mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-08-19 09:38:32 -04:00
Continue work on the new timer implementation. Nearly complete.
This commit is contained in:
Richard Barry
parent
07a2021676
commit
b4ff4820cb
5 changed files with 211 additions and 155 deletions
308
Source/timers.c
308
Source/timers.c
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@ -117,25 +117,45 @@ static void prvTimerTask( void *pvParameters ) PRIVILEGED_FUNCTION;
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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( portTickType xAssumedTimeNow ) PRIVILEGED_FUNCTION;
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static void prvProcessReceivedCommands( void ) PRIVILEGED_FUNCTION;
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/*
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* Insert the timer into either xActiveTimerList1, or xActiveTimerList2,
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* depending on if the expire time causes a timer counter overflow.
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* Insert the timer into either xActiveTimerList1, or xActiveTimerList2,
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* depending on if the expire time causes a timer counter overflow.
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*/
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static void prvInsertTimerInActiveList( xTIMER *pxTimer, portTickType xNextExpiryTime, portTickType xAssumedTimeNow ) PRIVILEGED_FUNCTION;
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static void prvInsertTimerInActiveList( xTIMER *pxTimer, portTickType xNextExpiryTime, portTickType xTimeNow ) PRIVILEGED_FUNCTION;
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/*
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* An active timer has reached its expire time. Reload the timer if it is an
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* auto reload timer, then call its callback.
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*/
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static void prvProcessExpiredTimer( portTickType xNextExpireTime, portTickType xAssumedTimeNow ) PRIVILEGED_FUNCTION;
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static void prvProcessExpiredTimer( portTickType xNextExpireTime, portTickType xTimeNow ) PRIVILEGED_FUNCTION;
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/*
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* The tick count has overflowed. Switch the timer lists after ensuring the
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* current timer list does not still reference some timers.
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*/
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static void prvSwitchTimerLists( portTickType xAssumedTimeNow ) PRIVILEGED_FUNCTION;
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static void prvSwitchTimerLists( portTickType xTimeNow, portTickType xLastTime ) PRIVILEGED_FUNCTION;
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/*
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* Obtain the current tick count, setting *pxTimerListsWereSwitched to pdTRUE
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* if a tick count overflow occurred since prvSampleTimeNow() was last called.
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*/
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static portTickType prvSampleTimeNow( portBASE_TYPE *pxTimerListsWereSwitched ) PRIVILEGED_FUNCTION;
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/*
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* If the timer list contains any active timers then return the expire time of
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* the timer that will expire first and set *pxListWasEmpty to false. If the
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* timer list does not contain any timers then return 0 and set *pxListWasEmpty
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* to pdTRUE.
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*/
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static portTickType prvLookForExpiredTimer( portBASE_TYPE *pxListWasEmpty ) PRIVILEGED_FUNCTION;
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/*
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* If a timer has expired, process it. Otherwise, block the timer service task
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* until either a timer does expire or a command is received.
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*/
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static void prvProcessTimerOrBlockTask( portTickType xNextExpireTime, portBASE_TYPE xListWasEmpty ) PRIVILEGED_FUNCTION;
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/*-----------------------------------------------------------*/
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@ -151,7 +171,7 @@ portBASE_TYPE xReturn = pdFAIL;
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if( xTimerQueue != NULL )
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{
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xReturn = xTaskCreate( prvTimerTask, ( const signed char * ) "Timer Service", configTIMER_TASK_STACK_DEPTH, NULL, configTIMER_TASK_PRIORITY, NULL );
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xReturn = xTaskCreate( prvTimerTask, ( const signed char * ) "Tmr Svc", configTIMER_TASK_STACK_DEPTH, NULL, configTIMER_TASK_PRIORITY, NULL);
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}
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return xReturn;
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@ -183,7 +203,7 @@ xTIMER *pxNewTimer;
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}
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/*-----------------------------------------------------------*/
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portBASE_TYPE xTimerGenericCommand( xTimerHandle xTimer, portBASE_TYPE xCommandID, portTickType xOptionalValue, portTickType xBlockTime )
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portBASE_TYPE xTimerGenericCommand( xTimerHandle xTimer, portBASE_TYPE xCommandID, portTickType xOptionalValue, portBASE_TYPE *pxHigherPriorityTaskWoken, portTickType xBlockTime )
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{
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portBASE_TYPE xReturn = pdFAIL;
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xTIMER_MESSAGE xMessage;
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@ -197,13 +217,20 @@ xTIMER_MESSAGE xMessage;
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xMessage.xMessageValue = xOptionalValue;
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xMessage.pxTimer = ( xTIMER * ) xTimer;
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if( xTaskGetSchedulerState() == taskSCHEDULER_RUNNING )
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if( pxHigherPriorityTaskWoken == NULL )
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{
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xReturn = xQueueSendToBack( xTimerQueue, &xMessage, xBlockTime );
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if( xTaskGetSchedulerState() == taskSCHEDULER_RUNNING )
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{
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xReturn = xQueueSendToBack( xTimerQueue, &xMessage, xBlockTime );
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}
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else
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{
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xReturn = xQueueSendToBack( xTimerQueue, &xMessage, tmrNO_DELAY );
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}
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}
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else
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{
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xReturn = xQueueSendToBack( xTimerQueue, &xMessage, tmrNO_DELAY );
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xReturn = xQueueSendToBackFromISR( xTimerQueue, &xMessage, pxHigherPriorityTaskWoken );
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}
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}
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@ -211,128 +238,155 @@ xTIMER_MESSAGE xMessage;
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}
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/*-----------------------------------------------------------*/
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static void prvProcessExpiredTimer( portTickType xNextExpireTime, portTickType xAssumedTimeNow )
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static void prvProcessExpiredTimer( portTickType xNextExpireTime, portTickType xTimeNow )
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{
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xTIMER *pxTimer;
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if( listLIST_IS_EMPTY( pxCurrentTimerList ) == pdFALSE )
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/* Remove the timer from the list of active timers. A check has already
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been performed to ensure the list is not empty. */
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pxTimer = ( xTIMER * ) listGET_OWNER_OF_HEAD_ENTRY( pxCurrentTimerList );
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vListRemove( &( pxTimer->xTimerListItem ) );
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/* If the timer is an auto reload 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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/* Remove the timer from the list of active timers. */
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pxTimer = ( xTIMER * ) listGET_OWNER_OF_HEAD_ENTRY( pxCurrentTimerList );
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vListRemove( &( pxTimer->xTimerListItem ) );
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/* If the timer is an auto reload 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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/* This is the only time a timer is inserted into a list using
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a time relative to anything other than the current time. It
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will therefore be inserted into the correct list relative to
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the time this task thinks it is now, even if a command to
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switch lists due to a tick count overflow is already waiting in
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the timer queue. */
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prvInsertTimerInActiveList( pxTimer, ( xNextExpireTime + pxTimer->xTimerPeriodInTicks ), xAssumedTimeNow );
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}
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/* Call the timer callback. */
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pxTimer->pxCallbackFunction( ( xTimerHandle ) pxTimer );
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/* This is the only time a timer is inserted into a list using
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a time relative to anything other than the current time. It
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will therefore be inserted into the correct list relative to
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the time this task thinks it is now, even if a command to
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switch lists due to a tick count overflow is already waiting in
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the timer queue. */
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prvInsertTimerInActiveList( pxTimer, ( xNextExpireTime + pxTimer->xTimerPeriodInTicks ), xTimeNow );
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}
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/* Call the timer callback. */
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pxTimer->pxCallbackFunction( ( xTimerHandle ) pxTimer );
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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 xNextExpireTime, xTimeNow, xFrozenTimeNow;
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portTickType xNextExpireTime;
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portBASE_TYPE xListWasEmpty;
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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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/* Take a snapshot of the time to use while assessing expiry and auto
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reload times. */
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xFrozenTimeNow = xTaskGetTickCount();
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/* Query the timers list to see if it contains any timers, and if so,
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obtain the time at which the next timer will expire. */
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xNextExpireTime = prvLookForExpiredTimer( &xListWasEmpty );
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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( pxCurrentTimerList ) == pdFALSE )
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{
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xNextExpireTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxCurrentTimerList );
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}
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else
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{
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xNextExpireTime = portMAX_DELAY;
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}
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/* Has the timer expired? This expiry time is relative to the snapshot
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of the time taken to be used in this loop iteration - so it doesn't
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matter at this point if a tick count overflows here. */
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if( xNextExpireTime <= xFrozenTimeNow )
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{
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prvProcessExpiredTimer( xNextExpireTime, xFrozenTimeNow );
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}
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else
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{
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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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vTaskSuspendAll();
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{
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/* Has the tick overflowed since a time snapshot was taken? */
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xTimeNow = xTaskGetTickCount();
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if( xTimeNow >= xFrozenTimeNow )
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{
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/* Has the expire not still not been met? The tick count
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may be greater now than when the time snapshot was taken. */
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if( xNextExpireTime <= xTimeNow )
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{
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prvProcessExpiredTimer( xNextExpireTime, xFrozenTimeNow );
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}
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else
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{
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/* The tick count has not overflowed since the time
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snapshot, and the next expire time has not been reached
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since the last snapshot was taken. This task should
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therefore block to wait for the next expire time. */
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vQueueWaitForMessageRestricted( xTimerQueue, ( xNextExpireTime - xTimeNow ) );
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}
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}
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else
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{
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/* The tick count has overflowed since the time snapshot
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was taken, therefore, the task should not block but continue
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with another loop. The command queue should contain a
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command to switch lists. */
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}
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}
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if( xTaskResumeAll() == pdFALSE )
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{
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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 yield 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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}
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/* Take a snapshot of the time now for use in this iteration of the
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task loop. */
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xFrozenTimeNow = xTaskGetTickCount();
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/* Empty the command queue, if it contains any commands. */
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prvProcessReceivedCommands( xFrozenTimeNow );
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}
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/* If a timer has expired, process it. Otherwise, block this task
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until either a timer does expire, or a command is received. */
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prvProcessTimerOrBlockTask( xNextExpireTime, xListWasEmpty );
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/* Empty the command queue. */
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prvProcessReceivedCommands();
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}
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}
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/*-----------------------------------------------------------*/
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static void prvInsertTimerInActiveList( xTIMER *pxTimer, portTickType xNextExpiryTime, portTickType xAssumedTimeNow )
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static void prvProcessTimerOrBlockTask( portTickType xNextExpireTime, portBASE_TYPE xListWasEmpty )
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{
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portTickType xTimeNow;
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portBASE_TYPE xTimerListsWereSwitched;
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vTaskSuspendAll();
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{
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/* Obtain the time now to make an assessment as to whether the timer
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has expired or not. If obtaining the time causes the lists to switch
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then don't process this timer as any timers that remained in the list
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when the lists were switched will have been processed within the
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prvSampelTimeNow() function. */
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xTimeNow = prvSampleTimeNow( &xTimerListsWereSwitched );
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if( xTimerListsWereSwitched == pdFALSE )
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{
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/* The tick count has not overflowed, has the timer expired? */
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if( ( xListWasEmpty == pdFALSE ) && ( xNextExpireTime <= xTimeNow ) )
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{
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prvProcessExpiredTimer( xNextExpireTime, xTimeNow );
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}
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else
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{
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/* The tick count has not overflowed, and the next expire
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time has not been reached yet. This task should therefore
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block to wait for the next expire time or a command to be
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received - whichever comes first. The following line cannot
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be reached unless xNextExpireTime > xTimeNow, except in the
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case when the current timer list is empty. */
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vQueueWaitForMessageRestricted( xTimerQueue, ( xNextExpireTime - xTimeNow ) );
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}
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}
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}
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if( xTaskResumeAll() == pdFALSE )
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{
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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 yield then the yield will not cause the task
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to block. */
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portYIELD_WITHIN_API();
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}
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}
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/*-----------------------------------------------------------*/
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static portTickType prvLookForExpiredTimer( portBASE_TYPE *pxListWasEmpty )
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{
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portTickType xNextExpireTime;
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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 0. That will cause
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this task to unblock when the tick count overflows, at which point the
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timer lists will be switched and the next expiry time can be
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re-assessed. */
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*pxListWasEmpty = listLIST_IS_EMPTY( pxCurrentTimerList );
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if( *pxListWasEmpty == pdFALSE )
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{
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xNextExpireTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxCurrentTimerList );
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}
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else
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{
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/* Ensure the task unblocks when the tick count rolls over. */
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xNextExpireTime = ( portTickType ) 0U;
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}
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return xNextExpireTime;
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}
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/*-----------------------------------------------------------*/
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static portTickType prvSampleTimeNow( portBASE_TYPE *pxTimerListsWereSwitched )
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{
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portTickType xTimeNow;
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static portTickType xLastTime = ( portTickType ) 0U;
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xTimeNow = xTaskGetTickCount();
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if( xTimeNow < xLastTime )
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{
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prvSwitchTimerLists( xTimeNow, xLastTime );
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*pxTimerListsWereSwitched = pdTRUE;
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}
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else
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{
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*pxTimerListsWereSwitched = pdFALSE;
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}
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xLastTime = xTimeNow;
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return xTimeNow;
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}
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/*-----------------------------------------------------------*/
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static void prvInsertTimerInActiveList( xTIMER *pxTimer, portTickType xNextExpiryTime, portTickType xTimeNow )
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{
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listSET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ), xNextExpiryTime );
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listSET_LIST_ITEM_OWNER( &( pxTimer->xTimerListItem ), pxTimer );
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if( xNextExpiryTime < xAssumedTimeNow )
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if( xNextExpiryTime < xTimeNow )
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{
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vListInsert( pxOverflowTimerList, &( pxTimer->xTimerListItem ) );
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}
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@ -343,11 +397,16 @@ static void prvInsertTimerInActiveList( xTIMER *pxTimer, portTickType xNextExpir
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}
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/*-----------------------------------------------------------*/
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static void prvProcessReceivedCommands( portTickType xAssumedTimeNow )
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static void prvProcessReceivedCommands( void )
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{
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xTIMER_MESSAGE xMessage;
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xTIMER *pxTimer;
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portBASE_TYPE xSwitchListsOnExit = pdFALSE;
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portBASE_TYPE xTimerListsWereSwitched;
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portTickType xTimeNow;
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/* In this case the xTimerListsWereSwitched parameter is not used, but it
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must be present in the function call. */
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xTimeNow = prvSampleTimeNow( &xTimerListsWereSwitched );
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while( xQueueReceive( xTimerQueue, &xMessage, tmrNO_DELAY ) != pdFAIL )
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{
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@ -369,7 +428,7 @@ portBASE_TYPE xSwitchListsOnExit = pdFALSE;
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{
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case tmrCOMMAND_START :
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/* Start or restart a timer. */
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prvInsertTimerInActiveList( pxTimer, xAssumedTimeNow + pxTimer->xTimerPeriodInTicks, xAssumedTimeNow );
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prvInsertTimerInActiveList( pxTimer, xTimeNow + pxTimer->xTimerPeriodInTicks, xTimeNow );
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break;
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case tmrCOMMAND_STOP :
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@ -379,7 +438,7 @@ portBASE_TYPE xSwitchListsOnExit = pdFALSE;
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case tmrCOMMAND_CHANGE_PERIOD :
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pxTimer->xTimerPeriodInTicks = xMessage.xMessageValue;
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prvInsertTimerInActiveList( pxTimer, ( xAssumedTimeNow + pxTimer->xTimerPeriodInTicks ), xAssumedTimeNow );
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prvInsertTimerInActiveList( pxTimer, ( xTimeNow + pxTimer->xTimerPeriodInTicks ), xTimeNow );
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break;
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case tmrCOMMAND_DELETE :
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@ -387,39 +446,32 @@ portBASE_TYPE xSwitchListsOnExit = pdFALSE;
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just free up the memory. */
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vPortFree( pxTimer );
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break;
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case trmCOMMAND_PROCESS_TIMER_OVERFLOW :
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/* Hold this pending until all the other messages have been
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processed. */
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xSwitchListsOnExit = pdTRUE;
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break;
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default :
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/* Don't expect to get here. */
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break;
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}
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}
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if( xSwitchListsOnExit == pdTRUE )
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{
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prvSwitchTimerLists( xAssumedTimeNow );
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}
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}
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/*-----------------------------------------------------------*/
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static void prvSwitchTimerLists( portTickType xAssumedTimeNow )
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static void prvSwitchTimerLists( portTickType xTimeNow, portTickType xLastTime )
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{
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portTickType xNextExpireTime;
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xList *pxTemp;
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/* The tick count has overflowed. The timer lists must be switched.
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If there are any timers still referenced from the current timer list
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then they must have expired and should be processed before the lists
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/* Remove compiler warnings if configASSERT() is not defined. */
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( void ) xLastTime;
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/* The tick count has overflowed. The timer lists must be switched.
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If there are any timers still referenced from the current timer list
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then they must have expired and should be processed before the lists
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are switched. */
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while( listLIST_IS_EMPTY( pxCurrentTimerList ) == pdFALSE )
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{
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xNextExpireTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxCurrentTimerList );
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prvProcessExpiredTimer( xNextExpireTime, xAssumedTimeNow );
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configASSERT( ( xNextExpireTime >= xLastTime ) );
|
||||
prvProcessExpiredTimer( xNextExpireTime, xTimeNow );
|
||||
}
|
||||
|
||||
pxTemp = pxCurrentTimerList;
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue