Struct jemalloc_sys::extent_hooks_s

source · [−]

#[repr(C)]pub struct extent_hooks_s {
    pub alloc: Option<extent_alloc_t>,
    pub dalloc: Option<extent_dalloc_t>,
    pub destroy: Option<extent_destroy_t>,
    pub commit: Option<extent_commit_t>,
    pub decommit: Option<extent_decommit_t>,
    pub purge_lazy: Option<extent_purge_t>,
    pub purge_forced: Option<extent_purge_t>,
    pub split: Option<extent_split_t>,
    pub merge: Option<extent_merge_t>,
}

Expand description

Extent lifetime management functions.

The extent_hooks_t structure comprises function pointers which are described individually below. jemalloc uses these functions to manage extent lifetime, which starts off with allocation of mapped committed memory, in the simplest case followed by deallocation. However, there are performance and platform reasons to retain extents for later reuse. Cleanup attempts cascade from deallocation to decommit to forced purging to lazy purging, which gives the extent management functions opportunities to reject the most permanent cleanup operations in favor of less permanent (and often less costly) operations. All operations except allocation can be universally opted out of by setting the hook pointers to NULL, or selectively opted out of by returning failure. Note that once the extent hook is set, the structure is accessed directly by the associated arenas, so it must remain valid for the entire lifetime of the arenas.

Fields

alloc: Option<extent_alloc_t>dalloc: Option<extent_dalloc_t>destroy: Option<extent_destroy_t>commit: Option<extent_commit_t>decommit: Option<extent_decommit_t>purge_lazy: Option<extent_purge_t>purge_forced: Option<extent_purge_t>split: Option<extent_split_t>merge: Option<extent_merge_t>