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/*
FreeRTOS V8.0.0:rc1 - 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
* two tasks. The original task is called the creator task, the two tasks it
* creates are called suicidal tasks.
*
* One of the created suicidal tasks kill one other suicidal task before killing
* itself - 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 V3.0.0
+ CreationCount sizes changed from unsigned portBASE_TYPE to
unsigned short to minimize the risk of overflowing.
+ Reset of usLastCreationCount added
Changes from V3.1.0
+ Changed the dummy calculation to use variables of type long, rather than
float. This allows the file to be used with ports that do not support
floating point.
*/
#include <stdlib.h>
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"
/* Demo program include files. */
#include "death.h"
#define deathSTACK_SIZE ( configMINIMAL_STACK_SIZE + 60 )
/* The task originally created which is responsible for periodically dynamically
creating another four tasks. */
static portTASK_FUNCTION_PROTO( vCreateTasks, pvParameters );
/* The task function of the dynamically created tasks. */
static portTASK_FUNCTION_PROTO( vSuicidalTask, 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 unsigned short usCreationCount = 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;
/* Tasks are deleted by the idle task. Under heavy load the idle task might
not get much processing time, so it would be legitimate for several tasks to
remain undeleted for a short period. */
static const unsigned portBASE_TYPE uxMaxNumberOfExtraTasksRunning = 3;
/* Used to store a handle to the task that should be killed by a suicidal task,
before it kills itself. */
TaskHandle_t xCreatedTask;
/*-----------------------------------------------------------*/
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 = ( unsigned portBASE_TYPE ) uxTaskGetNumberOfTasks();
/* FreeRTOS.org versions before V3.0 started the idle-task as the very
first task. The idle task was then already included in uxTasksRunningAtStart.
From FreeRTOS V3.0 on, the idle task is started when the scheduler is
started. Therefore the idle task is not yet accounted for. We correct
this by increasing uxTasksRunningAtStart by 1. */
uxTasksRunningAtStart++;
/* From FreeRTOS version 7.0.0 can optionally create a timer service task.
If this is done, then uxTasksRunningAtStart needs incrementing again as that
too is created when the scheduler is started. */
#if configUSE_TIMERS == 1
uxTasksRunningAtStart++;
#endif
}
/*-----------------------------------------------------------*/
static portTASK_FUNCTION( vSuicidalTask, pvParameters )
{
volatile long l1, l2;
TaskHandle_t xTaskToKill;
const TickType_t xDelay = ( TickType_t ) 200 / portTICK_PERIOD_MS;
if( pvParameters != NULL )
{
/* This task is periodically created four times. Two 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. */
l1 = 2;
l2 = 89;
l2 *= l1;
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 portTASK_FUNCTION( vCreateTasks, pvParameters )
{
const TickType_t xDelay = ( TickType_t ) 1000 / portTICK_PERIOD_MS;
unsigned portBASE_TYPE uxPriority;
uxPriority = *( unsigned portBASE_TYPE * ) pvParameters;
vPortFree( pvParameters );
for( ;; )
{
/* Just loop round, delaying then creating the four suicidal tasks. */
vTaskDelay( xDelay );
xCreatedTask = NULL;
xTaskCreate( vSuicidalTask, "SUICID1", configMINIMAL_STACK_SIZE, NULL, uxPriority, &xCreatedTask );
xTaskCreate( vSuicidalTask, "SUICID2", configMINIMAL_STACK_SIZE, &xCreatedTask, uxPriority, NULL );
++usCreationCount;
}
}
/*-----------------------------------------------------------*/
/* 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 unsigned short usLastCreationCount = 0xfff;
portBASE_TYPE xReturn = pdTRUE;
static unsigned portBASE_TYPE uxTasksRunningNow;
if( usLastCreationCount == usCreationCount )
{
xReturn = pdFALSE;
}
else
{
usLastCreationCount = usCreationCount;
}
uxTasksRunningNow = ( unsigned portBASE_TYPE ) uxTaskGetNumberOfTasks();
if( uxTasksRunningNow < uxTasksRunningAtStart )
{
xReturn = pdFALSE;
}
else if( ( uxTasksRunningNow - uxTasksRunningAtStart ) > uxMaxNumberOfExtraTasksRunning )
{
xReturn = pdFALSE;
}
else
{
/* Everything is okay. */
}
return xReturn;
}
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