2 * FreeRTOS Kernel <DEVELOPMENT BRANCH>
3 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
5 * SPDX-License-Identifier: MIT
7 * Permission is hereby granted, free of charge, to any person obtaining a copy of
8 * this software and associated documentation files (the "Software"), to deal in
9 * the Software without restriction, including without limitation the rights to
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11 * the Software, and to permit persons to whom the Software is furnished to do so,
12 * subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in all
15 * copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
19 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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24 * https://www.FreeRTOS.org
25 * https://github.com/FreeRTOS
29 /* Standard includes. */
32 /* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
33 * all the API functions to use the MPU wrappers. That should only be done when
34 * task.h is included from an application file. */
35 #define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
42 #if ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 0 )
43 #error configUSE_TIMERS must be set to 1 to make the xTimerPendFunctionCall() function available.
46 /* Lint e9021, e961 and e750 are suppressed as a MISRA exception justified
47 * because the MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be defined
48 * for the header files above, but not in this file, in order to generate the
49 * correct privileged Vs unprivileged linkage and placement. */
50 #undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*lint !e9021 !e961 !e750. */
53 /* This entire source file will be skipped if the application is not configured
54 * to include software timer functionality. This #if is closed at the very bottom
55 * of this file. If you want to include software timer functionality then ensure
56 * configUSE_TIMERS is set to 1 in FreeRTOSConfig.h. */
57 #if ( configUSE_TIMERS == 1 )
59 /* Misc definitions. */
60 #define tmrNO_DELAY ( ( TickType_t ) 0U )
61 #define tmrMAX_TIME_BEFORE_OVERFLOW ( ( TickType_t ) -1 )
63 /* The name assigned to the timer service task. This can be overridden by
64 * defining trmTIMER_SERVICE_TASK_NAME in FreeRTOSConfig.h. */
65 #ifndef configTIMER_SERVICE_TASK_NAME
66 #define configTIMER_SERVICE_TASK_NAME "Tmr Svc"
69 /* Bit definitions used in the ucStatus member of a timer structure. */
70 #define tmrSTATUS_IS_ACTIVE ( ( uint8_t ) 0x01 )
71 #define tmrSTATUS_IS_STATICALLY_ALLOCATED ( ( uint8_t ) 0x02 )
72 #define tmrSTATUS_IS_AUTORELOAD ( ( uint8_t ) 0x04 )
74 /* The definition of the timers themselves. */
75 typedef struct tmrTimerControl /* The old naming convention is used to prevent breaking kernel aware debuggers. */
77 const char * pcTimerName; /**< Text name. This is not used by the kernel, it is included simply to make debugging easier. */ /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
78 ListItem_t xTimerListItem; /**< Standard linked list item as used by all kernel features for event management. */
79 TickType_t xTimerPeriodInTicks; /**< How quickly and often the timer expires. */
80 void * pvTimerID; /**< An ID to identify the timer. This allows the timer to be identified when the same callback is used for multiple timers. */
81 TimerCallbackFunction_t pxCallbackFunction; /**< The function that will be called when the timer expires. */
82 #if ( configUSE_TRACE_FACILITY == 1 )
83 UBaseType_t uxTimerNumber; /**< An ID assigned by trace tools such as FreeRTOS+Trace */
85 uint8_t ucStatus; /**< Holds bits to say if the timer was statically allocated or not, and if it is active or not. */
88 /* The old xTIMER name is maintained above then typedefed to the new Timer_t
89 * name below to enable the use of older kernel aware debuggers. */
90 typedef xTIMER Timer_t;
92 /* The definition of messages that can be sent and received on the timer queue.
93 * Two types of message can be queued - messages that manipulate a software timer,
94 * and messages that request the execution of a non-timer related callback. The
95 * two message types are defined in two separate structures, xTimerParametersType
96 * and xCallbackParametersType respectively. */
97 typedef struct tmrTimerParameters
99 TickType_t xMessageValue; /**< An optional value used by a subset of commands, for example, when changing the period of a timer. */
100 Timer_t * pxTimer; /**< The timer to which the command will be applied. */
104 typedef struct tmrCallbackParameters
106 PendedFunction_t pxCallbackFunction; /* << The callback function to execute. */
107 void * pvParameter1; /* << The value that will be used as the callback functions first parameter. */
108 uint32_t ulParameter2; /* << The value that will be used as the callback functions second parameter. */
109 } CallbackParameters_t;
111 /* The structure that contains the two message types, along with an identifier
112 * that is used to determine which message type is valid. */
113 typedef struct tmrTimerQueueMessage
115 BaseType_t xMessageID; /**< The command being sent to the timer service task. */
118 TimerParameter_t xTimerParameters;
120 /* Don't include xCallbackParameters if it is not going to be used as
121 * it makes the structure (and therefore the timer queue) larger. */
122 #if ( INCLUDE_xTimerPendFunctionCall == 1 )
123 CallbackParameters_t xCallbackParameters;
124 #endif /* INCLUDE_xTimerPendFunctionCall */
126 } DaemonTaskMessage_t;
128 /*lint -save -e956 A manual analysis and inspection has been used to determine
129 * which static variables must be declared volatile. */
131 /* The list in which active timers are stored. Timers are referenced in expire
132 * time order, with the nearest expiry time at the front of the list. Only the
133 * timer service task is allowed to access these lists.
134 * xActiveTimerList1 and xActiveTimerList2 could be at function scope but that
135 * breaks some kernel aware debuggers, and debuggers that reply on removing the
136 * static qualifier. */
137 PRIVILEGED_DATA static List_t xActiveTimerList1;
138 PRIVILEGED_DATA static List_t xActiveTimerList2;
139 PRIVILEGED_DATA static List_t * pxCurrentTimerList;
140 PRIVILEGED_DATA static List_t * pxOverflowTimerList;
142 /* A queue that is used to send commands to the timer service task. */
143 PRIVILEGED_DATA static QueueHandle_t xTimerQueue = NULL;
144 PRIVILEGED_DATA static TaskHandle_t xTimerTaskHandle = NULL;
148 /*-----------------------------------------------------------*/
151 * Initialise the infrastructure used by the timer service task if it has not
152 * been initialised already.
154 static void prvCheckForValidListAndQueue( void ) PRIVILEGED_FUNCTION;
157 * The timer service task (daemon). Timer functionality is controlled by this
158 * task. Other tasks communicate with the timer service task using the
161 static portTASK_FUNCTION_PROTO( prvTimerTask, pvParameters ) portNORETURN PRIVILEGED_FUNCTION;
164 * Called by the timer service task to interpret and process a command it
165 * received on the timer queue.
167 static void prvProcessReceivedCommands( void ) PRIVILEGED_FUNCTION;
170 * Insert the timer into either xActiveTimerList1, or xActiveTimerList2,
171 * depending on if the expire time causes a timer counter overflow.
173 static BaseType_t prvInsertTimerInActiveList( Timer_t * const pxTimer,
174 const TickType_t xNextExpiryTime,
175 const TickType_t xTimeNow,
176 const TickType_t xCommandTime ) PRIVILEGED_FUNCTION;
179 * Reload the specified auto-reload timer. If the reloading is backlogged,
180 * clear the backlog, calling the callback for each additional reload. When
181 * this function returns, the next expiry time is after xTimeNow.
183 static void prvReloadTimer( Timer_t * const pxTimer,
184 TickType_t xExpiredTime,
185 const TickType_t xTimeNow ) PRIVILEGED_FUNCTION;
188 * An active timer has reached its expire time. Reload the timer if it is an
189 * auto-reload timer, then call its callback.
191 static void prvProcessExpiredTimer( const TickType_t xNextExpireTime,
192 const TickType_t xTimeNow ) PRIVILEGED_FUNCTION;
195 * The tick count has overflowed. Switch the timer lists after ensuring the
196 * current timer list does not still reference some timers.
198 static void prvSwitchTimerLists( void ) PRIVILEGED_FUNCTION;
201 * Obtain the current tick count, setting *pxTimerListsWereSwitched to pdTRUE
202 * if a tick count overflow occurred since prvSampleTimeNow() was last called.
204 static TickType_t prvSampleTimeNow( BaseType_t * const pxTimerListsWereSwitched ) PRIVILEGED_FUNCTION;
207 * If the timer list contains any active timers then return the expire time of
208 * the timer that will expire first and set *pxListWasEmpty to false. If the
209 * timer list does not contain any timers then return 0 and set *pxListWasEmpty
212 static TickType_t prvGetNextExpireTime( BaseType_t * const pxListWasEmpty ) PRIVILEGED_FUNCTION;
215 * If a timer has expired, process it. Otherwise, block the timer service task
216 * until either a timer does expire or a command is received.
218 static void prvProcessTimerOrBlockTask( const TickType_t xNextExpireTime,
219 BaseType_t xListWasEmpty ) PRIVILEGED_FUNCTION;
222 * Called after a Timer_t structure has been allocated either statically or
223 * dynamically to fill in the structure's members.
225 static void prvInitialiseNewTimer( const char * const pcTimerName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
226 const TickType_t xTimerPeriodInTicks,
227 const BaseType_t xAutoReload,
228 void * const pvTimerID,
229 TimerCallbackFunction_t pxCallbackFunction,
230 Timer_t * pxNewTimer ) PRIVILEGED_FUNCTION;
231 /*-----------------------------------------------------------*/
233 BaseType_t xTimerCreateTimerTask( void )
235 BaseType_t xReturn = pdFAIL;
237 /* This function is called when the scheduler is started if
238 * configUSE_TIMERS is set to 1. Check that the infrastructure used by the
239 * timer service task has been created/initialised. If timers have already
240 * been created then the initialisation will already have been performed. */
241 prvCheckForValidListAndQueue();
243 if( xTimerQueue != NULL )
245 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
247 StaticTask_t * pxTimerTaskTCBBuffer = NULL;
248 StackType_t * pxTimerTaskStackBuffer = NULL;
249 uint32_t ulTimerTaskStackSize;
251 vApplicationGetTimerTaskMemory( &pxTimerTaskTCBBuffer, &pxTimerTaskStackBuffer, &ulTimerTaskStackSize );
252 xTimerTaskHandle = xTaskCreateStatic( prvTimerTask,
253 configTIMER_SERVICE_TASK_NAME,
254 ulTimerTaskStackSize,
256 ( ( UBaseType_t ) configTIMER_TASK_PRIORITY ) | portPRIVILEGE_BIT,
257 pxTimerTaskStackBuffer,
258 pxTimerTaskTCBBuffer );
260 if( xTimerTaskHandle != NULL )
265 #else /* if ( configSUPPORT_STATIC_ALLOCATION == 1 ) */
267 xReturn = xTaskCreate( prvTimerTask,
268 configTIMER_SERVICE_TASK_NAME,
269 configTIMER_TASK_STACK_DEPTH,
271 ( ( UBaseType_t ) configTIMER_TASK_PRIORITY ) | portPRIVILEGE_BIT,
274 #endif /* configSUPPORT_STATIC_ALLOCATION */
278 mtCOVERAGE_TEST_MARKER();
281 configASSERT( xReturn );
284 /*-----------------------------------------------------------*/
286 #if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
288 TimerHandle_t xTimerCreate( const char * const pcTimerName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
289 const TickType_t xTimerPeriodInTicks,
290 const BaseType_t xAutoReload,
291 void * const pvTimerID,
292 TimerCallbackFunction_t pxCallbackFunction )
294 Timer_t * pxNewTimer;
296 pxNewTimer = ( Timer_t * ) pvPortMalloc( sizeof( Timer_t ) ); /*lint !e9087 !e9079 All values returned by pvPortMalloc() have at least the alignment required by the MCU's stack, and the first member of Timer_t is always a pointer to the timer's mame. */
298 if( pxNewTimer != NULL )
300 /* Status is thus far zero as the timer is not created statically
301 * and has not been started. The auto-reload bit may get set in
302 * prvInitialiseNewTimer. */
303 pxNewTimer->ucStatus = 0x00;
304 prvInitialiseNewTimer( pcTimerName, xTimerPeriodInTicks, xAutoReload, pvTimerID, pxCallbackFunction, pxNewTimer );
310 #endif /* configSUPPORT_DYNAMIC_ALLOCATION */
311 /*-----------------------------------------------------------*/
313 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
315 TimerHandle_t xTimerCreateStatic( const char * const pcTimerName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
316 const TickType_t xTimerPeriodInTicks,
317 const BaseType_t xAutoReload,
318 void * const pvTimerID,
319 TimerCallbackFunction_t pxCallbackFunction,
320 StaticTimer_t * pxTimerBuffer )
322 Timer_t * pxNewTimer;
324 #if ( configASSERT_DEFINED == 1 )
326 /* Sanity check that the size of the structure used to declare a
327 * variable of type StaticTimer_t equals the size of the real timer
329 volatile size_t xSize = sizeof( StaticTimer_t );
330 configASSERT( xSize == sizeof( Timer_t ) );
331 ( void ) xSize; /* Keeps lint quiet when configASSERT() is not defined. */
333 #endif /* configASSERT_DEFINED */
335 /* A pointer to a StaticTimer_t structure MUST be provided, use it. */
336 configASSERT( pxTimerBuffer );
337 pxNewTimer = ( Timer_t * ) pxTimerBuffer; /*lint !e740 !e9087 StaticTimer_t is a pointer to a Timer_t, so guaranteed to be aligned and sized correctly (checked by an assert()), so this is safe. */
339 if( pxNewTimer != NULL )
341 /* Timers can be created statically or dynamically so note this
342 * timer was created statically in case it is later deleted. The
343 * auto-reload bit may get set in prvInitialiseNewTimer(). */
344 pxNewTimer->ucStatus = tmrSTATUS_IS_STATICALLY_ALLOCATED;
346 prvInitialiseNewTimer( pcTimerName, xTimerPeriodInTicks, xAutoReload, pvTimerID, pxCallbackFunction, pxNewTimer );
352 #endif /* configSUPPORT_STATIC_ALLOCATION */
353 /*-----------------------------------------------------------*/
355 static void prvInitialiseNewTimer( const char * const pcTimerName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
356 const TickType_t xTimerPeriodInTicks,
357 const BaseType_t xAutoReload,
358 void * const pvTimerID,
359 TimerCallbackFunction_t pxCallbackFunction,
360 Timer_t * pxNewTimer )
362 /* 0 is not a valid value for xTimerPeriodInTicks. */
363 configASSERT( ( xTimerPeriodInTicks > 0 ) );
365 /* Ensure the infrastructure used by the timer service task has been
366 * created/initialised. */
367 prvCheckForValidListAndQueue();
369 /* Initialise the timer structure members using the function
371 pxNewTimer->pcTimerName = pcTimerName;
372 pxNewTimer->xTimerPeriodInTicks = xTimerPeriodInTicks;
373 pxNewTimer->pvTimerID = pvTimerID;
374 pxNewTimer->pxCallbackFunction = pxCallbackFunction;
375 vListInitialiseItem( &( pxNewTimer->xTimerListItem ) );
377 if( xAutoReload != pdFALSE )
379 pxNewTimer->ucStatus |= tmrSTATUS_IS_AUTORELOAD;
382 traceTIMER_CREATE( pxNewTimer );
384 /*-----------------------------------------------------------*/
386 BaseType_t xTimerGenericCommand( TimerHandle_t xTimer,
387 const BaseType_t xCommandID,
388 const TickType_t xOptionalValue,
389 BaseType_t * const pxHigherPriorityTaskWoken,
390 const TickType_t xTicksToWait )
392 BaseType_t xReturn = pdFAIL;
393 DaemonTaskMessage_t xMessage;
395 configASSERT( xTimer );
397 /* Send a message to the timer service task to perform a particular action
398 * on a particular timer definition. */
399 if( xTimerQueue != NULL )
401 /* Send a command to the timer service task to start the xTimer timer. */
402 xMessage.xMessageID = xCommandID;
403 xMessage.u.xTimerParameters.xMessageValue = xOptionalValue;
404 xMessage.u.xTimerParameters.pxTimer = xTimer;
406 if( xCommandID < tmrFIRST_FROM_ISR_COMMAND )
408 if( xTaskGetSchedulerState() == taskSCHEDULER_RUNNING )
410 xReturn = xQueueSendToBack( xTimerQueue, &xMessage, xTicksToWait );
414 xReturn = xQueueSendToBack( xTimerQueue, &xMessage, tmrNO_DELAY );
419 xReturn = xQueueSendToBackFromISR( xTimerQueue, &xMessage, pxHigherPriorityTaskWoken );
422 traceTIMER_COMMAND_SEND( xTimer, xCommandID, xOptionalValue, xReturn );
426 mtCOVERAGE_TEST_MARKER();
431 /*-----------------------------------------------------------*/
433 TaskHandle_t xTimerGetTimerDaemonTaskHandle( void )
435 /* If xTimerGetTimerDaemonTaskHandle() is called before the scheduler has been
436 * started, then xTimerTaskHandle will be NULL. */
437 configASSERT( ( xTimerTaskHandle != NULL ) );
438 return xTimerTaskHandle;
440 /*-----------------------------------------------------------*/
442 TickType_t xTimerGetPeriod( TimerHandle_t xTimer )
444 Timer_t * pxTimer = xTimer;
446 configASSERT( xTimer );
447 return pxTimer->xTimerPeriodInTicks;
449 /*-----------------------------------------------------------*/
451 void vTimerSetReloadMode( TimerHandle_t xTimer,
452 const BaseType_t xAutoReload )
454 Timer_t * pxTimer = xTimer;
456 configASSERT( xTimer );
457 taskENTER_CRITICAL();
459 if( xAutoReload != pdFALSE )
461 pxTimer->ucStatus |= tmrSTATUS_IS_AUTORELOAD;
465 pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_AUTORELOAD );
470 /*-----------------------------------------------------------*/
472 BaseType_t xTimerGetReloadMode( TimerHandle_t xTimer )
474 Timer_t * pxTimer = xTimer;
477 configASSERT( xTimer );
478 taskENTER_CRITICAL();
480 if( ( pxTimer->ucStatus & tmrSTATUS_IS_AUTORELOAD ) == 0 )
482 /* Not an auto-reload timer. */
487 /* Is an auto-reload timer. */
496 UBaseType_t uxTimerGetReloadMode( TimerHandle_t xTimer )
498 return ( UBaseType_t ) xTimerGetReloadMode( xTimer );
500 /*-----------------------------------------------------------*/
502 TickType_t xTimerGetExpiryTime( TimerHandle_t xTimer )
504 Timer_t * pxTimer = xTimer;
507 configASSERT( xTimer );
508 xReturn = listGET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ) );
511 /*-----------------------------------------------------------*/
513 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
514 BaseType_t xTimerGetStaticBuffer( TimerHandle_t xTimer,
515 StaticTimer_t ** ppxTimerBuffer )
518 Timer_t * pxTimer = xTimer;
520 configASSERT( ppxTimerBuffer != NULL );
522 if( ( pxTimer->ucStatus & tmrSTATUS_IS_STATICALLY_ALLOCATED ) != 0 )
524 *ppxTimerBuffer = ( StaticTimer_t * ) pxTimer;
534 #endif /* configSUPPORT_STATIC_ALLOCATION */
535 /*-----------------------------------------------------------*/
537 const char * pcTimerGetName( TimerHandle_t xTimer ) /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
539 Timer_t * pxTimer = xTimer;
541 configASSERT( xTimer );
542 return pxTimer->pcTimerName;
544 /*-----------------------------------------------------------*/
546 static void prvReloadTimer( Timer_t * const pxTimer,
547 TickType_t xExpiredTime,
548 const TickType_t xTimeNow )
550 /* Insert the timer into the appropriate list for the next expiry time.
551 * If the next expiry time has already passed, advance the expiry time,
552 * call the callback function, and try again. */
553 while( prvInsertTimerInActiveList( pxTimer, ( xExpiredTime + pxTimer->xTimerPeriodInTicks ), xTimeNow, xExpiredTime ) != pdFALSE )
555 /* Advance the expiry time. */
556 xExpiredTime += pxTimer->xTimerPeriodInTicks;
558 /* Call the timer callback. */
559 traceTIMER_EXPIRED( pxTimer );
560 pxTimer->pxCallbackFunction( ( TimerHandle_t ) pxTimer );
563 /*-----------------------------------------------------------*/
565 static void prvProcessExpiredTimer( const TickType_t xNextExpireTime,
566 const TickType_t xTimeNow )
568 Timer_t * const pxTimer = ( Timer_t * ) listGET_OWNER_OF_HEAD_ENTRY( pxCurrentTimerList ); /*lint !e9087 !e9079 void * is used as this macro is used with tasks too. Alignment is known to be fine as the type of the pointer stored and retrieved is the same. */
570 /* Remove the timer from the list of active timers. A check has already
571 * been performed to ensure the list is not empty. */
573 ( void ) uxListRemove( &( pxTimer->xTimerListItem ) );
575 /* If the timer is an auto-reload timer then calculate the next
576 * expiry time and re-insert the timer in the list of active timers. */
577 if( ( pxTimer->ucStatus & tmrSTATUS_IS_AUTORELOAD ) != 0 )
579 prvReloadTimer( pxTimer, xNextExpireTime, xTimeNow );
583 pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
586 /* Call the timer callback. */
587 traceTIMER_EXPIRED( pxTimer );
588 pxTimer->pxCallbackFunction( ( TimerHandle_t ) pxTimer );
590 /*-----------------------------------------------------------*/
592 static portTASK_FUNCTION( prvTimerTask, pvParameters )
594 TickType_t xNextExpireTime;
595 BaseType_t xListWasEmpty;
597 /* Just to avoid compiler warnings. */
598 ( void ) pvParameters;
600 #if ( configUSE_DAEMON_TASK_STARTUP_HOOK == 1 )
602 /* Allow the application writer to execute some code in the context of
603 * this task at the point the task starts executing. This is useful if the
604 * application includes initialisation code that would benefit from
605 * executing after the scheduler has been started. */
606 vApplicationDaemonTaskStartupHook();
608 #endif /* configUSE_DAEMON_TASK_STARTUP_HOOK */
612 /* Query the timers list to see if it contains any timers, and if so,
613 * obtain the time at which the next timer will expire. */
614 xNextExpireTime = prvGetNextExpireTime( &xListWasEmpty );
616 /* If a timer has expired, process it. Otherwise, block this task
617 * until either a timer does expire, or a command is received. */
618 prvProcessTimerOrBlockTask( xNextExpireTime, xListWasEmpty );
620 /* Empty the command queue. */
621 prvProcessReceivedCommands();
624 /*-----------------------------------------------------------*/
626 static void prvProcessTimerOrBlockTask( const TickType_t xNextExpireTime,
627 BaseType_t xListWasEmpty )
630 BaseType_t xTimerListsWereSwitched;
634 /* Obtain the time now to make an assessment as to whether the timer
635 * has expired or not. If obtaining the time causes the lists to switch
636 * then don't process this timer as any timers that remained in the list
637 * when the lists were switched will have been processed within the
638 * prvSampleTimeNow() function. */
639 xTimeNow = prvSampleTimeNow( &xTimerListsWereSwitched );
641 if( xTimerListsWereSwitched == pdFALSE )
643 /* The tick count has not overflowed, has the timer expired? */
644 if( ( xListWasEmpty == pdFALSE ) && ( xNextExpireTime <= xTimeNow ) )
646 ( void ) xTaskResumeAll();
647 prvProcessExpiredTimer( xNextExpireTime, xTimeNow );
651 /* The tick count has not overflowed, and the next expire
652 * time has not been reached yet. This task should therefore
653 * block to wait for the next expire time or a command to be
654 * received - whichever comes first. The following line cannot
655 * be reached unless xNextExpireTime > xTimeNow, except in the
656 * case when the current timer list is empty. */
657 if( xListWasEmpty != pdFALSE )
659 /* The current timer list is empty - is the overflow list
661 xListWasEmpty = listLIST_IS_EMPTY( pxOverflowTimerList );
664 vQueueWaitForMessageRestricted( xTimerQueue, ( xNextExpireTime - xTimeNow ), xListWasEmpty );
666 if( xTaskResumeAll() == pdFALSE )
668 /* Yield to wait for either a command to arrive, or the
669 * block time to expire. If a command arrived between the
670 * critical section being exited and this yield then the yield
671 * will not cause the task to block. */
672 portYIELD_WITHIN_API();
676 mtCOVERAGE_TEST_MARKER();
682 ( void ) xTaskResumeAll();
686 /*-----------------------------------------------------------*/
688 static TickType_t prvGetNextExpireTime( BaseType_t * const pxListWasEmpty )
690 TickType_t xNextExpireTime;
692 /* Timers are listed in expiry time order, with the head of the list
693 * referencing the task that will expire first. Obtain the time at which
694 * the timer with the nearest expiry time will expire. If there are no
695 * active timers then just set the next expire time to 0. That will cause
696 * this task to unblock when the tick count overflows, at which point the
697 * timer lists will be switched and the next expiry time can be
699 *pxListWasEmpty = listLIST_IS_EMPTY( pxCurrentTimerList );
701 if( *pxListWasEmpty == pdFALSE )
703 xNextExpireTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxCurrentTimerList );
707 /* Ensure the task unblocks when the tick count rolls over. */
708 xNextExpireTime = ( TickType_t ) 0U;
711 return xNextExpireTime;
713 /*-----------------------------------------------------------*/
715 static TickType_t prvSampleTimeNow( BaseType_t * const pxTimerListsWereSwitched )
718 PRIVILEGED_DATA static TickType_t xLastTime = ( TickType_t ) 0U; /*lint !e956 Variable is only accessible to one task. */
720 xTimeNow = xTaskGetTickCount();
722 if( xTimeNow < xLastTime )
724 prvSwitchTimerLists();
725 *pxTimerListsWereSwitched = pdTRUE;
729 *pxTimerListsWereSwitched = pdFALSE;
732 xLastTime = xTimeNow;
736 /*-----------------------------------------------------------*/
738 static BaseType_t prvInsertTimerInActiveList( Timer_t * const pxTimer,
739 const TickType_t xNextExpiryTime,
740 const TickType_t xTimeNow,
741 const TickType_t xCommandTime )
743 BaseType_t xProcessTimerNow = pdFALSE;
745 listSET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ), xNextExpiryTime );
746 listSET_LIST_ITEM_OWNER( &( pxTimer->xTimerListItem ), pxTimer );
748 if( xNextExpiryTime <= xTimeNow )
750 /* Has the expiry time elapsed between the command to start/reset a
751 * timer was issued, and the time the command was processed? */
752 if( ( ( TickType_t ) ( xTimeNow - xCommandTime ) ) >= pxTimer->xTimerPeriodInTicks ) /*lint !e961 MISRA exception as the casts are only redundant for some ports. */
754 /* The time between a command being issued and the command being
755 * processed actually exceeds the timers period. */
756 xProcessTimerNow = pdTRUE;
760 vListInsert( pxOverflowTimerList, &( pxTimer->xTimerListItem ) );
765 if( ( xTimeNow < xCommandTime ) && ( xNextExpiryTime >= xCommandTime ) )
767 /* If, since the command was issued, the tick count has overflowed
768 * but the expiry time has not, then the timer must have already passed
769 * its expiry time and should be processed immediately. */
770 xProcessTimerNow = pdTRUE;
774 vListInsert( pxCurrentTimerList, &( pxTimer->xTimerListItem ) );
778 return xProcessTimerNow;
780 /*-----------------------------------------------------------*/
782 static void prvProcessReceivedCommands( void )
784 DaemonTaskMessage_t xMessage;
786 BaseType_t xTimerListsWereSwitched;
789 while( xQueueReceive( xTimerQueue, &xMessage, tmrNO_DELAY ) != pdFAIL ) /*lint !e603 xMessage does not have to be initialised as it is passed out, not in, and it is not used unless xQueueReceive() returns pdTRUE. */
791 #if ( INCLUDE_xTimerPendFunctionCall == 1 )
793 /* Negative commands are pended function calls rather than timer
795 if( xMessage.xMessageID < ( BaseType_t ) 0 )
797 const CallbackParameters_t * const pxCallback = &( xMessage.u.xCallbackParameters );
799 /* The timer uses the xCallbackParameters member to request a
800 * callback be executed. Check the callback is not NULL. */
801 configASSERT( pxCallback );
803 /* Call the function. */
804 pxCallback->pxCallbackFunction( pxCallback->pvParameter1, pxCallback->ulParameter2 );
808 mtCOVERAGE_TEST_MARKER();
811 #endif /* INCLUDE_xTimerPendFunctionCall */
813 /* Commands that are positive are timer commands rather than pended
815 if( xMessage.xMessageID >= ( BaseType_t ) 0 )
817 /* The messages uses the xTimerParameters member to work on a
819 pxTimer = xMessage.u.xTimerParameters.pxTimer;
821 if( listIS_CONTAINED_WITHIN( NULL, &( pxTimer->xTimerListItem ) ) == pdFALSE ) /*lint !e961. The cast is only redundant when NULL is passed into the macro. */
823 /* The timer is in a list, remove it. */
824 ( void ) uxListRemove( &( pxTimer->xTimerListItem ) );
828 mtCOVERAGE_TEST_MARKER();
831 traceTIMER_COMMAND_RECEIVED( pxTimer, xMessage.xMessageID, xMessage.u.xTimerParameters.xMessageValue );
833 /* In this case the xTimerListsWereSwitched parameter is not used, but
834 * it must be present in the function call. prvSampleTimeNow() must be
835 * called after the message is received from xTimerQueue so there is no
836 * possibility of a higher priority task adding a message to the message
837 * queue with a time that is ahead of the timer daemon task (because it
838 * pre-empted the timer daemon task after the xTimeNow value was set). */
839 xTimeNow = prvSampleTimeNow( &xTimerListsWereSwitched );
841 switch( xMessage.xMessageID )
843 case tmrCOMMAND_START:
844 case tmrCOMMAND_START_FROM_ISR:
845 case tmrCOMMAND_RESET:
846 case tmrCOMMAND_RESET_FROM_ISR:
847 /* Start or restart a timer. */
848 pxTimer->ucStatus |= tmrSTATUS_IS_ACTIVE;
850 if( prvInsertTimerInActiveList( pxTimer, xMessage.u.xTimerParameters.xMessageValue + pxTimer->xTimerPeriodInTicks, xTimeNow, xMessage.u.xTimerParameters.xMessageValue ) != pdFALSE )
852 /* The timer expired before it was added to the active
853 * timer list. Process it now. */
854 if( ( pxTimer->ucStatus & tmrSTATUS_IS_AUTORELOAD ) != 0 )
856 prvReloadTimer( pxTimer, xMessage.u.xTimerParameters.xMessageValue + pxTimer->xTimerPeriodInTicks, xTimeNow );
860 pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
863 /* Call the timer callback. */
864 traceTIMER_EXPIRED( pxTimer );
865 pxTimer->pxCallbackFunction( ( TimerHandle_t ) pxTimer );
869 mtCOVERAGE_TEST_MARKER();
874 case tmrCOMMAND_STOP:
875 case tmrCOMMAND_STOP_FROM_ISR:
876 /* The timer has already been removed from the active list. */
877 pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
880 case tmrCOMMAND_CHANGE_PERIOD:
881 case tmrCOMMAND_CHANGE_PERIOD_FROM_ISR:
882 pxTimer->ucStatus |= tmrSTATUS_IS_ACTIVE;
883 pxTimer->xTimerPeriodInTicks = xMessage.u.xTimerParameters.xMessageValue;
884 configASSERT( ( pxTimer->xTimerPeriodInTicks > 0 ) );
886 /* The new period does not really have a reference, and can
887 * be longer or shorter than the old one. The command time is
888 * therefore set to the current time, and as the period cannot
889 * be zero the next expiry time can only be in the future,
890 * meaning (unlike for the xTimerStart() case above) there is
891 * no fail case that needs to be handled here. */
892 ( void ) prvInsertTimerInActiveList( pxTimer, ( xTimeNow + pxTimer->xTimerPeriodInTicks ), xTimeNow, xTimeNow );
895 case tmrCOMMAND_DELETE:
896 #if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
898 /* The timer has already been removed from the active list,
899 * just free up the memory if the memory was dynamically
901 if( ( pxTimer->ucStatus & tmrSTATUS_IS_STATICALLY_ALLOCATED ) == ( uint8_t ) 0 )
903 vPortFree( pxTimer );
907 pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
910 #else /* if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) */
912 /* If dynamic allocation is not enabled, the memory
913 * could not have been dynamically allocated. So there is
914 * no need to free the memory - just mark the timer as
916 pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
918 #endif /* configSUPPORT_DYNAMIC_ALLOCATION */
922 /* Don't expect to get here. */
928 /*-----------------------------------------------------------*/
930 static void prvSwitchTimerLists( void )
932 TickType_t xNextExpireTime;
935 /* The tick count has overflowed. The timer lists must be switched.
936 * If there are any timers still referenced from the current timer list
937 * then they must have expired and should be processed before the lists
939 while( listLIST_IS_EMPTY( pxCurrentTimerList ) == pdFALSE )
941 xNextExpireTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxCurrentTimerList );
943 /* Process the expired timer. For auto-reload timers, be careful to
944 * process only expirations that occur on the current list. Further
945 * expirations must wait until after the lists are switched. */
946 prvProcessExpiredTimer( xNextExpireTime, tmrMAX_TIME_BEFORE_OVERFLOW );
949 pxTemp = pxCurrentTimerList;
950 pxCurrentTimerList = pxOverflowTimerList;
951 pxOverflowTimerList = pxTemp;
953 /*-----------------------------------------------------------*/
955 static void prvCheckForValidListAndQueue( void )
957 /* Check that the list from which active timers are referenced, and the
958 * queue used to communicate with the timer service, have been
960 taskENTER_CRITICAL();
962 if( xTimerQueue == NULL )
964 vListInitialise( &xActiveTimerList1 );
965 vListInitialise( &xActiveTimerList2 );
966 pxCurrentTimerList = &xActiveTimerList1;
967 pxOverflowTimerList = &xActiveTimerList2;
969 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
971 /* The timer queue is allocated statically in case
972 * configSUPPORT_DYNAMIC_ALLOCATION is 0. */
973 PRIVILEGED_DATA static StaticQueue_t xStaticTimerQueue; /*lint !e956 Ok to declare in this manner to prevent additional conditional compilation guards in other locations. */
974 PRIVILEGED_DATA static uint8_t ucStaticTimerQueueStorage[ ( size_t ) configTIMER_QUEUE_LENGTH * sizeof( DaemonTaskMessage_t ) ]; /*lint !e956 Ok to declare in this manner to prevent additional conditional compilation guards in other locations. */
976 xTimerQueue = xQueueCreateStatic( ( UBaseType_t ) configTIMER_QUEUE_LENGTH, ( UBaseType_t ) sizeof( DaemonTaskMessage_t ), &( ucStaticTimerQueueStorage[ 0 ] ), &xStaticTimerQueue );
980 xTimerQueue = xQueueCreate( ( UBaseType_t ) configTIMER_QUEUE_LENGTH, sizeof( DaemonTaskMessage_t ) );
982 #endif /* if ( configSUPPORT_STATIC_ALLOCATION == 1 ) */
984 #if ( configQUEUE_REGISTRY_SIZE > 0 )
986 if( xTimerQueue != NULL )
988 vQueueAddToRegistry( xTimerQueue, "TmrQ" );
992 mtCOVERAGE_TEST_MARKER();
995 #endif /* configQUEUE_REGISTRY_SIZE */
999 mtCOVERAGE_TEST_MARKER();
1002 taskEXIT_CRITICAL();
1004 /*-----------------------------------------------------------*/
1006 BaseType_t xTimerIsTimerActive( TimerHandle_t xTimer )
1009 Timer_t * pxTimer = xTimer;
1011 configASSERT( xTimer );
1013 /* Is the timer in the list of active timers? */
1014 taskENTER_CRITICAL();
1016 if( ( pxTimer->ucStatus & tmrSTATUS_IS_ACTIVE ) == 0 )
1025 taskEXIT_CRITICAL();
1028 } /*lint !e818 Can't be pointer to const due to the typedef. */
1029 /*-----------------------------------------------------------*/
1031 void * pvTimerGetTimerID( const TimerHandle_t xTimer )
1033 Timer_t * const pxTimer = xTimer;
1036 configASSERT( xTimer );
1038 taskENTER_CRITICAL();
1040 pvReturn = pxTimer->pvTimerID;
1042 taskEXIT_CRITICAL();
1046 /*-----------------------------------------------------------*/
1048 void vTimerSetTimerID( TimerHandle_t xTimer,
1051 Timer_t * const pxTimer = xTimer;
1053 configASSERT( xTimer );
1055 taskENTER_CRITICAL();
1057 pxTimer->pvTimerID = pvNewID;
1059 taskEXIT_CRITICAL();
1061 /*-----------------------------------------------------------*/
1063 #if ( INCLUDE_xTimerPendFunctionCall == 1 )
1065 BaseType_t xTimerPendFunctionCallFromISR( PendedFunction_t xFunctionToPend,
1066 void * pvParameter1,
1067 uint32_t ulParameter2,
1068 BaseType_t * pxHigherPriorityTaskWoken )
1070 DaemonTaskMessage_t xMessage;
1073 /* Complete the message with the function parameters and post it to the
1075 xMessage.xMessageID = tmrCOMMAND_EXECUTE_CALLBACK_FROM_ISR;
1076 xMessage.u.xCallbackParameters.pxCallbackFunction = xFunctionToPend;
1077 xMessage.u.xCallbackParameters.pvParameter1 = pvParameter1;
1078 xMessage.u.xCallbackParameters.ulParameter2 = ulParameter2;
1080 xReturn = xQueueSendFromISR( xTimerQueue, &xMessage, pxHigherPriorityTaskWoken );
1082 tracePEND_FUNC_CALL_FROM_ISR( xFunctionToPend, pvParameter1, ulParameter2, xReturn );
1087 #endif /* INCLUDE_xTimerPendFunctionCall */
1088 /*-----------------------------------------------------------*/
1090 #if ( INCLUDE_xTimerPendFunctionCall == 1 )
1092 BaseType_t xTimerPendFunctionCall( PendedFunction_t xFunctionToPend,
1093 void * pvParameter1,
1094 uint32_t ulParameter2,
1095 TickType_t xTicksToWait )
1097 DaemonTaskMessage_t xMessage;
1100 /* This function can only be called after a timer has been created or
1101 * after the scheduler has been started because, until then, the timer
1102 * queue does not exist. */
1103 configASSERT( xTimerQueue );
1105 /* Complete the message with the function parameters and post it to the
1107 xMessage.xMessageID = tmrCOMMAND_EXECUTE_CALLBACK;
1108 xMessage.u.xCallbackParameters.pxCallbackFunction = xFunctionToPend;
1109 xMessage.u.xCallbackParameters.pvParameter1 = pvParameter1;
1110 xMessage.u.xCallbackParameters.ulParameter2 = ulParameter2;
1112 xReturn = xQueueSendToBack( xTimerQueue, &xMessage, xTicksToWait );
1114 tracePEND_FUNC_CALL( xFunctionToPend, pvParameter1, ulParameter2, xReturn );
1119 #endif /* INCLUDE_xTimerPendFunctionCall */
1120 /*-----------------------------------------------------------*/
1122 #if ( configUSE_TRACE_FACILITY == 1 )
1124 UBaseType_t uxTimerGetTimerNumber( TimerHandle_t xTimer )
1126 return ( ( Timer_t * ) xTimer )->uxTimerNumber;
1129 #endif /* configUSE_TRACE_FACILITY */
1130 /*-----------------------------------------------------------*/
1132 #if ( configUSE_TRACE_FACILITY == 1 )
1134 void vTimerSetTimerNumber( TimerHandle_t xTimer,
1135 UBaseType_t uxTimerNumber )
1137 ( ( Timer_t * ) xTimer )->uxTimerNumber = uxTimerNumber;
1140 #endif /* configUSE_TRACE_FACILITY */
1141 /*-----------------------------------------------------------*/
1143 /* This entire source file will be skipped if the application is not configured
1144 * to include software timer functionality. If you want to include software timer
1145 * functionality then ensure configUSE_TIMERS is set to 1 in FreeRTOSConfig.h. */
1146 #endif /* configUSE_TIMERS == 1 */