listFOR_EACH macro
Helper macro to iterate over a list. pxLink contains the link node in each iteration.
Syntax
#define listFOR_EACH( pxLink, pxHead ) \
for( ( pxLink ) = ( pxHead )->pxNext; \
( pxLink ) != ( pxHead ); \
( pxLink ) = ( pxLink )->pxNext )