len0rd/FreeRTOS-Kernel
1
0
Fork 0
mirror of https://github.com/FreeRTOS/FreeRTOS-Kernel.git synced 2025-09-13 01:27:48 -04:00
Code Issues Projects Releases Packages Wiki Activity

Apply SpacesAvailable() fix

Browse source 
Original author: RichardBarry
This commit is contained in:
Miles Frain 2021-02-22 21:27:26 -08:00
parent 4223fd5326
commit 1e4aab6d40
1 changed files with 11 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

12
stream_buffer.c
View file

@ -497,11 +497,19 @@ size_t xStreamBufferSpacesAvailable( StreamBufferHandle_t xStreamBuffer )
{ {
const StreamBuffer_t * const pxStreamBuffer = xStreamBuffer; const StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
size_t xSpace; size_t xSpace;
volatile size_t xOriginalTail;
configASSERT( pxStreamBuffer ); configASSERT( pxStreamBuffer );
xSpace = pxStreamBuffer->xLength + pxStreamBuffer->xTail; /* The code below reads xTail and then xHead. This is safe if the stream
xSpace -= pxStreamBuffer->xHead; buffer is updated once between the two reads - but not if the stream buffer
is updated more than once between the two reads - hence the loop. */
do
{
xOriginalTail = pxStreamBuffer->xTail;
xSpace = pxStreamBuffer->xLength + pxStreamBuffer->xTail;
xSpace -= pxStreamBuffer->xHead;
} while( xOriginalTail != pxStreamBuffer->xTail );
xSpace -= ( size_t ) 1; xSpace -= ( size_t ) 1;
if( xSpace >= pxStreamBuffer->xLength ) if( xSpace >= pxStreamBuffer->xLength )