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


Edge triggered queue

Posted by beginend1 on January 9, 2014

Problem is to solve classic race condition in single data producer and multiple consumer model in double buffering. 1st task is generating some data (eg. gsensor) other tasks are reading those data.

Target is to inform all waiting tasks that there is new data, or pass data directly to those tasks and do not "miss" any sample or inform task that he missed a data and return old one.

Is there a simple way to do that in FreeRTOS 7.5.2 without creating a queue for every task? Edge triggered everwitable queue would be very handy here.

Edge triggered queue

Posted by edwards3 on January 9, 2014

It might be something you can do in version 8 using an event group. You could use the xQueueOverwrite() function to post a message, have each task use xQueuePeek() to view the message, and the xEventGropuSync() function to create a synchronisation point after each task has read the new data. http://www.freertos.org/xEventGroupSync.html

[ 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