Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Real time embedded FreeRTOS mailing list 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem TCP & FAT Training


#define in FreeRTOS.h

Posted by eaoiyrioeaf on February 18, 2017

In the FreeRTOS.h file, there are lots of definition as shown in below:

#define traceTASK_INCREMENT_TICK( xTickCount )

the statement "#define traceTASKINCREMENTTICK( xTickCount )" seems actually doing nothing, I'm not quite understand it. Could anyone kindly help?

#define in FreeRTOS.h

Posted by heinbali01 on February 18, 2017

Look here in task.c :

~~~~ BaseTypet xTaskIncrementTick( void ) { TCBt * pxTCB; TickTypet xItemValue; BaseTypet xSwitchRequired = pdFALSE;

/* Called by the portable layer each time a tick interrupt occurs.
Increments the tick then checks to see if the new tick value will cause any
tasks to be unblocked. */
traceTASK_INCREMENT_TICK( xTickCount );
if( uxSchedulerSuspended == ( UBaseType_t ) pdFALSE )


For every tick increment, it calls a macro or a function called traceTASK_INCREMENT_TICK().

By default, the macro does nothing:


#define traceTASK_INCREMENT_TICK( xTickCount )


Now if you want to do something during every tick-increment, you can define the macro in a new way. Write that new definition in you FreeRTOSConfig.h file, so it will be included before include/FreeRTOS.h.

~~~~ extern void vMyTickIncrement( TickType_t xCount );

define traceTASKINCREMENTTICK( xTickCount )
do \
{ \
	vMyTickIncrement( xTickCount ); \
} while( 0 )


When you run this, your function will be called for every increment.

So what you see in FreeRTOS is giving a proper default value for every macro.

Be careful: most trace-macro's are being called from critical situations. The task scheduler is often temporarily disabled, interrupts might have been disabled. When a trace macro is called from the idle task, there are many things you're not supposed to do, and the task-stack will be very small.

The good thing about trace macro's: they avoid the necessity to change the FreeRTOS source code. Regards.

#define in FreeRTOS.h

Posted by eaoiyrioeaf on February 18, 2017

That help me a lot, Thank you so much!

[ Back to the top ]    [ About FreeRTOS ]    [ Sitemap ]    [ ]

Copyright (C) 2004-2010 Richard Barry. Copyright (C) 2010-2016 Real Time Engineers Ltd.
Any and all data, files, source code, html content and documentation included in the FreeRTOSTM distribution or available on this site are the exclusive property of Real Time Engineers Ltd.. See the files license.txt (included in the distribution) and this copyright notice for more information. FreeRTOSTM and FreeRTOS.orgTM are trade marks of Real Time Engineers Ltd.

Latest News:

FreeRTOS V9.0.0 is now available for download.

Free TCP/IP and file system demos for the RTOS

Sponsored Links

⇓ Now With No Code Size Limit! ⇓
⇑ Free Download Without Registering ⇑

FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Renesas Electronics Gold Alliance RTOS Partner.jpg

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

Atmel RTOS partner supporting ARM Cortex-M3 and AVR32 microcontrollers

STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0

Xilinx Microblaze and Zynq partner

Silicon Labs low power RTOS partner

Altera RTOS partner for Nios II and Cortex-A9 SoC

Freescale Alliance RTOS Member supporting ARM and ColdFire microcontrollers

Infineon ARM Cortex-M microcontrollers

Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers

Cypress RTOS partner supporting ARM Cortex-M3

Fujitsu RTOS partner supporting ARM Cortex-M3 and FM3

Microsemi (previously Actel) RTOS partner supporting ARM Cortex-M3

Atollic Partner

IAR Partner

Keil ARM Partner

Embedded Artists