Updated the Win32 MSVC demo files.
Richard Barry
14 years ago
parent
37b6fb5773
commit
abadea4557
@ -0,0 +1,398 @@
|
||||
/*
|
||||
FreeRTOS V6.1.0 - 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 books - available as PDF or paperback *
|
||||
* *
|
||||
* "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.
|
||||
*/
|
||||
|
||||
/*
|
||||
The tasks defined on this page demonstrate the use of recursive mutexes.
|
||||
|
||||
For recursive mutex functionality the created mutex should be created using
|
||||
xSemaphoreCreateRecursiveMutex(), then be manipulated
|
||||
using the xSemaphoreTakeRecursive() and xSemaphoreGiveRecursive() API
|
||||
functions.
|
||||
|
||||
This demo creates three tasks all of which access the same recursive mutex:
|
||||
|
||||
prvRecursiveMutexControllingTask() has the highest priority so executes
|
||||
first and grabs the mutex. It then performs some recursive accesses -
|
||||
between each of which it sleeps for a short period to let the lower
|
||||
priority tasks execute. When it has completed its demo functionality
|
||||
it gives the mutex back before suspending itself.
|
||||
|
||||
prvRecursiveMutexBlockingTask() attempts to access the mutex by performing
|
||||
a blocking 'take'. The blocking task has a lower priority than the
|
||||
controlling task so by the time it executes the mutex has already been
|
||||
taken by the controlling task, causing the blocking task to block. It
|
||||
does not unblock until the controlling task has given the mutex back,
|
||||
and it does not actually run until the controlling task has suspended
|
||||
itself (due to the relative priorities). When it eventually does obtain
|
||||
the mutex all it does is give the mutex back prior to also suspending
|
||||
itself. At this point both the controlling task and the blocking task are
|
||||
suspended.
|
||||
|
||||
prvRecursiveMutexPollingTask() runs at the idle priority. It spins round
|
||||
a tight loop attempting to obtain the mutex with a non-blocking call. As
|
||||
the lowest priority task it will not successfully obtain the mutex until
|
||||
both the controlling and blocking tasks are suspended. Once it eventually
|
||||
does obtain the mutex it first unsuspends both the controlling task and
|
||||
blocking task prior to giving the mutex back - resulting in the polling
|
||||
task temporarily inheriting the controlling tasks priority.
|
||||
*/
|
||||
|
||||
/* Scheduler include files. */
|
||||
#include "FreeRTOS.h"
|
||||
#include "task.h"
|
||||
#include "semphr.h"
|
||||
|
||||
/* Demo app include files. */
|
||||
#include "recmutex.h"
|
||||
|
||||
/* Priorities assigned to the three tasks. */
|
||||
#define recmuCONTROLLING_TASK_PRIORITY ( tskIDLE_PRIORITY + 2 )
|
||||
#define recmuBLOCKING_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 )
|
||||
#define recmuPOLLING_TASK_PRIORITY ( tskIDLE_PRIORITY + 0 )
|
||||
|
||||
/* In this version the tick period is very long, so the short delay cannot be
|
||||
for too many ticks, or the check task will execute and find that the recmutex
|
||||
tasks have not completed their functionality and then signal an error. The
|
||||
delay does however have to be long enough to allow the lower priority tasks
|
||||
a chance of executing - this is basically achieved by reducing the number
|
||||
of times the loop that takes/gives the recursive mutex executes. */
|
||||
#define recmuMAX_COUNT ( 2 )
|
||||
#define recmuSHORT_DELAY ( 20 )
|
||||
#define recmuNO_DELAY ( ( portTickType ) 0 )
|
||||
#define recmuFIVE_TICK_DELAY ( ( portTickType ) 5 )
|
||||
|
||||
/* The three tasks as described at the top of this file. */
|
||||
static void prvRecursiveMutexControllingTask( void *pvParameters );
|
||||
static void prvRecursiveMutexBlockingTask( void *pvParameters );
|
||||
static void prvRecursiveMutexPollingTask( void *pvParameters );
|
||||
|
||||
/* The mutex used by the demo. */
|
||||
static xSemaphoreHandle xMutex;
|
||||
|
||||
/* Variables used to detect and latch errors. */
|
||||
static volatile portBASE_TYPE xErrorOccurred = pdFALSE, xControllingIsSuspended = pdFALSE, xBlockingIsSuspended = pdFALSE;
|
||||
static volatile unsigned portBASE_TYPE uxControllingCycles = 0, uxBlockingCycles = 0, uxPollingCycles = 0;
|
||||
|
||||
/* Handles of the two higher priority tasks, required so they can be resumed
|
||||
(unsuspended). */
|
||||
static xTaskHandle xControllingTaskHandle, xBlockingTaskHandle;
|
||||
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
void vStartRecursiveMutexTasks( void )
|
||||
{
|
||||
/* Just creates the mutex and the three tasks. */
|
||||
|
||||
xMutex = xSemaphoreCreateRecursiveMutex();
|
||||
|
||||
/* vQueueAddToRegistry() adds the mutex to the registry, if one is
|
||||
in use. The registry is provided as a means for kernel aware
|
||||
debuggers to locate mutex and has no purpose if a kernel aware debugger
|
||||
is not being used. The call to vQueueAddToRegistry() will be removed
|
||||
by the pre-processor if configQUEUE_REGISTRY_SIZE is not defined or is
|
||||
defined to be less than 1. */
|
||||
vQueueAddToRegistry( ( xQueueHandle ) xMutex, ( signed portCHAR * ) "Recursive_Mutex" );
|
||||
|
||||
|
||||
if( xMutex != NULL )
|
||||
{
|
||||
xTaskCreate( prvRecursiveMutexControllingTask, ( signed portCHAR * ) "Rec1Ctrl", configMINIMAL_STACK_SIZE, NULL, recmuCONTROLLING_TASK_PRIORITY, &xControllingTaskHandle );
|
||||
xTaskCreate( prvRecursiveMutexBlockingTask, ( signed portCHAR * ) "Rec2Blck", configMINIMAL_STACK_SIZE, NULL, recmuBLOCKING_TASK_PRIORITY, &xBlockingTaskHandle );
|
||||
xTaskCreate( prvRecursiveMutexPollingTask, ( signed portCHAR * ) "Rec3Poll", configMINIMAL_STACK_SIZE, NULL, recmuPOLLING_TASK_PRIORITY, NULL );
|
||||
}
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
static void prvRecursiveMutexControllingTask( void *pvParameters )
|
||||
{
|
||||
unsigned portBASE_TYPE ux;
|
||||
|
||||
/* Just to remove compiler warning. */
|
||||
( void ) pvParameters;
|
||||
|
||||
for( ;; )
|
||||
{
|
||||
/* Should not be able to 'give' the mutex, as we have not yet 'taken'
|
||||
it. The first time through, the mutex will not have been used yet,
|
||||
subsequent times through, at this point the mutex will be held by the
|
||||
polling task. */
|
||||
if( xSemaphoreGiveRecursive( xMutex ) == pdPASS )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
|
||||
for( ux = 0; ux < recmuMAX_COUNT; ux++ )
|
||||
{
|
||||
/* We should now be able to take the mutex as many times as
|
||||
we like.
|
||||
|
||||
The first time through the mutex will be immediately available, on
|
||||
subsequent times through the mutex will be held by the polling task
|
||||
at this point and this Take will cause the polling task to inherit
|
||||
the priority of this task. In this case the block time must be
|
||||
long enough to ensure the polling task will execute again before the
|
||||
block time expires. If the block time does expire then the error
|
||||
flag will be set here. */
|
||||
if( xSemaphoreTakeRecursive( xMutex, recmuFIVE_TICK_DELAY ) != pdPASS )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
|
||||
/* Ensure the other task attempting to access the mutex (and the
|
||||
other demo tasks) are able to execute to ensure they either block
|
||||
(where a block time is specified) or return an error (where no
|
||||
block time is specified) as the mutex is held by this task. */
|
||||
vTaskDelay( recmuSHORT_DELAY );
|
||||
}
|
||||
|
||||
/* For each time we took the mutex, give it back. */
|
||||
for( ux = 0; ux < recmuMAX_COUNT; ux++ )
|
||||
{
|
||||
/* Ensure the other task attempting to access the mutex (and the
|
||||
other demo tasks) are able to execute. */
|
||||
vTaskDelay( recmuSHORT_DELAY );
|
||||
|
||||
/* We should now be able to give the mutex as many times as we
|
||||
took it. When the mutex is available again the Blocking task
|
||||
should be unblocked but not run because it has a lower priority
|
||||
than this task. The polling task should also not run at this point
|
||||
as it too has a lower priority than this task. */
|
||||
if( xSemaphoreGiveRecursive( xMutex ) != pdPASS )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
}
|
||||
|
||||
/* Having given it back the same number of times as it was taken, we
|
||||
should no longer be the mutex owner, so the next give should fail. */
|
||||
if( xSemaphoreGiveRecursive( xMutex ) == pdPASS )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
|
||||
/* Keep count of the number of cycles this task has performed so a
|
||||
stall can be detected. */
|
||||
uxControllingCycles++;
|
||||
|
||||
/* Suspend ourselves so the blocking task can execute. */
|
||||
xControllingIsSuspended = pdTRUE;
|
||||
vTaskSuspend( NULL );
|
||||
xControllingIsSuspended = pdFALSE;
|
||||
}
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
static void prvRecursiveMutexBlockingTask( void *pvParameters )
|
||||
{
|
||||
/* Just to remove compiler warning. */
|
||||
( void ) pvParameters;
|
||||
|
||||
for( ;; )
|
||||
{
|
||||
/* This task will run while the controlling task is blocked, and the
|
||||
controlling task will block only once it has the mutex - therefore
|
||||
this call should block until the controlling task has given up the
|
||||
mutex, and not actually execute past this call until the controlling
|
||||
task is suspended. */
|
||||
if( xSemaphoreTakeRecursive( xMutex, portMAX_DELAY ) == pdPASS )
|
||||
{
|
||||
if( xControllingIsSuspended != pdTRUE )
|
||||
{
|
||||
/* Did not expect to execute until the controlling task was
|
||||
suspended. */
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Give the mutex back before suspending ourselves to allow
|
||||
the polling task to obtain the mutex. */
|
||||
if( xSemaphoreGiveRecursive( xMutex ) != pdPASS )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
|
||||
xBlockingIsSuspended = pdTRUE;
|
||||
vTaskSuspend( NULL );
|
||||
xBlockingIsSuspended = pdFALSE;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
/* We should not leave the xSemaphoreTakeRecursive() function
|
||||
until the mutex was obtained. */
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
|
||||
/* The controlling and blocking tasks should be in lock step. */
|
||||
if( uxControllingCycles != ( uxBlockingCycles + 1 ) )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
|
||||
/* Keep count of the number of cycles this task has performed so a
|
||||
stall can be detected. */
|
||||
uxBlockingCycles++;
|
||||
}
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
static void prvRecursiveMutexPollingTask( void *pvParameters )
|
||||
{
|
||||
/* Just to remove compiler warning. */
|
||||
( void ) pvParameters;
|
||||
|
||||
for( ;; )
|
||||
{
|
||||
/* Keep attempting to obtain the mutex. We should only obtain it when
|
||||
the blocking task has suspended itself, which in turn should only
|
||||
happen when the controlling task is also suspended. */
|
||||
if( xSemaphoreTakeRecursive( xMutex, recmuNO_DELAY ) == pdPASS )
|
||||
{
|
||||
/* Is the blocking task suspended? */
|
||||
if( ( xBlockingIsSuspended != pdTRUE ) || ( xControllingIsSuspended != pdTRUE ) )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Keep count of the number of cycles this task has performed
|
||||
so a stall can be detected. */
|
||||
uxPollingCycles++;
|
||||
|
||||
/* We can resume the other tasks here even though they have a
|
||||
higher priority than the polling task. When they execute they
|
||||
will attempt to obtain the mutex but fail because the polling
|
||||
task is still the mutex holder. The polling task (this task)
|
||||
will then inherit the higher priority. The Blocking task will
|
||||
block indefinitely when it attempts to obtain the mutex, the
|
||||
Controlling task will only block for a fixed period and an
|
||||
error will be latched if the polling task has not returned the
|
||||
mutex by the time this fixed period has expired. */
|
||||
vTaskResume( xBlockingTaskHandle );
|
||||
vTaskResume( xControllingTaskHandle );
|
||||
|
||||
/* The other two tasks should now have executed and no longer
|
||||
be suspended. */
|
||||
if( ( xBlockingIsSuspended == pdTRUE ) || ( xControllingIsSuspended == pdTRUE ) )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
|
||||
/* Release the mutex, disinheriting the higher priority again. */
|
||||
if( xSemaphoreGiveRecursive( xMutex ) != pdPASS )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#if configUSE_PREEMPTION == 0
|
||||
{
|
||||
taskYIELD();
|
||||
}
|
||||
#endif
|
||||
}
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
/* This is called to check that all the created tasks are still running. */
|
||||
portBASE_TYPE xAreRecursiveMutexTasksStillRunning( void )
|
||||
{
|
||||
portBASE_TYPE xReturn;
|
||||
static unsigned portBASE_TYPE uxLastControllingCycles = 0, uxLastBlockingCycles = 0, uxLastPollingCycles = 0;
|
||||
|
||||
/* Is the controlling task still cycling? */
|
||||
if( uxLastControllingCycles == uxControllingCycles )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
else
|
||||
{
|
||||
uxLastControllingCycles = uxControllingCycles;
|
||||
}
|
||||
|
||||
/* Is the blocking task still cycling? */
|
||||
if( uxLastBlockingCycles == uxBlockingCycles )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
else
|
||||
{
|
||||
uxLastBlockingCycles = uxBlockingCycles;
|
||||
}
|
||||
|
||||
/* Is the polling task still cycling? */
|
||||
if( uxLastPollingCycles == uxPollingCycles )
|
||||
{
|
||||
xErrorOccurred = pdTRUE;
|
||||
}
|
||||
else
|
||||
{
|
||||
uxLastPollingCycles = uxPollingCycles;
|
||||
}
|
||||
|
||||
if( xErrorOccurred == pdTRUE )
|
||||
{
|
||||
xReturn = pdFAIL;
|
||||
}
|
||||
else
|
||||
{
|
||||
xReturn = pdTRUE;
|
||||
}
|
||||
|
||||
return xReturn;
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
Binary file not shown.
Loading…
Reference in New Issue