2 FreeRTOS V8.2.3 - Copyright (C) 2015 Real Time Engineers Ltd.
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5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 This file is part of the FreeRTOS distribution.
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9 FreeRTOS is free software; you can redistribute it and/or modify it under
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10 the terms of the GNU General Public License (version 2) as published by the
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11 Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.
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13 ***************************************************************************
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14 >>! NOTE: The modification to the GPL is included to allow you to !<<
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15 >>! distribute a combined work that includes FreeRTOS without being !<<
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16 >>! obliged to provide the source code for proprietary components !<<
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17 >>! outside of the FreeRTOS kernel. !<<
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18 ***************************************************************************
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20 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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21 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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22 FOR A PARTICULAR PURPOSE. Full license text is available on the following
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23 link: http://www.freertos.org/a00114.html
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25 ***************************************************************************
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27 * FreeRTOS provides completely free yet professionally developed, *
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28 * robust, strictly quality controlled, supported, and cross *
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29 * platform software that is more than just the market leader, it *
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30 * is the industry's de facto standard. *
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32 * Help yourself get started quickly while simultaneously helping *
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33 * to support the FreeRTOS project by purchasing a FreeRTOS *
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34 * tutorial book, reference manual, or both: *
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35 * http://www.FreeRTOS.org/Documentation *
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37 ***************************************************************************
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39 http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading
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40 the FAQ page "My application does not run, what could be wrong?". Have you
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41 defined configASSERT()?
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43 http://www.FreeRTOS.org/support - In return for receiving this top quality
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44 embedded software for free we request you assist our global community by
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45 participating in the support forum.
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47 http://www.FreeRTOS.org/training - Investing in training allows your team to
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48 be as productive as possible as early as possible. Now you can receive
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49 FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
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50 Ltd, and the world's leading authority on the world's leading RTOS.
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52 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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53 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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54 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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56 http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
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57 Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
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59 http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
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60 Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
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61 licenses offer ticketed support, indemnification and commercial middleware.
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63 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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64 engineered and independently SIL3 certified version for use in safety and
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65 mission critical applications that require provable dependability.
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71 * Create a single persistent task which periodically dynamically creates another
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72 * two tasks. The original task is called the creator task, the two tasks it
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73 * creates are called suicidal tasks.
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75 * One of the created suicidal tasks kill one other suicidal task before killing
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76 * itself - leaving just the original task remaining.
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78 * The creator task must be spawned after all of the other demo application tasks
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79 * as it keeps a check on the number of tasks under the scheduler control. The
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80 * number of tasks it expects to see running should never be greater than the
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81 * number of tasks that were in existence when the creator task was spawned, plus
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82 * one set of four suicidal tasks. If this number is exceeded an error is flagged.
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84 * \page DeathC death.c
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85 * \ingroup DemoFiles
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92 /* Scheduler include files. */
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93 #include "FreeRTOS.h"
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96 /* Demo program include files. */
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99 #define deathSTACK_SIZE ( configMINIMAL_STACK_SIZE + 60 )
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101 /* The task originally created which is responsible for periodically dynamically
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102 creating another four tasks. */
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103 static portTASK_FUNCTION_PROTO( vCreateTasks, pvParameters );
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105 /* The task function of the dynamically created tasks. */
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106 static portTASK_FUNCTION_PROTO( vSuicidalTask, pvParameters );
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108 /* A variable which is incremented every time the dynamic tasks are created. This
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109 is used to check that the task is still running. */
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110 static volatile uint16_t usCreationCount = 0;
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112 /* Used to store the number of tasks that were originally running so the creator
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113 task can tell if any of the suicidal tasks have failed to die.
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115 static volatile UBaseType_t uxTasksRunningAtStart = 0;
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117 /* When a task deletes itself, it stack and TCB are cleaned up by the Idle task.
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118 Under heavy load the idle task might not get much processing time, so it would
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119 be legitimate for several tasks to remain undeleted for a short period. There
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120 may also be a few other unexpected tasks if, for example, the tasks that test
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121 static allocation are also being used. */
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122 static const UBaseType_t uxMaxNumberOfExtraTasksRunning = 3;
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124 /* Used to store a handle to the task that should be killed by a suicidal task,
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125 before it kills itself. */
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126 TaskHandle_t xCreatedTask;
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128 /*-----------------------------------------------------------*/
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130 void vCreateSuicidalTasks( UBaseType_t uxPriority )
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132 UBaseType_t *puxPriority;
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134 /* Create the Creator tasks - passing in as a parameter the priority at which
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135 the suicidal tasks should be created. */
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136 puxPriority = ( UBaseType_t * ) pvPortMalloc( sizeof( UBaseType_t ) );
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137 *puxPriority = uxPriority;
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139 xTaskCreate( vCreateTasks, "CREATOR", deathSTACK_SIZE, ( void * ) puxPriority, uxPriority, NULL );
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141 /* Record the number of tasks that are running now so we know if any of the
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142 suicidal tasks have failed to be killed. */
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143 uxTasksRunningAtStart = ( UBaseType_t ) uxTaskGetNumberOfTasks();
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145 /* FreeRTOS.org versions before V3.0 started the idle-task as the very
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146 first task. The idle task was then already included in uxTasksRunningAtStart.
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147 From FreeRTOS V3.0 on, the idle task is started when the scheduler is
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148 started. Therefore the idle task is not yet accounted for. We correct
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149 this by increasing uxTasksRunningAtStart by 1. */
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150 uxTasksRunningAtStart++;
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152 /* From FreeRTOS version 7.0.0 can optionally create a timer service task.
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153 If this is done, then uxTasksRunningAtStart needs incrementing again as that
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154 too is created when the scheduler is started. */
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155 #if configUSE_TIMERS == 1
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157 uxTasksRunningAtStart++;
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161 /*-----------------------------------------------------------*/
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163 static portTASK_FUNCTION( vSuicidalTask, pvParameters )
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165 volatile long l1, l2;
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166 TaskHandle_t xTaskToKill;
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167 const TickType_t xDelay = ( TickType_t ) 200 / portTICK_PERIOD_MS;
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169 if( pvParameters != NULL )
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171 /* This task is periodically created four times. Two created tasks are
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172 passed a handle to the other task so it can kill it before killing itself.
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173 The other task is passed in null. */
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174 xTaskToKill = *( TaskHandle_t* )pvParameters;
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178 xTaskToKill = NULL;
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183 /* Do something random just to use some stack and registers. */
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187 vTaskDelay( xDelay );
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189 if( xTaskToKill != NULL )
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191 /* Make sure the other task has a go before we delete it. */
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192 vTaskDelay( ( TickType_t ) 0 );
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194 /* Kill the other task that was created by vCreateTasks(). */
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195 vTaskDelete( xTaskToKill );
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197 /* Kill ourselves. */
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198 vTaskDelete( NULL );
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201 }/*lint !e818 !e550 Function prototype must be as per standard for task functions. */
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202 /*-----------------------------------------------------------*/
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204 static portTASK_FUNCTION( vCreateTasks, pvParameters )
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206 const TickType_t xDelay = ( TickType_t ) 1000 / portTICK_PERIOD_MS;
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207 UBaseType_t uxPriority;
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209 uxPriority = *( UBaseType_t * ) pvParameters;
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210 vPortFree( pvParameters );
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214 /* Just loop round, delaying then creating the four suicidal tasks. */
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215 vTaskDelay( xDelay );
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217 xCreatedTask = NULL;
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219 xTaskCreate( vSuicidalTask, "SUICID1", configMINIMAL_STACK_SIZE, NULL, uxPriority, &xCreatedTask );
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220 xTaskCreate( vSuicidalTask, "SUICID2", configMINIMAL_STACK_SIZE, &xCreatedTask, uxPriority, NULL );
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225 /*-----------------------------------------------------------*/
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227 /* This is called to check that the creator task is still running and that there
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228 are not any more than four extra tasks. */
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229 BaseType_t xIsCreateTaskStillRunning( void )
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231 static uint16_t usLastCreationCount = 0xfff;
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232 BaseType_t xReturn = pdTRUE;
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233 static UBaseType_t uxTasksRunningNow;
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235 if( usLastCreationCount == usCreationCount )
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241 usLastCreationCount = usCreationCount;
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244 uxTasksRunningNow = ( UBaseType_t ) uxTaskGetNumberOfTasks();
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246 if( uxTasksRunningNow < uxTasksRunningAtStart )
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250 else if( ( uxTasksRunningNow - uxTasksRunningAtStart ) > uxMaxNumberOfExtraTasksRunning )
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256 /* Everything is okay. */
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