Function extents_evict

deps/jemalloc/src/extent.c:566–628

}

extent_t *
extents_evict(tsdn_t *tsdn, arena_t *arena, extent_hooks_t **r_extent_hooks,
    extents_t *extents, size_t npages_min) {
	rtree_ctx_t rtree_ctx_fallback;
	rtree_ctx_t *rtree_ctx = tsdn_rtree_ctx(tsdn, &rtree_ctx_fallback);

	malloc_mutex_lock(tsdn, &extents->mtx);

	/*
	 * Get the LRU coalesced extent, if any.  If coalescing was delayed,
	 * the loop will iterate until the LRU extent is fully coalesced.
	 */
	extent_t *extent;
	while (true) {
		/* Get the LRU extent, if any. */
		extent = extent_list_first(&extents->lru);
		if (extent == NULL) {
			goto label_return;
		}
		/* Check the eviction limit. */
		size_t extents_npages = atomic_load_zu(&extents->npages,
		    ATOMIC_RELAXED);
		if (extents_npages <= npages_min) {
			extent = NULL;
			goto label_return;
		}
		extents_remove_locked(tsdn, extents, extent);
		if (!extents->delay_coalesce) {
			break;
		}
		/* Try to coalesce. */
		if (extent_try_delayed_coalesce(tsdn, arena, r_extent_hooks,
		    rtree_ctx, extents, extent)) {
			break;
		}
		/*
		 * The LRU extent was just coalesced and the result placed in
		 * the LRU at its neighbor's position.  Start over.
		 */
	}

	/*
	 * Either mark the extent active or deregister it to protect against
	 * concurrent operations.
	 */
	switch (extents_state_get(extents)) {
	case extent_state_active:
		not_reached();
	case extent_state_dirty:
	case extent_state_muzzy:
		extent_state_set(extent, extent_state_active);
		break;
	case extent_state_retained:
		extent_deregister(tsdn, extent);
		break;
	default:
		not_reached();
	}