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/*
* FreeRTOS V202104.00
* 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!
*/
/*
* 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( CoRoutineHandle_t xHandle,
UBaseType_t 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 QueueHandle_t 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 QueueHandle_t xHookTxQueues[ hookNUM_HOOK_CO_ROUTINES ];
/* Set to true if an error is detected at any time. */
static BaseType_t xCoRoutineErrorDetected = pdFALSE;
/*-----------------------------------------------------------*/
void vStartHookCoRoutines( void )
{
UBaseType_t 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( UBaseType_t ) );
xHookTxQueues[ uxIndex ] = xQueueCreate( hookHOOK_QUEUE_LENGTH, sizeof( UBaseType_t ) );
/* 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 UBaseType_t uxCallCounter = 0, uxNumberToPost = 0;
void vApplicationTickHook( void )
{
UBaseType_t uxReceivedNumber;
BaseType_t 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( CoRoutineHandle_t xHandle,
UBaseType_t uxIndex )
{
static UBaseType_t uxReceivedValue[ hookNUM_HOOK_CO_ROUTINES ];
BaseType_t 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();
}
/*-----------------------------------------------------------*/
BaseType_t xAreHookCoRoutinesStillRunning( void )
{
if( xCoRoutineErrorDetected )
{
return pdFALSE;
}
else
{
return pdTRUE;
}
}
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