Type Definition tikv_jemalloc_sys::extent_purge_t

pub type extent_purge_t = unsafe extern "C" fn(extent_hooks: *mut extent_hooks_t, addr: *mut c_void, size: size_t, offset: size_t, length: size_t, arena_ind: c_uint) -> c_int;

Extent purge function.

Discards physical pages within the virtual memory mapping associated with an extent at given addr and size at offset bytes, extending for length on behalf of arena arena_ind.

A lazy extent purge function (e.g. implemented via madvise(...MADV_FREE)) can delay purging indefinitely and leave the pages within the purged virtual memory range in an indeterminite state, whereas a forced extent purge function immediately purges, and the pages within the virtual memory range will be zero-filled the next time they are accessed. If the function returns true, this indicates failure to purge.