mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-08-18 09:08:33 -04:00
First version under SVN is V4.0.1
This commit is contained in:
Richard Barry
parent
243393860c
commit
b6df57c7e3
918 changed files with 269038 additions and 0 deletions
290
Demo/Common/Full/semtest.c
Normal file
290
Demo/Common/Full/semtest.c
Normal file
|
|
@ -0,0 +1,290 @@
|
|||
/*
|
||||
FreeRTOS V4.0.1 - Copyright (C) 2003-2006 Richard Barry.
|
||||
|
||||
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 as published by
|
||||
the Free Software Foundation; either version 2 of the License, or
|
||||
(at your option) any later version.
|
||||
|
||||
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
|
||||
|
||||
A special exception to the GPL can be applied should you wish to distribute
|
||||
a combined work that includes FreeRTOS, without being obliged to provide
|
||||
the source code for any proprietary components. See the licensing section
|
||||
of http://www.FreeRTOS.org for full details of how and when the exception
|
||||
can be applied.
|
||||
|
||||
***************************************************************************
|
||||
See http://www.FreeRTOS.org for documentation, latest information, license
|
||||
and contact details. Please ensure to read the configuration and relevant
|
||||
port sections of the online documentation.
|
||||
***************************************************************************
|
||||
*/
|
||||
|
||||
/**
|
||||
* Creates two sets of two tasks. The tasks within a set share a variable, access
|
||||
* to which is guarded by a semaphore.
|
||||
*
|
||||
* Each task starts by attempting to obtain the semaphore. On obtaining a
|
||||
* semaphore a task checks to ensure that the guarded variable has an expected
|
||||
* value. It then clears the variable to zero before counting it back up to the
|
||||
* expected value in increments of 1. After each increment the variable is checked
|
||||
* to ensure it contains the value to which it was just set. When the starting
|
||||
* value is again reached the task releases the semaphore giving the other task in
|
||||
* the set a chance to do exactly the same thing. The starting value is high
|
||||
* enough to ensure that a tick is likely to occur during the incrementing loop.
|
||||
*
|
||||
* An error is flagged if at any time during the process a shared variable is
|
||||
* found to have a value other than that expected. Such an occurrence would
|
||||
* suggest an error in the mutual exclusion mechanism by which access to the
|
||||
* variable is restricted.
|
||||
*
|
||||
* The first set of two tasks poll their semaphore. The second set use blocking
|
||||
* calls.
|
||||
*
|
||||
* \page SemTestC semtest.c
|
||||
* \ingroup DemoFiles
|
||||
* <HR>
|
||||
*/
|
||||
|
||||
/*
|
||||
Changes from V1.2.0:
|
||||
|
||||
+ The tasks that operate at the idle priority now use a lower expected
|
||||
count than those running at a higher priority. This prevents the low
|
||||
priority tasks from signaling an error because they have not been
|
||||
scheduled enough time for each of them to count the shared variable to
|
||||
the high value.
|
||||
|
||||
Changes from V2.0.0
|
||||
|
||||
+ Delay periods are now specified using variables and constants of
|
||||
portTickType rather than unsigned portLONG.
|
||||
|
||||
Changes from V2.1.1
|
||||
|
||||
+ The stack size now uses configMINIMAL_STACK_SIZE.
|
||||
+ String constants made file scope to decrease stack depth on 8051 port.
|
||||
*/
|
||||
|
||||
#include <stdlib.h>
|
||||
|
||||
/* Scheduler include files. */
|
||||
#include "FreeRTOS.h"
|
||||
#include "task.h"
|
||||
#include "semphr.h"
|
||||
|
||||
/* Demo app include files. */
|
||||
#include "semtest.h"
|
||||
#include "print.h"
|
||||
|
||||
/* The value to which the shared variables are counted. */
|
||||
#define semtstBLOCKING_EXPECTED_VALUE ( ( unsigned portLONG ) 0xfff )
|
||||
#define semtstNON_BLOCKING_EXPECTED_VALUE ( ( unsigned portLONG ) 0xff )
|
||||
|
||||
#define semtstSTACK_SIZE configMINIMAL_STACK_SIZE
|
||||
|
||||
#define semtstNUM_TASKS ( 4 )
|
||||
|
||||
#define semtstDELAY_FACTOR ( ( portTickType ) 10 )
|
||||
|
||||
/* The task function as described at the top of the file. */
|
||||
static void prvSemaphoreTest( void *pvParameters );
|
||||
|
||||
/* Structure used to pass parameters to each task. */
|
||||
typedef struct SEMAPHORE_PARAMETERS
|
||||
{
|
||||
xSemaphoreHandle xSemaphore;
|
||||
volatile unsigned portLONG *pulSharedVariable;
|
||||
portTickType xBlockTime;
|
||||
} xSemaphoreParameters;
|
||||
|
||||
/* Variables used to check that all the tasks are still running without errors. */
|
||||
static volatile portSHORT sCheckVariables[ semtstNUM_TASKS ] = { 0 };
|
||||
static volatile portSHORT sNextCheckVariable = 0;
|
||||
|
||||
/* Strings to print if USE_STDIO is defined. */
|
||||
const portCHAR * const pcPollingSemaphoreTaskError = "Guarded shared variable in unexpected state.\r\n";
|
||||
const portCHAR * const pcSemaphoreTaskStart = "Guarded shared variable task started.\r\n";
|
||||
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
void vStartSemaphoreTasks( unsigned portBASE_TYPE uxPriority )
|
||||
{
|
||||
xSemaphoreParameters *pxFirstSemaphoreParameters, *pxSecondSemaphoreParameters;
|
||||
const portTickType xBlockTime = ( portTickType ) 100;
|
||||
|
||||
/* Create the structure used to pass parameters to the first two tasks. */
|
||||
pxFirstSemaphoreParameters = ( xSemaphoreParameters * ) pvPortMalloc( sizeof( xSemaphoreParameters ) );
|
||||
|
||||
if( pxFirstSemaphoreParameters != NULL )
|
||||
{
|
||||
/* Create the semaphore used by the first two tasks. */
|
||||
vSemaphoreCreateBinary( pxFirstSemaphoreParameters->xSemaphore );
|
||||
|
||||
if( pxFirstSemaphoreParameters->xSemaphore != NULL )
|
||||
{
|
||||
/* Create the variable which is to be shared by the first two tasks. */
|
||||
pxFirstSemaphoreParameters->pulSharedVariable = ( unsigned portLONG * ) pvPortMalloc( sizeof( unsigned portLONG ) );
|
||||
|
||||
/* Initialise the share variable to the value the tasks expect. */
|
||||
*( pxFirstSemaphoreParameters->pulSharedVariable ) = semtstNON_BLOCKING_EXPECTED_VALUE;
|
||||
|
||||
/* The first two tasks do not block on semaphore calls. */
|
||||
pxFirstSemaphoreParameters->xBlockTime = ( portTickType ) 0;
|
||||
|
||||
/* Spawn the first two tasks. As they poll they operate at the idle priority. */
|
||||
xTaskCreate( prvSemaphoreTest, "PolSEM1", semtstSTACK_SIZE, ( void * ) pxFirstSemaphoreParameters, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );
|
||||
xTaskCreate( prvSemaphoreTest, "PolSEM2", semtstSTACK_SIZE, ( void * ) pxFirstSemaphoreParameters, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );
|
||||
}
|
||||
}
|
||||
|
||||
/* Do exactly the same to create the second set of tasks, only this time
|
||||
provide a block time for the semaphore calls. */
|
||||
pxSecondSemaphoreParameters = ( xSemaphoreParameters * ) pvPortMalloc( sizeof( xSemaphoreParameters ) );
|
||||
if( pxSecondSemaphoreParameters != NULL )
|
||||
{
|
||||
vSemaphoreCreateBinary( pxSecondSemaphoreParameters->xSemaphore );
|
||||
|
||||
if( pxSecondSemaphoreParameters->xSemaphore != NULL )
|
||||
{
|
||||
pxSecondSemaphoreParameters->pulSharedVariable = ( unsigned portLONG * ) pvPortMalloc( sizeof( unsigned portLONG ) );
|
||||
*( pxSecondSemaphoreParameters->pulSharedVariable ) = semtstBLOCKING_EXPECTED_VALUE;
|
||||
pxSecondSemaphoreParameters->xBlockTime = xBlockTime / portTICK_RATE_MS;
|
||||
|
||||
xTaskCreate( prvSemaphoreTest, "BlkSEM1", semtstSTACK_SIZE, ( void * ) pxSecondSemaphoreParameters, uxPriority, ( xTaskHandle * ) NULL );
|
||||
xTaskCreate( prvSemaphoreTest, "BlkSEM2", semtstSTACK_SIZE, ( void * ) pxSecondSemaphoreParameters, uxPriority, ( xTaskHandle * ) NULL );
|
||||
}
|
||||
}
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
static void prvSemaphoreTest( void *pvParameters )
|
||||
{
|
||||
xSemaphoreParameters *pxParameters;
|
||||
volatile unsigned portLONG *pulSharedVariable, ulExpectedValue;
|
||||
unsigned portLONG ulCounter;
|
||||
portSHORT sError = pdFALSE, sCheckVariableToUse;
|
||||
|
||||
/* See which check variable to use. sNextCheckVariable is not semaphore
|
||||
protected! */
|
||||
portENTER_CRITICAL();
|
||||
sCheckVariableToUse = sNextCheckVariable;
|
||||
sNextCheckVariable++;
|
||||
portEXIT_CRITICAL();
|
||||
|
||||
/* Queue a message for printing to say the task has started. */
|
||||
vPrintDisplayMessage( &pcSemaphoreTaskStart );
|
||||
|
||||
/* A structure is passed in as the parameter. This contains the shared
|
||||
variable being guarded. */
|
||||
pxParameters = ( xSemaphoreParameters * ) pvParameters;
|
||||
pulSharedVariable = pxParameters->pulSharedVariable;
|
||||
|
||||
/* If we are blocking we use a much higher count to ensure loads of context
|
||||
switches occur during the count. */
|
||||
if( pxParameters->xBlockTime > ( portTickType ) 0 )
|
||||
{
|
||||
ulExpectedValue = semtstBLOCKING_EXPECTED_VALUE;
|
||||
}
|
||||
else
|
||||
{
|
||||
ulExpectedValue = semtstNON_BLOCKING_EXPECTED_VALUE;
|
||||
}
|
||||
|
||||
for( ;; )
|
||||
{
|
||||
/* Try to obtain the semaphore. */
|
||||
if( xSemaphoreTake( pxParameters->xSemaphore, pxParameters->xBlockTime ) == pdPASS )
|
||||
{
|
||||
/* We have the semaphore and so expect any other tasks using the
|
||||
shared variable to have left it in the state we expect to find
|
||||
it. */
|
||||
if( *pulSharedVariable != ulExpectedValue )
|
||||
{
|
||||
vPrintDisplayMessage( &pcPollingSemaphoreTaskError );
|
||||
sError = pdTRUE;
|
||||
}
|
||||
|
||||
/* Clear the variable, then count it back up to the expected value
|
||||
before releasing the semaphore. Would expect a context switch or
|
||||
two during this time. */
|
||||
for( ulCounter = ( unsigned portLONG ) 0; ulCounter <= ulExpectedValue; ulCounter++ )
|
||||
{
|
||||
*pulSharedVariable = ulCounter;
|
||||
if( *pulSharedVariable != ulCounter )
|
||||
{
|
||||
if( sError == pdFALSE )
|
||||
{
|
||||
vPrintDisplayMessage( &pcPollingSemaphoreTaskError );
|
||||
}
|
||||
sError = pdTRUE;
|
||||
}
|
||||
}
|
||||
|
||||
/* Release the semaphore, and if no errors have occurred increment the check
|
||||
variable. */
|
||||
if( xSemaphoreGive( pxParameters->xSemaphore ) == pdFALSE )
|
||||
{
|
||||
vPrintDisplayMessage( &pcPollingSemaphoreTaskError );
|
||||
sError = pdTRUE;
|
||||
}
|
||||
|
||||
if( sError == pdFALSE )
|
||||
{
|
||||
if( sCheckVariableToUse < semtstNUM_TASKS )
|
||||
{
|
||||
( sCheckVariables[ sCheckVariableToUse ] )++;
|
||||
}
|
||||
}
|
||||
|
||||
/* If we have a block time then we are running at a priority higher
|
||||
than the idle priority. This task takes a long time to complete
|
||||
a cycle (deliberately so to test the guarding) so will be starving
|
||||
out lower priority tasks. Block for some time to allow give lower
|
||||
priority tasks some processor time. */
|
||||
vTaskDelay( pxParameters->xBlockTime * semtstDELAY_FACTOR );
|
||||
}
|
||||
else
|
||||
{
|
||||
if( pxParameters->xBlockTime == ( portTickType ) 0 )
|
||||
{
|
||||
/* We have not got the semaphore yet, so no point using the
|
||||
processor. We are not blocking when attempting to obtain the
|
||||
semaphore. */
|
||||
taskYIELD();
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
/* This is called to check that all the created tasks are still running. */
|
||||
portBASE_TYPE xAreSemaphoreTasksStillRunning( void )
|
||||
{
|
||||
static portSHORT sLastCheckVariables[ semtstNUM_TASKS ] = { 0 };
|
||||
portBASE_TYPE xTask, xReturn = pdTRUE;
|
||||
|
||||
for( xTask = 0; xTask < semtstNUM_TASKS; xTask++ )
|
||||
{
|
||||
if( sLastCheckVariables[ xTask ] == sCheckVariables[ xTask ] )
|
||||
{
|
||||
xReturn = pdFALSE;
|
||||
}
|
||||
|
||||
sLastCheckVariables[ xTask ] = sCheckVariables[ xTask ];
|
||||
}
|
||||
|
||||
return xReturn;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Add table
Add a link
Reference in a new issue