2 FreeRTOS V4.0.1 - Copyright (C) 2003-2006 Richard Barry.
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4 This file is part of the FreeRTOS distribution.
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6 FreeRTOS is free software; you can redistribute it and/or modify
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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 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; 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, 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 + Call to portRESTORE_CONTEXT has been removed. The first context
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37 switch is now performed within sPortStartScheduler().
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41 + More use of 8bit data types.
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42 + Function name prefixes changed where the data type returned has changed.
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43 + configUSE_TRACE_FACILITY is no longer defined by default.
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47 + Introduced ucTopReadyPriority. This tracks the highest priority ready
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48 queue that contains a valid TCB and thus makes the context switch
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51 + prvAddTaskToReadyQueue() has been made a macro.
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55 + Added conditional compilation directives.
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57 + Rearranged function order.
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58 + Creating a task now causes a context switch if the task being created
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59 has a higher priority than the calling task - assuming the kernel is
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61 + vTaskDelete() now only causes a context switch if the calling task is
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62 the task being deleted.
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66 + Allow the type of the tick count to be 16 or 32 bits.
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67 + Introduce xPendingReadyList feature to allow the time interrupts have to
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68 be disabled to be minimised.
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69 + Remove the #if( INCLUDE_vTaskSuspendAll ) statements. vTaskSuspendAll()
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70 is now always included as it is used by the scheduler itself.
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74 + Bug fix - pxCurrentTCB is now initialised before the call to
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75 prvInitializeTaskLists(). Previously pxCurrentTCB could be accessed
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80 + Change to where lStackSize is declared within sTaskCreate() to prevent
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81 compiler warnings with 8051 port.
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85 + Explicit use of 'signed' qualifier on portCHAR types added.
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86 + Changed odd calculation of initial pxTopOfStack value when
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87 portSTACK_GROWTH < 0.
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88 + Removed pcVersionNumber definition.
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92 + cTaskResumeAll() modified to ensure it can be called prior to the task
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93 lists being initialised.
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97 + Added API function vTaskDelayUntil().
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98 + Added INCLUDE_vTaskDelay conditional compilation.
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100 Changes from V2.6.0
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102 + Updated the vWriteTraceToBuffer macro to always be 4 byte aligned so it
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103 can be used on ARM architectures.
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104 + tskMAX_TASK_NAME_LEN definition replaced with the port specific
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105 configMAX_TASK_NAME_LEN definition.
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106 + Removed the call to strcpy when copying across the task name into the
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108 + Added ucTasksDeleted variable to prevent vTaskSuspendAll() being called
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109 too often in the idle task.
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111 Changes between V3.0.0 and V2.6.1
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113 + When resuming the scheduler a yield is performed if either a tick has
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114 been missed, or a task is moved from the pending ready list into a ready
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115 list. Previously a yield was not performed on this second condition.
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116 + Introduced the type portBASE_TYPE. This necessitates several API
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118 + Removed the sUsingPreemption variable. The constant defined in
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119 portmacro.h is now used directly.
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120 + The idle task can now include an optional hook function - and no longer
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121 completes its time slice if other tasks with equal priority to it are
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123 + See the FreeRTOS.org documentation for more information on V2.x.x to
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124 V3.x.x modifications.
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126 Changes from V3.1.1
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128 + Modified vTaskPrioritySet() and vTaskResume() to allow these functions to
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129 be called while the scheduler is suspended.
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130 + Corrected the task ordering within event lists.
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132 Changes from V3.2.0
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134 + Added function xTaskGetCurrentTaskHandle().
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136 Changes from V3.2.4
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138 + Changed the volatile declarations on some variables to reflect the
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139 changes to the list definitions.
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140 + Changed the order of the TCB definition so there is commonality between
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141 the task control block and a co-routine control block.
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142 + Allow the scheduler to be started even if no tasks other than the idle
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143 task has been created. This allows co-routines to run even when no tasks
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145 + The need for a context switch is now signalled if a task woken by an
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146 event has a priority greater or equal to the currently running task.
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147 Previously this was only greater than.
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149 Changes from V4.0.0
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151 + Added the xMissedYield handling.
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155 #include <stdlib.h>
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156 #include <string.h>
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158 #include "FreeRTOS.h"
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162 * Macro to define the amount of stack available to the idle task.
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164 #define tskIDLE_STACK_SIZE configMINIMAL_STACK_SIZE
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168 * Default a definitions for backwards compatibility with old
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169 * portmacro.h files.
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171 #ifndef configMAX_TASK_NAME_LEN
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172 #define configMAX_TASK_NAME_LEN 16
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175 #ifndef INCLUDE_xTaskGetCurrentTaskHandle
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176 #define INCLUDE_xTaskGetCurrentTaskHandle 0
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179 #ifndef configIDLE_SHOULD_YIELD
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180 #define configIDLE_SHOULD_YIELD 1
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183 #if configMAX_TASK_NAME_LEN < 1
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184 #undef configMAX_TASK_NAME_LEN
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185 #define configMAX_TASK_NAME_LEN 1
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190 * Task control block. A task control block (TCB) is allocated to each task,
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191 * and stores the context of the task.
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193 typedef struct tskTaskControlBlock
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195 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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196 xListItem xGenericListItem; /*< List item used to place the TCB in ready and blocked queues. */
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197 xListItem xEventListItem; /*< List item used to place the TCB in event lists. */
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198 unsigned portBASE_TYPE uxPriority; /*< The priority of the task where 0 is the lowest priority. */
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199 portSTACK_TYPE *pxStack; /*< Points to the start of the stack. */
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200 unsigned portBASE_TYPE uxTCBNumber; /*< This is used for tracing the scheduler and making debugging easier only. */
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201 signed portCHAR pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created. Facilitates debugging only. */
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202 unsigned portSHORT usStackDepth; /*< Total depth of the stack (when empty). This is defined as the number of variables the stack can hold, not the number of bytes. */
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207 tskTCB * volatile pxCurrentTCB = NULL;
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209 /* Lists for ready and blocked tasks. --------------------*/
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211 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */
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212 static xList xDelayedTaskList1; /*< Delayed tasks. */
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213 static xList xDelayedTaskList2; /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */
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214 static xList * volatile pxDelayedTaskList; /*< Points to the delayed task list currently being used. */
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215 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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216 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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218 #if ( INCLUDE_vTaskDelete == 1 )
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220 static volatile xList xTasksWaitingTermination; /*< Tasks that have been deleted - but the their memory not yet freed. */
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221 static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;
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225 #if ( INCLUDE_vTaskSuspend == 1 )
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227 static xList xSuspendedTaskList; /*< Tasks that are currently suspended. */
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231 /* File private variables. --------------------------------*/
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232 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks = ( unsigned portBASE_TYPE ) 0;
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233 static volatile portTickType xTickCount = ( portTickType ) 0;
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234 static unsigned portBASE_TYPE uxTopUsedPriority = tskIDLE_PRIORITY;
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235 static volatile unsigned portBASE_TYPE uxTopReadyPriority = tskIDLE_PRIORITY;
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236 static volatile signed portBASE_TYPE xSchedulerRunning = pdFALSE;
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237 static volatile unsigned portBASE_TYPE uxSchedulerSuspended = ( unsigned portBASE_TYPE ) pdFALSE;
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238 static volatile unsigned portBASE_TYPE uxMissedTicks = ( unsigned portBASE_TYPE ) 0;
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239 static volatile portBASE_TYPE xMissedYield = ( portBASE_TYPE ) pdFALSE;
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241 /* Debugging and trace facilities private variables and macros. ------------*/
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244 * The value used to fill the stack of a task when the task is created. This
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245 * is used purely for checking the high water mark for tasks.
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247 #define tskSTACK_FILL_BYTE ( 0xa5 )
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250 * Macros used by vListTask to indicate which state a task is in.
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252 #define tskBLOCKED_CHAR ( ( signed portCHAR ) 'B' )
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253 #define tskREADY_CHAR ( ( signed portCHAR ) 'R' )
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254 #define tskDELETED_CHAR ( ( signed portCHAR ) 'D' )
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255 #define tskSUSPENDED_CHAR ( ( signed portCHAR ) 'S' )
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258 * Macros and private variables used by the trace facility.
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260 #if ( configUSE_TRACE_FACILITY == 1 )
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262 #define tskSIZE_OF_EACH_TRACE_LINE ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )
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263 static volatile signed portCHAR * volatile pcTraceBuffer;
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264 static signed portCHAR *pcTraceBufferStart;
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265 static signed portCHAR *pcTraceBufferEnd;
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266 static signed portBASE_TYPE xTracing = pdFALSE;
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271 * Macro that writes a trace of scheduler activity to a buffer. This trace
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272 * shows which task is running when and is very useful as a debugging tool.
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273 * As this macro is called each context switch it is a good idea to undefine
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274 * it if not using the facility.
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276 #if ( configUSE_TRACE_FACILITY == 1 )
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278 #define vWriteTraceToBuffer() \
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282 static unsigned portBASE_TYPE uxPreviousTask = 255; \
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284 if( uxPreviousTask != pxCurrentTCB->uxTCBNumber ) \
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286 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd ) \
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288 uxPreviousTask = pxCurrentTCB->uxTCBNumber; \
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289 *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount; \
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290 pcTraceBuffer += sizeof( unsigned portLONG ); \
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291 *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask; \
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292 pcTraceBuffer += sizeof( unsigned portLONG ); \
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296 xTracing = pdFALSE; \
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304 #define vWriteTraceToBuffer()
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310 * Place the task represented by pxTCB into the appropriate ready queue for
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311 * the task. It is inserted at the end of the list. One quirk of this is
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312 * that if the task being inserted is at the same priority as the currently
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313 * executing task, then it will only be rescheduled after the currently
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314 * executing task has been rescheduled.
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316 #define prvAddTaskToReadyQueue( pxTCB ) \
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318 if( pxTCB->uxPriority > uxTopReadyPriority ) \
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320 uxTopReadyPriority = pxTCB->uxPriority; \
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322 vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ); \
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327 * Macro that looks at the list of tasks that are currently delayed to see if
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328 * any require waking.
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330 * Tasks are stored in the queue in the order of their wake time - meaning
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331 * once one tasks has been found whose timer has not expired we need not look
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332 * any further down the list.
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334 #define prvCheckDelayedTasks() \
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336 register tskTCB *pxTCB; \
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338 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL ) \
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340 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) ) \
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344 vListRemove( &( pxTCB->xGenericListItem ) ); \
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345 /* Is the task waiting on an event also? */ \
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346 if( pxTCB->xEventListItem.pvContainer ) \
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348 vListRemove( &( pxTCB->xEventListItem ) ); \
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350 prvAddTaskToReadyQueue( pxTCB ); \
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355 * Several functions take an xTaskHandle parameter that can optionally be NULL,
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356 * where NULL is used to indicate that the handle of the currently executing
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357 * task should be used in place of the parameter. This macro simply checks to
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358 * see if the parameter is NULL and returns a pointer to the appropriate TCB.
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360 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )
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363 /* File private functions. --------------------------------*/
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366 * Utility to ready a TCB for a given task. Mainly just copies the parameters
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367 * into the TCB structure.
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369 static void prvInitialiseTCBVariables( tskTCB *pxTCB, unsigned portSHORT usStackDepth, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );
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372 * Utility to ready all the lists used by the scheduler. This is called
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373 * automatically upon the creation of the first task.
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375 static void prvInitialiseTaskLists( void );
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378 * The idle task, which as all tasks is implemented as a never ending loop.
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379 * The idle task is automatically created and added to the ready lists upon
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380 * creation of the first user task.
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382 * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific
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383 * language extensions. The equivalent prototype for this function is:
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385 * void prvIdleTask( void *pvParameters );
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388 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );
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391 * Utility to free all memory allocated by the scheduler to hold a TCB,
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392 * including the stack pointed to by the TCB.
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394 * This does not free memory allocated by the task itself (i.e. memory
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395 * allocated by calls to pvPortMalloc from within the tasks application code).
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397 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )
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398 static void prvDeleteTCB( tskTCB *pxTCB );
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402 * Used only by the idle task. This checks to see if anything has been placed
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403 * in the list of tasks waiting to be deleted. If so the task is cleaned up
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404 * and its TCB deleted.
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406 static void prvCheckTasksWaitingTermination( void );
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409 * Allocates memory from the heap for a TCB and associated stack. Checks the
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410 * allocation was successful.
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412 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );
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415 * Called from vTaskList. vListTasks details all the tasks currently under
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416 * control of the scheduler. The tasks may be in one of a number of lists.
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417 * prvListTaskWithinSingleList accepts a list and details the tasks from
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418 * within just that list.
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420 * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM
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421 * NORMAL APPLICATION CODE.
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423 #if ( configUSE_TRACE_FACILITY == 1 )
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425 static void prvListTaskWithinSingleList( signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );
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430 * When a task is created, the stack of the task is filled with a known value.
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431 * This function determines the 'high water mark' of the task stack by
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432 * determining how much of the stack remains at the original preset value.
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434 #if ( configUSE_TRACE_FACILITY == 1 )
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436 unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR *pucStackByte );
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446 /*-----------------------------------------------------------
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447 * TASK CREATION API documented in task.h
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448 *----------------------------------------------------------*/
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450 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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452 signed portBASE_TYPE xReturn;
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454 static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */
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456 /* Allocate the memory required by the TCB and stack for the new task.
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457 checking that the allocation was successful. */
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458 pxNewTCB = prvAllocateTCBAndStack( usStackDepth );
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460 if( pxNewTCB != NULL )
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462 portSTACK_TYPE *pxTopOfStack;
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464 /* Setup the newly allocated TCB with the initial state of the task. */
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465 prvInitialiseTCBVariables( pxNewTCB, usStackDepth, pcName, uxPriority );
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467 /* Calculate the top of stack address. This depends on whether the
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468 stack grows from high memory to low (as per the 80x86) or visa versa.
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469 portSTACK_GROWTH is used to make the result positive or negative as
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470 required by the port. */
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471 #if portSTACK_GROWTH < 0
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473 pxTopOfStack = pxNewTCB->pxStack + ( pxNewTCB->usStackDepth - 1 );
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477 pxTopOfStack = pxNewTCB->pxStack;
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481 /* Initialize the TCB stack to look as if the task was already running,
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482 but had been interrupted by the scheduler. The return address is set
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483 to the start of the task function. Once the stack has been initialised
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484 the top of stack variable is updated. */
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485 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );
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487 /* We are going to manipulate the task queues to add this task to a
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488 ready list, so must make sure no interrupts occur. */
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489 portENTER_CRITICAL();
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491 uxCurrentNumberOfTasks++;
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492 if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )
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494 /* As this is the first task it must also be the current task. */
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495 pxCurrentTCB = pxNewTCB;
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497 /* This is the first task to be created so do the preliminary
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498 initialisation required. We will not recover if this call
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499 fails, but we will report the failure. */
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500 prvInitialiseTaskLists();
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504 /* If the scheduler is not already running, make this task the
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505 current task if it is the highest priority task to be created
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507 if( xSchedulerRunning == pdFALSE )
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509 if( pxCurrentTCB->uxPriority <= uxPriority )
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511 pxCurrentTCB = pxNewTCB;
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516 /* Remember the top priority to make context switching faster. Use
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517 the priority in pxNewTCB as this has been capped to a valid value. */
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518 if( pxNewTCB->uxPriority > uxTopUsedPriority )
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520 uxTopUsedPriority = pxNewTCB->uxPriority;
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523 /* Add a counter into the TCB for tracing only. */
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524 pxNewTCB->uxTCBNumber = uxTaskNumber;
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527 prvAddTaskToReadyQueue( pxNewTCB );
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531 portEXIT_CRITICAL();
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535 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;
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538 if( xReturn == pdPASS )
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540 if( ( void * ) pxCreatedTask != NULL )
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542 /* Pass the TCB out - in an anonymous way. The calling function/
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543 task can use this as a handle to delete the task later if
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545 *pxCreatedTask = ( xTaskHandle ) pxNewTCB;
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548 if( xSchedulerRunning != pdFALSE )
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550 /* If the created task is of a higher priority than the current task
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551 then it should run now. */
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552 if( pxCurrentTCB->uxPriority < uxPriority )
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561 /*-----------------------------------------------------------*/
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563 #if ( INCLUDE_vTaskDelete == 1 )
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565 void vTaskDelete( xTaskHandle pxTaskToDelete )
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569 taskENTER_CRITICAL();
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571 /* If null is passed in here then we are deleting ourselves. */
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572 pxTCB = prvGetTCBFromHandle( pxTaskToDelete );
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574 /* Remove task from the ready list and place in the termination list.
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575 This will stop the task from be scheduled. The idle task will check
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576 the termination list and free up any memory allocated by the
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577 scheduler for the TCB and stack. */
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578 vListRemove( &( pxTCB->xGenericListItem ) );
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580 /* Is the task waiting on an event also? */
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581 if( pxTCB->xEventListItem.pvContainer )
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583 vListRemove( &( pxTCB->xEventListItem ) );
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586 vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );
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588 /* Increment the ucTasksDeleted variable so the idle task knows
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589 there is a task that has been deleted and that it should therefore
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590 check the xTasksWaitingTermination list. */
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593 taskEXIT_CRITICAL();
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595 /* Force a reschedule if we have just deleted the current task. */
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596 if( ( void * ) pxTaskToDelete == NULL )
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609 /*-----------------------------------------------------------
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610 * TASK CONTROL API documented in task.h
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611 *----------------------------------------------------------*/
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613 #if ( INCLUDE_vTaskDelayUntil == 1 )
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615 void vTaskDelayUntil( portTickType *pxPreviousWakeTime, portTickType xTimeIncrement )
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617 portTickType xTimeToWake;
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618 portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;
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622 /* Generate the tick time at which the task wants to wake. */
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623 xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;
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625 if( xTickCount < *pxPreviousWakeTime )
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627 /* The tick count has overflowed since this function was
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628 lasted called. In this case the only time we should ever
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629 actually delay is if the wake time has also overflowed,
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630 and the wake time is greater than the tick time. When this
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631 is the case it is as if neither time had overflowed. */
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632 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )
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634 xShouldDelay = pdTRUE;
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639 /* The tick time has not overflowed. In this case we will
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640 delay if either the wake time has overflowed, and/or the
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641 tick time is less than the wake time. */
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642 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )
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644 xShouldDelay = pdTRUE;
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648 /* Update the wake time ready for the next call. */
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649 *pxPreviousWakeTime = xTimeToWake;
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653 /* We must remove ourselves from the ready list before adding
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654 ourselves to the blocked list as the same list item is used for
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656 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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658 /* The list item will be inserted in wake time order. */
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659 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );
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661 if( xTimeToWake < xTickCount )
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663 /* Wake time has overflowed. Place this item in the
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665 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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669 /* The wake time has not overflowed, so we can use the
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670 current block list. */
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671 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
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675 xAlreadyYielded = xTaskResumeAll();
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677 /* Force a reschedule if xTaskResumeAll has not already done so, we may
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678 have put ourselves to sleep. */
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679 if( !xAlreadyYielded )
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686 /*-----------------------------------------------------------*/
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688 #if ( INCLUDE_vTaskDelay == 1 )
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690 void vTaskDelay( portTickType xTicksToDelay )
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692 portTickType xTimeToWake;
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693 signed portBASE_TYPE xAlreadyYielded = pdFALSE;
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695 /* A delay time of zero just forces a reschedule. */
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696 if( xTicksToDelay > ( portTickType ) 0 )
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700 /* A task that is removed from the event list while the
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701 scheduler is suspended will not get placed in the ready
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702 list or removed from the blocked list until the scheduler
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705 This task cannot be in an event list as it is the currently
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708 /* Calculate the time to wake - this may overflow but this is
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710 xTimeToWake = xTickCount + xTicksToDelay;
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712 /* We must remove ourselves from the ready list before adding
\r
713 ourselves to the blocked list as the same list item is used for
\r
715 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
717 /* The list item will be inserted in wake time order. */
\r
718 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );
\r
720 if( xTimeToWake < xTickCount )
\r
722 /* Wake time has overflowed. Place this item in the
\r
724 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
728 /* The wake time has not overflowed, so we can use the
\r
729 current block list. */
\r
730 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
733 xAlreadyYielded = xTaskResumeAll();
\r
736 /* Force a reschedule if xTaskResumeAll has not already done so, we may
\r
737 have put ourselves to sleep. */
\r
738 if( !xAlreadyYielded )
\r
745 /*-----------------------------------------------------------*/
\r
747 #if ( INCLUDE_uxTaskPriorityGet == 1 )
\r
749 unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )
\r
752 unsigned portBASE_TYPE uxReturn;
\r
754 taskENTER_CRITICAL();
\r
756 /* If null is passed in here then we are changing the
\r
757 priority of the calling function. */
\r
758 pxTCB = prvGetTCBFromHandle( pxTask );
\r
759 uxReturn = pxTCB->uxPriority;
\r
761 taskEXIT_CRITICAL();
\r
767 /*-----------------------------------------------------------*/
\r
769 #if ( INCLUDE_vTaskPrioritySet == 1 )
\r
771 void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )
\r
774 unsigned portBASE_TYPE uxCurrentPriority;
\r
776 /* Ensure the new priority is valid. */
\r
777 if( uxNewPriority >= configMAX_PRIORITIES )
\r
779 uxNewPriority = configMAX_PRIORITIES - 1;
\r
782 taskENTER_CRITICAL();
\r
784 /* If null is passed in here then we are changing the
\r
785 priority of the calling function. */
\r
786 pxTCB = prvGetTCBFromHandle( pxTask );
\r
787 uxCurrentPriority = pxTCB->uxPriority;
\r
789 if( uxCurrentPriority != uxNewPriority )
\r
791 pxTCB->uxPriority = uxNewPriority;
\r
793 /* If the task is in the blocked or suspended list we need do
\r
794 nothing more than change it's priority variable. However, if
\r
795 the task is in a ready list it needs to be removed and placed
\r
796 in the queue appropriate to its new priority. */
\r
797 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )
\r
799 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
801 /* The task is currently in its ready list - remove before adding
\r
802 it to it's new ready list. */
\r
803 vListRemove( &( pxTCB->xGenericListItem ) );
\r
804 prvAddTaskToReadyQueue( pxTCB );
\r
808 /* We cannot access the delayed or ready lists, so will hold this
\r
809 task pending until the scheduler is resumed. */
\r
810 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );
\r
815 taskEXIT_CRITICAL();
\r
817 /* The priority change may have readied a task of higher
\r
818 priority than the calling task. */
\r
823 /*-----------------------------------------------------------*/
\r
825 #if ( INCLUDE_vTaskSuspend == 1 )
\r
827 void vTaskSuspend( xTaskHandle pxTaskToSuspend )
\r
831 taskENTER_CRITICAL();
\r
833 /* If null is passed in here then we are suspending ourselves. */
\r
834 pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );
\r
836 /* Remove task from the ready/delayed list and place in the suspended list. */
\r
837 vListRemove( &( pxTCB->xGenericListItem ) );
\r
839 /* Is the task waiting on an event also? */
\r
840 if( pxTCB->xEventListItem.pvContainer )
\r
842 vListRemove( &( pxTCB->xEventListItem ) );
\r
845 vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );
\r
847 taskEXIT_CRITICAL();
\r
849 /* We may have just suspended the current task. */
\r
850 if( ( void * ) pxTaskToSuspend == NULL )
\r
857 /*-----------------------------------------------------------*/
\r
859 #if ( INCLUDE_vTaskSuspend == 1 )
\r
861 void vTaskResume( xTaskHandle pxTaskToResume )
\r
864 portBASE_TYPE xYieldRequired;
\r
866 /* Remove the task from whichever list it is currently in, and place
\r
867 it in the ready list. */
\r
868 pxTCB = ( tskTCB * ) pxTaskToResume;
\r
870 /* The parameter cannot be NULL as it is impossible to resume the
\r
871 currently executing task. */
\r
872 if( pxTCB != NULL )
\r
874 taskENTER_CRITICAL();
\r
876 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
878 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );
\r
879 vListRemove( &( pxTCB->xGenericListItem ) );
\r
880 prvAddTaskToReadyQueue( pxTCB );
\r
884 /* We cannot access the delayed or ready lists, so will hold this
\r
885 task pending until the scheduler is resumed. */
\r
886 xYieldRequired = pdFALSE;
\r
887 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );
\r
890 taskEXIT_CRITICAL();
\r
892 /* We may have just resumed a higher priority task. */
\r
893 if( xYieldRequired )
\r
895 /* This yield may not cause the task just resumed to run, but
\r
896 will leave the lists in the correct state for the next yield. */
\r
908 /*-----------------------------------------------------------
\r
909 * PUBLIC SCHEDULER CONTROL documented in task.h
\r
910 *----------------------------------------------------------*/
\r
913 void vTaskStartScheduler( void )
\r
915 portBASE_TYPE xReturn;
\r
917 /* Add the idle task at the lowest priority. */
\r
918 xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );
\r
920 if( xReturn == pdPASS )
\r
922 /* Interrupts are turned off here, to ensure a tick does not occur
\r
923 before or during the call to xPortStartScheduler(). The stacks of
\r
924 the created tasks contain a status word with interrupts switched on
\r
925 so interrupts will automatically get re-enabled when the first task
\r
928 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE
\r
929 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */
\r
930 portDISABLE_INTERRUPTS();
\r
932 xSchedulerRunning = pdTRUE;
\r
933 xTickCount = ( portTickType ) 0;
\r
935 /* Setting up the timer tick is hardware specific and thus in the
\r
936 portable interface. */
\r
937 if( xPortStartScheduler() )
\r
939 /* Should not reach here as if the scheduler is running the
\r
940 function will not return. */
\r
944 /* Should only reach here if a task calls xTaskEndScheduler(). */
\r
948 /*-----------------------------------------------------------*/
\r
950 void vTaskEndScheduler( void )
\r
952 /* Stop the scheduler interrupts and call the portable scheduler end
\r
953 routine so the original ISRs can be restored if necessary. The port
\r
954 layer must ensure interrupts enable bit is left in the correct state. */
\r
955 portDISABLE_INTERRUPTS();
\r
956 xSchedulerRunning = pdFALSE;
\r
957 vPortEndScheduler();
\r
959 /*----------------------------------------------------------*/
\r
961 void vTaskSuspendAll( void )
\r
963 portENTER_CRITICAL();
\r
964 ++uxSchedulerSuspended;
\r
965 portEXIT_CRITICAL();
\r
967 /*----------------------------------------------------------*/
\r
969 signed portBASE_TYPE xTaskResumeAll( void )
\r
971 register tskTCB *pxTCB;
\r
972 signed portBASE_TYPE xAlreadyYielded = pdFALSE;
\r
974 /* It is possible that an ISR caused a task to be removed from an event
\r
975 list while the scheduler was suspended. If this was the case then the
\r
976 removed task will have been added to the xPendingReadyList. Once the
\r
977 scheduler has been resumed it is safe to move all the pending ready
\r
978 tasks from this list into their appropriate ready list. */
\r
979 portENTER_CRITICAL();
\r
981 --uxSchedulerSuspended;
\r
983 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
985 if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )
\r
987 portBASE_TYPE xYieldRequired = pdFALSE;
\r
989 /* Move any readied tasks from the pending list into the
\r
990 appropriate ready list. */
\r
991 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xPendingReadyList ) ) ) != NULL )
\r
993 vListRemove( &( pxTCB->xEventListItem ) );
\r
994 vListRemove( &( pxTCB->xGenericListItem ) );
\r
995 prvAddTaskToReadyQueue( pxTCB );
\r
997 /* If we have moved a task that has a priority higher than
\r
998 the current task then we should yield. */
\r
999 if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )
\r
1001 xYieldRequired = pdTRUE;
\r
1005 /* If any ticks occurred while the scheduler was suspended then
\r
1006 they should be processed now. This ensures the tick count does not
\r
1007 slip, and that any delayed tasks are resumed at the correct time. */
\r
1008 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )
\r
1010 while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )
\r
1012 vTaskIncrementTick();
\r
1016 /* As we have processed some ticks it is appropriate to yield
\r
1017 to ensure the highest priority task that is ready to run is
\r
1018 the task actually running. */
\r
1019 xYieldRequired = pdTRUE;
\r
1022 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )
\r
1024 xAlreadyYielded = pdTRUE;
\r
1025 xMissedYield = pdFALSE;
\r
1031 portEXIT_CRITICAL();
\r
1033 return xAlreadyYielded;
\r
1041 /*-----------------------------------------------------------
\r
1042 * PUBLIC TASK UTILITIES documented in task.h
\r
1043 *----------------------------------------------------------*/
\r
1047 portTickType xTaskGetTickCount( void )
\r
1049 portTickType xTicks;
\r
1051 /* Critical section required if running on a 16 bit processor. */
\r
1052 taskENTER_CRITICAL();
\r
1054 xTicks = xTickCount;
\r
1056 taskEXIT_CRITICAL();
\r
1060 /*-----------------------------------------------------------*/
\r
1062 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )
\r
1064 unsigned portBASE_TYPE uxNumberOfTasks;
\r
1066 taskENTER_CRITICAL();
\r
1067 uxNumberOfTasks = uxCurrentNumberOfTasks;
\r
1068 taskEXIT_CRITICAL();
\r
1070 return uxNumberOfTasks;
\r
1072 /*-----------------------------------------------------------*/
\r
1074 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )
\r
1076 void vTaskList( signed portCHAR *pcWriteBuffer )
\r
1078 unsigned portBASE_TYPE uxQueue;
\r
1080 /* This is a VERY costly function that should be used for debug only.
\r
1081 It leaves interrupts disabled for a LONG time. */
\r
1083 taskENTER_CRITICAL();
\r
1085 /* Run through all the lists that could potentially contain a TCB and
\r
1086 report the task name, state and stack high water mark. */
\r
1088 pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;
\r
1089 strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );
\r
1091 uxQueue = uxTopUsedPriority + 1;
\r
1097 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )
\r
1099 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );
\r
1101 }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );
\r
1103 if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )
\r
1105 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );
\r
1108 if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )
\r
1110 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );
\r
1113 if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )
\r
1115 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );
\r
1118 if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )
\r
1120 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );
\r
1123 taskEXIT_CRITICAL();
\r
1127 /*----------------------------------------------------------*/
\r
1129 #if ( configUSE_TRACE_FACILITY == 1 )
\r
1131 void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )
\r
1133 portENTER_CRITICAL();
\r
1135 pcTraceBuffer = ( volatile signed portCHAR * volatile )pcBuffer;
\r
1136 pcTraceBufferStart = pcBuffer;
\r
1137 pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );
\r
1138 xTracing = pdTRUE;
\r
1140 portEXIT_CRITICAL();
\r
1144 /*----------------------------------------------------------*/
\r
1146 #if ( configUSE_TRACE_FACILITY == 1 )
\r
1148 unsigned portLONG ulTaskEndTrace( void )
\r
1150 unsigned portLONG ulBufferLength;
\r
1152 portENTER_CRITICAL();
\r
1153 xTracing = pdFALSE;
\r
1154 portEXIT_CRITICAL();
\r
1156 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );
\r
1158 return ulBufferLength;
\r
1165 /*-----------------------------------------------------------
\r
1166 * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES
\r
1167 * documented in task.h
\r
1168 *----------------------------------------------------------*/
\r
1171 inline void vTaskIncrementTick( void )
\r
1173 /* Called by the portable layer each time a tick interrupt occurs.
\r
1174 Increments the tick then checks to see if the new tick value will cause any
\r
1175 tasks to be unblocked. */
\r
1176 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
1179 if( xTickCount == ( portTickType ) 0 )
\r
1183 /* Tick count has overflowed so we need to swap the delay lists. If there are
\r
1184 any items in pxDelayedTaskList here then there is an error! */
\r
1185 pxTemp = pxDelayedTaskList;
\r
1186 pxDelayedTaskList = pxOverflowDelayedTaskList;
\r
1187 pxOverflowDelayedTaskList = pxTemp;
\r
1190 /* See if this tick has made a timeout expire. */
\r
1191 prvCheckDelayedTasks();
\r
1198 #if ( configUSE_TICK_HOOK == 1 )
\r
1200 extern void vApplicationTickHook( void );
\r
1202 vApplicationTickHook();
\r
1206 /*-----------------------------------------------------------*/
\r
1208 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )
\r
1210 void vTaskCleanUpResources( void )
\r
1212 unsigned portSHORT usQueue;
\r
1213 volatile tskTCB *pxTCB;
\r
1215 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;
\r
1217 /* Remove any TCB's from the ready queues. */
\r
1222 while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )
\r
1224 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );
\r
1225 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1227 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1229 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );
\r
1231 /* Remove any TCB's from the delayed queue. */
\r
1232 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )
\r
1234 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );
\r
1235 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1237 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1240 /* Remove any TCB's from the overflow delayed queue. */
\r
1241 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )
\r
1243 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );
\r
1244 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1246 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1249 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )
\r
1251 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );
\r
1252 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1254 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1257 while( !listLIST_IS_EMPTY( &xPendingReadyList ) )
\r
1259 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xPendingReadyList );
\r
1260 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );
\r
1262 prvDeleteTCB( ( tskTCB * ) pxTCB );
\r
1267 /*-----------------------------------------------------------*/
\r
1269 void vTaskSwitchContext( void )
\r
1271 if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )
\r
1273 /* The scheduler is currently suspended - do not allow a context
\r
1275 xMissedYield = pdTRUE;
\r
1279 /* Find the highest priority queue that contains ready tasks. */
\r
1280 while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )
\r
1282 --uxTopReadyPriority;
\r
1285 /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the
\r
1286 same priority get an equal share of the processor time. */
\r
1287 listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );
\r
1288 vWriteTraceToBuffer();
\r
1290 /*-----------------------------------------------------------*/
\r
1292 void vTaskPlaceOnEventList( xList *pxEventList, portTickType xTicksToWait )
\r
1294 portTickType xTimeToWake;
\r
1296 /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE
\r
1297 SCHEDULER SUSPENDED. */
\r
1299 /* Place the event list item of the TCB in the appropriate event list.
\r
1300 This is placed in the list in priority order so the highest priority task
\r
1301 is the first to be woken by the event. */
\r
1302 vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );
\r
1304 /* Calculate the time at which the task should be woken if the event does
\r
1305 not occur. This may overflow but this doesn't matter. */
\r
1306 xTimeToWake = xTickCount + xTicksToWait;
\r
1308 /* We must remove ourselves from the ready list before adding ourselves
\r
1309 to the blocked list as the same list item is used for both lists. We have
\r
1310 exclusive access to the ready lists as the scheduler is locked. */
\r
1311 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1313 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );
\r
1315 if( xTimeToWake < xTickCount )
\r
1317 /* Wake time has overflowed. Place this item in the overflow list. */
\r
1318 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1322 /* The wake time has not overflowed, so we can use the current block list. */
\r
1323 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
\r
1326 /*-----------------------------------------------------------*/
\r
1328 signed portBASE_TYPE xTaskRemoveFromEventList( const xList *pxEventList )
\r
1330 tskTCB *pxUnblockedTCB;
\r
1331 portBASE_TYPE xReturn;
\r
1333 /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE
\r
1334 SCHEDULER SUSPENDED. It can also be called from within an ISR. */
\r
1336 /* The event list is sorted in priority order, so we can remove the
\r
1337 first in the list, remove the TCB from the delayed list, and add
\r
1338 it to the ready list.
\r
1340 If an event is for a queue that is locked then this function will never
\r
1341 get called - the lock count on the queue will get modified instead. This
\r
1342 means we can always expect exclusive access to the event list here. */
\r
1343 pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );
\r
1344 vListRemove( &( pxUnblockedTCB->xEventListItem ) );
\r
1346 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )
\r
1348 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );
\r
1349 prvAddTaskToReadyQueue( pxUnblockedTCB );
\r
1353 /* We cannot access the delayed or ready lists, so will hold this
\r
1354 task pending until the scheduler is resumed. */
\r
1355 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );
\r
1358 if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )
\r
1360 /* Return true if the task removed from the event list has
\r
1361 a higher priority than the calling task. This allows
\r
1362 the calling task to know if it should force a context
\r
1368 xReturn = pdFALSE;
\r
1379 * -----------------------------------------------------------
\r
1381 * ----------------------------------------------------------
\r
1383 * The portTASK_FUNCTION() macro is used to allow port/compiler specific
\r
1384 * language extensions. The equivalent prototype for this function is:
\r
1386 * void prvIdleTask( void *pvParameters );
\r
1389 static portTASK_FUNCTION( prvIdleTask, pvParameters )
\r
1391 /* Stop warnings. */
\r
1392 ( void ) pvParameters;
\r
1396 /* See if any tasks have been deleted. */
\r
1397 prvCheckTasksWaitingTermination();
\r
1399 #if ( configUSE_PREEMPTION == 0 )
\r
1401 /* If we are not using preemption we keep forcing a task switch to
\r
1402 see if any other task has become available. If we are using
\r
1403 preemption we don't need to do this as any task becoming available
\r
1404 will automatically get the processor anyway. */
\r
1409 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )
\r
1411 /* When using preemption tasks of equal priority will be
\r
1412 timesliced. If a task that is sharing the idle priority is ready
\r
1413 to run then the idle task should yield before the end of the
\r
1416 A critical region is not required here as we are just reading from
\r
1417 the list, and an occasional incorrect value will not matter. If
\r
1418 the ready list at the idle priority contains more than one task
\r
1419 then a task other than the idle task is ready to execute. */
\r
1420 if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )
\r
1427 #if ( configUSE_IDLE_HOOK == 1 )
\r
1429 extern void vApplicationIdleHook( void );
\r
1431 /* Call the user defined function from within the idle task. This
\r
1432 allows the application designer to add background functionality
\r
1433 without the overhead of a separate task.
\r
1434 NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,
\r
1435 CALL A FUNCTION THAT MIGHT BLOCK. */
\r
1436 vApplicationIdleHook();
\r
1440 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */
\r
1448 /*-----------------------------------------------------------
\r
1449 * File private functions documented at the top of the file.
\r
1450 *----------------------------------------------------------*/
\r
1454 static void prvInitialiseTCBVariables( tskTCB *pxTCB, unsigned portSHORT usStackDepth, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )
\r
1456 pxTCB->usStackDepth = usStackDepth;
\r
1458 /* Store the function name in the TCB. */
\r
1459 strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );
\r
1460 pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';
\r
1462 /* This is used as an array index so must ensure it's not too large. */
\r
1463 if( uxPriority >= configMAX_PRIORITIES )
\r
1465 uxPriority = configMAX_PRIORITIES - 1;
\r
1468 pxTCB->uxPriority = uxPriority;
\r
1470 vListInitialiseItem( &( pxTCB->xGenericListItem ) );
\r
1471 vListInitialiseItem( &( pxTCB->xEventListItem ) );
\r
1473 /* Set the pxTCB as a link back from the xListItem. This is so we can get
\r
1474 back to the containing TCB from a generic item in a list. */
\r
1475 listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );
\r
1477 /* Event lists are always in priority order. */
\r
1478 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );
\r
1479 listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );
\r
1481 /*-----------------------------------------------------------*/
\r
1483 static void prvInitialiseTaskLists( void )
\r
1485 unsigned portBASE_TYPE uxPriority;
\r
1487 for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )
\r
1489 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );
\r
1492 vListInitialise( ( xList * ) &xDelayedTaskList1 );
\r
1493 vListInitialise( ( xList * ) &xDelayedTaskList2 );
\r
1494 vListInitialise( ( xList * ) &xPendingReadyList );
\r
1496 #if ( INCLUDE_vTaskDelete == 1 )
\r
1498 vListInitialise( ( xList * ) &xTasksWaitingTermination );
\r
1502 #if ( INCLUDE_vTaskSuspend == 1 )
\r
1504 vListInitialise( ( xList * ) &xSuspendedTaskList );
\r
1508 /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList
\r
1510 pxDelayedTaskList = &xDelayedTaskList1;
\r
1511 pxOverflowDelayedTaskList = &xDelayedTaskList2;
\r
1513 /*-----------------------------------------------------------*/
\r
1515 static void prvCheckTasksWaitingTermination( void )
\r
1517 #if ( INCLUDE_vTaskDelete == 1 )
\r
1519 portBASE_TYPE xListIsEmpty;
\r
1521 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called
\r
1522 too often in the idle task. */
\r
1523 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )
\r
1525 vTaskSuspendAll();
\r
1526 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );
\r
1529 if( !xListIsEmpty )
\r
1533 portENTER_CRITICAL();
\r
1535 pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );
\r
1536 vListRemove( &( pxTCB->xGenericListItem ) );
\r
1537 --uxCurrentNumberOfTasks;
\r
1540 portEXIT_CRITICAL();
\r
1542 prvDeleteTCB( pxTCB );
\r
1548 /*-----------------------------------------------------------*/
\r
1550 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )
\r
1554 /* Allocate space for the TCB. Where the memory comes from depends on
\r
1555 the implementation of the port malloc function. */
\r
1556 pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );
\r
1558 if( pxNewTCB != NULL )
\r
1560 /* Allocate space for the stack used by the task being created.
\r
1561 The base of the stack memory stored in the TCB so the task can
\r
1562 be deleted later if required. */
\r
1563 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );
\r
1565 if( pxNewTCB->pxStack == NULL )
\r
1567 /* Could not allocate the stack. Delete the allocated TCB. */
\r
1568 vPortFree( pxNewTCB );
\r
1573 /* Just to help debugging. */
\r
1574 memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );
\r
1580 /*-----------------------------------------------------------*/
\r
1582 #if ( configUSE_TRACE_FACILITY == 1 )
\r
1584 static void prvListTaskWithinSingleList( signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )
\r
1586 volatile tskTCB *pxNextTCB, *pxFirstTCB;
\r
1587 static portCHAR pcStatusString[ 50 ];
\r
1588 unsigned portSHORT usStackRemaining;
\r
1590 /* Write the details of all the TCB's in pxList into the buffer. */
\r
1591 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );
\r
1594 listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );
\r
1595 usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );
\r
1596 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
1597 strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );
\r
1599 } while( pxNextTCB != pxFirstTCB );
\r
1603 /*-----------------------------------------------------------*/
\r
1605 #if ( configUSE_TRACE_FACILITY == 1 )
\r
1606 unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR *pucStackByte )
\r
1608 register unsigned portSHORT usCount = 0;
\r
1610 while( *pucStackByte == tskSTACK_FILL_BYTE )
\r
1612 pucStackByte -= portSTACK_GROWTH;
\r
1616 usCount /= sizeof( portSTACK_TYPE );
\r
1621 /*-----------------------------------------------------------*/
\r
1625 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )
\r
1627 static void prvDeleteTCB( tskTCB *pxTCB )
\r
1629 /* Free up the memory allocated by the scheduler for the task. It is up to
\r
1630 the task to free any memory allocated at the application level. */
\r
1631 vPortFree( pxTCB->pxStack );
\r
1632 vPortFree( pxTCB );
\r
1638 /*-----------------------------------------------------------*/
\r
1640 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )
\r
1642 xTaskHandle xTaskGetCurrentTaskHandle( void )
\r
1644 xTaskHandle xReturn;
\r
1646 portENTER_CRITICAL();
\r
1648 xReturn = ( xTaskHandle ) pxCurrentTCB;
\r
1650 portEXIT_CRITICAL();
\r