Set reader low water mark.
- Parameters:
-
| mark | The new water mark; -1 disables the mark. |
A 'low water mark' is used in a buffer to indicate a minimum fill before action is/should be taken; it is often used in combination with a high water mark. It prevents things like the 'silly buffer syndrome' or nefarious polling on the buffer.
Basicly, the low and high water marks specify the preferred minimum and maximum fill of the buffer; you expect the buffer to have at least low mark, but not more than high mark bytes of data in it; however, the buffer may still drain completely or fill up. But usually action is taken when the low or high water mark is crossed. |