len0rd/FreeRTOS-Kernel
1
0
Fork 0
mirror of https://github.com/FreeRTOS/FreeRTOS-Kernel.git synced 2025-09-08 07:07:47 -04:00
Code Issues Projects Releases Packages Wiki Activity

Add xQueueOverwrite() and a common demo task to demonstrate its use.

Browse source 
Update MSVC Win32 demo to include the xQueueOverwrite() common demo tasks.
This commit is contained in:
Richard Barry 2013-06-27 09:21:43 +00:00
parent 59f75a12f6
commit 671949ad78
8 changed files with 491 additions and 74 deletions
Download patch file Download diff file Expand all files Collapse all files

26
FreeRTOS/Source/queue.c
View file

@ -570,6 +570,7 @@ xQUEUE *pxQueue;
pxQueue = ( xQUEUE * ) xQueue;
configASSERT( pxQueue );
configASSERT( !( ( pvItemToQueue == NULL ) && ( pxQueue->uxItemSize != ( unsigned portBASE_TYPE ) 0U ) ) );
configASSERT( !( ( xCopyPosition == queueOVERWRITE ) && ( pxQueue->uxLength != 1 ) ) );
/* This function relaxes the coding standard somewhat to allow return
statements within the function itself. This is done in the interest
@ -578,9 +579,11 @@ xQUEUE *pxQueue;
{
taskENTER_CRITICAL();
{
/* Is there room on the queue now? To be running we must be
the highest priority task wanting to access the queue. */
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
/* Is there room on the queue now? The running task must be
the highest priority task wanting to access the queue. If
the head item in the queue is to be overwritten then it does
not matter if the queue is full. */
if( ( pxQueue->uxMessagesWaiting < pxQueue->uxLength ) || ( xCopyPosition == queueOVERWRITE ) )
{
traceQUEUE_SEND( pxQueue );
prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
@ -1046,7 +1049,8 @@ xQUEUE *pxQueue;
the highest priority task wanting to access the queue. */
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
{
/* Remember our read position in case we are just peeking. */
/* Remember the read position in case the queue is only being
peeked. */
pcOriginalReadPosition = pxQueue->u.pcReadFrom;
prvCopyDataFromQueue( pxQueue, pvBuffer );
@ -1320,7 +1324,7 @@ static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, port
pxQueue->pxMutexHolder = NULL;
}
}
#endif
#endif /* configUSE_MUTEXES */
}
else if( xPosition == queueSEND_TO_BACK )
{
@ -1339,6 +1343,18 @@ static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, port
{
pxQueue->u.pcReadFrom = ( pxQueue->pcTail - pxQueue->uxItemSize );
}
if( xPosition == queueOVERWRITE )
{
if( pxQueue->uxMessagesWaiting > 0 )
{
/* An item is not being added but overwritten, so subtract
one from the recorded number of items in the queue so when
one is added again below the number of recorded items remains
correct. */
--( pxQueue->uxMessagesWaiting );
}
}
}
++( pxQueue->uxMessagesWaiting );