/* | |
FreeRTOS V6.0.2 - Copyright (C) 2010 Real Time Engineers Ltd. | |
*************************************************************************** | |
* * | |
* If you are: * | |
* * | |
* + New to FreeRTOS, * | |
* + Wanting to learn FreeRTOS or multitasking in general quickly * | |
* + Looking for basic training, * | |
* + Wanting to improve your FreeRTOS skills and productivity * | |
* * | |
* then take a look at the FreeRTOS eBook * | |
* * | |
* "Using the FreeRTOS Real Time Kernel - a Practical Guide" * | |
* http://www.FreeRTOS.org/Documentation * | |
* * | |
* A pdf reference manual is also available. Both are usually delivered * | |
* to your inbox within 20 minutes to two hours when purchased between 8am * | |
* and 8pm GMT (although please allow up to 24 hours in case of * | |
* exceptional circumstances). Thank you for your support! * | |
* * | |
*************************************************************************** | |
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 exception 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. See the GNU General Public License for | |
more details. You should have received a copy of the GNU General Public | |
License and the FreeRTOS license exception along with FreeRTOS; if not it | |
can be viewed here: http://www.freertos.org/a00114.html and also obtained | |
by writing to Richard Barry, contact details for whom are available on the | |
FreeRTOS WEB site. | |
1 tab == 4 spaces! | |
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. | |
*/ | |
/** | |
* Manages a queue of strings that are waiting to be displayed. This is used to | |
* ensure mutual exclusion of console output. | |
* | |
* A task wishing to display a message will call vPrintDisplayMessage (), with a | |
* pointer to the string as the parameter. The pointer is posted onto the | |
* xPrintQueue queue. | |
* | |
* The task spawned in main. c blocks on xPrintQueue. When a message becomes | |
* available it calls pcPrintGetNextMessage () to obtain a pointer to the next | |
* string, then uses the functions defined in the portable layer FileIO. c to | |
* display the message. | |
* | |
* <b>NOTE:</b> | |
* Using console IO can disrupt real time performance - depending on the port. | |
* Standard C IO routines are not designed for real time applications. While | |
* standard IO is useful for demonstration and debugging an alternative method | |
* should be used if you actually require console IO as part of your application. | |
* | |
* \page PrintC print.c | |
* \ingroup DemoFiles | |
* <HR> | |
*/ | |
/* | |
Changes from V2.0.0 | |
+ Delay periods are now specified using variables and constants of | |
portTickType rather than unsigned long. | |
*/ | |
#include <stdlib.h> | |
/* Scheduler include files. */ | |
#include "FreeRTOS.h" | |
#include "queue.h" | |
/* Demo program include files. */ | |
#include "print.h" | |
static xQueueHandle xPrintQueue; | |
/*-----------------------------------------------------------*/ | |
void vPrintInitialise( void ) | |
{ | |
const unsigned portBASE_TYPE uxQueueSize = 20; | |
/* Create the queue on which errors will be reported. */ | |
xPrintQueue = xQueueCreate( uxQueueSize, ( unsigned portBASE_TYPE ) sizeof( char * ) ); | |
} | |
/*-----------------------------------------------------------*/ | |
void vPrintDisplayMessage( const char * const * ppcMessageToSend ) | |
{ | |
#ifdef USE_STDIO | |
xQueueSend( xPrintQueue, ( void * ) ppcMessageToSend, ( portTickType ) 0 ); | |
#else | |
/* Stop warnings. */ | |
( void ) ppcMessageToSend; | |
#endif | |
} | |
/*-----------------------------------------------------------*/ | |
const char *pcPrintGetNextMessage( portTickType xPrintRate ) | |
{ | |
char *pcMessage; | |
if( xQueueReceive( xPrintQueue, &pcMessage, xPrintRate ) == pdPASS ) | |
{ | |
return pcMessage; | |
} | |
else | |
{ | |
return NULL; | |
} | |
} | |