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


xSemaphoreGive in critial section

Posted by paha11 on December 22, 2014


I wonder if it's possible to call xSemaphoreGive withing critical section. Something like

taskENTERCRITICAL(); .... xSemaphoreGive(AppTasks[curr->taskId].loopSem); .... taskEXIT_CRITICAL();

I used it in situation where needed to do some linked list operation.

From the source code of FreeRTOS 7.0.0 of function xQueueGenericSend(..) in queue.c I saw that immediate task swith can be made so the above code shall be NO NO? Thank you for any comment Regards

xSemaphoreGive in critial section

Posted by davedoors on December 22, 2014

The rule is dont do it, but you might get away with it on a give depending on task priorities. At best the wrong task might be scheduled because a context switch away cant happen, at worst you will get a horrible logic error and crash for the same reason. Definitely dont do it on a take!

xSemaphoreGive in critial section

Posted by paha11 on December 23, 2014


thanks for the link. That's what I was looking for. Regards Pavel

[ 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