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diff --git a/freertos/include/timers.h b/freertos/include/timers.h new file mode 100644 index 0000000..798c955 --- /dev/null +++ b/freertos/include/timers.h @@ -0,0 +1,1314 @@ +/* + FreeRTOS V9.0.0 - Copyright (C) 2016 Real Time Engineers Ltd. + All rights reserved + + VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. + + This file is part of the FreeRTOS distribution. + + FreeRTOS is free software; you can redistribute it and/or modify it under + the terms of the GNU General Public License (version 2) as published by the + Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception. + + *************************************************************************** + >>! NOTE: The modification to the GPL is included to allow you to !<< + >>! distribute a combined work that includes FreeRTOS without being !<< + >>! obliged to provide the source code for proprietary components !<< + >>! outside of the FreeRTOS kernel. !<< + *************************************************************************** + + FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + FOR A PARTICULAR PURPOSE. Full license text is available on the following + link: http://www.freertos.org/a00114.html + + *************************************************************************** + * * + * FreeRTOS provides completely free yet professionally developed, * + * robust, strictly quality controlled, supported, and cross * + * platform software that is more than just the market leader, it * + * is the industry's de facto standard. * + * * + * Help yourself get started quickly while simultaneously helping * + * to support the FreeRTOS project by purchasing a FreeRTOS * + * tutorial book, reference manual, or both: * + * http://www.FreeRTOS.org/Documentation * + * * + *************************************************************************** + + http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading + the FAQ page "My application does not run, what could be wrong?". Have you + defined configASSERT()? + + http://www.FreeRTOS.org/support - In return for receiving this top quality + embedded software for free we request you assist our global community by + participating in the support forum. + + http://www.FreeRTOS.org/training - Investing in training allows your team to + be as productive as possible as early as possible. Now you can receive + FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers + Ltd, and the world's leading authority on the world's leading RTOS. + + http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, + including FreeRTOS+Trace - an indispensable productivity tool, a DOS + compatible FAT file system, and our tiny thread aware UDP/IP stack. + + http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate. + Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. + + http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High + Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS + licenses offer ticketed support, indemnification and commercial middleware. + + http://www.SafeRTOS.com - High Integrity Systems also provide a safety + engineered and independently SIL3 certified version for use in safety and + mission critical applications that require provable dependability. + + 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 -e537 This headers are only multiply included if the application code +happens to also be including task.h. */ +#include "task.h" +/*lint +e537 */ + +#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.). + */ +typedef void * 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, + const TickType_t xTimerPeriodInTicks, + const UBaseType_t uxAutoReload, + void * const pvTimerID, + TimerCallbackFunction_t pxCallbackFunction ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */ +#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, + const TickType_t xTimerPeriodInTicks, + const UBaseType_t uxAutoReload, + void * const pvTimerID, + TimerCallbackFunction_t pxCallbackFunction, + StaticTimer_t *pxTimerBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */ +#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. */ + +/** + * 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; + +#ifdef __cplusplus +} +#endif +#endif /* TIMERS_H */ + + + |