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EBIKE-FreeRTOS/Common/Full/comtest.c
aixiao af0dfbbbb8 init
2024-04-14 18:38:39 +08:00

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/*
* FreeRTOS V202212.00
* 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.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/**
* Creates two tasks that operate on an interrupt driven serial port. A loopback
* connector should be used so that everything that is transmitted is also received.
* The serial port does not use any flow control. On a standard 9way 'D' connector
* pins two and three should be connected together.
*
* The first task repeatedly sends a string to a queue, character at a time. The
* serial port interrupt will empty the queue and transmit the characters. The
* task blocks for a pseudo random period before resending the string.
*
* The second task blocks on a queue waiting for a character to be received.
* Characters received by the serial port interrupt routine are posted onto the
* queue - unblocking the task making it ready to execute. If this is then the
* highest priority task ready to run it will run immediately - with a context
* switch occurring at the end of the interrupt service routine. The task
* receiving characters is spawned with a higher priority than the task
* transmitting the characters.
*
* With the loop back connector in place, one task will transmit a string and the
* other will immediately receive it. The receiving task knows the string it
* expects to receive so can detect an error.
*
* This also creates a third task. This is used to test semaphore usage from an
* ISR and does nothing interesting.
*
* \page ComTestC comtest.c
* \ingroup DemoFiles
* <HR>
*/
/*
* Changes from V1.00:
*
+ The priority of the Rx task has been lowered. Received characters are
+ now processed (read from the queue) at the idle priority, allowing low
+ priority tasks to run evenly at times of a high communications overhead.
+
+ Changes from V1.01:
+
+ The Tx task now waits a pseudo random time between transmissions.
+ Previously a fixed period was used but this was not such a good test as
+ interrupts fired at regular intervals.
+
+ Changes From V1.2.0:
+
+ Use vSerialPutString() instead of single character puts.
+ Only stop the check variable incrementing after two consecutive errors.
+
+ Changed from V1.2.5
+
+ Made the Rx task 2 priorities higher than the Tx task. Previously it was
+ only 1. This is done to tie in better with the other demo application
+ tasks.
+
+ Changes from V2.0.0
+
+ Delay periods are now specified using variables and constants of
+ TickType_t rather than unsigned long.
+ Slight modification to task priorities.
+
*/
/* Scheduler include files. */
#include <stdlib.h>
#include <string.h>
#include "FreeRTOS.h"
#include "task.h"
/* Demo program include files. */
#include "serial.h"
#include "comtest.h"
#include "print.h"
/* The Tx task will transmit the sequence of characters at a pseudo random
* interval. This is the maximum and minimum block time between sends. */
#define comTX_MAX_BLOCK_TIME ( ( TickType_t ) 0x15e )
#define comTX_MIN_BLOCK_TIME ( ( TickType_t ) 0xc8 )
#define comMAX_CONSECUTIVE_ERRORS ( 2 )
#define comSTACK_SIZE ( ( unsigned short ) 256 )
#define comRX_RELATIVE_PRIORITY ( 1 )
/* Handle to the com port used by both tasks. */
static xComPortHandle xPort;
/* The transmit function as described at the top of the file. */
static void vComTxTask( void * pvParameters );
/* The receive function as described at the top of the file. */
static void vComRxTask( void * pvParameters );
/* The semaphore test function as described at the top of the file. */
static void vSemTestTask( void * pvParameters );
/* The string that is repeatedly transmitted. */
const char * const pcMessageToExchange = "Send this message over and over again to check communications interrupts. "
"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ\r\n";
/* Variables that are incremented on each cycle of each task. These are used to
* check that both tasks are still executing. */
volatile short sTxCount = 0, sRxCount = 0, sSemCount = 0;
/* The handle to the semaphore test task. */
static TaskHandle_t xSemTestTaskHandle = NULL;
/*-----------------------------------------------------------*/
void vStartComTestTasks( unsigned portBASE_TYPE uxPriority,
eCOMPort ePort,
eBaud eBaudRate )
{
const unsigned portBASE_TYPE uxBufferLength = 255;
/* Initialise the com port then spawn both tasks. */
xPort = xSerialPortInit( ePort, eBaudRate, serNO_PARITY, serBITS_8, serSTOP_1, uxBufferLength );
xTaskCreate( vComTxTask, "COMTx", comSTACK_SIZE, NULL, uxPriority, NULL );
xTaskCreate( vComRxTask, "COMRx", comSTACK_SIZE, NULL, uxPriority + comRX_RELATIVE_PRIORITY, NULL );
xTaskCreate( vSemTestTask, "ISRSem", comSTACK_SIZE, NULL, tskIDLE_PRIORITY, &xSemTestTaskHandle );
}
/*-----------------------------------------------------------*/
static void vComTxTask( void * pvParameters )
{
const char * const pcTaskStartMsg = "COM Tx task started.\r\n";
TickType_t xTimeToWait;
/* Stop warnings. */
( void ) pvParameters;
/* Queue a message for printing to say the task has started. */
vPrintDisplayMessage( &pcTaskStartMsg );
for( ; ; )
{
/* Send the string to the serial port. */
vSerialPutString( xPort, pcMessageToExchange, strlen( pcMessageToExchange ) );
/* We have posted all the characters in the string - increment the variable
* used to check that this task is still running, then wait before re-sending
* the string. */
sTxCount++;
xTimeToWait = xTaskGetTickCount();
/* Make sure we don't wait too long... */
xTimeToWait %= comTX_MAX_BLOCK_TIME;
/* ...but we do want to wait. */
if( xTimeToWait < comTX_MIN_BLOCK_TIME )
{
xTimeToWait = comTX_MIN_BLOCK_TIME;
}
vTaskDelay( xTimeToWait );
}
} /*lint !e715 !e818 pvParameters is required for a task function even if it is not referenced. */
/*-----------------------------------------------------------*/
static void vComRxTask( void * pvParameters )
{
const char * const pcTaskStartMsg = "COM Rx task started.\r\n";
const char * const pcTaskErrorMsg = "COM read error\r\n";
const char * const pcTaskRestartMsg = "COM resynced\r\n";
const char * const pcTaskTimeoutMsg = "COM Rx timed out\r\n";
const TickType_t xBlockTime = ( TickType_t ) 0xffff / portTICK_PERIOD_MS;
const char * pcExpectedChar;
portBASE_TYPE xGotChar;
char cRxedChar;
short sResyncRequired, sConsecutiveErrors, sLatchedError;
/* Stop warnings. */
( void ) pvParameters;
/* Queue a message for printing to say the task has started. */
vPrintDisplayMessage( &pcTaskStartMsg );
/* The first expected character is the first character in the string. */
pcExpectedChar = pcMessageToExchange;
sResyncRequired = pdFALSE;
sConsecutiveErrors = 0;
sLatchedError = pdFALSE;
for( ; ; )
{
/* Receive a message from the com port interrupt routine. If a message is
* not yet available the call will block the task. */
xGotChar = xSerialGetChar( xPort, &cRxedChar, xBlockTime );
if( xGotChar == pdTRUE )
{
if( sResyncRequired == pdTRUE )
{
/* We got out of sequence and are waiting for the start of the next
* transmission of the string. */
if( cRxedChar == '\n' )
{
/* This is the end of the message so we can start again - with
* the first character in the string being the next thing we expect
* to receive. */
pcExpectedChar = pcMessageToExchange;
sResyncRequired = pdFALSE;
/* Queue a message for printing to say that we are going to try
* again. */
vPrintDisplayMessage( &pcTaskRestartMsg );
/* Stop incrementing the check variable, if consecutive errors occur. */
sConsecutiveErrors++;
if( sConsecutiveErrors >= comMAX_CONSECUTIVE_ERRORS )
{
sLatchedError = pdTRUE;
}
}
}
else
{
/* We have received a character, but is it the expected character? */
if( cRxedChar != *pcExpectedChar )
{
/* This was not the expected character so post a message for
* printing to say that an error has occurred. We will then wait
* to resynchronize. */
vPrintDisplayMessage( &pcTaskErrorMsg );
sResyncRequired = pdTRUE;
}
else
{
/* This was the expected character so next time we will expect
* the next character in the string. Wrap back to the beginning
* of the string when the null terminator has been reached. */
pcExpectedChar++;
if( *pcExpectedChar == '\0' )
{
pcExpectedChar = pcMessageToExchange;
/* We have got through the entire string without error. */
sConsecutiveErrors = 0;
}
}
}
/* Increment the count that is used to check that this task is still
* running. This is only done if an error has never occurred. */
if( sLatchedError == pdFALSE )
{
sRxCount++;
}
}
else
{
vPrintDisplayMessage( &pcTaskTimeoutMsg );
}
}
} /*lint !e715 !e818 pvParameters is required for a task function even if it is not referenced. */
/*-----------------------------------------------------------*/
static void vSemTestTask( void * pvParameters )
{
const char * const pcTaskStartMsg = "ISR Semaphore test started.\r\n";
portBASE_TYPE xError = pdFALSE;
/* Stop warnings. */
( void ) pvParameters;
/* Queue a message for printing to say the task has started. */
vPrintDisplayMessage( &pcTaskStartMsg );
for( ; ; )
{
if( xSerialWaitForSemaphore( xPort ) )
{
if( xError == pdFALSE )
{
sSemCount++;
}
}
else
{
xError = pdTRUE;
}
}
} /*lint !e715 !e830 !e818 pvParameters not used but function prototype must be standard for task function. */
/*-----------------------------------------------------------*/
/* This is called to check that all the created tasks are still running. */
portBASE_TYPE xAreComTestTasksStillRunning( void )
{
static short sLastTxCount = 0, sLastRxCount = 0, sLastSemCount = 0;
portBASE_TYPE xReturn;
/* Not too worried about mutual exclusion on these variables as they are 16
* bits and we are only reading them. We also only care to see if they have
* changed or not. */
if( ( sTxCount == sLastTxCount ) || ( sRxCount == sLastRxCount ) || ( sSemCount == sLastSemCount ) )
{
xReturn = pdFALSE;
}
else
{
xReturn = pdTRUE;
}
sLastTxCount = sTxCount;
sLastRxCount = sRxCount;
sLastSemCount = sSemCount;
return xReturn;
}
/*-----------------------------------------------------------*/
void vComTestUnsuspendTask( void )
{
/* The task that is suspended on the semaphore will be referenced from the
* Suspended list as it is blocking indefinitely. This call just checks that
* the kernel correctly detects this and does not attempt to unsuspend the
* task. */
xTaskResumeFromISR( xSemTestTaskHandle );
}
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