log4c_rollingpolicy_sizewin_udata_t(3) on Linux
The text 9242bbde7434, as Debian 11 (Bullseye) shipped it.
Log4c rolling file size-win interface. Log4c ships with (and defaults to) the classic size-window rollover policy: this triggers rollover when files reach a maximum size. The first file in the list is always the current file; when a rollover event occurs files are shifted up by one position in the list--if the number of files in the list has already reached the max then the oldest file is rotated out of the window.