/* | |
* FreeRTOS Kernel V10.2.1 | |
* Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. | |
* | |
* 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. | |
* | |
* http://www.FreeRTOS.org | |
* http://aws.amazon.com/freertos | |
* | |
* 1 tab == 4 spaces! | |
*/ | |
#ifndef TIMERS_H | |
#define TIMERS_H | |
#ifndef INC_FREERTOS_H | |
#error "include FreeRTOS.h must appear in source files before include timers.h" | |
#endif | |
/*lint -save -e537 This headers are only multiply included if the application code | |
happens to also be including task.h. */ | |
#include "task.h" | |
/*lint -restore */ | |
#ifdef __cplusplus | |
extern "C" { | |
#endif | |
/*----------------------------------------------------------- | |
* MACROS AND DEFINITIONS | |
*----------------------------------------------------------*/ | |
/* IDs for commands that can be sent/received on the timer queue. These are to | |
be used solely through the macros that make up the public software timer API, | |
as defined below. The commands that are sent from interrupts must use the | |
highest numbers as tmrFIRST_FROM_ISR_COMMAND is used to determine if the task | |
or interrupt version of the queue send function should be used. */ | |
#define tmrCOMMAND_EXECUTE_CALLBACK_FROM_ISR ( ( BaseType_t ) -2 ) | |
#define tmrCOMMAND_EXECUTE_CALLBACK ( ( BaseType_t ) -1 ) | |
#define tmrCOMMAND_START_DONT_TRACE ( ( BaseType_t ) 0 ) | |
#define tmrCOMMAND_START ( ( BaseType_t ) 1 ) | |
#define tmrCOMMAND_RESET ( ( BaseType_t ) 2 ) | |
#define tmrCOMMAND_STOP ( ( BaseType_t ) 3 ) | |
#define tmrCOMMAND_CHANGE_PERIOD ( ( BaseType_t ) 4 ) | |
#define tmrCOMMAND_DELETE ( ( BaseType_t ) 5 ) | |
#define tmrFIRST_FROM_ISR_COMMAND ( ( BaseType_t ) 6 ) | |
#define tmrCOMMAND_START_FROM_ISR ( ( BaseType_t ) 6 ) | |
#define tmrCOMMAND_RESET_FROM_ISR ( ( BaseType_t ) 7 ) | |
#define tmrCOMMAND_STOP_FROM_ISR ( ( BaseType_t ) 8 ) | |
#define tmrCOMMAND_CHANGE_PERIOD_FROM_ISR ( ( BaseType_t ) 9 ) | |
/** | |
* Type by which software timers are referenced. For example, a call to | |
* xTimerCreate() returns an TimerHandle_t variable that can then be used to | |
* reference the subject timer in calls to other software timer API functions | |
* (for example, xTimerStart(), xTimerReset(), etc.). | |
*/ | |
struct tmrTimerControl; /* The old naming convention is used to prevent breaking kernel aware debuggers. */ | |
typedef struct tmrTimerControl * TimerHandle_t; | |
/* | |
* Defines the prototype to which timer callback functions must conform. | |
*/ | |
typedef void (*TimerCallbackFunction_t)( TimerHandle_t xTimer ); | |
/* | |
* Defines the prototype to which functions used with the | |
* xTimerPendFunctionCallFromISR() function must conform. | |
*/ | |
typedef void (*PendedFunction_t)( void *, uint32_t ); | |
/** | |
* TimerHandle_t xTimerCreate( const char * const pcTimerName, | |
* TickType_t xTimerPeriodInTicks, | |
* UBaseType_t uxAutoReload, | |
* void * pvTimerID, | |
* TimerCallbackFunction_t pxCallbackFunction ); | |
* | |
* Creates a new software timer instance, and returns a handle by which the | |
* created software timer can be referenced. | |
* | |
* Internally, within the FreeRTOS implementation, software timers use a block | |
* of memory, in which the timer data structure is stored. If a software timer | |
* is created using xTimerCreate() then the required memory is automatically | |
* dynamically allocated inside the xTimerCreate() function. (see | |
* http://www.freertos.org/a00111.html). If a software timer is created using | |
* xTimerCreateStatic() then the application writer must provide the memory that | |
* will get used by the software timer. xTimerCreateStatic() therefore allows a | |
* software timer to be created without using any dynamic memory allocation. | |
* | |
* Timers are created in the dormant state. The xTimerStart(), xTimerReset(), | |
* xTimerStartFromISR(), xTimerResetFromISR(), xTimerChangePeriod() and | |
* xTimerChangePeriodFromISR() API functions can all be used to transition a | |
* timer into the active state. | |
* | |
* @param pcTimerName A text name that is assigned to the timer. This is done | |
* purely to assist debugging. The kernel itself only ever references a timer | |
* by its handle, and never by its name. | |
* | |
* @param xTimerPeriodInTicks The timer period. The time is defined in tick | |
* periods so the constant portTICK_PERIOD_MS can be used to convert a time that | |
* has been specified in milliseconds. For example, if the timer must expire | |
* after 100 ticks, then xTimerPeriodInTicks should be set to 100. | |
* Alternatively, if the timer must expire after 500ms, then xPeriod can be set | |
* to ( 500 / portTICK_PERIOD_MS ) provided configTICK_RATE_HZ is less than or | |
* equal to 1000. | |
* | |
* @param uxAutoReload If uxAutoReload is set to pdTRUE then the timer will | |
* expire repeatedly with a frequency set by the xTimerPeriodInTicks parameter. | |
* If uxAutoReload is set to pdFALSE then the timer will be a one-shot timer and | |
* enter the dormant state after it expires. | |
* | |
* @param pvTimerID An identifier that is assigned to the timer being created. | |
* Typically this would be used in the timer callback function to identify which | |
* timer expired when the same callback function is assigned to more than one | |
* timer. | |
* | |
* @param pxCallbackFunction The function to call when the timer expires. | |
* Callback functions must have the prototype defined by TimerCallbackFunction_t, | |
* which is "void vCallbackFunction( TimerHandle_t xTimer );". | |
* | |
* @return If the timer is successfully created then a handle to the newly | |
* created timer is returned. If the timer cannot be created (because either | |
* there is insufficient FreeRTOS heap remaining to allocate the timer | |
* structures, or the timer period was set to 0) then NULL is returned. | |
* | |
* Example usage: | |
* @verbatim | |
* #define NUM_TIMERS 5 | |
* | |
* // An array to hold handles to the created timers. | |
* TimerHandle_t xTimers[ NUM_TIMERS ]; | |
* | |
* // An array to hold a count of the number of times each timer expires. | |
* int32_t lExpireCounters[ NUM_TIMERS ] = { 0 }; | |
* | |
* // Define a callback function that will be used by multiple timer instances. | |
* // The callback function does nothing but count the number of times the | |
* // associated timer expires, and stop the timer once the timer has expired | |
* // 10 times. | |
* void vTimerCallback( TimerHandle_t pxTimer ) | |
* { | |
* int32_t lArrayIndex; | |
* const int32_t xMaxExpiryCountBeforeStopping = 10; | |
* | |
* // Optionally do something if the pxTimer parameter is NULL. | |
* configASSERT( pxTimer ); | |
* | |
* // Which timer expired? | |
* lArrayIndex = ( int32_t ) pvTimerGetTimerID( pxTimer ); | |
* | |
* // Increment the number of times that pxTimer has expired. | |
* lExpireCounters[ lArrayIndex ] += 1; | |
* | |
* // If the timer has expired 10 times then stop it from running. | |
* if( lExpireCounters[ lArrayIndex ] == xMaxExpiryCountBeforeStopping ) | |
* { | |
* // Do not use a block time if calling a timer API function from a | |
* // timer callback function, as doing so could cause a deadlock! | |
* xTimerStop( pxTimer, 0 ); | |
* } | |
* } | |
* | |
* void main( void ) | |
* { | |
* int32_t x; | |
* | |
* // Create then start some timers. Starting the timers before the scheduler | |
* // has been started means the timers will start running immediately that | |
* // the scheduler starts. | |
* for( x = 0; x < NUM_TIMERS; x++ ) | |
* { | |
* xTimers[ x ] = xTimerCreate( "Timer", // Just a text name, not used by the kernel. | |
* ( 100 * x ), // The timer period in ticks. | |
* pdTRUE, // The timers will auto-reload themselves when they expire. | |
* ( void * ) x, // Assign each timer a unique id equal to its array index. | |
* vTimerCallback // Each timer calls the same callback when it expires. | |
* ); | |
* | |
* if( xTimers[ x ] == NULL ) | |
* { | |
* // The timer was not created. | |
* } | |
* else | |
* { | |
* // Start the timer. No block time is specified, and even if one was | |
* // it would be ignored because the scheduler has not yet been | |
* // started. | |
* if( xTimerStart( xTimers[ x ], 0 ) != pdPASS ) | |
* { | |
* // The timer could not be set into the Active state. | |
* } | |
* } | |
* } | |
* | |
* // ... | |
* // Create tasks here. | |
* // ... | |
* | |
* // Starting the scheduler will start the timers running as they have already | |
* // been set into the active state. | |
* vTaskStartScheduler(); | |
* | |
* // Should not reach here. | |
* for( ;; ); | |
* } | |
* @endverbatim | |
*/ | |
#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 UBaseType_t uxAutoReload, | |
void * const pvTimerID, | |
TimerCallbackFunction_t pxCallbackFunction ) PRIVILEGED_FUNCTION; | |
#endif | |
/** | |
* TimerHandle_t xTimerCreateStatic(const char * const pcTimerName, | |
* TickType_t xTimerPeriodInTicks, | |
* UBaseType_t uxAutoReload, | |
* void * pvTimerID, | |
* TimerCallbackFunction_t pxCallbackFunction, | |
* StaticTimer_t *pxTimerBuffer ); | |
* | |
* Creates a new software timer instance, and returns a handle by which the | |
* created software timer can be referenced. | |
* | |
* Internally, within the FreeRTOS implementation, software timers use a block | |
* of memory, in which the timer data structure is stored. If a software timer | |
* is created using xTimerCreate() then the required memory is automatically | |
* dynamically allocated inside the xTimerCreate() function. (see | |
* http://www.freertos.org/a00111.html). If a software timer is created using | |
* xTimerCreateStatic() then the application writer must provide the memory that | |
* will get used by the software timer. xTimerCreateStatic() therefore allows a | |
* software timer to be created without using any dynamic memory allocation. | |
* | |
* Timers are created in the dormant state. The xTimerStart(), xTimerReset(), | |
* xTimerStartFromISR(), xTimerResetFromISR(), xTimerChangePeriod() and | |
* xTimerChangePeriodFromISR() API functions can all be used to transition a | |
* timer into the active state. | |
* | |
* @param pcTimerName A text name that is assigned to the timer. This is done | |
* purely to assist debugging. The kernel itself only ever references a timer | |
* by its handle, and never by its name. | |
* | |
* @param xTimerPeriodInTicks The timer period. The time is defined in tick | |
* periods so the constant portTICK_PERIOD_MS can be used to convert a time that | |
* has been specified in milliseconds. For example, if the timer must expire | |
* after 100 ticks, then xTimerPeriodInTicks should be set to 100. | |
* Alternatively, if the timer must expire after 500ms, then xPeriod can be set | |
* to ( 500 / portTICK_PERIOD_MS ) provided configTICK_RATE_HZ is less than or | |
* equal to 1000. | |
* | |
* @param uxAutoReload If uxAutoReload is set to pdTRUE then the timer will | |
* expire repeatedly with a frequency set by the xTimerPeriodInTicks parameter. | |
* If uxAutoReload is set to pdFALSE then the timer will be a one-shot timer and | |
* enter the dormant state after it expires. | |
* | |
* @param pvTimerID An identifier that is assigned to the timer being created. | |
* Typically this would be used in the timer callback function to identify which | |
* timer expired when the same callback function is assigned to more than one | |
* timer. | |
* | |
* @param pxCallbackFunction The function to call when the timer expires. | |
* Callback functions must have the prototype defined by TimerCallbackFunction_t, | |
* which is "void vCallbackFunction( TimerHandle_t xTimer );". | |
* | |
* @param pxTimerBuffer Must point to a variable of type StaticTimer_t, which | |
* will be then be used to hold the software timer's data structures, removing | |
* the need for the memory to be allocated dynamically. | |
* | |
* @return If the timer is created then a handle to the created timer is | |
* returned. If pxTimerBuffer was NULL then NULL is returned. | |
* | |
* Example usage: | |
* @verbatim | |
* | |
* // The buffer used to hold the software timer's data structure. | |
* static StaticTimer_t xTimerBuffer; | |
* | |
* // A variable that will be incremented by the software timer's callback | |
* // function. | |
* UBaseType_t uxVariableToIncrement = 0; | |
* | |
* // A software timer callback function that increments a variable passed to | |
* // it when the software timer was created. After the 5th increment the | |
* // callback function stops the software timer. | |
* static void prvTimerCallback( TimerHandle_t xExpiredTimer ) | |
* { | |
* UBaseType_t *puxVariableToIncrement; | |
* BaseType_t xReturned; | |
* | |
* // Obtain the address of the variable to increment from the timer ID. | |
* puxVariableToIncrement = ( UBaseType_t * ) pvTimerGetTimerID( xExpiredTimer ); | |
* | |
* // Increment the variable to show the timer callback has executed. | |
* ( *puxVariableToIncrement )++; | |
* | |
* // If this callback has executed the required number of times, stop the | |
* // timer. | |
* if( *puxVariableToIncrement == 5 ) | |
* { | |
* // This is called from a timer callback so must not block. | |
* xTimerStop( xExpiredTimer, staticDONT_BLOCK ); | |
* } | |
* } | |
* | |
* | |
* void main( void ) | |
* { | |
* // Create the software time. xTimerCreateStatic() has an extra parameter | |
* // than the normal xTimerCreate() API function. The parameter is a pointer | |
* // to the StaticTimer_t structure that will hold the software timer | |
* // structure. If the parameter is passed as NULL then the structure will be | |
* // allocated dynamically, just as if xTimerCreate() had been called. | |
* xTimer = xTimerCreateStatic( "T1", // Text name for the task. Helps debugging only. Not used by FreeRTOS. | |
* xTimerPeriod, // The period of the timer in ticks. | |
* pdTRUE, // This is an auto-reload timer. | |
* ( void * ) &uxVariableToIncrement, // A variable incremented by the software timer's callback function | |
* prvTimerCallback, // The function to execute when the timer expires. | |
* &xTimerBuffer ); // The buffer that will hold the software timer structure. | |
* | |
* // The scheduler has not started yet so a block time is not used. | |
* xReturned = xTimerStart( xTimer, 0 ); | |
* | |
* // ... | |
* // Create tasks here. | |
* // ... | |
* | |
* // Starting the scheduler will start the timers running as they have already | |
* // been set into the active state. | |
* vTaskStartScheduler(); | |
* | |
* // Should not reach here. | |
* for( ;; ); | |
* } | |
* @endverbatim | |
*/ | |
#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 UBaseType_t uxAutoReload, | |
void * const pvTimerID, | |
TimerCallbackFunction_t pxCallbackFunction, | |
StaticTimer_t *pxTimerBuffer ) PRIVILEGED_FUNCTION; | |
#endif /* configSUPPORT_STATIC_ALLOCATION */ | |
/** | |
* void *pvTimerGetTimerID( TimerHandle_t xTimer ); | |
* | |
* Returns the ID assigned to the timer. | |
* | |
* IDs are assigned to timers using the pvTimerID parameter of the call to | |
* xTimerCreated() that was used to create the timer, and by calling the | |
* vTimerSetTimerID() API function. | |
* | |
* If the same callback function is assigned to multiple timers then the timer | |
* ID can be used as time specific (timer local) storage. | |
* | |
* @param xTimer The timer being queried. | |
* | |
* @return The ID assigned to the timer being queried. | |
* | |
* Example usage: | |
* | |
* See the xTimerCreate() API function example usage scenario. | |
*/ | |
void *pvTimerGetTimerID( const TimerHandle_t xTimer ) PRIVILEGED_FUNCTION; | |
/** | |
* void vTimerSetTimerID( TimerHandle_t xTimer, void *pvNewID ); | |
* | |
* Sets the ID assigned to the timer. | |
* | |
* IDs are assigned to timers using the pvTimerID parameter of the call to | |
* xTimerCreated() that was used to create the timer. | |
* | |
* If the same callback function is assigned to multiple timers then the timer | |
* ID can be used as time specific (timer local) storage. | |
* | |
* @param xTimer The timer being updated. | |
* | |
* @param pvNewID The ID to assign to the timer. | |
* | |
* Example usage: | |
* | |
* See the xTimerCreate() API function example usage scenario. | |
*/ | |
void vTimerSetTimerID( TimerHandle_t xTimer, void *pvNewID ) PRIVILEGED_FUNCTION; | |
/** | |
* BaseType_t xTimerIsTimerActive( TimerHandle_t xTimer ); | |
* | |
* Queries a timer to see if it is active or dormant. | |
* | |
* A timer will be dormant if: | |
* 1) It has been created but not started, or | |
* 2) It is an expired one-shot timer that has not been restarted. | |
* | |
* Timers are created in the dormant state. The xTimerStart(), xTimerReset(), | |
* xTimerStartFromISR(), xTimerResetFromISR(), xTimerChangePeriod() and | |
* xTimerChangePeriodFromISR() API functions can all be used to transition a timer into the | |
* active state. | |
* | |
* @param xTimer The timer being queried. | |
* | |
* @return pdFALSE will be returned if the timer is dormant. A value other than | |
* pdFALSE will be returned if the timer is active. | |
* | |
* Example usage: | |
* @verbatim | |
* // This function assumes xTimer has already been created. | |
* void vAFunction( TimerHandle_t xTimer ) | |
* { | |
* if( xTimerIsTimerActive( xTimer ) != pdFALSE ) // or more simply and equivalently "if( xTimerIsTimerActive( xTimer ) )" | |
* { | |
* // xTimer is active, do something. | |
* } | |
* else | |
* { | |
* // xTimer is not active, do something else. | |
* } | |
* } | |
* @endverbatim | |
*/ | |
BaseType_t xTimerIsTimerActive( TimerHandle_t xTimer ) PRIVILEGED_FUNCTION; | |
/** | |
* TaskHandle_t xTimerGetTimerDaemonTaskHandle( void ); | |
* | |
* Simply returns the handle of the timer service/daemon task. It it not valid | |
* to call xTimerGetTimerDaemonTaskHandle() before the scheduler has been started. | |
*/ | |
TaskHandle_t xTimerGetTimerDaemonTaskHandle( void ) PRIVILEGED_FUNCTION; | |
/** | |
* BaseType_t xTimerStart( TimerHandle_t xTimer, TickType_t xTicksToWait ); | |
* | |
* Timer functionality is provided by a timer service/daemon task. Many of the | |
* public FreeRTOS timer API functions send commands to the timer service task | |
* through a queue called the timer command queue. The timer command queue is | |
* private to the kernel itself and is not directly accessible to application | |
* code. The length of the timer command queue is set by the | |
* configTIMER_QUEUE_LENGTH configuration constant. | |
* | |
* xTimerStart() starts a timer that was previously created using the | |
* xTimerCreate() API function. If the timer had already been started and was | |
* already in the active state, then xTimerStart() has equivalent functionality | |
* to the xTimerReset() API function. | |
* | |
* Starting a timer ensures the timer is in the active state. If the timer | |
* is not stopped, deleted, or reset in the mean time, the callback function | |
* associated with the timer will get called 'n' ticks after xTimerStart() was | |
* called, where 'n' is the timers defined period. | |
* | |
* It is valid to call xTimerStart() before the scheduler has been started, but | |
* when this is done the timer will not actually start until the scheduler is | |
* started, and the timers expiry time will be relative to when the scheduler is | |
* started, not relative to when xTimerStart() was called. | |
* | |
* The configUSE_TIMERS configuration constant must be set to 1 for xTimerStart() | |
* to be available. | |
* | |
* @param xTimer The handle of the timer being started/restarted. | |
* | |
* @param xTicksToWait Specifies the time, in ticks, that the calling task should | |
* be held in the Blocked state to wait for the start command to be successfully | |
* sent to the timer command queue, should the queue already be full when | |
* xTimerStart() was called. xTicksToWait is ignored if xTimerStart() is called | |
* before the scheduler is started. | |
* | |
* @return pdFAIL will be returned if the start command could not be sent to | |
* the timer command queue even after xTicksToWait ticks had passed. pdPASS will | |
* be returned if the command was successfully sent to the timer command queue. | |
* When the command is actually processed will depend on the priority of the | |
* timer service/daemon task relative to other tasks in the system, although the | |
* timers expiry time is relative to when xTimerStart() is actually called. The | |
* timer service/daemon task priority is set by the configTIMER_TASK_PRIORITY | |
* configuration constant. | |
* | |
* Example usage: | |
* | |
* See the xTimerCreate() API function example usage scenario. | |
* | |
*/ | |
#define xTimerStart( xTimer, xTicksToWait ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_START, ( xTaskGetTickCount() ), NULL, ( xTicksToWait ) ) | |
/** | |
* BaseType_t xTimerStop( TimerHandle_t xTimer, TickType_t xTicksToWait ); | |
* | |
* Timer functionality is provided by a timer service/daemon task. Many of the | |
* public FreeRTOS timer API functions send commands to the timer service task | |
* through a queue called the timer command queue. The timer command queue is | |
* private to the kernel itself and is not directly accessible to application | |
* code. The length of the timer command queue is set by the | |
* configTIMER_QUEUE_LENGTH configuration constant. | |
* | |
* xTimerStop() stops a timer that was previously started using either of the | |
* The xTimerStart(), xTimerReset(), xTimerStartFromISR(), xTimerResetFromISR(), | |
* xTimerChangePeriod() or xTimerChangePeriodFromISR() API functions. | |
* | |
* Stopping a timer ensures the timer is not in the active state. | |
* | |
* The configUSE_TIMERS configuration constant must be set to 1 for xTimerStop() | |
* to be available. | |
* | |
* @param xTimer The handle of the timer being stopped. | |
* | |
* @param xTicksToWait Specifies the time, in ticks, that the calling task should | |
* be held in the Blocked state to wait for the stop command to be successfully | |
* sent to the timer command queue, should the queue already be full when | |
* xTimerStop() was called. xTicksToWait is ignored if xTimerStop() is called | |
* before the scheduler is started. | |
* | |
* @return pdFAIL will be returned if the stop command could not be sent to | |
* the timer command queue even after xTicksToWait ticks had passed. pdPASS will | |
* be returned if the command was successfully sent to the timer command queue. | |
* When the command is actually processed will depend on the priority of the | |
* timer service/daemon task relative to other tasks in the system. The timer | |
* service/daemon task priority is set by the configTIMER_TASK_PRIORITY | |
* configuration constant. | |
* | |
* Example usage: | |
* | |
* See the xTimerCreate() API function example usage scenario. | |
* | |
*/ | |
#define xTimerStop( xTimer, xTicksToWait ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_STOP, 0U, NULL, ( xTicksToWait ) ) | |
/** | |
* BaseType_t xTimerChangePeriod( TimerHandle_t xTimer, | |
* TickType_t xNewPeriod, | |
* TickType_t xTicksToWait ); | |
* | |
* Timer functionality is provided by a timer service/daemon task. Many of the | |
* public FreeRTOS timer API functions send commands to the timer service task | |
* through a queue called the timer command queue. The timer command queue is | |
* private to the kernel itself and is not directly accessible to application | |
* code. The length of the timer command queue is set by the | |
* configTIMER_QUEUE_LENGTH configuration constant. | |
* | |
* xTimerChangePeriod() changes the period of a timer that was previously | |
* created using the xTimerCreate() API function. | |
* | |
* xTimerChangePeriod() can be called to change the period of an active or | |
* dormant state timer. | |
* | |
* The configUSE_TIMERS configuration constant must be set to 1 for | |
* xTimerChangePeriod() to be available. | |
* | |
* @param xTimer The handle of the timer that is having its period changed. | |
* | |
* @param xNewPeriod The new period for xTimer. Timer periods are specified in | |
* tick periods, so the constant portTICK_PERIOD_MS can be used to convert a time | |
* that has been specified in milliseconds. For example, if the timer must | |
* expire after 100 ticks, then xNewPeriod should be set to 100. Alternatively, | |
* if the timer must expire after 500ms, then xNewPeriod can be set to | |
* ( 500 / portTICK_PERIOD_MS ) provided configTICK_RATE_HZ is less than | |
* or equal to 1000. | |
* | |
* @param xTicksToWait Specifies the time, in ticks, that the calling task should | |
* be held in the Blocked state to wait for the change period command to be | |
* successfully sent to the timer command queue, should the queue already be | |
* full when xTimerChangePeriod() was called. xTicksToWait is ignored if | |
* xTimerChangePeriod() is called before the scheduler is started. | |
* | |
* @return pdFAIL will be returned if the change period command could not be | |
* sent to the timer command queue even after xTicksToWait ticks had passed. | |
* pdPASS will be returned if the command was successfully sent to the timer | |
* command queue. When the command is actually processed will depend on the | |
* priority of the timer service/daemon task relative to other tasks in the | |
* system. The timer service/daemon task priority is set by the | |
* configTIMER_TASK_PRIORITY configuration constant. | |
* | |
* Example usage: | |
* @verbatim | |
* // This function assumes xTimer has already been created. If the timer | |
* // referenced by xTimer is already active when it is called, then the timer | |
* // is deleted. If the timer referenced by xTimer is not active when it is | |
* // called, then the period of the timer is set to 500ms and the timer is | |
* // started. | |
* void vAFunction( TimerHandle_t xTimer ) | |
* { | |
* if( xTimerIsTimerActive( xTimer ) != pdFALSE ) // or more simply and equivalently "if( xTimerIsTimerActive( xTimer ) )" | |
* { | |
* // xTimer is already active - delete it. | |
* xTimerDelete( xTimer ); | |
* } | |
* else | |
* { | |
* // xTimer is not active, change its period to 500ms. This will also | |
* // cause the timer to start. Block for a maximum of 100 ticks if the | |
* // change period command cannot immediately be sent to the timer | |
* // command queue. | |
* if( xTimerChangePeriod( xTimer, 500 / portTICK_PERIOD_MS, 100 ) == pdPASS ) | |
* { | |
* // The command was successfully sent. | |
* } | |
* else | |
* { | |
* // The command could not be sent, even after waiting for 100 ticks | |
* // to pass. Take appropriate action here. | |
* } | |
* } | |
* } | |
* @endverbatim | |
*/ | |
#define xTimerChangePeriod( xTimer, xNewPeriod, xTicksToWait ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_CHANGE_PERIOD, ( xNewPeriod ), NULL, ( xTicksToWait ) ) | |
/** | |
* BaseType_t xTimerDelete( TimerHandle_t xTimer, TickType_t xTicksToWait ); | |
* | |
* Timer functionality is provided by a timer service/daemon task. Many of the | |
* public FreeRTOS timer API functions send commands to the timer service task | |
* through a queue called the timer command queue. The timer command queue is | |
* private to the kernel itself and is not directly accessible to application | |
* code. The length of the timer command queue is set by the | |
* configTIMER_QUEUE_LENGTH configuration constant. | |
* | |
* xTimerDelete() deletes a timer that was previously created using the | |
* xTimerCreate() API function. | |
* | |
* The configUSE_TIMERS configuration constant must be set to 1 for | |
* xTimerDelete() to be available. | |
* | |
* @param xTimer The handle of the timer being deleted. | |
* | |
* @param xTicksToWait Specifies the time, in ticks, that the calling task should | |
* be held in the Blocked state to wait for the delete command to be | |
* successfully sent to the timer command queue, should the queue already be | |
* full when xTimerDelete() was called. xTicksToWait is ignored if xTimerDelete() | |
* is called before the scheduler is started. | |
* | |
* @return pdFAIL will be returned if the delete command could not be sent to | |
* the timer command queue even after xTicksToWait ticks had passed. pdPASS will | |
* be returned if the command was successfully sent to the timer command queue. | |
* When the command is actually processed will depend on the priority of the | |
* timer service/daemon task relative to other tasks in the system. The timer | |
* service/daemon task priority is set by the configTIMER_TASK_PRIORITY | |
* configuration constant. | |
* | |
* Example usage: | |
* | |
* See the xTimerChangePeriod() API function example usage scenario. | |
*/ | |
#define xTimerDelete( xTimer, xTicksToWait ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_DELETE, 0U, NULL, ( xTicksToWait ) ) | |
/** | |
* BaseType_t xTimerReset( TimerHandle_t xTimer, TickType_t xTicksToWait ); | |
* | |
* Timer functionality is provided by a timer service/daemon task. Many of the | |
* public FreeRTOS timer API functions send commands to the timer service task | |
* through a queue called the timer command queue. The timer command queue is | |
* private to the kernel itself and is not directly accessible to application | |
* code. The length of the timer command queue is set by the | |
* configTIMER_QUEUE_LENGTH configuration constant. | |
* | |
* xTimerReset() re-starts a timer that was previously created using the | |
* xTimerCreate() API function. If the timer had already been started and was | |
* already in the active state, then xTimerReset() will cause the timer to | |
* re-evaluate its expiry time so that it is relative to when xTimerReset() was | |
* called. If the timer was in the dormant state then xTimerReset() has | |
* equivalent functionality to the xTimerStart() API function. | |
* | |
* Resetting a timer ensures the timer is in the active state. If the timer | |
* is not stopped, deleted, or reset in the mean time, the callback function | |
* associated with the timer will get called 'n' ticks after xTimerReset() was | |
* called, where 'n' is the timers defined period. | |
* | |
* It is valid to call xTimerReset() before the scheduler has been started, but | |
* when this is done the timer will not actually start until the scheduler is | |
* started, and the timers expiry time will be relative to when the scheduler is | |
* started, not relative to when xTimerReset() was called. | |
* | |
* The configUSE_TIMERS configuration constant must be set to 1 for xTimerReset() | |
* to be available. | |
* | |
* @param xTimer The handle of the timer being reset/started/restarted. | |
* | |
* @param xTicksToWait Specifies the time, in ticks, that the calling task should | |
* be held in the Blocked state to wait for the reset command to be successfully | |
* sent to the timer command queue, should the queue already be full when | |
* xTimerReset() was called. xTicksToWait is ignored if xTimerReset() is called | |
* before the scheduler is started. | |
* | |
* @return pdFAIL will be returned if the reset command could not be sent to | |
* the timer command queue even after xTicksToWait ticks had passed. pdPASS will | |
* be returned if the command was successfully sent to the timer command queue. | |
* When the command is actually processed will depend on the priority of the | |
* timer service/daemon task relative to other tasks in the system, although the | |
* timers expiry time is relative to when xTimerStart() is actually called. The | |
* timer service/daemon task priority is set by the configTIMER_TASK_PRIORITY | |
* configuration constant. | |
* | |
* Example usage: | |
* @verbatim | |
* // When a key is pressed, an LCD back-light is switched on. If 5 seconds pass | |
* // without a key being pressed, then the LCD back-light is switched off. In | |
* // this case, the timer is a one-shot timer. | |
* | |
* TimerHandle_t xBacklightTimer = NULL; | |
* | |
* // The callback function assigned to the one-shot timer. In this case the | |
* // parameter is not used. | |
* void vBacklightTimerCallback( TimerHandle_t pxTimer ) | |
* { | |
* // The timer expired, therefore 5 seconds must have passed since a key | |
* // was pressed. Switch off the LCD back-light. | |
* vSetBacklightState( BACKLIGHT_OFF ); | |
* } | |
* | |
* // The key press event handler. | |
* void vKeyPressEventHandler( char cKey ) | |
* { | |
* // Ensure the LCD back-light is on, then reset the timer that is | |
* // responsible for turning the back-light off after 5 seconds of | |
* // key inactivity. Wait 10 ticks for the command to be successfully sent | |
* // if it cannot be sent immediately. | |
* vSetBacklightState( BACKLIGHT_ON ); | |
* if( xTimerReset( xBacklightTimer, 100 ) != pdPASS ) | |
* { | |
* // The reset command was not executed successfully. Take appropriate | |
* // action here. | |
* } | |
* | |
* // Perform the rest of the key processing here. | |
* } | |
* | |
* void main( void ) | |
* { | |
* int32_t x; | |
* | |
* // Create then start the one-shot timer that is responsible for turning | |
* // the back-light off if no keys are pressed within a 5 second period. | |
* xBacklightTimer = xTimerCreate( "BacklightTimer", // Just a text name, not used by the kernel. | |
* ( 5000 / portTICK_PERIOD_MS), // The timer period in ticks. | |
* pdFALSE, // The timer is a one-shot timer. | |
* 0, // The id is not used by the callback so can take any value. | |
* vBacklightTimerCallback // The callback function that switches the LCD back-light off. | |
* ); | |
* | |
* if( xBacklightTimer == NULL ) | |
* { | |
* // The timer was not created. | |
* } | |
* else | |
* { | |
* // Start the timer. No block time is specified, and even if one was | |
* // it would be ignored because the scheduler has not yet been | |
* // started. | |
* if( xTimerStart( xBacklightTimer, 0 ) != pdPASS ) | |
* { | |
* // The timer could not be set into the Active state. | |
* } | |
* } | |
* | |
* // ... | |
* // Create tasks here. | |
* // ... | |
* | |
* // Starting the scheduler will start the timer running as it has already | |
* // been set into the active state. | |
* vTaskStartScheduler(); | |
* | |
* // Should not reach here. | |
* for( ;; ); | |
* } | |
* @endverbatim | |
*/ | |
#define xTimerReset( xTimer, xTicksToWait ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_RESET, ( xTaskGetTickCount() ), NULL, ( xTicksToWait ) ) | |
/** | |
* BaseType_t xTimerStartFromISR( TimerHandle_t xTimer, | |
* BaseType_t *pxHigherPriorityTaskWoken ); | |
* | |
* A version of xTimerStart() that can be called from an interrupt service | |
* routine. | |
* | |
* @param xTimer The handle of the timer being started/restarted. | |
* | |
* @param pxHigherPriorityTaskWoken The timer service/daemon task spends most | |
* of its time in the Blocked state, waiting for messages to arrive on the timer | |
* command queue. Calling xTimerStartFromISR() writes a message to the timer | |
* command queue, so has the potential to transition the timer service/daemon | |
* task out of the Blocked state. If calling xTimerStartFromISR() causes the | |
* timer service/daemon task to leave the Blocked state, and the timer service/ | |
* daemon task has a priority equal to or greater than the currently executing | |
* task (the task that was interrupted), then *pxHigherPriorityTaskWoken will | |
* get set to pdTRUE internally within the xTimerStartFromISR() function. If | |
* xTimerStartFromISR() sets this value to pdTRUE then a context switch should | |
* be performed before the interrupt exits. | |
* | |
* @return pdFAIL will be returned if the start command could not be sent to | |
* the timer command queue. pdPASS will be returned if the command was | |
* successfully sent to the timer command queue. When the command is actually | |
* processed will depend on the priority of the timer service/daemon task | |
* relative to other tasks in the system, although the timers expiry time is | |
* relative to when xTimerStartFromISR() is actually called. The timer | |
* service/daemon task priority is set by the configTIMER_TASK_PRIORITY | |
* configuration constant. | |
* | |
* Example usage: | |
* @verbatim | |
* // This scenario assumes xBacklightTimer has already been created. When a | |
* // key is pressed, an LCD back-light is switched on. If 5 seconds pass | |
* // without a key being pressed, then the LCD back-light is switched off. In | |
* // this case, the timer is a one-shot timer, and unlike the example given for | |
* // the xTimerReset() function, the key press event handler is an interrupt | |
* // service routine. | |
* | |
* // The callback function assigned to the one-shot timer. In this case the | |
* // parameter is not used. | |
* void vBacklightTimerCallback( TimerHandle_t pxTimer ) | |
* { | |
* // The timer expired, therefore 5 seconds must have passed since a key | |
* // was pressed. Switch off the LCD back-light. | |
* vSetBacklightState( BACKLIGHT_OFF ); | |
* } | |
* | |
* // The key press interrupt service routine. | |
* void vKeyPressEventInterruptHandler( void ) | |
* { | |
* BaseType_t xHigherPriorityTaskWoken = pdFALSE; | |
* | |
* // Ensure the LCD back-light is on, then restart the timer that is | |
* // responsible for turning the back-light off after 5 seconds of | |
* // key inactivity. This is an interrupt service routine so can only | |
* // call FreeRTOS API functions that end in "FromISR". | |
* vSetBacklightState( BACKLIGHT_ON ); | |
* | |
* // xTimerStartFromISR() or xTimerResetFromISR() could be called here | |
* // as both cause the timer to re-calculate its expiry time. | |
* // xHigherPriorityTaskWoken was initialised to pdFALSE when it was | |
* // declared (in this function). | |
* if( xTimerStartFromISR( xBacklightTimer, &xHigherPriorityTaskWoken ) != pdPASS ) | |
* { | |
* // The start command was not executed successfully. Take appropriate | |
* // action here. | |
* } | |
* | |
* // Perform the rest of the key processing here. | |
* | |
* // If xHigherPriorityTaskWoken equals pdTRUE, then a context switch | |
* // should be performed. The syntax required to perform a context switch | |
* // from inside an ISR varies from port to port, and from compiler to | |
* // compiler. Inspect the demos for the port you are using to find the | |
* // actual syntax required. | |
* if( xHigherPriorityTaskWoken != pdFALSE ) | |
* { | |
* // Call the interrupt safe yield function here (actual function | |
* // depends on the FreeRTOS port being used). | |
* } | |
* } | |
* @endverbatim | |
*/ | |
#define xTimerStartFromISR( xTimer, pxHigherPriorityTaskWoken ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_START_FROM_ISR, ( xTaskGetTickCountFromISR() ), ( pxHigherPriorityTaskWoken ), 0U ) | |
/** | |
* BaseType_t xTimerStopFromISR( TimerHandle_t xTimer, | |
* BaseType_t *pxHigherPriorityTaskWoken ); | |
* | |
* A version of xTimerStop() that can be called from an interrupt service | |
* routine. | |
* | |
* @param xTimer The handle of the timer being stopped. | |
* | |
* @param pxHigherPriorityTaskWoken The timer service/daemon task spends most | |
* of its time in the Blocked state, waiting for messages to arrive on the timer | |
* command queue. Calling xTimerStopFromISR() writes a message to the timer | |
* command queue, so has the potential to transition the timer service/daemon | |
* task out of the Blocked state. If calling xTimerStopFromISR() causes the | |
* timer service/daemon task to leave the Blocked state, and the timer service/ | |
* daemon task has a priority equal to or greater than the currently executing | |
* task (the task that was interrupted), then *pxHigherPriorityTaskWoken will | |
* get set to pdTRUE internally within the xTimerStopFromISR() function. If | |
* xTimerStopFromISR() sets this value to pdTRUE then a context switch should | |
* be performed before the interrupt exits. | |
* | |
* @return pdFAIL will be returned if the stop command could not be sent to | |
* the timer command queue. pdPASS will be returned if the command was | |
* successfully sent to the timer command queue. When the command is actually | |
* processed will depend on the priority of the timer service/daemon task | |
* relative to other tasks in the system. The timer service/daemon task | |
* priority is set by the configTIMER_TASK_PRIORITY configuration constant. | |
* | |
* Example usage: | |
* @verbatim | |
* // This scenario assumes xTimer has already been created and started. When | |
* // an interrupt occurs, the timer should be simply stopped. | |
* | |
* // The interrupt service routine that stops the timer. | |
* void vAnExampleInterruptServiceRoutine( void ) | |
* { | |
* BaseType_t xHigherPriorityTaskWoken = pdFALSE; | |
* | |
* // The interrupt has occurred - simply stop the timer. | |
* // xHigherPriorityTaskWoken was set to pdFALSE where it was defined | |
* // (within this function). As this is an interrupt service routine, only | |
* // FreeRTOS API functions that end in "FromISR" can be used. | |
* if( xTimerStopFromISR( xTimer, &xHigherPriorityTaskWoken ) != pdPASS ) | |
* { | |
* // The stop command was not executed successfully. Take appropriate | |
* // action here. | |
* } | |
* | |
* // If xHigherPriorityTaskWoken equals pdTRUE, then a context switch | |
* // should be performed. The syntax required to perform a context switch | |
* // from inside an ISR varies from port to port, and from compiler to | |
* // compiler. Inspect the demos for the port you are using to find the | |
* // actual syntax required. | |
* if( xHigherPriorityTaskWoken != pdFALSE ) | |
* { | |
* // Call the interrupt safe yield function here (actual function | |
* // depends on the FreeRTOS port being used). | |
* } | |
* } | |
* @endverbatim | |
*/ | |
#define xTimerStopFromISR( xTimer, pxHigherPriorityTaskWoken ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_STOP_FROM_ISR, 0, ( pxHigherPriorityTaskWoken ), 0U ) | |
/** | |
* BaseType_t xTimerChangePeriodFromISR( TimerHandle_t xTimer, | |
* TickType_t xNewPeriod, | |
* BaseType_t *pxHigherPriorityTaskWoken ); | |
* | |
* A version of xTimerChangePeriod() that can be called from an interrupt | |
* service routine. | |
* | |
* @param xTimer The handle of the timer that is having its period changed. | |
* | |
* @param xNewPeriod The new period for xTimer. Timer periods are specified in | |
* tick periods, so the constant portTICK_PERIOD_MS can be used to convert a time | |
* that has been specified in milliseconds. For example, if the timer must | |
* expire after 100 ticks, then xNewPeriod should be set to 100. Alternatively, | |
* if the timer must expire after 500ms, then xNewPeriod can be set to | |
* ( 500 / portTICK_PERIOD_MS ) provided configTICK_RATE_HZ is less than | |
* or equal to 1000. | |
* | |
* @param pxHigherPriorityTaskWoken The timer service/daemon task spends most | |
* of its time in the Blocked state, waiting for messages to arrive on the timer | |
* command queue. Calling xTimerChangePeriodFromISR() writes a message to the | |
* timer command queue, so has the potential to transition the timer service/ | |
* daemon task out of the Blocked state. If calling xTimerChangePeriodFromISR() | |
* causes the timer service/daemon task to leave the Blocked state, and the | |
* timer service/daemon task has a priority equal to or greater than the | |
* currently executing task (the task that was interrupted), then | |
* *pxHigherPriorityTaskWoken will get set to pdTRUE internally within the | |
* xTimerChangePeriodFromISR() function. If xTimerChangePeriodFromISR() sets | |
* this value to pdTRUE then a context switch should be performed before the | |
* interrupt exits. | |
* | |
* @return pdFAIL will be returned if the command to change the timers period | |
* could not be sent to the timer command queue. pdPASS will be returned if the | |
* command was successfully sent to the timer command queue. When the command | |
* is actually processed will depend on the priority of the timer service/daemon | |
* task relative to other tasks in the system. The timer service/daemon task | |
* priority is set by the configTIMER_TASK_PRIORITY configuration constant. | |
* | |
* Example usage: | |
* @verbatim | |
* // This scenario assumes xTimer has already been created and started. When | |
* // an interrupt occurs, the period of xTimer should be changed to 500ms. | |
* | |
* // The interrupt service routine that changes the period of xTimer. | |
* void vAnExampleInterruptServiceRoutine( void ) | |
* { | |
* BaseType_t xHigherPriorityTaskWoken = pdFALSE; | |
* | |
* // The interrupt has occurred - change the period of xTimer to 500ms. | |
* // xHigherPriorityTaskWoken was set to pdFALSE where it was defined | |
* // (within this function). As this is an interrupt service routine, only | |
* // FreeRTOS API functions that end in "FromISR" can be used. | |
* if( xTimerChangePeriodFromISR( xTimer, &xHigherPriorityTaskWoken ) != pdPASS ) | |
* { | |
* // The command to change the timers period was not executed | |
* // successfully. Take appropriate action here. | |
* } | |
* | |
* // If xHigherPriorityTaskWoken equals pdTRUE, then a context switch | |
* // should be performed. The syntax required to perform a context switch | |
* // from inside an ISR varies from port to port, and from compiler to | |
* // compiler. Inspect the demos for the port you are using to find the | |
* // actual syntax required. | |
* if( xHigherPriorityTaskWoken != pdFALSE ) | |
* { | |
* // Call the interrupt safe yield function here (actual function | |
* // depends on the FreeRTOS port being used). | |
* } | |
* } | |
* @endverbatim | |
*/ | |
#define xTimerChangePeriodFromISR( xTimer, xNewPeriod, pxHigherPriorityTaskWoken ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_CHANGE_PERIOD_FROM_ISR, ( xNewPeriod ), ( pxHigherPriorityTaskWoken ), 0U ) | |
/** | |
* BaseType_t xTimerResetFromISR( TimerHandle_t xTimer, | |
* BaseType_t *pxHigherPriorityTaskWoken ); | |
* | |
* A version of xTimerReset() that can be called from an interrupt service | |
* routine. | |
* | |
* @param xTimer The handle of the timer that is to be started, reset, or | |
* restarted. | |
* | |
* @param pxHigherPriorityTaskWoken The timer service/daemon task spends most | |
* of its time in the Blocked state, waiting for messages to arrive on the timer | |
* command queue. Calling xTimerResetFromISR() writes a message to the timer | |
* command queue, so has the potential to transition the timer service/daemon | |
* task out of the Blocked state. If calling xTimerResetFromISR() causes the | |
* timer service/daemon task to leave the Blocked state, and the timer service/ | |
* daemon task has a priority equal to or greater than the currently executing | |
* task (the task that was interrupted), then *pxHigherPriorityTaskWoken will | |
* get set to pdTRUE internally within the xTimerResetFromISR() function. If | |
* xTimerResetFromISR() sets this value to pdTRUE then a context switch should | |
* be performed before the interrupt exits. | |
* | |
* @return pdFAIL will be returned if the reset command could not be sent to | |
* the timer command queue. pdPASS will be returned if the command was | |
* successfully sent to the timer command queue. When the command is actually | |
* processed will depend on the priority of the timer service/daemon task | |
* relative to other tasks in the system, although the timers expiry time is | |
* relative to when xTimerResetFromISR() is actually called. The timer service/daemon | |
* task priority is set by the configTIMER_TASK_PRIORITY configuration constant. | |
* | |
* Example usage: | |
* @verbatim | |
* // This scenario assumes xBacklightTimer has already been created. When a | |
* // key is pressed, an LCD back-light is switched on. If 5 seconds pass | |
* // without a key being pressed, then the LCD back-light is switched off. In | |
* // this case, the timer is a one-shot timer, and unlike the example given for | |
* // the xTimerReset() function, the key press event handler is an interrupt | |
* // service routine. | |
* | |
* // The callback function assigned to the one-shot timer. In this case the | |
* // parameter is not used. | |
* void vBacklightTimerCallback( TimerHandle_t pxTimer ) | |
* { | |
* // The timer expired, therefore 5 seconds must have passed since a key | |
* // was pressed. Switch off the LCD back-light. | |
* vSetBacklightState( BACKLIGHT_OFF ); | |
* } | |
* | |
* // The key press interrupt service routine. | |
* void vKeyPressEventInterruptHandler( void ) | |
* { | |
* BaseType_t xHigherPriorityTaskWoken = pdFALSE; | |
* | |
* // Ensure the LCD back-light is on, then reset the timer that is | |
* // responsible for turning the back-light off after 5 seconds of | |
* // key inactivity. This is an interrupt service routine so can only | |
* // call FreeRTOS API functions that end in "FromISR". | |
* vSetBacklightState( BACKLIGHT_ON ); | |
* | |
* // xTimerStartFromISR() or xTimerResetFromISR() could be called here | |
* // as both cause the timer to re-calculate its expiry time. | |
* // xHigherPriorityTaskWoken was initialised to pdFALSE when it was | |
* // declared (in this function). | |
* if( xTimerResetFromISR( xBacklightTimer, &xHigherPriorityTaskWoken ) != pdPASS ) | |
* { | |
* // The reset command was not executed successfully. Take appropriate | |
* // action here. | |
* } | |
* | |
* // Perform the rest of the key processing here. | |
* | |
* // If xHigherPriorityTaskWoken equals pdTRUE, then a context switch | |
* // should be performed. The syntax required to perform a context switch | |
* // from inside an ISR varies from port to port, and from compiler to | |
* // compiler. Inspect the demos for the port you are using to find the | |
* // actual syntax required. | |
* if( xHigherPriorityTaskWoken != pdFALSE ) | |
* { | |
* // Call the interrupt safe yield function here (actual function | |
* // depends on the FreeRTOS port being used). | |
* } | |
* } | |
* @endverbatim | |
*/ | |
#define xTimerResetFromISR( xTimer, pxHigherPriorityTaskWoken ) xTimerGenericCommand( ( xTimer ), tmrCOMMAND_RESET_FROM_ISR, ( xTaskGetTickCountFromISR() ), ( pxHigherPriorityTaskWoken ), 0U ) | |
/** | |
* BaseType_t xTimerPendFunctionCallFromISR( PendedFunction_t xFunctionToPend, | |
* void *pvParameter1, | |
* uint32_t ulParameter2, | |
* BaseType_t *pxHigherPriorityTaskWoken ); | |
* | |
* | |
* Used from application interrupt service routines to defer the execution of a | |
* function to the RTOS daemon task (the timer service task, hence this function | |
* is implemented in timers.c and is prefixed with 'Timer'). | |
* | |
* Ideally an interrupt service routine (ISR) is kept as short as possible, but | |
* sometimes an ISR either has a lot of processing to do, or needs to perform | |
* processing that is not deterministic. In these cases | |
* xTimerPendFunctionCallFromISR() can be used to defer processing of a function | |
* to the RTOS daemon task. | |
* | |
* A mechanism is provided that allows the interrupt to return directly to the | |
* task that will subsequently execute the pended callback function. This | |
* allows the callback function to execute contiguously in time with the | |
* interrupt - just as if the callback had executed in the interrupt itself. | |
* | |
* @param xFunctionToPend The function to execute from the timer service/ | |
* daemon task. The function must conform to the PendedFunction_t | |
* prototype. | |
* | |
* @param pvParameter1 The value of the callback function's first parameter. | |
* The parameter has a void * type to allow it to be used to pass any type. | |
* For example, unsigned longs can be cast to a void *, or the void * can be | |
* used to point to a structure. | |
* | |
* @param ulParameter2 The value of the callback function's second parameter. | |
* | |
* @param pxHigherPriorityTaskWoken As mentioned above, calling this function | |
* will result in a message being sent to the timer daemon task. If the | |
* priority of the timer daemon task (which is set using | |
* configTIMER_TASK_PRIORITY in FreeRTOSConfig.h) is higher than the priority of | |
* the currently running task (the task the interrupt interrupted) then | |
* *pxHigherPriorityTaskWoken will be set to pdTRUE within | |
* xTimerPendFunctionCallFromISR(), indicating that a context switch should be | |
* requested before the interrupt exits. For that reason | |
* *pxHigherPriorityTaskWoken must be initialised to pdFALSE. See the | |
* example code below. | |
* | |
* @return pdPASS is returned if the message was successfully sent to the | |
* timer daemon task, otherwise pdFALSE is returned. | |
* | |
* Example usage: | |
* @verbatim | |
* | |
* // The callback function that will execute in the context of the daemon task. | |
* // Note callback functions must all use this same prototype. | |
* void vProcessInterface( void *pvParameter1, uint32_t ulParameter2 ) | |
* { | |
* BaseType_t xInterfaceToService; | |
* | |
* // The interface that requires servicing is passed in the second | |
* // parameter. The first parameter is not used in this case. | |
* xInterfaceToService = ( BaseType_t ) ulParameter2; | |
* | |
* // ...Perform the processing here... | |
* } | |
* | |
* // An ISR that receives data packets from multiple interfaces | |
* void vAnISR( void ) | |
* { | |
* BaseType_t xInterfaceToService, xHigherPriorityTaskWoken; | |
* | |
* // Query the hardware to determine which interface needs processing. | |
* xInterfaceToService = prvCheckInterfaces(); | |
* | |
* // The actual processing is to be deferred to a task. Request the | |
* // vProcessInterface() callback function is executed, passing in the | |
* // number of the interface that needs processing. The interface to | |
* // service is passed in the second parameter. The first parameter is | |
* // not used in this case. | |
* xHigherPriorityTaskWoken = pdFALSE; | |
* xTimerPendFunctionCallFromISR( vProcessInterface, NULL, ( uint32_t ) xInterfaceToService, &xHigherPriorityTaskWoken ); | |
* | |
* // If xHigherPriorityTaskWoken is now set to pdTRUE then a context | |
* // switch should be requested. The macro used is port specific and will | |
* // be either portYIELD_FROM_ISR() or portEND_SWITCHING_ISR() - refer to | |
* // the documentation page for the port being used. | |
* portYIELD_FROM_ISR( xHigherPriorityTaskWoken ); | |
* | |
* } | |
* @endverbatim | |
*/ | |
BaseType_t xTimerPendFunctionCallFromISR( PendedFunction_t xFunctionToPend, void *pvParameter1, uint32_t ulParameter2, BaseType_t *pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION; | |
/** | |
* BaseType_t xTimerPendFunctionCall( PendedFunction_t xFunctionToPend, | |
* void *pvParameter1, | |
* uint32_t ulParameter2, | |
* TickType_t xTicksToWait ); | |
* | |
* | |
* Used to defer the execution of a function to the RTOS daemon task (the timer | |
* service task, hence this function is implemented in timers.c and is prefixed | |
* with 'Timer'). | |
* | |
* @param xFunctionToPend The function to execute from the timer service/ | |
* daemon task. The function must conform to the PendedFunction_t | |
* prototype. | |
* | |
* @param pvParameter1 The value of the callback function's first parameter. | |
* The parameter has a void * type to allow it to be used to pass any type. | |
* For example, unsigned longs can be cast to a void *, or the void * can be | |
* used to point to a structure. | |
* | |
* @param ulParameter2 The value of the callback function's second parameter. | |
* | |
* @param xTicksToWait Calling this function will result in a message being | |
* sent to the timer daemon task on a queue. xTicksToWait is the amount of | |
* time the calling task should remain in the Blocked state (so not using any | |
* processing time) for space to become available on the timer queue if the | |
* queue is found to be full. | |
* | |
* @return pdPASS is returned if the message was successfully sent to the | |
* timer daemon task, otherwise pdFALSE is returned. | |
* | |
*/ | |
BaseType_t xTimerPendFunctionCall( PendedFunction_t xFunctionToPend, void *pvParameter1, uint32_t ulParameter2, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION; | |
/** | |
* const char * const pcTimerGetName( TimerHandle_t xTimer ); | |
* | |
* Returns the name that was assigned to a timer when the timer was created. | |
* | |
* @param xTimer The handle of the timer being queried. | |
* | |
* @return The name assigned to the timer specified by the xTimer parameter. | |
*/ | |
const char * pcTimerGetName( TimerHandle_t xTimer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */ | |
/** | |
* void vTimerSetReloadMode( TimerHandle_t xTimer, const UBaseType_t uxAutoReload ); | |
* | |
* Updates a timer to be either an auto-reload timer, in which case the timer | |
* automatically resets itself each time it expires, or a one-shot timer, in | |
* which case the timer will only expire once unless it is manually restarted. | |
* | |
* @param xTimer The handle of the timer being updated. | |
* | |
* @param uxAutoReload If uxAutoReload is set to pdTRUE then the timer will | |
* expire repeatedly with a frequency set by the timer's period (see the | |
* xTimerPeriodInTicks parameter of the xTimerCreate() API function). If | |
* uxAutoReload is set to pdFALSE then the timer will be a one-shot timer and | |
* enter the dormant state after it expires. | |
*/ | |
void vTimerSetReloadMode( TimerHandle_t xTimer, const UBaseType_t uxAutoReload ) PRIVILEGED_FUNCTION; | |
/** | |
* UBaseType_t uxTimerGetReloadMode( TimerHandle_t xTimer ); | |
* | |
* Queries a timer to determine if it is an auto-reload timer, in which case the timer | |
* automatically resets itself each time it expires, or a one-shot timer, in | |
* which case the timer will only expire once unless it is manually restarted. | |
* | |
* @param xTimer The handle of the timer being queried. | |
* | |
* @return If the timer is an auto-reload timer then pdTRUE is returned, otherwise | |
* pdFALSE is returned. | |
*/ | |
UBaseType_t uxTimerGetReloadMode( TimerHandle_t xTimer ) PRIVILEGED_FUNCTION; | |
/** | |
* TickType_t xTimerGetPeriod( TimerHandle_t xTimer ); | |
* | |
* Returns the period of a timer. | |
* | |
* @param xTimer The handle of the timer being queried. | |
* | |
* @return The period of the timer in ticks. | |
*/ | |
TickType_t xTimerGetPeriod( TimerHandle_t xTimer ) PRIVILEGED_FUNCTION; | |
/** | |
* TickType_t xTimerGetExpiryTime( TimerHandle_t xTimer ); | |
* | |
* Returns the time in ticks at which the timer will expire. If this is less | |
* than the current tick count then the expiry time has overflowed from the | |
* current time. | |
* | |
* @param xTimer The handle of the timer being queried. | |
* | |
* @return If the timer is running then the time in ticks at which the timer | |
* will next expire is returned. If the timer is not running then the return | |
* value is undefined. | |
*/ | |
TickType_t xTimerGetExpiryTime( TimerHandle_t xTimer ) PRIVILEGED_FUNCTION; | |
/* | |
* Functions beyond this part are not part of the public API and are intended | |
* for use by the kernel only. | |
*/ | |
BaseType_t xTimerCreateTimerTask( void ) PRIVILEGED_FUNCTION; | |
BaseType_t xTimerGenericCommand( TimerHandle_t xTimer, const BaseType_t xCommandID, const TickType_t xOptionalValue, BaseType_t * const pxHigherPriorityTaskWoken, const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION; | |
#if( configUSE_TRACE_FACILITY == 1 ) | |
void vTimerSetTimerNumber( TimerHandle_t xTimer, UBaseType_t uxTimerNumber ) PRIVILEGED_FUNCTION; | |
UBaseType_t uxTimerGetTimerNumber( TimerHandle_t xTimer ) PRIVILEGED_FUNCTION; | |
#endif | |
#ifdef __cplusplus | |
} | |
#endif | |
#endif /* TIMERS_H */ | |