root/webserver/example/freeRTOS/Demo/Common/Minimal/crhook.c

/*
        FreeRTOS V5.4.1 - Copyright (C) 2009 Real Time Engineers Ltd.

        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.  
        Alternative commercial license and support terms are also available upon 
        request.  See the licensing section of http://www.FreeRTOS.org for full 
        license details.

        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 along
        with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
        Temple Place, Suite 330, Boston, MA  02111-1307  USA.


        ***************************************************************************
        *                                                                         *
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        * See http://www.FreeRTOS.org/Documentation for details                   *
        *                                                                         *
        ***************************************************************************

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        Please ensure to read the configuration and relevant port sections of the
        online documentation.

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*/

/*
 * This demo file demonstrates how to send data between an ISR and a 
 * co-routine.  A tick hook function is used to periodically pass data between
 * the RTOS tick and a set of 'hook' co-routines.
 *
 * hookNUM_HOOK_CO_ROUTINES co-routines are created.  Each co-routine blocks
 * to wait for a character to be received on a queue from the tick ISR, checks
 * to ensure the character received was that expected, then sends the number
 * back to the tick ISR on a different queue.
 * 
 * The tick ISR checks the numbers received back from the 'hook' co-routines 
 * matches the number previously sent.
 *
 * If at any time a queue function returns unexpectedly, or an incorrect value
 * is received either by the tick hook or a co-routine then an error is 
 * latched.
 *
 * This demo relies on each 'hook' co-routine to execute between each 
 * hookTICK_CALLS_BEFORE_POST tick interrupts.  This and the heavy use of 
 * queues from within an interrupt may result in an error being detected on 
 * slower targets simply due to timing.
 */

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "croutine.h"
#include "queue.h"

/* Demo application includes. */
#include "crhook.h"

/* The number of 'hook' co-routines that are to be created. */
#define hookNUM_HOOK_CO_ROUTINES        ( 4 )

/* The number of times the tick hook should be called before a character is 
posted to the 'hook' co-routines. */
#define hookTICK_CALLS_BEFORE_POST      ( 500 )

/* There should never be more than one item in any queue at any time. */
#define hookHOOK_QUEUE_LENGTH           ( 1 )

/* Don't block when initially posting to the queue. */
#define hookNO_BLOCK_TIME               ( 0 )

/* The priority relative to other co-routines (rather than tasks) that the
'hook' co-routines should take. */
#define mainHOOK_CR_PRIORITY                    ( 1 )
/*-----------------------------------------------------------*/

/*
 * The co-routine function itself.
 */
static void prvHookCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );


/*
 * The tick hook function.  This receives a number from each 'hook' co-routine
 * then sends a number to each co-routine.  An error is flagged if a send or 
 * receive fails, or an unexpected number is received.
 */
void vApplicationTickHook( void );

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

/* Queues used to send data FROM a co-routine TO the tick hook function.
The hook functions received (Rx's) on these queues.  One queue per
'hook' co-routine. */
static xQueueHandle xHookRxQueues[ hookNUM_HOOK_CO_ROUTINES ];

/* Queues used to send data FROM the tick hook TO a co-routine function.
The hood function transmits (Tx's) on these queues.  One queue per
'hook' co-routine. */
static xQueueHandle xHookTxQueues[ hookNUM_HOOK_CO_ROUTINES ];

/* Set to true if an error is detected at any time. */
static portBASE_TYPE xCoRoutineErrorDetected = pdFALSE;

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

void vStartHookCoRoutines( void )
{
unsigned portBASE_TYPE uxIndex, uxValueToPost = 0;

        for( uxIndex = 0; uxIndex < hookNUM_HOOK_CO_ROUTINES; uxIndex++ )
        {
                /* Create a queue to transmit to and receive from each 'hook' 
                co-routine. */
                xHookRxQueues[ uxIndex ] = xQueueCreate( hookHOOK_QUEUE_LENGTH, sizeof( unsigned portBASE_TYPE ) );
                xHookTxQueues[ uxIndex ] = xQueueCreate( hookHOOK_QUEUE_LENGTH, sizeof( unsigned portBASE_TYPE ) );

                /* To start things off the tick hook function expects the queue it 
                uses to receive data to contain a value.  */
                xQueueSend( xHookRxQueues[ uxIndex ], &uxValueToPost, hookNO_BLOCK_TIME );

                /* Create the 'hook' co-routine itself. */
                xCoRoutineCreate( prvHookCoRoutine, mainHOOK_CR_PRIORITY, uxIndex );
        }
}
/*-----------------------------------------------------------*/

static unsigned portBASE_TYPE uxCallCounter = 0, uxNumberToPost = 0;
void vApplicationTickHook( void )
{
unsigned portBASE_TYPE uxReceivedNumber;
signed portBASE_TYPE xIndex, xCoRoutineWoken;

        /* Is it time to talk to the 'hook' co-routines again? */
        uxCallCounter++;
        if( uxCallCounter >= hookTICK_CALLS_BEFORE_POST )
        {
                uxCallCounter = 0;

                for( xIndex = 0; xIndex < hookNUM_HOOK_CO_ROUTINES; xIndex++ )
                {
                        xCoRoutineWoken = pdFALSE;
                        if( crQUEUE_RECEIVE_FROM_ISR( xHookRxQueues[ xIndex ], &uxReceivedNumber, &xCoRoutineWoken ) != pdPASS )
                        {
                                /* There is no reason why we would not expect the queue to 
                                contain a value. */
                                xCoRoutineErrorDetected = pdTRUE;
                        }
                        else
                        {
                                /* Each queue used to receive data from the 'hook' co-routines 
                                should contain the number we last posted to the same co-routine. */
                                if( uxReceivedNumber != uxNumberToPost )
                                {
                                        xCoRoutineErrorDetected = pdTRUE;
                                }

                                /* Nothing should be blocked waiting to post to the queue. */
                                if( xCoRoutineWoken != pdFALSE )
                                {
                                        xCoRoutineErrorDetected = pdTRUE;
                                }
                        }
                }

                /* Start the next cycle by posting the next number onto each Tx queue. */
                uxNumberToPost++;

                for( xIndex = 0; xIndex < hookNUM_HOOK_CO_ROUTINES; xIndex++ )
                {
                        if( crQUEUE_SEND_FROM_ISR( xHookTxQueues[ xIndex ], &uxNumberToPost, pdFALSE ) != pdTRUE )
                        {
                                /* Posting to the queue should have woken the co-routine that 
                                was blocked on the queue. */
                                xCoRoutineErrorDetected = pdTRUE;
                        }
                }
        }
}
/*-----------------------------------------------------------*/

static void prvHookCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
{
static unsigned portBASE_TYPE uxReceivedValue[ hookNUM_HOOK_CO_ROUTINES ];
portBASE_TYPE xResult;

        /* Each co-routine MUST start with a call to crSTART(); */
        crSTART( xHandle );

        for( ;; )
        {
                /* Wait to receive a value from the tick hook. */
                xResult = pdFAIL;
                crQUEUE_RECEIVE( xHandle, xHookTxQueues[ uxIndex ], &( uxReceivedValue[ uxIndex ] ), portMAX_DELAY, &xResult );

                /* There is no reason why we should not have received something on
                the queue. */
                if( xResult != pdPASS )
                {
                        xCoRoutineErrorDetected = pdTRUE;
                }

                /* Send the same number back to the idle hook so it can verify it. */
                xResult = pdFAIL;
                crQUEUE_SEND( xHandle, xHookRxQueues[ uxIndex ], &( uxReceivedValue[ uxIndex ] ), hookNO_BLOCK_TIME, &xResult );
                if( xResult != pdPASS )
                {
                        /* There is no reason why we should not have been able to post to 
                        the queue. */
                        xCoRoutineErrorDetected = pdTRUE;
                }
        }

        /* Each co-routine MUST end with a call to crEND(). */
        crEND();
}
/*-----------------------------------------------------------*/

portBASE_TYPE xAreHookCoRoutinesStillRunning( void )
{
        if( xCoRoutineErrorDetected )
        {
                return pdFALSE;
        }
        else
        {
                return pdTRUE;
        }
}