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/*
* FreeRTOS Kernel V10.4.0
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
/**
* 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
TickType_t rather than unsigned long.
*/
#include <stdlib.h>
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "queue.h"
/* Demo program include files. */
#include "print.h"
static QueueHandle_t 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, ( TickType_t ) 0 );
#else
/* Stop warnings. */
( void ) ppcMessageToSend;
#endif
}
/*-----------------------------------------------------------*/
const char *pcPrintGetNextMessage( TickType_t xPrintRate )
{
char *pcMessage;
if( xQueueReceive( xPrintQueue, &pcMessage, xPrintRate ) == pdPASS )
{
return pcMessage;
}
else
{
return NULL;
}
}
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