1278 lines
		
	
	
		
			57 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			1278 lines
		
	
	
		
			57 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * FreeRTOS Kernel V10.0.1
 | |
|  * Copyright (C) 2017 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
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|  *
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|  * 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:
 | |
|  *
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|  * The above copyright notice and this permission notice shall be included in all
 | |
|  * copies or substantial portions of the Software.
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|  *
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|  * 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.
 | |
|  *
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|  * http://www.FreeRTOS.org
 | |
|  * http://aws.amazon.com/freertos
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|  *
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|  * 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
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| 
 | |
| /*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
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| highest numbers as tmrFIRST_FROM_ISR_COMMAND is used to determine if the task
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| 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 )
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| #define tmrCOMMAND_START_DONT_TRACE				( ( BaseType_t ) 0 )
 | |
| #define tmrCOMMAND_START					    ( ( BaseType_t ) 1 )
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| #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 )
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| 
 | |
| #define tmrFIRST_FROM_ISR_COMMAND				( ( BaseType_t ) 6 )
 | |
| #define tmrCOMMAND_START_FROM_ISR				( ( BaseType_t ) 6 )
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| #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;
 | |
| 
 | |
| /*
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|  * 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
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|  * equal to 1000.
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|  *
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|  * @param uxAutoReload If uxAutoReload is set to pdTRUE then the timer will
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|  * 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.
 | |
|  *
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|  * @param pxCallbackFunction The function to call when the timer expires.
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|  * Callback functions must have the prototype defined by TimerCallbackFunction_t,
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|  * which is	"void vCallbackFunction( TimerHandle_t xTimer );".
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|  *
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|  * @return If the timer is successfully created then a handle to the newly
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|  * created timer is returned.  If the timer cannot be created (because either
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|  * there is insufficient FreeRTOS heap remaining to allocate the timer
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|  * structures, or the timer period was set to 0) then NULL is returned.
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|  *
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|  * 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.
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|  * void vTimerCallback( TimerHandle_t pxTimer )
 | |
|  * {
 | |
|  * int32_t lArrayIndex;
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|  * const int32_t xMaxExpiryCountBeforeStopping = 10;
 | |
|  *
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|  * 	   // Optionally do something if the pxTimer parameter is NULL.
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|  * 	   configASSERT( pxTimer );
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|  *
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|  *     // Which timer expired?
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|  *     lArrayIndex = ( int32_t ) pvTimerGetTimerID( pxTimer );
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|  *
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|  *     // Increment the number of times that pxTimer has expired.
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|  *     lExpireCounters[ lArrayIndex ] += 1;
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|  *
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|  *     // If the timer has expired 10 times then stop it from running.
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|  *     if( lExpireCounters[ lArrayIndex ] == xMaxExpiryCountBeforeStopping )
 | |
|  *     {
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|  *         // Do not use a block time if calling a timer API function from a
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|  *         // timer callback function, as doing so could cause a deadlock!
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|  *         xTimerStop( pxTimer, 0 );
 | |
|  *     }
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|  * }
 | |
|  *
 | |
|  * void main( void )
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|  * {
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|  * int32_t x;
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|  *
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|  *     // Create then start some timers.  Starting the timers before the scheduler
 | |
|  *     // has been started means the timers will start running immediately that
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|  *     // the scheduler starts.
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|  *     for( x = 0; x < NUM_TIMERS; x++ )
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|  *     {
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|  *         xTimers[ x ] = xTimerCreate(    "Timer",       // Just a text name, not used by the kernel.
 | |
|  *                                         ( 100 * x ),   // The timer period in ticks.
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|  *                                         pdTRUE,        // The timers will auto-reload themselves when they expire.
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|  *                                         ( void * ) x,  // Assign each timer a unique id equal to its array index.
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|  *                                         vTimerCallback // Each timer calls the same callback when it expires.
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|  *                                     );
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|  *
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|  *         if( xTimers[ x ] == NULL )
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|  *         {
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|  *             // The timer was not created.
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|  *         }
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|  *         else
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|  *         {
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|  *             // Start the timer.  No block time is specified, and even if one was
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|  *             // it would be ignored because the scheduler has not yet been
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|  *             // started.
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|  *             if( xTimerStart( xTimers[ x ], 0 ) != pdPASS )
 | |
|  *             {
 | |
|  *                 // The timer could not be set into the Active state.
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|  *             }
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|  *         }
 | |
|  *     }
 | |
|  *
 | |
|  *     // ...
 | |
|  *     // Create tasks here.
 | |
|  *     // ...
 | |
|  *
 | |
|  *     // Starting the scheduler will start the timers running as they have already
 | |
|  *     // been set into the active state.
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|  *     vTaskStartScheduler();
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|  *
 | |
|  *     // 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,
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| 								void * const pvTimerID,
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| 								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. */
 | |
| 
 | |
| /**
 | |
|  * 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;
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| #endif
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| 
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| #ifdef __cplusplus
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| }
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| #endif
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| #endif /* TIMERS_H */
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| 
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| 
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| 
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