Kismet implements multiprocess lock-free[^lock-free-fs] crash-safe and (roughly) bounded persistent caches stored in filesystem directories, with a Second Chance eviction strategy. The maintenance logic is batched and invoked at periodic jittered intervals to make sure accesses amortise to a constant number of filesystem system calls and logarithmic (in the number of cached file) time complexity. That's good for performance, and enables lock-freedom,[^unlike-ccache] but does mean that caches are expected to temporarily grow past their capacity hlimits, although rarely by more than a factor of 2 or 3.