Quality RTOS & Embedded Software

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




Loading

Waiting for more than one MsgQs

Posted by grumpy on September 25, 2007
Hi everyone

I have some basic questions to freeRTOS:
Is it possible to build a task which waits (blocks) for a semaphore (triggered by a timer interrupt or external HW interrupt) and a message queue at the same time and gets unblocked by either the semaphore or the message queue (whatever event happens first)? Or for several message queues? If that is not possible, which is the best way to implement it?

Cheers

RE: Waiting for more than one MsgQs

Posted by Richard on September 25, 2007
You can implement this by using one queue, then having the data that is posted to the queue contain a code as to what the data contains. For example:

typedef struct
{
____unsigned portLONG ulCode;
____unsigned portLONG ulValue;
} xData;

then

void vHandleEvents( void )
{
____xQueueReceive( xQueue, &xData, portMAX_DELAY );
____switch( xData.ulCode )
____{
________case SEMAPHORE_DATA : /* Processing as if it was the semaphore goes here. */
______________________________break;
________case QUEUE_DATA : /* Processing as if it was the queue goes here. */
ulReceivedValue = xData.ulValue;
______________________________break;
____}
}

When you send data to the queue, you send an xData object with ulCode set to QUEUE_DATA, and ulValue set to the value you want to post. Etc.

Regards.


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




Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.

Latest News

FreeRTOS kernel V10 is available for immediate download. Now MIT licensed.


FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

IAR Partner

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

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

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

OpenRTOS and SafeRTOS