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https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-04-19 21:11:57 -04:00
Continue work on timers module - work in progress.
This commit is contained in:
Richard Barry
parent
812632fd1c
commit
4a5f1529d0
168
Source/timers.c
168
Source/timers.c
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@ -66,10 +66,10 @@ task.h is included from an application file. */
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#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
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/* IDs for commands that can be sent/received on the timer queue. */
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#define tmrSTART 0
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#define tmrCOMMAND_START 0
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/* Misc definitions. */
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#define timerNO_DELAY ( portTickType ) 0U
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#define tmrNO_DELAY ( portTickType ) 0U
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/* The definition of the timers themselves. */
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typedef struct tmrTimerControl
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@ -108,16 +108,37 @@ PRIVILEGED_DATA static xQueueHandle xTimerQueue = NULL;
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*/
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static void prvRemoveTimerFromActiveList( xTIMER *pxTimer ) PRIVILEGED_FUNCTION;
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/*
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* Send pxMessage to xTimerQueue using a block time of xBlockTime if the
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* scheduler is running, or a block time of zero if the scheduler is not
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* running.
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*/
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static portBASE_TYPE prvSendMessageToTimerServiceTask( xTIMER_MESSAGE *pxMessage, portTickType xBlockTime ) PRIVILEGED_FUNCTION;
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/*
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* Initialise the infrustructure used by the timer service task if it has not
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* been initialised already.
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*/
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static void prvCheckForValidListAndQueue( void ) PRIVILEGED_FUNCTION;
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/*
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* The timer service task (daemon).
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* The timer service task (daemon). Timer functionality is controlled by this
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* task. Other tasks communicate with the timer service task using the
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* xTimerQueue queue.
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*/
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static void prvTimerTask( void *pvParameters ) PRIVILEGED_FUNCTION;
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/*
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* The following functions handle the commands that are sent to the timer
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* service task via the xTimerQueue queue.
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*/
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static void prvTimerStart( xTIMER *pxTimer ) PRIVILEGED_FUNCTION;
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/* Handlers for commands received on the timer queue. */
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static void prvTimerStart( xTIMER *pxTimer );
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/*
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* Called by the timer service task to interpret and process a command it
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* received on the timer queue.
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*/
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static void prvProcessReceivedCommands( void ) PRIVILEGED_FUNCTION;
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/*-----------------------------------------------------------*/
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@ -126,12 +147,14 @@ portBASE_TYPE xTimerCreateTimerTask( void )
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portBASE_TYPE xReturn = pdFAIL;
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/* This function is called when the scheduler is started if
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configUSE_TIMERS is set to 1. */
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configUSE_TIMERS is set to 1. Check that the infrustructure used by the
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timer service task has been created/initialised. If timers have already
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been created then the initialisation will already have been performed. */
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prvCheckForValidListAndQueue();
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if( xTimerQueue != NULL )
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{
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xReturn = xTaskCreate( prvTimerTask, ( const signed char * ) "Timers", configMINIMAL_STACK_SIZE, NULL, configTIMER_TASK_PRIORITY, NULL );
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xReturn = xTaskCreate( prvTimerTask, ( const signed char * ) "Timers", configTIMER_TASK_STACK_DEPTH, NULL, configTIMER_TASK_PRIORITY, NULL );
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}
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return xReturn;
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@ -146,9 +169,11 @@ xTIMER *pxNewTimer;
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pxNewTimer = ( xTIMER * ) pvPortMalloc( sizeof( xTIMER ) );
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if( pxNewTimer != NULL )
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{
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/* Ensure the infrustructure used by the timer service task has been
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created/initialised. */
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prvCheckForValidListAndQueue();
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/* Initialise the timer structure members. */
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/* Initialise the timer structure members using the function parameters. */
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pxNewTimer->pcTimerName = pcTimerName;
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pxNewTimer->xTimerPeriodInTicks = xTimerPeriodInTicks;
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pxNewTimer->uxAutoReload = uxAutoReload;
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@ -166,68 +191,57 @@ portBASE_TYPE xTimerStart( xTimerHandle xTimer, portTickType xBlockTime )
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portBASE_TYPE xReturn = pdFAIL;
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xTIMER_MESSAGE xMessage;
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/* A timer cannot be started unless it is created, and creating a timer
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will have resulted in the timer queue also being created. */
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if( xTimerQueue != NULL )
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{
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xMessage.xMessageID = tmrSTART;
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/* Send a command to the timer service task to start the xTimer timer. */
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xMessage.xMessageID = tmrCOMMAND_START;
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xMessage.pxTimer = ( xTIMER * ) xTimer;
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xReturn = xQueueSendToBack( xTimerQueue, &xMessage, xBlockTime );
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prvSendMessageToTimerServiceTask( &xMessage, xBlockTime );
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}
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return xReturn;
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}
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/*-----------------------------------------------------------*/
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void *pvTimerGetTimerID( xTimerHandle xTimer )
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{
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xTIMER *pxTimer = ( xTIMER * ) xTimer;
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return pxTimer->pvTimerID;
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}
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/*-----------------------------------------------------------*/
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static void prvRemoveTimerFromActiveList( xTIMER *pxTimer )
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{
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/* Is the timer already in the list of active timers? */
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if( listIS_CONTAINED_WITHIN( NULL, &( pxTimer->xTimerListItem ) ) == pdFALSE )
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{
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/* The timer is in the list, remove it. */
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vListRemove( &( pxTimer->xTimerListItem ) );
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}
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}
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/*-----------------------------------------------------------*/
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static void prvTimerTask( void *pvParameters )
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{
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portTickType xNextWakeTime, xTimeNow;
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portTickType xNextExpireTime, xTimeNow;
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xTIMER *pxTimer;
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xTIMER_MESSAGE xMessage;
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/* Just to avoid compiler warnings. */
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( void ) pvParameters;
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for( ;; )
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{
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/* Timers are listed in expiry time order, with the head of the list
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referencing the task that will expire first. Obtain the time at which
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the timer with the nearest expiry time will expire. If there are no
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active timers then just set the next expire time to the maximum possible
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time to ensure this task does not run unnecessarily. */
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if( listLIST_IS_EMPTY( &xActiveTimerList ) == pdFALSE )
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{
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xNextWakeTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( &xActiveTimerList );
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xNextExpireTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( &xActiveTimerList );
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}
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else
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{
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xNextWakeTime = portMAX_DELAY;
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xNextExpireTime = portMAX_DELAY;
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}
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if( xNextWakeTime <= xTaskGetTickCount() )
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/* Has the timer expired? */
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if( xNextExpireTime <= xTaskGetTickCount() )
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{
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/* Remove the timer from the list. This functionality relies on
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the list of active timers not being accessed from outside of this
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task. */
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/* Remove the timer from the list of active timers. */
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pxTimer = listGET_OWNER_OF_HEAD_ENTRY( &xActiveTimerList );
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vListRemove( &( pxTimer->xTimerListItem ) );
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/* If the timer is an autoreload timer then calculate the next
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expiry time and re-insert the timer in the list of active timers. */
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if( pxTimer->uxAutoReload == pdTRUE )
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{
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listSET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ), ( xNextWakeTime + pxTimer->xTimerPeriodInTicks ) );
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listSET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ), ( xNextExpireTime + pxTimer->xTimerPeriodInTicks ) );
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vListInsert( &xActiveTimerList, &( pxTimer->xTimerListItem ) );
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}
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@ -236,31 +250,60 @@ xTIMER_MESSAGE xMessage;
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}
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else
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{
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/* Calculate the block time. */
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/* Block this task until the next timer expires, or a command is
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received. */
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taskENTER_CRITICAL();
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{
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xTimeNow = xTaskGetTickCount();
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if( xTimeNow < xNextWakeTime )
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if( xTimeNow < xNextExpireTime )
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{
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vQueueWaitForMessageRestricted( xTimerQueue, ( xNextWakeTime - xTimeNow ) );
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/* This is a simple fast function - a yield will not be
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performed until after this critical section exits. */
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vQueueWaitForMessageRestricted( xTimerQueue, ( xNextExpireTime - xTimeNow ) );
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}
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}
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taskEXIT_CRITICAL();
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/* Yield to wait for either a command to arrive, or the block time
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to expire. If a command arrived between the critical section being
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exited and this yeild then the yield will just return to the same
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task. */
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portYIELD_WITHIN_API();
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while( xQueueReceive( xTimerQueue, &xMessage, timerNO_DELAY ) != pdFAIL )
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/* Empty the command queue, if it contains any commands. */
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prvProcessReceivedCommands();
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}
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}
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}
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/*-----------------------------------------------------------*/
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static void prvProcessReceivedCommands( void )
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{
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xTIMER_MESSAGE xMessage;
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portTickType xTimeToExpire;
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xTIMER *pxTimer;
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while( xQueueReceive( xTimerQueue, &xMessage, tmrNO_DELAY ) != pdFAIL )
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{
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pxTimer = xMessage.pxTimer;
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/* Is the timer already in the list of active timers? */
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prvRemoveTimerFromActiveList( pxTimer );
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switch( xMessage.xMessageID )
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{
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case tmrSTART : prvTimerStart( xMessage.pxTimer );
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case tmrCOMMAND_START : /* Start or restart a timer. */
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xTimeToExpire = xTaskGetTickCount() + pxTimer->xTimerPeriodInTicks;
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listSET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ), xTimeToExpire );
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listSET_LIST_ITEM_OWNER( &( pxTimer->xTimerListItem ), pxTimer );
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vListInsert( &xActiveTimerList, &( pxTimer->xTimerListItem ) );
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break;
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default : /* Don't expect to get here. */
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break;
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}
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}
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}
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}
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}
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/*-----------------------------------------------------------*/
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static void prvCheckForValidListAndQueue( void )
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@ -280,24 +323,41 @@ static void prvCheckForValidListAndQueue( void )
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}
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/*-----------------------------------------------------------*/
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static void prvTimerStart( xTIMER *pxTimer )
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void *pvTimerGetTimerID( xTimerHandle xTimer )
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{
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portTickType xTimeToWake;
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xTIMER *pxTimer = ( xTIMER * ) xTimer;
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if( pxTimer != NULL )
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return pxTimer->pvTimerID;
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}
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/*-----------------------------------------------------------*/
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static void prvRemoveTimerFromActiveList( xTIMER *pxTimer )
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{
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/* Is the timer already in the list of active timers? */
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prvRemoveTimerFromActiveList( pxTimer );
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xTimeToWake = xTaskGetTickCount() + pxTimer->xTimerPeriodInTicks;
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listSET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ), xTimeToWake );
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listSET_LIST_ITEM_OWNER( &( pxTimer->xTimerListItem ), pxTimer );
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vListInsert( &xActiveTimerList, &( pxTimer->xTimerListItem ) );
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if( listIS_CONTAINED_WITHIN( NULL, &( pxTimer->xTimerListItem ) ) == pdFALSE )
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{
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/* The timer is in the list, remove it. */
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vListRemove( &( pxTimer->xTimerListItem ) );
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}
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}
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/*-----------------------------------------------------------*/
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static portBASE_TYPE prvSendMessageToTimerServiceTask( xTIMER_MESSAGE *pxMessage, portTickType xBlockTime )
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{
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portBASE_TYPE xReturn;
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if( xTaskGetSchedulerState() == taskSCHEDULER_RUNNING )
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{
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xReturn = xQueueSendToBack( xTimerQueue, pxMessage, xBlockTime );
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}
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else
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{
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xReturn = xQueueSendToBack( xTimerQueue, pxMessage, tmrNO_DELAY );
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}
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return xReturn;
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}
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/*-----------------------------------------------------------*/
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