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/*
FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd.
All rights reserved
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* 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 *
* *
* Thank you! *
* *
***************************************************************************
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
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
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
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
http://www.SafeRTOS.com - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
1 tab == 4 spaces!
*/
/**
* 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;
}
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