Embedded Systems Design, 2nd Edition

346 Embedded systems design

— or even a different one — can be used to send a message to warn

that filling must stop soon. By adding more pointers, it is possible

to not completely fill the area below the low water mark and then

use this to calculate the number of entries to move and thus the

next filling location.

This method has a problem in that there is a delay while the

data is copied. A more efficient alternative to copying the data, is

to copy the pointer. This approach works by still using the low

water mark, except that the remaining data is not copied. The

filling will start at the top of the buffer and the next data pointer

is moved to the top ...