\r
1874 return usTaskCheckFreeStackSpace( pcEndOfStack );
\r
1878 /*-----------------------------------------------------------*/
\r
1880 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )
\r
1882 static void prvDeleteTCB( tskTCB *pxTCB )
\r
1884 /* Free up the memory allocated by the scheduler for the task. It is up to
\r
1885 the task to free any memory allocated at the application level. */
\r
1886 vPortFree( pxTCB->pxStack );
\r
1887 vPortFree( pxTCB );
\r
1893 /*-----------------------------------------------------------*/
\r
1895 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )
\r
1897 xTaskHandle xTaskGetCurrentTaskHandle( void )
\r
1899 xTaskHandle xReturn;
\r
1901 portENTER_CRITICAL();
\r
1903 xReturn = ( xTaskHandle ) pxCurrentTCB;
\r
1905 portEXIT_CRITICAL();
\r
1912 /*-----------------------------------------------------------*/
\r
1914 #if ( INCLUDE_xTaskGetSchedulerState == 1 )
\r
1916 portBASE_TYPE xTaskGetSchedulerState( void )
\r
1918 portBASE_TYPE xReturn;
\r
1920 if( xSchedulerRunning == pdFALSE )
\r
1922 xReturn = taskSCHEDULER_NOT_STARTED;
\r
1926 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
1928 xReturn = taskSCHEDULER_RUNNING;
\r
1932 xReturn = taskSCHEDULER_SUSPENDED;
\r
1940 /*-----------------------------------------------------------*/
\r
1942 #if ( configUSE_MUTEXES == 1 )
\r
1944 void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )
\r
1946 tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;
\r
1948 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )
\r
1950 /* Adjust the mutex holder state to account for its new priority. */
\r
1951 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );
\r
1953 /* If the task being modified is in the ready state it will need to
\r
1954 be moved in to a new list. */
\r
1955 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )
\r
1957 vListRemove( &( pxTCB->xGenericListItem ) );
\r
1959 /* Inherit the priority before being moved into the new list. */
\r
1960 pxTCB->uxPriority = pxCurrentTCB->uxPriority;
\r
1961 prvAddTaskToReadyQueue( pxTCB );
\r
1965 /* Just inherit the priority. */
\r
1966 pxTCB->uxPriority = pxCurrentTCB->uxPriority;
\r
1972 /*-----------------------------------------------------------*/
\r
1974 #if ( configUSE_MUTEXES == 1 )
\r
1976 void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )
\r
1978 tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;
\r
1980 if( pxMutexHolder != NULL )
\r
1982 if( pxTCB->uxPriority != pxTCB->uxBasePriority )
\r
1984 /* We must be the running task to be able to give the mutex back.
\r
1985 Remove ourselves from the ready list we currently appear in. */
\r
1986 vListRemove( &( pxTCB->xGenericListItem ) );
\r
1988 /* Disinherit the priority before adding ourselves into the new
\r
1990 pxTCB->uxPriority = pxTCB->uxBasePriority;
\r
1991 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );
\r
1992 prvAddTaskToReadyQueue( pxTCB );
\r
1998 /*-----------------------------------------------------------*/
\r
2000 #if ( portCRITICAL_NESTING_IN_TCB == 1 )
\r
2002 void vTaskEnterCritical( void )
\r
2004 portDISABLE_INTERRUPTS();
\r
2006 if( xSchedulerRunning != pdFALSE )
\r
2008 pxCurrentTCB->uxCriticalNesting++;
\r
2013 /*-----------------------------------------------------------*/
\r
2015 #if ( portCRITICAL_NESTING_IN_TCB == 1 )
\r
2017 void vTaskExitCritical( void )
\r
2019 if( xSchedulerRunning != pdFALSE )
\r
2021 if( pxCurrentTCB->uxCriticalNesting > 0 )
\r
2023 pxCurrentTCB->uxCriticalNesting--;
\r
2025 if( pxCurrentTCB->uxCriticalNesting == 0 )
\r
2027 portENABLE_INTERRUPTS();
\r
2034 /*-----------------------------------------------------------*/
\r