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timers.c 48.56 KB
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/*
* FreeRTOS Kernel <DEVELOPMENT BRANCH>
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/* Standard includes. */
#include <stdlib.h>
/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
* all the API functions to use the MPU wrappers. That should only be done when
* task.h is included from an application file. */
#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "timers.h"
#if ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 0 )
#error configUSE_TIMERS must be set to 1 to make the xTimerPendFunctionCall() function available.
#endif
/* Lint e9021, e961 and e750 are suppressed as a MISRA exception justified
* because the MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be defined
* for the header files above, but not in this file, in order to generate the
* correct privileged Vs unprivileged linkage and placement. */
#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*lint !e9021 !e961 !e750. */
/* This entire source file will be skipped if the application is not configured
* to include software timer functionality. This #if is closed at the very bottom
* of this file. If you want to include software timer functionality then ensure
* configUSE_TIMERS is set to 1 in FreeRTOSConfig.h. */
#if ( configUSE_TIMERS == 1 )
/* Misc definitions. */
#define tmrNO_DELAY ( ( TickType_t ) 0U )
#define tmrMAX_TIME_BEFORE_OVERFLOW ( ( TickType_t ) -1 )
/* The name assigned to the timer service task. This can be overridden by
* defining trmTIMER_SERVICE_TASK_NAME in FreeRTOSConfig.h. */
#ifndef configTIMER_SERVICE_TASK_NAME
#define configTIMER_SERVICE_TASK_NAME "Tmr Svc"
#endif
/* Bit definitions used in the ucStatus member of a timer structure. */
#define tmrSTATUS_IS_ACTIVE ( ( uint8_t ) 0x01 )
#define tmrSTATUS_IS_STATICALLY_ALLOCATED ( ( uint8_t ) 0x02 )
#define tmrSTATUS_IS_AUTORELOAD ( ( uint8_t ) 0x04 )
/* The definition of the timers themselves. */
typedef struct tmrTimerControl /* The old naming convention is used to prevent breaking kernel aware debuggers. */
{
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. */
ListItem_t xTimerListItem; /**< Standard linked list item as used by all kernel features for event management. */
TickType_t xTimerPeriodInTicks; /**< How quickly and often the timer expires. */
void * pvTimerID; /**< An ID to identify the timer. This allows the timer to be identified when the same callback is used for multiple timers. */
TimerCallbackFunction_t pxCallbackFunction; /**< The function that will be called when the timer expires. */
#if ( configUSE_TRACE_FACILITY == 1 )
UBaseType_t uxTimerNumber; /**< An ID assigned by trace tools such as FreeRTOS+Trace */
#endif
uint8_t ucStatus; /**< Holds bits to say if the timer was statically allocated or not, and if it is active or not. */
} xTIMER;
/* The old xTIMER name is maintained above then typedefed to the new Timer_t
* name below to enable the use of older kernel aware debuggers. */
typedef xTIMER Timer_t;
/* The definition of messages that can be sent and received on the timer queue.
* Two types of message can be queued - messages that manipulate a software timer,
* and messages that request the execution of a non-timer related callback. The
* two message types are defined in two separate structures, xTimerParametersType
* and xCallbackParametersType respectively. */
typedef struct tmrTimerParameters
{
TickType_t xMessageValue; /**< An optional value used by a subset of commands, for example, when changing the period of a timer. */
Timer_t * pxTimer; /**< The timer to which the command will be applied. */
} TimerParameter_t;
typedef struct tmrCallbackParameters
{
PendedFunction_t pxCallbackFunction; /* << The callback function to execute. */
void * pvParameter1; /* << The value that will be used as the callback functions first parameter. */
uint32_t ulParameter2; /* << The value that will be used as the callback functions second parameter. */
} CallbackParameters_t;
/* The structure that contains the two message types, along with an identifier
* that is used to determine which message type is valid. */
typedef struct tmrTimerQueueMessage
{
BaseType_t xMessageID; /**< The command being sent to the timer service task. */
union
{
TimerParameter_t xTimerParameters;
/* Don't include xCallbackParameters if it is not going to be used as
* it makes the structure (and therefore the timer queue) larger. */
#if ( INCLUDE_xTimerPendFunctionCall == 1 )
CallbackParameters_t xCallbackParameters;
#endif /* INCLUDE_xTimerPendFunctionCall */
} u;
} DaemonTaskMessage_t;
/*lint -save -e956 A manual analysis and inspection has been used to determine
* which static variables must be declared volatile. */
/* The list in which active timers are stored. Timers are referenced in expire
* time order, with the nearest expiry time at the front of the list. Only the
* timer service task is allowed to access these lists.
* xActiveTimerList1 and xActiveTimerList2 could be at function scope but that
* breaks some kernel aware debuggers, and debuggers that reply on removing the
* static qualifier. */
PRIVILEGED_DATA static List_t xActiveTimerList1;
PRIVILEGED_DATA static List_t xActiveTimerList2;
PRIVILEGED_DATA static List_t * pxCurrentTimerList;
PRIVILEGED_DATA static List_t * pxOverflowTimerList;
/* A queue that is used to send commands to the timer service task. */
PRIVILEGED_DATA static QueueHandle_t xTimerQueue = NULL;
PRIVILEGED_DATA static TaskHandle_t xTimerTaskHandle = NULL;
/*lint -restore */
/*-----------------------------------------------------------*/
/*
* Initialise the infrastructure used by the timer service task if it has not
* been initialised already.
*/
static void prvCheckForValidListAndQueue( void ) PRIVILEGED_FUNCTION;
/*
* The timer service task (daemon). Timer functionality is controlled by this
* task. Other tasks communicate with the timer service task using the
* xTimerQueue queue.
*/
static portTASK_FUNCTION_PROTO( prvTimerTask, pvParameters ) portNORETURN PRIVILEGED_FUNCTION;
/*
* Called by the timer service task to interpret and process a command it
* received on the timer queue.
*/
static void prvProcessReceivedCommands( void ) PRIVILEGED_FUNCTION;
/*
* Insert the timer into either xActiveTimerList1, or xActiveTimerList2,
* depending on if the expire time causes a timer counter overflow.
*/
static BaseType_t prvInsertTimerInActiveList( Timer_t * const pxTimer,
const TickType_t xNextExpiryTime,
const TickType_t xTimeNow,
const TickType_t xCommandTime ) PRIVILEGED_FUNCTION;
/*
* Reload the specified auto-reload timer. If the reloading is backlogged,
* clear the backlog, calling the callback for each additional reload. When
* this function returns, the next expiry time is after xTimeNow.
*/
static void prvReloadTimer( Timer_t * const pxTimer,
TickType_t xExpiredTime,
const TickType_t xTimeNow ) PRIVILEGED_FUNCTION;
/*
* An active timer has reached its expire time. Reload the timer if it is an
* auto-reload timer, then call its callback.
*/
static void prvProcessExpiredTimer( const TickType_t xNextExpireTime,
const TickType_t xTimeNow ) PRIVILEGED_FUNCTION;
/*
* The tick count has overflowed. Switch the timer lists after ensuring the
* current timer list does not still reference some timers.
*/
static void prvSwitchTimerLists( void ) PRIVILEGED_FUNCTION;
/*
* Obtain the current tick count, setting *pxTimerListsWereSwitched to pdTRUE
* if a tick count overflow occurred since prvSampleTimeNow() was last called.
*/
static TickType_t prvSampleTimeNow( BaseType_t * const pxTimerListsWereSwitched ) PRIVILEGED_FUNCTION;
/*
* If the timer list contains any active timers then return the expire time of
* the timer that will expire first and set *pxListWasEmpty to false. If the
* timer list does not contain any timers then return 0 and set *pxListWasEmpty
* to pdTRUE.
*/
static TickType_t prvGetNextExpireTime( BaseType_t * const pxListWasEmpty ) PRIVILEGED_FUNCTION;
/*
* If a timer has expired, process it. Otherwise, block the timer service task
* until either a timer does expire or a command is received.
*/
static void prvProcessTimerOrBlockTask( const TickType_t xNextExpireTime,
BaseType_t xListWasEmpty ) PRIVILEGED_FUNCTION;
/*
* Called after a Timer_t structure has been allocated either statically or
* dynamically to fill in the structure's members.
*/
static void prvInitialiseNewTimer( const char * const pcTimerName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
const TickType_t xTimerPeriodInTicks,
const BaseType_t xAutoReload,
void * const pvTimerID,
TimerCallbackFunction_t pxCallbackFunction,
Timer_t * pxNewTimer ) PRIVILEGED_FUNCTION;
/*-----------------------------------------------------------*/
BaseType_t xTimerCreateTimerTask( void )
{
BaseType_t xReturn = pdFAIL;
/* This function is called when the scheduler is started if
* configUSE_TIMERS is set to 1. Check that the infrastructure used by the
* timer service task has been created/initialised. If timers have already
* been created then the initialisation will already have been performed. */
prvCheckForValidListAndQueue();
if( xTimerQueue != NULL )
{
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
{
StaticTask_t * pxTimerTaskTCBBuffer = NULL;
StackType_t * pxTimerTaskStackBuffer = NULL;
uint32_t ulTimerTaskStackSize;
vApplicationGetTimerTaskMemory( &pxTimerTaskTCBBuffer, &pxTimerTaskStackBuffer, &ulTimerTaskStackSize );
xTimerTaskHandle = xTaskCreateStatic( prvTimerTask,
configTIMER_SERVICE_TASK_NAME,
ulTimerTaskStackSize,
NULL,
( ( UBaseType_t ) configTIMER_TASK_PRIORITY ) | portPRIVILEGE_BIT,
pxTimerTaskStackBuffer,
pxTimerTaskTCBBuffer );
if( xTimerTaskHandle != NULL )
{
xReturn = pdPASS;
}
}
#else /* if ( configSUPPORT_STATIC_ALLOCATION == 1 ) */
{
xReturn = xTaskCreate( prvTimerTask,
configTIMER_SERVICE_TASK_NAME,
configTIMER_TASK_STACK_DEPTH,
NULL,
( ( UBaseType_t ) configTIMER_TASK_PRIORITY ) | portPRIVILEGE_BIT,
&xTimerTaskHandle );
}
#endif /* configSUPPORT_STATIC_ALLOCATION */
}
else
{
mtCOVERAGE_TEST_MARKER();
}
configASSERT( xReturn );
return xReturn;
}
/*-----------------------------------------------------------*/
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
TimerHandle_t xTimerCreate( const char * const pcTimerName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
const TickType_t xTimerPeriodInTicks,
const BaseType_t xAutoReload,
void * const pvTimerID,
TimerCallbackFunction_t pxCallbackFunction )
{
Timer_t * pxNewTimer;
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. */
if( pxNewTimer != NULL )
{
/* Status is thus far zero as the timer is not created statically
* and has not been started. The auto-reload bit may get set in
* prvInitialiseNewTimer. */
pxNewTimer->ucStatus = 0x00;
prvInitialiseNewTimer( pcTimerName, xTimerPeriodInTicks, xAutoReload, pvTimerID, pxCallbackFunction, pxNewTimer );
}
return pxNewTimer;
}
#endif /* configSUPPORT_DYNAMIC_ALLOCATION */
/*-----------------------------------------------------------*/
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
TimerHandle_t xTimerCreateStatic( const char * const pcTimerName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
const TickType_t xTimerPeriodInTicks,
const BaseType_t xAutoReload,
void * const pvTimerID,
TimerCallbackFunction_t pxCallbackFunction,
StaticTimer_t * pxTimerBuffer )
{
Timer_t * pxNewTimer;
#if ( configASSERT_DEFINED == 1 )
{
/* Sanity check that the size of the structure used to declare a
* variable of type StaticTimer_t equals the size of the real timer
* structure. */
volatile size_t xSize = sizeof( StaticTimer_t );
configASSERT( xSize == sizeof( Timer_t ) );
( void ) xSize; /* Keeps lint quiet when configASSERT() is not defined. */
}
#endif /* configASSERT_DEFINED */
/* A pointer to a StaticTimer_t structure MUST be provided, use it. */
configASSERT( pxTimerBuffer );
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. */
if( pxNewTimer != NULL )
{
/* Timers can be created statically or dynamically so note this
* timer was created statically in case it is later deleted. The
* auto-reload bit may get set in prvInitialiseNewTimer(). */
pxNewTimer->ucStatus = tmrSTATUS_IS_STATICALLY_ALLOCATED;
prvInitialiseNewTimer( pcTimerName, xTimerPeriodInTicks, xAutoReload, pvTimerID, pxCallbackFunction, pxNewTimer );
}
return pxNewTimer;
}
#endif /* configSUPPORT_STATIC_ALLOCATION */
/*-----------------------------------------------------------*/
static void prvInitialiseNewTimer( const char * const pcTimerName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
const TickType_t xTimerPeriodInTicks,
const BaseType_t xAutoReload,
void * const pvTimerID,
TimerCallbackFunction_t pxCallbackFunction,
Timer_t * pxNewTimer )
{
/* 0 is not a valid value for xTimerPeriodInTicks. */
configASSERT( ( xTimerPeriodInTicks > 0 ) );
/* Ensure the infrastructure used by the timer service task has been
* created/initialised. */
prvCheckForValidListAndQueue();
/* Initialise the timer structure members using the function
* parameters. */
pxNewTimer->pcTimerName = pcTimerName;
pxNewTimer->xTimerPeriodInTicks = xTimerPeriodInTicks;
pxNewTimer->pvTimerID = pvTimerID;
pxNewTimer->pxCallbackFunction = pxCallbackFunction;
vListInitialiseItem( &( pxNewTimer->xTimerListItem ) );
if( xAutoReload != pdFALSE )
{
pxNewTimer->ucStatus |= tmrSTATUS_IS_AUTORELOAD;
}
traceTIMER_CREATE( pxNewTimer );
}
/*-----------------------------------------------------------*/
BaseType_t xTimerGenericCommand( TimerHandle_t xTimer,
const BaseType_t xCommandID,
const TickType_t xOptionalValue,
BaseType_t * const pxHigherPriorityTaskWoken,
const TickType_t xTicksToWait )
{
BaseType_t xReturn = pdFAIL;
DaemonTaskMessage_t xMessage;
configASSERT( xTimer );
/* Send a message to the timer service task to perform a particular action
* on a particular timer definition. */
if( xTimerQueue != NULL )
{
/* Send a command to the timer service task to start the xTimer timer. */
xMessage.xMessageID = xCommandID;
xMessage.u.xTimerParameters.xMessageValue = xOptionalValue;
xMessage.u.xTimerParameters.pxTimer = xTimer;
if( xCommandID < tmrFIRST_FROM_ISR_COMMAND )
{
if( xTaskGetSchedulerState() == taskSCHEDULER_RUNNING )
{
xReturn = xQueueSendToBack( xTimerQueue, &xMessage, xTicksToWait );
}
else
{
xReturn = xQueueSendToBack( xTimerQueue, &xMessage, tmrNO_DELAY );
}
}
else
{
xReturn = xQueueSendToBackFromISR( xTimerQueue, &xMessage, pxHigherPriorityTaskWoken );
}
traceTIMER_COMMAND_SEND( xTimer, xCommandID, xOptionalValue, xReturn );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
return xReturn;
}
/*-----------------------------------------------------------*/
TaskHandle_t xTimerGetTimerDaemonTaskHandle( void )
{
/* If xTimerGetTimerDaemonTaskHandle() is called before the scheduler has been
* started, then xTimerTaskHandle will be NULL. */
configASSERT( ( xTimerTaskHandle != NULL ) );
return xTimerTaskHandle;
}
/*-----------------------------------------------------------*/
TickType_t xTimerGetPeriod( TimerHandle_t xTimer )
{
Timer_t * pxTimer = xTimer;
configASSERT( xTimer );
return pxTimer->xTimerPeriodInTicks;
}
/*-----------------------------------------------------------*/
void vTimerSetReloadMode( TimerHandle_t xTimer,
const BaseType_t xAutoReload )
{
Timer_t * pxTimer = xTimer;
configASSERT( xTimer );
taskENTER_CRITICAL();
{
if( xAutoReload != pdFALSE )
{
pxTimer->ucStatus |= tmrSTATUS_IS_AUTORELOAD;
}
else
{
pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_AUTORELOAD );
}
}
taskEXIT_CRITICAL();
}
/*-----------------------------------------------------------*/
BaseType_t xTimerGetReloadMode( TimerHandle_t xTimer )
{
Timer_t * pxTimer = xTimer;
BaseType_t xReturn;
configASSERT( xTimer );
taskENTER_CRITICAL();
{
if( ( pxTimer->ucStatus & tmrSTATUS_IS_AUTORELOAD ) == 0 )
{
/* Not an auto-reload timer. */
xReturn = pdFALSE;
}
else
{
/* Is an auto-reload timer. */
xReturn = pdTRUE;
}
}
taskEXIT_CRITICAL();
return xReturn;
}
UBaseType_t uxTimerGetReloadMode( TimerHandle_t xTimer )
{
return ( UBaseType_t ) xTimerGetReloadMode( xTimer );
}
/*-----------------------------------------------------------*/
TickType_t xTimerGetExpiryTime( TimerHandle_t xTimer )
{
Timer_t * pxTimer = xTimer;
TickType_t xReturn;
configASSERT( xTimer );
xReturn = listGET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ) );
return xReturn;
}
/*-----------------------------------------------------------*/
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
BaseType_t xTimerGetStaticBuffer( TimerHandle_t xTimer,
StaticTimer_t ** ppxTimerBuffer )
{
BaseType_t xReturn;
Timer_t * pxTimer = xTimer;
configASSERT( ppxTimerBuffer != NULL );
if( ( pxTimer->ucStatus & tmrSTATUS_IS_STATICALLY_ALLOCATED ) != 0 )
{
*ppxTimerBuffer = ( StaticTimer_t * ) pxTimer;
xReturn = pdTRUE;
}
else
{
xReturn = pdFALSE;
}
return xReturn;
}
#endif /* configSUPPORT_STATIC_ALLOCATION */
/*-----------------------------------------------------------*/
const char * pcTimerGetName( TimerHandle_t xTimer ) /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
{
Timer_t * pxTimer = xTimer;
configASSERT( xTimer );
return pxTimer->pcTimerName;
}
/*-----------------------------------------------------------*/
static void prvReloadTimer( Timer_t * const pxTimer,
TickType_t xExpiredTime,
const TickType_t xTimeNow )
{
/* Insert the timer into the appropriate list for the next expiry time.
* If the next expiry time has already passed, advance the expiry time,
* call the callback function, and try again. */
while( prvInsertTimerInActiveList( pxTimer, ( xExpiredTime + pxTimer->xTimerPeriodInTicks ), xTimeNow, xExpiredTime ) != pdFALSE )
{
/* Advance the expiry time. */
xExpiredTime += pxTimer->xTimerPeriodInTicks;
/* Call the timer callback. */
traceTIMER_EXPIRED( pxTimer );
pxTimer->pxCallbackFunction( ( TimerHandle_t ) pxTimer );
}
}
/*-----------------------------------------------------------*/
static void prvProcessExpiredTimer( const TickType_t xNextExpireTime,
const TickType_t xTimeNow )
{
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. */
/* Remove the timer from the list of active timers. A check has already
* been performed to ensure the list is not empty. */
( void ) uxListRemove( &( pxTimer->xTimerListItem ) );
/* If the timer is an auto-reload timer then calculate the next
* expiry time and re-insert the timer in the list of active timers. */
if( ( pxTimer->ucStatus & tmrSTATUS_IS_AUTORELOAD ) != 0 )
{
prvReloadTimer( pxTimer, xNextExpireTime, xTimeNow );
}
else
{
pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
}
/* Call the timer callback. */
traceTIMER_EXPIRED( pxTimer );
pxTimer->pxCallbackFunction( ( TimerHandle_t ) pxTimer );
}
/*-----------------------------------------------------------*/
static portTASK_FUNCTION( prvTimerTask, pvParameters )
{
TickType_t xNextExpireTime;
BaseType_t xListWasEmpty;
/* Just to avoid compiler warnings. */
( void ) pvParameters;
#if ( configUSE_DAEMON_TASK_STARTUP_HOOK == 1 )
{
/* Allow the application writer to execute some code in the context of
* this task at the point the task starts executing. This is useful if the
* application includes initialisation code that would benefit from
* executing after the scheduler has been started. */
vApplicationDaemonTaskStartupHook();
}
#endif /* configUSE_DAEMON_TASK_STARTUP_HOOK */
for( ; ; )
{
/* Query the timers list to see if it contains any timers, and if so,
* obtain the time at which the next timer will expire. */
xNextExpireTime = prvGetNextExpireTime( &xListWasEmpty );
/* If a timer has expired, process it. Otherwise, block this task
* until either a timer does expire, or a command is received. */
prvProcessTimerOrBlockTask( xNextExpireTime, xListWasEmpty );
/* Empty the command queue. */
prvProcessReceivedCommands();
}
}
/*-----------------------------------------------------------*/
static void prvProcessTimerOrBlockTask( const TickType_t xNextExpireTime,
BaseType_t xListWasEmpty )
{
TickType_t xTimeNow;
BaseType_t xTimerListsWereSwitched;
vTaskSuspendAll();
{
/* Obtain the time now to make an assessment as to whether the timer
* has expired or not. If obtaining the time causes the lists to switch
* then don't process this timer as any timers that remained in the list
* when the lists were switched will have been processed within the
* prvSampleTimeNow() function. */
xTimeNow = prvSampleTimeNow( &xTimerListsWereSwitched );
if( xTimerListsWereSwitched == pdFALSE )
{
/* The tick count has not overflowed, has the timer expired? */
if( ( xListWasEmpty == pdFALSE ) && ( xNextExpireTime <= xTimeNow ) )
{
( void ) xTaskResumeAll();
prvProcessExpiredTimer( xNextExpireTime, xTimeNow );
}
else
{
/* The tick count has not overflowed, and the next expire
* time has not been reached yet. This task should therefore
* block to wait for the next expire time or a command to be
* received - whichever comes first. The following line cannot
* be reached unless xNextExpireTime > xTimeNow, except in the
* case when the current timer list is empty. */
if( xListWasEmpty != pdFALSE )
{
/* The current timer list is empty - is the overflow list
* also empty? */
xListWasEmpty = listLIST_IS_EMPTY( pxOverflowTimerList );
}
vQueueWaitForMessageRestricted( xTimerQueue, ( xNextExpireTime - xTimeNow ), xListWasEmpty );
if( xTaskResumeAll() == pdFALSE )
{
/* Yield to wait for either a command to arrive, or the
* block time to expire. If a command arrived between the
* critical section being exited and this yield then the yield
* will not cause the task to block. */
portYIELD_WITHIN_API();
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
}
else
{
( void ) xTaskResumeAll();
}
}
}
/*-----------------------------------------------------------*/
static TickType_t prvGetNextExpireTime( BaseType_t * const pxListWasEmpty )
{
TickType_t xNextExpireTime;
/* Timers are listed in expiry time order, with the head of the list
* referencing the task that will expire first. Obtain the time at which
* the timer with the nearest expiry time will expire. If there are no
* active timers then just set the next expire time to 0. That will cause
* this task to unblock when the tick count overflows, at which point the
* timer lists will be switched and the next expiry time can be
* re-assessed. */
*pxListWasEmpty = listLIST_IS_EMPTY( pxCurrentTimerList );
if( *pxListWasEmpty == pdFALSE )
{
xNextExpireTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxCurrentTimerList );
}
else
{
/* Ensure the task unblocks when the tick count rolls over. */
xNextExpireTime = ( TickType_t ) 0U;
}
return xNextExpireTime;
}
/*-----------------------------------------------------------*/
static TickType_t prvSampleTimeNow( BaseType_t * const pxTimerListsWereSwitched )
{
TickType_t xTimeNow;
PRIVILEGED_DATA static TickType_t xLastTime = ( TickType_t ) 0U; /*lint !e956 Variable is only accessible to one task. */
xTimeNow = xTaskGetTickCount();
if( xTimeNow < xLastTime )
{
prvSwitchTimerLists();
*pxTimerListsWereSwitched = pdTRUE;
}
else
{
*pxTimerListsWereSwitched = pdFALSE;
}
xLastTime = xTimeNow;
return xTimeNow;
}
/*-----------------------------------------------------------*/
static BaseType_t prvInsertTimerInActiveList( Timer_t * const pxTimer,
const TickType_t xNextExpiryTime,
const TickType_t xTimeNow,
const TickType_t xCommandTime )
{
BaseType_t xProcessTimerNow = pdFALSE;
listSET_LIST_ITEM_VALUE( &( pxTimer->xTimerListItem ), xNextExpiryTime );
listSET_LIST_ITEM_OWNER( &( pxTimer->xTimerListItem ), pxTimer );
if( xNextExpiryTime <= xTimeNow )
{
/* Has the expiry time elapsed between the command to start/reset a
* timer was issued, and the time the command was processed? */
if( ( ( TickType_t ) ( xTimeNow - xCommandTime ) ) >= pxTimer->xTimerPeriodInTicks ) /*lint !e961 MISRA exception as the casts are only redundant for some ports. */
{
/* The time between a command being issued and the command being
* processed actually exceeds the timers period. */
xProcessTimerNow = pdTRUE;
}
else
{
vListInsert( pxOverflowTimerList, &( pxTimer->xTimerListItem ) );
}
}
else
{
if( ( xTimeNow < xCommandTime ) && ( xNextExpiryTime >= xCommandTime ) )
{
/* If, since the command was issued, the tick count has overflowed
* but the expiry time has not, then the timer must have already passed
* its expiry time and should be processed immediately. */
xProcessTimerNow = pdTRUE;
}
else
{
vListInsert( pxCurrentTimerList, &( pxTimer->xTimerListItem ) );
}
}
return xProcessTimerNow;
}
/*-----------------------------------------------------------*/
static void prvProcessReceivedCommands( void )
{
DaemonTaskMessage_t xMessage;
Timer_t * pxTimer;
BaseType_t xTimerListsWereSwitched;
TickType_t xTimeNow;
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. */
{
#if ( INCLUDE_xTimerPendFunctionCall == 1 )
{
/* Negative commands are pended function calls rather than timer
* commands. */
if( xMessage.xMessageID < ( BaseType_t ) 0 )
{
const CallbackParameters_t * const pxCallback = &( xMessage.u.xCallbackParameters );
/* The timer uses the xCallbackParameters member to request a
* callback be executed. Check the callback is not NULL. */
configASSERT( pxCallback );
/* Call the function. */
pxCallback->pxCallbackFunction( pxCallback->pvParameter1, pxCallback->ulParameter2 );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
#endif /* INCLUDE_xTimerPendFunctionCall */
/* Commands that are positive are timer commands rather than pended
* function calls. */
if( xMessage.xMessageID >= ( BaseType_t ) 0 )
{
/* The messages uses the xTimerParameters member to work on a
* software timer. */
pxTimer = xMessage.u.xTimerParameters.pxTimer;
if( listIS_CONTAINED_WITHIN( NULL, &( pxTimer->xTimerListItem ) ) == pdFALSE ) /*lint !e961. The cast is only redundant when NULL is passed into the macro. */
{
/* The timer is in a list, remove it. */
( void ) uxListRemove( &( pxTimer->xTimerListItem ) );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
traceTIMER_COMMAND_RECEIVED( pxTimer, xMessage.xMessageID, xMessage.u.xTimerParameters.xMessageValue );
/* In this case the xTimerListsWereSwitched parameter is not used, but
* it must be present in the function call. prvSampleTimeNow() must be
* called after the message is received from xTimerQueue so there is no
* possibility of a higher priority task adding a message to the message
* queue with a time that is ahead of the timer daemon task (because it
* pre-empted the timer daemon task after the xTimeNow value was set). */
xTimeNow = prvSampleTimeNow( &xTimerListsWereSwitched );
switch( xMessage.xMessageID )
{
case tmrCOMMAND_START:
case tmrCOMMAND_START_FROM_ISR:
case tmrCOMMAND_RESET:
case tmrCOMMAND_RESET_FROM_ISR:
/* Start or restart a timer. */
pxTimer->ucStatus |= tmrSTATUS_IS_ACTIVE;
if( prvInsertTimerInActiveList( pxTimer, xMessage.u.xTimerParameters.xMessageValue + pxTimer->xTimerPeriodInTicks, xTimeNow, xMessage.u.xTimerParameters.xMessageValue ) != pdFALSE )
{
/* The timer expired before it was added to the active
* timer list. Process it now. */
if( ( pxTimer->ucStatus & tmrSTATUS_IS_AUTORELOAD ) != 0 )
{
prvReloadTimer( pxTimer, xMessage.u.xTimerParameters.xMessageValue + pxTimer->xTimerPeriodInTicks, xTimeNow );
}
else
{
pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
}
/* Call the timer callback. */
traceTIMER_EXPIRED( pxTimer );
pxTimer->pxCallbackFunction( ( TimerHandle_t ) pxTimer );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
break;
case tmrCOMMAND_STOP:
case tmrCOMMAND_STOP_FROM_ISR:
/* The timer has already been removed from the active list. */
pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
break;
case tmrCOMMAND_CHANGE_PERIOD:
case tmrCOMMAND_CHANGE_PERIOD_FROM_ISR:
pxTimer->ucStatus |= tmrSTATUS_IS_ACTIVE;
pxTimer->xTimerPeriodInTicks = xMessage.u.xTimerParameters.xMessageValue;
configASSERT( ( pxTimer->xTimerPeriodInTicks > 0 ) );
/* The new period does not really have a reference, and can
* be longer or shorter than the old one. The command time is
* therefore set to the current time, and as the period cannot
* be zero the next expiry time can only be in the future,
* meaning (unlike for the xTimerStart() case above) there is
* no fail case that needs to be handled here. */
( void ) prvInsertTimerInActiveList( pxTimer, ( xTimeNow + pxTimer->xTimerPeriodInTicks ), xTimeNow, xTimeNow );
break;
case tmrCOMMAND_DELETE:
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
{
/* The timer has already been removed from the active list,
* just free up the memory if the memory was dynamically
* allocated. */
if( ( pxTimer->ucStatus & tmrSTATUS_IS_STATICALLY_ALLOCATED ) == ( uint8_t ) 0 )
{
vPortFree( pxTimer );
}
else
{
pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
}
}
#else /* if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) */
{
/* If dynamic allocation is not enabled, the memory
* could not have been dynamically allocated. So there is
* no need to free the memory - just mark the timer as
* "not active". */
pxTimer->ucStatus &= ( ( uint8_t ) ~tmrSTATUS_IS_ACTIVE );
}
#endif /* configSUPPORT_DYNAMIC_ALLOCATION */
break;
default:
/* Don't expect to get here. */
break;
}
}
}
}
/*-----------------------------------------------------------*/
static void prvSwitchTimerLists( void )
{
TickType_t xNextExpireTime;
List_t * pxTemp;
/* The tick count has overflowed. The timer lists must be switched.
* If there are any timers still referenced from the current timer list
* then they must have expired and should be processed before the lists
* are switched. */
while( listLIST_IS_EMPTY( pxCurrentTimerList ) == pdFALSE )
{
xNextExpireTime = listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxCurrentTimerList );
/* Process the expired timer. For auto-reload timers, be careful to
* process only expirations that occur on the current list. Further
* expirations must wait until after the lists are switched. */
prvProcessExpiredTimer( xNextExpireTime, tmrMAX_TIME_BEFORE_OVERFLOW );
}
pxTemp = pxCurrentTimerList;
pxCurrentTimerList = pxOverflowTimerList;
pxOverflowTimerList = pxTemp;
}
/*-----------------------------------------------------------*/
static void prvCheckForValidListAndQueue( void )
{
/* Check that the list from which active timers are referenced, and the
* queue used to communicate with the timer service, have been
* initialised. */
taskENTER_CRITICAL();
{
if( xTimerQueue == NULL )
{
vListInitialise( &xActiveTimerList1 );
vListInitialise( &xActiveTimerList2 );
pxCurrentTimerList = &xActiveTimerList1;
pxOverflowTimerList = &xActiveTimerList2;
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
{
/* The timer queue is allocated statically in case
* configSUPPORT_DYNAMIC_ALLOCATION is 0. */
PRIVILEGED_DATA static StaticQueue_t xStaticTimerQueue; /*lint !e956 Ok to declare in this manner to prevent additional conditional compilation guards in other locations. */
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. */
xTimerQueue = xQueueCreateStatic( ( UBaseType_t ) configTIMER_QUEUE_LENGTH, ( UBaseType_t ) sizeof( DaemonTaskMessage_t ), &( ucStaticTimerQueueStorage[ 0 ] ), &xStaticTimerQueue );
}
#else
{
xTimerQueue = xQueueCreate( ( UBaseType_t ) configTIMER_QUEUE_LENGTH, sizeof( DaemonTaskMessage_t ) );
}
#endif /* if ( configSUPPORT_STATIC_ALLOCATION == 1 ) */
#if ( configQUEUE_REGISTRY_SIZE > 0 )
{
if( xTimerQueue != NULL )
{
vQueueAddToRegistry( xTimerQueue, "TmrQ" );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
#endif /* configQUEUE_REGISTRY_SIZE */
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
taskEXIT_CRITICAL();
}
/*-----------------------------------------------------------*/
BaseType_t xTimerIsTimerActive( TimerHandle_t xTimer )
{
BaseType_t xReturn;
Timer_t * pxTimer = xTimer;
configASSERT( xTimer );
/* Is the timer in the list of active timers? */
taskENTER_CRITICAL();
{
if( ( pxTimer->ucStatus & tmrSTATUS_IS_ACTIVE ) == 0 )
{
xReturn = pdFALSE;
}
else
{
xReturn = pdTRUE;
}
}
taskEXIT_CRITICAL();
return xReturn;
} /*lint !e818 Can't be pointer to const due to the typedef. */
/*-----------------------------------------------------------*/
void * pvTimerGetTimerID( const TimerHandle_t xTimer )
{
Timer_t * const pxTimer = xTimer;
void * pvReturn;
configASSERT( xTimer );
taskENTER_CRITICAL();
{
pvReturn = pxTimer->pvTimerID;
}
taskEXIT_CRITICAL();
return pvReturn;
}
/*-----------------------------------------------------------*/
void vTimerSetTimerID( TimerHandle_t xTimer,
void * pvNewID )
{
Timer_t * const pxTimer = xTimer;
configASSERT( xTimer );
taskENTER_CRITICAL();
{
pxTimer->pvTimerID = pvNewID;
}
taskEXIT_CRITICAL();
}
/*-----------------------------------------------------------*/
#if ( INCLUDE_xTimerPendFunctionCall == 1 )
BaseType_t xTimerPendFunctionCallFromISR( PendedFunction_t xFunctionToPend,
void * pvParameter1,
uint32_t ulParameter2,
BaseType_t * pxHigherPriorityTaskWoken )
{
DaemonTaskMessage_t xMessage;
BaseType_t xReturn;
/* Complete the message with the function parameters and post it to the
* daemon task. */
xMessage.xMessageID = tmrCOMMAND_EXECUTE_CALLBACK_FROM_ISR;
xMessage.u.xCallbackParameters.pxCallbackFunction = xFunctionToPend;
xMessage.u.xCallbackParameters.pvParameter1 = pvParameter1;
xMessage.u.xCallbackParameters.ulParameter2 = ulParameter2;
xReturn = xQueueSendFromISR( xTimerQueue, &xMessage, pxHigherPriorityTaskWoken );
tracePEND_FUNC_CALL_FROM_ISR( xFunctionToPend, pvParameter1, ulParameter2, xReturn );
return xReturn;
}
#endif /* INCLUDE_xTimerPendFunctionCall */
/*-----------------------------------------------------------*/
#if ( INCLUDE_xTimerPendFunctionCall == 1 )
BaseType_t xTimerPendFunctionCall( PendedFunction_t xFunctionToPend,
void * pvParameter1,
uint32_t ulParameter2,
TickType_t xTicksToWait )
{
DaemonTaskMessage_t xMessage;
BaseType_t xReturn;
/* This function can only be called after a timer has been created or
* after the scheduler has been started because, until then, the timer
* queue does not exist. */
configASSERT( xTimerQueue );
/* Complete the message with the function parameters and post it to the
* daemon task. */
xMessage.xMessageID = tmrCOMMAND_EXECUTE_CALLBACK;
xMessage.u.xCallbackParameters.pxCallbackFunction = xFunctionToPend;
xMessage.u.xCallbackParameters.pvParameter1 = pvParameter1;
xMessage.u.xCallbackParameters.ulParameter2 = ulParameter2;
xReturn = xQueueSendToBack( xTimerQueue, &xMessage, xTicksToWait );
tracePEND_FUNC_CALL( xFunctionToPend, pvParameter1, ulParameter2, xReturn );
return xReturn;
}
#endif /* INCLUDE_xTimerPendFunctionCall */
/*-----------------------------------------------------------*/
#if ( configUSE_TRACE_FACILITY == 1 )
UBaseType_t uxTimerGetTimerNumber( TimerHandle_t xTimer )
{
return ( ( Timer_t * ) xTimer )->uxTimerNumber;
}
#endif /* configUSE_TRACE_FACILITY */
/*-----------------------------------------------------------*/
#if ( configUSE_TRACE_FACILITY == 1 )
void vTimerSetTimerNumber( TimerHandle_t xTimer,
UBaseType_t uxTimerNumber )
{
( ( Timer_t * ) xTimer )->uxTimerNumber = uxTimerNumber;
}
#endif /* configUSE_TRACE_FACILITY */
/*-----------------------------------------------------------*/
/* This entire source file will be skipped if the application is not configured
* to include software timer functionality. If you want to include software timer
* functionality then ensure configUSE_TIMERS is set to 1 in FreeRTOSConfig.h. */
#endif /* configUSE_TIMERS == 1 */
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