/* | |
FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd. | |
All rights reserved | |
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* * | |
* FreeRTOS provides completely free yet professionally developed, * | |
* robust, strictly quality controlled, supported, and cross * | |
* platform software that has become a de facto standard. * | |
* * | |
* Help yourself get started quickly and support the FreeRTOS * | |
* project by purchasing a FreeRTOS tutorial book, reference * | |
* manual, or both from: http://www.FreeRTOS.org/Documentation * | |
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* Thank you! * | |
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This file is part of the FreeRTOS distribution. | |
FreeRTOS is free software; you can redistribute it and/or modify it under | |
the terms of the GNU General Public License (version 2) as published by the | |
Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception. | |
>>! NOTE: The modification to the GPL is included to allow you to !<< | |
>>! distribute a combined work that includes FreeRTOS without being !<< | |
>>! obliged to provide the source code for proprietary components !<< | |
>>! outside of the FreeRTOS kernel. !<< | |
FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY | |
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
FOR A PARTICULAR PURPOSE. Full license text is available from the following | |
link: http://www.freertos.org/a00114.html | |
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* * | |
* Having a problem? Start by reading the FAQ "My application does * | |
* not run, what could be wrong?" * | |
* * | |
* http://www.FreeRTOS.org/FAQHelp.html * | |
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http://www.FreeRTOS.org - Documentation, books, training, latest versions, | |
license and Real Time Engineers Ltd. contact details. | |
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, | |
including FreeRTOS+Trace - an indispensable productivity tool, a DOS | |
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*/ | |
/** | |
* Create a single persistent task which periodically dynamically creates another | |
* four tasks. The original task is called the creator task, the four tasks it | |
* creates are called suicidal tasks. | |
* | |
* Two of the created suicidal tasks kill one other suicidal task before killing | |
* themselves - leaving just the original task remaining. | |
* | |
* The creator task must be spawned after all of the other demo application tasks | |
* as it keeps a check on the number of tasks under the scheduler control. The | |
* number of tasks it expects to see running should never be greater than the | |
* number of tasks that were in existence when the creator task was spawned, plus | |
* one set of four suicidal tasks. If this number is exceeded an error is flagged. | |
* | |
* \page DeathC death.c | |
* \ingroup DemoFiles | |
* <HR> | |
*/ | |
/* | |
Changes from V2.0.0 | |
+ Delay periods are now specified using variables and constants of | |
TickType_t rather than unsigned long. | |
*/ | |
#include <stdlib.h> | |
/* Scheduler include files. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
/* Demo program include files. */ | |
#include "death.h" | |
#include "print.h" | |
#define deathSTACK_SIZE ( ( unsigned short ) 512 ) | |
/* The task originally created which is responsible for periodically dynamically | |
creating another four tasks. */ | |
static void vCreateTasks( void *pvParameters ); | |
/* The task function of the dynamically created tasks. */ | |
static void vSuicidalTask( void *pvParameters ); | |
/* A variable which is incremented every time the dynamic tasks are created. This | |
is used to check that the task is still running. */ | |
static volatile short sCreationCount = 0; | |
/* Used to store the number of tasks that were originally running so the creator | |
task can tell if any of the suicidal tasks have failed to die. */ | |
static volatile unsigned portBASE_TYPE uxTasksRunningAtStart = 0; | |
static const unsigned portBASE_TYPE uxMaxNumberOfExtraTasksRunning = 5; | |
/* Used to store a handle to the tasks that should be killed by a suicidal task, | |
before it kills itself. */ | |
TaskHandle_t xCreatedTask1, xCreatedTask2; | |
/*-----------------------------------------------------------*/ | |
void vCreateSuicidalTasks( unsigned portBASE_TYPE uxPriority ) | |
{ | |
unsigned portBASE_TYPE *puxPriority; | |
/* Create the Creator tasks - passing in as a parameter the priority at which | |
the suicidal tasks should be created. */ | |
puxPriority = ( unsigned portBASE_TYPE * ) pvPortMalloc( sizeof( unsigned portBASE_TYPE ) ); | |
*puxPriority = uxPriority; | |
xTaskCreate( vCreateTasks, "CREATOR", deathSTACK_SIZE, ( void * ) puxPriority, uxPriority, NULL ); | |
/* Record the number of tasks that are running now so we know if any of the | |
suicidal tasks have failed to be killed. */ | |
uxTasksRunningAtStart = uxTaskGetNumberOfTasks(); | |
} | |
/*-----------------------------------------------------------*/ | |
static void vSuicidalTask( void *pvParameters ) | |
{ | |
portDOUBLE d1, d2; | |
TaskHandle_t xTaskToKill; | |
const TickType_t xDelay = ( TickType_t ) 500 / portTICK_PERIOD_MS; | |
if( pvParameters != NULL ) | |
{ | |
/* This task is periodically created four times. Tow created tasks are | |
passed a handle to the other task so it can kill it before killing itself. | |
The other task is passed in null. */ | |
xTaskToKill = *( TaskHandle_t* )pvParameters; | |
} | |
else | |
{ | |
xTaskToKill = NULL; | |
} | |
for( ;; ) | |
{ | |
/* Do something random just to use some stack and registers. */ | |
d1 = 2.4; | |
d2 = 89.2; | |
d2 *= d1; | |
vTaskDelay( xDelay ); | |
if( xTaskToKill != NULL ) | |
{ | |
/* Make sure the other task has a go before we delete it. */ | |
vTaskDelay( ( TickType_t ) 0 ); | |
/* Kill the other task that was created by vCreateTasks(). */ | |
vTaskDelete( xTaskToKill ); | |
/* Kill ourselves. */ | |
vTaskDelete( NULL ); | |
} | |
} | |
}/*lint !e818 !e550 Function prototype must be as per standard for task functions. */ | |
/*-----------------------------------------------------------*/ | |
static void vCreateTasks( void *pvParameters ) | |
{ | |
const TickType_t xDelay = ( TickType_t ) 1000 / portTICK_PERIOD_MS; | |
unsigned portBASE_TYPE uxPriority; | |
const char * const pcTaskStartMsg = "Create task started.\r\n"; | |
/* Queue a message for printing to say the task has started. */ | |
vPrintDisplayMessage( &pcTaskStartMsg ); | |
uxPriority = *( unsigned portBASE_TYPE * ) pvParameters; | |
vPortFree( pvParameters ); | |
for( ;; ) | |
{ | |
/* Just loop round, delaying then creating the four suicidal tasks. */ | |
vTaskDelay( xDelay ); | |
xTaskCreate( vSuicidalTask, "SUICIDE1", deathSTACK_SIZE, NULL, uxPriority, &xCreatedTask1 ); | |
xTaskCreate( vSuicidalTask, "SUICIDE2", deathSTACK_SIZE, &xCreatedTask1, uxPriority, NULL ); | |
xTaskCreate( vSuicidalTask, "SUICIDE1", deathSTACK_SIZE, NULL, uxPriority, &xCreatedTask2 ); | |
xTaskCreate( vSuicidalTask, "SUICIDE2", deathSTACK_SIZE, &xCreatedTask2, uxPriority, NULL ); | |
++sCreationCount; | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
/* This is called to check that the creator task is still running and that there | |
are not any more than four extra tasks. */ | |
portBASE_TYPE xIsCreateTaskStillRunning( void ) | |
{ | |
static short sLastCreationCount = 0; | |
short sReturn = pdTRUE; | |
unsigned portBASE_TYPE uxTasksRunningNow; | |
if( sLastCreationCount == sCreationCount ) | |
{ | |
sReturn = pdFALSE; | |
} | |
uxTasksRunningNow = uxTaskGetNumberOfTasks(); | |
if( uxTasksRunningNow < uxTasksRunningAtStart ) | |
{ | |
sReturn = pdFALSE; | |
} | |
else if( ( uxTasksRunningNow - uxTasksRunningAtStart ) > uxMaxNumberOfExtraTasksRunning ) | |
{ | |
sReturn = pdFALSE; | |
} | |
else | |
{ | |
/* Everything is okay. */ | |
} | |
return sReturn; | |
} | |