Demo/PIC18_MPLAB/main1.c - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
     FreeRTOS V6.0.4 - 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.
 */

 /*
  * Instead of the normal single demo application, the PIC18F demo is split
  * into several smaller programs of which this is the first.  This enables the
  * demo's to be executed on the RAM limited 40 pin devices.  The 64 and 80 pin
  * devices require a more costly development platform and are not so readily
  * available.
  *
  * The RTOSDemo1 project is configured for a PIC18F452 device.  Main1.c starts 5
  * tasks (including the idle task).
  *
  * The first task runs at the idle priority.  It repeatedly performs a 32bit
  * calculation and checks it's result against the expected value.  This checks
  * that the temporary storage utilised by the compiler to hold intermediate
  * results does not get corrupted when the task gets switched in and out.  See
  * demo/common/minimal/integer.c for more information.
  *
  * The second and third tasks pass an incrementing value between each other on
  * a message queue.  See demo/common/minimal/PollQ.c for more information.
  *
  * Main1.c also creates a check task.  This periodically checks that all the
  * other tasks are still running and have not experienced any unexpected
  * results.  If all the other tasks are executing correctly an LED is flashed
  * once every mainCHECK_PERIOD milliseconds.  If any of the tasks have not
  * executed, or report and error, the frequency of the LED flash will increase
  * to mainERROR_FLASH_RATE.
  *
  * On entry to main an 'X' is transmitted.  Monitoring the serial port using a
  * dumb terminal allows for verification that the device is not continuously
  * being reset (no more than one 'X' should be transmitted).
  *
  * http://www.FreeRTOS.org contains important information on the use of the
  * PIC18F port.
  */

 /*
 Changes from V2.0.0

 	+ Delay periods are now specified using variables and constants of
 	  portTickType rather than unsigned long.
 */

 /* Scheduler include files. */
 #include "FreeRTOS.h"
 #include "task.h"

 /* Demo app include files. */
 #include "PollQ.h"
 #include "integer.h"
 #include "partest.h"
 #include "serial.h"

 /* The period between executions of the check task before and after an error
 has been discovered.  If an error has been discovered the check task runs
 more frequently - increasing the LED flash rate. */
 #define mainNO_ERROR_CHECK_PERIOD		( ( portTickType ) 1000 / portTICK_RATE_MS )
 #define mainERROR_CHECK_PERIOD			( ( portTickType ) 100 / portTICK_RATE_MS )

 /* Priority definitions for some of the tasks.  Other tasks just use the idle
 priority. */
 #define mainQUEUE_POLL_PRIORITY			( tskIDLE_PRIORITY + 2 )
 #define mainCHECK_TASK_PRIORITY			( tskIDLE_PRIORITY + 3 )

 /* The LED that is flashed by the check task. */
 #define mainCHECK_TASK_LED				( 0 )

 /* Constants required for the communications.  Only one character is ever
 transmitted. */
 #define mainCOMMS_QUEUE_LENGTH			( 5 )
 #define mainNO_BLOCK					( ( portTickType ) 0 )
 #define mainBAUD_RATE					( ( unsigned long ) 9600 )

 /*
  * The task function for the "Check" task.
  */
 static void vErrorChecks( void *pvParameters );

 /*
  * Checks the unique counts of other tasks to ensure they are still operational.
  * Returns pdTRUE if an error is detected, otherwise pdFALSE.
  */
 static portBASE_TYPE prvCheckOtherTasksAreStillRunning( void );

 /*-----------------------------------------------------------*/

 /* Creates the tasks, then starts the scheduler. */
 void main( void )
 {
 	/* Initialise the required hardware. */
 	vParTestInitialise();
 	vPortInitialiseBlocks();

 	/* Send a character so we have some visible feedback of a reset. */
 	xSerialPortInitMinimal( mainBAUD_RATE, mainCOMMS_QUEUE_LENGTH );
 	xSerialPutChar( NULL, 'X', mainNO_BLOCK );

 	/* Start the standard demo tasks found in the demo\common directory. */
 	vStartIntegerMathTasks( tskIDLE_PRIORITY );
 	vStartPolledQueueTasks( mainQUEUE_POLL_PRIORITY );

 	/* Start the check task defined in this file. */
 	xTaskCreate( vErrorChecks, ( const char * const ) "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL );

 	/* Start the scheduler.  Will never return here. */
 	vTaskStartScheduler();
 }
 /*-----------------------------------------------------------*/

 static void vErrorChecks( void *pvParameters )
 {
 portTickType xDelayTime = mainNO_ERROR_CHECK_PERIOD;
 portBASE_TYPE xErrorOccurred;

 	/* Cycle for ever, delaying then checking all the other tasks are still
 	operating without error. */
 	for( ;; )
 	{
 		/* Wait until it is time to check the other tasks. */
 		vTaskDelay( xDelayTime );

 		/* Check all the other tasks are running, and running without ever
 		having an error. */
 		xErrorOccurred = prvCheckOtherTasksAreStillRunning();

 		/* If an error was detected increase the frequency of the LED flash. */
 		if( xErrorOccurred == pdTRUE )
 		{
 			xDelayTime = mainERROR_CHECK_PERIOD;
 		}

 		/* Flash the LED for visual feedback. */
 		vParTestToggleLED( mainCHECK_TASK_LED );
 	}
 }
 /*-----------------------------------------------------------*/

 static portBASE_TYPE prvCheckOtherTasksAreStillRunning( void )
 {
 portBASE_TYPE xErrorHasOccurred = pdFALSE;

 	if( xAreIntegerMathsTaskStillRunning() != pdTRUE )
 	{
 		xErrorHasOccurred = pdTRUE;
 	}

 	if( xArePollingQueuesStillRunning() != pdTRUE )
 	{
 		xErrorHasOccurred = pdTRUE;
 	}

 	return xErrorHasOccurred;
 }
 /*-----------------------------------------------------------*/
	/*
	FreeRTOS V6.0.4 - 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.
	*/

	/*
	* Instead of the normal single demo application, the PIC18F demo is split
	* into several smaller programs of which this is the first. This enables the
	* demo's to be executed on the RAM limited 40 pin devices. The 64 and 80 pin
	* devices require a more costly development platform and are not so readily
	* available.
	*
	* The RTOSDemo1 project is configured for a PIC18F452 device. Main1.c starts 5
	* tasks (including the idle task).
	*
	* The first task runs at the idle priority. It repeatedly performs a 32bit
	* calculation and checks it's result against the expected value. This checks
	* that the temporary storage utilised by the compiler to hold intermediate
	* results does not get corrupted when the task gets switched in and out. See
	* demo/common/minimal/integer.c for more information.
	*
	* The second and third tasks pass an incrementing value between each other on
	* a message queue. See demo/common/minimal/PollQ.c for more information.
	*
	* Main1.c also creates a check task. This periodically checks that all the
	* other tasks are still running and have not experienced any unexpected
	* results. If all the other tasks are executing correctly an LED is flashed
	* once every mainCHECK_PERIOD milliseconds. If any of the tasks have not
	* executed, or report and error, the frequency of the LED flash will increase
	* to mainERROR_FLASH_RATE.
	*
	* On entry to main an 'X' is transmitted. Monitoring the serial port using a
	* dumb terminal allows for verification that the device is not continuously
	* being reset (no more than one 'X' should be transmitted).
	*
	* http://www.FreeRTOS.org contains important information on the use of the
	* PIC18F port.
	*/

	/*
	Changes from V2.0.0

	+ Delay periods are now specified using variables and constants of
	portTickType rather than unsigned long.
	*/

	/* Scheduler include files. */
	#include "FreeRTOS.h"
	#include "task.h"

	/* Demo app include files. */
	#include "PollQ.h"
	#include "integer.h"
	#include "partest.h"
	#include "serial.h"

	/* The period between executions of the check task before and after an error
	has been discovered. If an error has been discovered the check task runs
	more frequently - increasing the LED flash rate. */
	#define mainNO_ERROR_CHECK_PERIOD ( ( portTickType ) 1000 / portTICK_RATE_MS )
	#define mainERROR_CHECK_PERIOD ( ( portTickType ) 100 / portTICK_RATE_MS )

	/* Priority definitions for some of the tasks. Other tasks just use the idle
	priority. */
	#define mainQUEUE_POLL_PRIORITY ( tskIDLE_PRIORITY + 2 )
	#define mainCHECK_TASK_PRIORITY ( tskIDLE_PRIORITY + 3 )

	/* The LED that is flashed by the check task. */
	#define mainCHECK_TASK_LED ( 0 )

	/* Constants required for the communications. Only one character is ever
	transmitted. */
	#define mainCOMMS_QUEUE_LENGTH ( 5 )
	#define mainNO_BLOCK ( ( portTickType ) 0 )
	#define mainBAUD_RATE ( ( unsigned long ) 9600 )

	/*
	* The task function for the "Check" task.
	*/
	static void vErrorChecks( void *pvParameters );

	/*
	* Checks the unique counts of other tasks to ensure they are still operational.
	* Returns pdTRUE if an error is detected, otherwise pdFALSE.
	*/
	static portBASE_TYPE prvCheckOtherTasksAreStillRunning( void );

	/-----------------------------------------------------------/

	/* Creates the tasks, then starts the scheduler. */
	void main( void )
	{
	/* Initialise the required hardware. */
	vParTestInitialise();
	vPortInitialiseBlocks();

	/* Send a character so we have some visible feedback of a reset. */
	xSerialPortInitMinimal( mainBAUD_RATE, mainCOMMS_QUEUE_LENGTH );
	xSerialPutChar( NULL, 'X', mainNO_BLOCK );

	/* Start the standard demo tasks found in the demo\common directory. */
	vStartIntegerMathTasks( tskIDLE_PRIORITY );
	vStartPolledQueueTasks( mainQUEUE_POLL_PRIORITY );

	/* Start the check task defined in this file. */
	xTaskCreate( vErrorChecks, ( const char * const ) "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL );

	/* Start the scheduler. Will never return here. */
	vTaskStartScheduler();
	}
	/-----------------------------------------------------------/

	static void vErrorChecks( void *pvParameters )
	{
	portTickType xDelayTime = mainNO_ERROR_CHECK_PERIOD;
	portBASE_TYPE xErrorOccurred;

	/* Cycle for ever, delaying then checking all the other tasks are still
	operating without error. */
	for( ;; )
	{
	/* Wait until it is time to check the other tasks. */
	vTaskDelay( xDelayTime );

	/* Check all the other tasks are running, and running without ever
	having an error. */
	xErrorOccurred = prvCheckOtherTasksAreStillRunning();

	/* If an error was detected increase the frequency of the LED flash. */
	if( xErrorOccurred == pdTRUE )
	{
	xDelayTime = mainERROR_CHECK_PERIOD;
	}

	/* Flash the LED for visual feedback. */
	vParTestToggleLED( mainCHECK_TASK_LED );
	}
	}
	/-----------------------------------------------------------/

	static portBASE_TYPE prvCheckOtherTasksAreStillRunning( void )
	{
	portBASE_TYPE xErrorHasOccurred = pdFALSE;

	if( xAreIntegerMathsTaskStillRunning() != pdTRUE )
	{
	xErrorHasOccurred = pdTRUE;
	}

	if( xArePollingQueuesStillRunning() != pdTRUE )
	{
	xErrorHasOccurred = pdTRUE;
	}

	return xErrorHasOccurred;
	}
	/-----------------------------------------------------------/