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[FreeRTOS Home] [Live FreeRTOS Forum] [FAQ] [Archive Top] [September 2007 Threads] Waiting for more than one MsgQsPosted 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 MsgQsPosted 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.
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