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



Posted by Ivan on May 3, 2011
Hi all,

I'm currently working on an application that requires a WAIT-SUSPEND like state. By that I mean, if a Task waits on a queue and is subsequently suspended, it should enter the hypothetical WAIT-SUSPEND state. The following 2 outcomes would be possible from the WAIT-SUSPEND State:

1) From the WAIT-SUSPEND State, if the Task receives a Queue item, it will proceed to be in the SUSPEND State. This means that the Task will only proceed back into the READY State when a Resume is invoked on it.

2) From the WAIT'SUSPEND State, if the Task is resumed before it is able to receive a Queue item, it will return to the WAIT State.

I was wondering if such a mechanism can be achieved in FreeRTOS? Also, has anyone encountered such a need for the WAIT-SUSPEND State? Are there any elegant solutions around?

Currently, the issue is that whenever a Task waits on a Queue and a vTaskSuspend() is invoked, the Task will "forget" that it is waiting on the Queue as vTaskSuspend() sets xEventListItem to NULL. This issue also comes about when a Task is made to delay with a timeout, but a vTaskSuspend() is invoked on it before the timeout returns. This causes the Task to resume in its ready state rather than a timeout state.

Thanks to all in advance!

[ 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