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/*
FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry.
This file is part of the FreeRTOS.org distribution.
FreeRTOS.org is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FreeRTOS.org 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. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FreeRTOS.org; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes FreeRTOS.org, without being obliged to provide
the source code for any proprietary components. See the licensing section
of http://www.FreeRTOS.org for full details of how and when the exception
can be applied.
***************************************************************************
***************************************************************************
* *
* Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
* *
* This is a concise, step by step, 'hands on' guide that describes both *
* general multitasking concepts and FreeRTOS specifics. It presents and *
* explains numerous examples that are written using the FreeRTOS API. *
* Full source code for all the examples is provided in an accompanying *
* .zip file. *
* *
***************************************************************************
***************************************************************************
Please ensure to read the configuration and relevant port sections of the
online documentation.
http://www.FreeRTOS.org - Documentation, latest information, license and
contact details.
http://www.SafeRTOS.com - A version that is certified for use in safety
critical systems.
http://www.OpenRTOS.com - Commercial support, development, porting,
licensing and training services.
*/
/*
* This demo application file demonstrates the use of queues to pass data
* between co-routines.
*
* N represents the number of 'fixed delay' co-routines that are created and
* is set during initialisation.
*
* N 'fixed delay' co-routines are created that just block for a fixed
* period then post the number of an LED onto a queue. Each such co-routine
* uses a different block period. A single 'flash' co-routine is also created
* that blocks on the same queue, waiting for the number of the next LED it
* should flash. Upon receiving a number it simply toggle the instructed LED
* then blocks on the queue once more. In this manner each LED from LED 0 to
* LED N-1 is caused to flash at a different rate.
*
* The 'fixed delay' co-routines are created with co-routine priority 0. The
* flash co-routine is created with co-routine priority 1. This means that
* the queue should never contain more than a single item. This is because
* posting to the queue will unblock the 'flash' co-routine, and as this has
* a priority greater than the tasks posting to the queue it is guaranteed to
* have emptied the queue and blocked once again before the queue can contain
* any more date. An error is indicated if an attempt to post data to the
* queue fails - indicating that the queue is already full.
*
*/
/* Scheduler includes. */
#include "FreeRTOS.h"
#include "croutine.h"
#include "queue.h"
/* Demo application includes. */
#include "partest.h"
#include "crflash.h"
/* The queue should only need to be of length 1. See the description at the
top of the file. */
#define crfQUEUE_LENGTH 1
#define crfFIXED_DELAY_PRIORITY 0
#define crfFLASH_PRIORITY 1
/* Only one flash co-routine is created so the index is not significant. */
#define crfFLASH_INDEX 0
/* Don't allow more than crfMAX_FLASH_TASKS 'fixed delay' co-routines to be
created. */
#define crfMAX_FLASH_TASKS 8
/* We don't want to block when posting to the queue. */
#define crfPOSTING_BLOCK_TIME 0
/*
* The 'fixed delay' co-routine as described at the top of the file.
*/
static void prvFixedDelayCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
/*
* The 'flash' co-routine as described at the top of the file.
*/
static void prvFlashCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
/* The queue used to pass data between the 'fixed delay' co-routines and the
'flash' co-routine. */
static xQueueHandle xFlashQueue;
/* This will be set to pdFALSE if we detect an error. */
static portBASE_TYPE xCoRoutineFlashStatus = pdPASS;
/*-----------------------------------------------------------*/
/*
* See the header file for details.
*/
void vStartFlashCoRoutines( unsigned portBASE_TYPE uxNumberToCreate )
{
unsigned portBASE_TYPE uxIndex;
if( uxNumberToCreate > crfMAX_FLASH_TASKS )
{
uxNumberToCreate = crfMAX_FLASH_TASKS;
}
/* Create the queue used to pass data between the co-routines. */
xFlashQueue = xQueueCreate( crfQUEUE_LENGTH, sizeof( unsigned portBASE_TYPE ) );
if( xFlashQueue )
{
/* Create uxNumberToCreate 'fixed delay' co-routines. */
for( uxIndex = 0; uxIndex < uxNumberToCreate; uxIndex++ )
{
xCoRoutineCreate( prvFixedDelayCoRoutine, crfFIXED_DELAY_PRIORITY, uxIndex );
}
/* Create the 'flash' co-routine. */
xCoRoutineCreate( prvFlashCoRoutine, crfFLASH_PRIORITY, crfFLASH_INDEX );
}
}
/*-----------------------------------------------------------*/
static void prvFixedDelayCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
{
/* Even though this is a co-routine the xResult variable does not need to be
static as we do not need it to maintain its state between blocks. */
signed portBASE_TYPE xResult;
/* The uxIndex parameter of the co-routine function is used as an index into
the xFlashRates array to obtain the delay period to use. */
static const portTickType xFlashRates[ crfMAX_FLASH_TASKS ] = { 150 / portTICK_RATE_MS,
200 / portTICK_RATE_MS,
250 / portTICK_RATE_MS,
300 / portTICK_RATE_MS,
350 / portTICK_RATE_MS,
400 / portTICK_RATE_MS,
450 / portTICK_RATE_MS,
500 / portTICK_RATE_MS };
/* Co-routines MUST start with a call to crSTART. */
crSTART( xHandle );
for( ;; )
{
/* Post our uxIndex value onto the queue. This is used as the LED to
flash. */
crQUEUE_SEND( xHandle, xFlashQueue, ( void * ) &uxIndex, crfPOSTING_BLOCK_TIME, &xResult );
if( xResult != pdPASS )
{
/* For the reasons stated at the top of the file we should always
find that we can post to the queue. If we could not then an error
has occurred. */
xCoRoutineFlashStatus = pdFAIL;
}
crDELAY( xHandle, xFlashRates[ uxIndex ] );
}
/* Co-routines MUST end with a call to crEND. */
crEND();
}
/*-----------------------------------------------------------*/
static void prvFlashCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
{
/* Even though this is a co-routine the variable do not need to be
static as we do not need it to maintain their state between blocks. */
signed portBASE_TYPE xResult;
unsigned portBASE_TYPE uxLEDToFlash;
/* Co-routines MUST start with a call to crSTART. */
crSTART( xHandle );
( void ) uxIndex;
for( ;; )
{
/* Block to wait for the number of the LED to flash. */
crQUEUE_RECEIVE( xHandle, xFlashQueue, &uxLEDToFlash, portMAX_DELAY, &xResult );
if( xResult != pdPASS )
{
/* We would not expect to wake unless we received something. */
xCoRoutineFlashStatus = pdFAIL;
}
else
{
/* We received the number of an LED to flash - flash it! */
vParTestToggleLED( uxLEDToFlash );
}
}
/* Co-routines MUST end with a call to crEND. */
crEND();
}
/*-----------------------------------------------------------*/
portBASE_TYPE xAreFlashCoRoutinesStillRunning( void )
{
/* Return pdPASS or pdFAIL depending on whether an error has been detected
or not. */
return xCoRoutineFlashStatus;
}
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