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how to empty the queue??

Posted by Nobody/Anonymous on February 15, 2007

Hi all,

I need to empty the queue at certain places in my code.

The only way I can find is reading from queue untill it is empty. But this is not an efficeint method as reading is implemented as a memory copy, and it is wasting time reading all queue data just to throw away.

Is there a function which will just adjust the pointers of queue as it is empty?

I need a very fast queue empty mechanism.


RE: how to empty the queue??

Posted by embeddedc on February 15, 2007
You can add the following function to queue.c

void vQueueEmpty( xQueueHandle pxQueue )
pxNewQueue->uxMessagesWaiting = 0;
pxNewQueue->pcWriteTo = pxNewQueue->pcHead;
pxNewQueue->pcReadFrom = pxNewQueue->pcHead + ( ( uxQueueLength - 1 ) * uxItemSize );
pxNewQueue->xRxLock = queueUNLOCKED;
pxNewQueue->xTxLock = queueUNLOCKED;
vListInitialise( &( pxNewQueue->xTasksWaitingToSend ) );
vListInitialise( &( pxNewQueue->xTasksWaitingToReceive ) );

Be vary careful not to call it when there are tasks blocked on the queue!

RE: how to empty the queue??

Posted by Nobody/Anonymous on February 16, 2007


Thank you for your help.

My need involves the need to empty queue even when some tasks are waiting on the queue.

Is there any way to do that??

I will try to use the funtion you provided and modify it according to my need, But it will be good if I get a tested function.


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