Adding upstream version 0.6.0.upstream/0.6.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1480 insertions, 0 deletions

diff --git a/src/ck_rhs.c b/src/ck_rhs.c
new file mode 100644
index 0000000..f6dd2ee
--- /dev/null
+++ b/src/ck_rhs.c
@@ -0,0 +1,1480 @@
+/*
+ * Copyright 2014-2015 Olivier Houchard.
+ * Copyright 2012-2015 Samy Al Bahra.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <ck_cc.h>
+#include <ck_rhs.h>
+#include <ck_limits.h>
+#include <ck_md.h>
+#include <ck_pr.h>
+#include <ck_stdint.h>
+#include <ck_stdbool.h>
+#include <ck_string.h>
+
+#include "ck_internal.h"
+
+#ifndef CK_RHS_PROBE_L1_SHIFT
+#define CK_RHS_PROBE_L1_SHIFT 3ULL
+#endif /* CK_RHS_PROBE_L1_SHIFT */
+
+#define CK_RHS_PROBE_L1 (1 << CK_RHS_PROBE_L1_SHIFT)
+#define CK_RHS_PROBE_L1_MASK (CK_RHS_PROBE_L1 - 1)
+
+#ifndef CK_RHS_PROBE_L1_DEFAULT
+#define CK_RHS_PROBE_L1_DEFAULT CK_MD_CACHELINE
+#endif
+
+#define CK_RHS_VMA_MASK ((uintptr_t)((1ULL << CK_MD_VMA_BITS) - 1))
+#define CK_RHS_VMA(x)	\
+	((void *)((uintptr_t)(x) & CK_RHS_VMA_MASK))
+
+#define CK_RHS_EMPTY     NULL
+#define CK_RHS_G		(1024)
+#define CK_RHS_G_MASK	(CK_RHS_G - 1)
+
+#if defined(CK_F_PR_LOAD_8) && defined(CK_F_PR_STORE_8)
+#define CK_RHS_WORD          uint8_t
+#define CK_RHS_WORD_MAX	    UINT8_MAX
+#define CK_RHS_STORE(x, y)   ck_pr_store_8(x, y)
+#define CK_RHS_LOAD(x)       ck_pr_load_8(x)
+#elif defined(CK_F_PR_LOAD_16) && defined(CK_F_PR_STORE_16)
+#define CK_RHS_WORD          uint16_t
+#define CK_RHS_WORD_MAX	    UINT16_MAX
+#define CK_RHS_STORE(x, y)   ck_pr_store_16(x, y)
+#define CK_RHS_LOAD(x)       ck_pr_load_16(x)
+#elif defined(CK_F_PR_LOAD_32) && defined(CK_F_PR_STORE_32)
+#define CK_RHS_WORD          uint32_t
+#define CK_RHS_WORD_MAX	    UINT32_MAX
+#define CK_RHS_STORE(x, y)   ck_pr_store_32(x, y)
+#define CK_RHS_LOAD(x)       ck_pr_load_32(x)
+#else
+#error "ck_rhs is not supported on your platform."
+#endif
+
+#define CK_RHS_MAX_WANTED	0xffff
+
+enum ck_rhs_probe_behavior {
+	CK_RHS_PROBE = 0,	/* Default behavior. */
+	CK_RHS_PROBE_RH,	/* Short-circuit if RH slot found. */
+	CK_RHS_PROBE_INSERT,	/* Short-circuit on probe bound if tombstone found. */
+
+	CK_RHS_PROBE_ROBIN_HOOD,/* Look for the first slot available for the entry we are about to replace, only used to internally implement Robin Hood */
+	CK_RHS_PROBE_NO_RH,	/* Don't do the RH dance */
+};
+struct ck_rhs_entry_desc {
+	unsigned int probes;
+	unsigned short wanted;
+	CK_RHS_WORD probe_bound;
+	bool in_rh;
+	const void *entry;
+} CK_CC_ALIGN(16);
+
+struct ck_rhs_no_entry_desc {
+	unsigned int probes;
+	unsigned short wanted;
+	CK_RHS_WORD probe_bound;
+	bool in_rh;
+} CK_CC_ALIGN(8);
+
+typedef long ck_rhs_probe_cb_t(struct ck_rhs *hs,
+    struct ck_rhs_map *map,
+    unsigned long *n_probes,
+    long *priority,
+    unsigned long h,
+    const void *key,
+    const void **object,
+    unsigned long probe_limit,
+    enum ck_rhs_probe_behavior behavior);
+
+struct ck_rhs_map {
+	unsigned int generation[CK_RHS_G];
+	unsigned int probe_maximum;
+	unsigned long mask;
+	unsigned long step;
+	unsigned int probe_limit;
+	unsigned long n_entries;
+	unsigned long capacity;
+	unsigned long size;
+	unsigned long max_entries;
+	char offset_mask;
+	union {
+		struct ck_rhs_entry_desc *descs;
+		struct ck_rhs_no_entry {
+			const void **entries;
+			struct ck_rhs_no_entry_desc *descs;
+		} no_entries;
+	} entries;
+	bool read_mostly;
+	ck_rhs_probe_cb_t *probe_func;
+};
+
+static CK_CC_INLINE const void *
+ck_rhs_entry(struct ck_rhs_map *map, long offset)
+{
+
+	if (map->read_mostly)
+		return (map->entries.no_entries.entries[offset]);
+	else
+		return (map->entries.descs[offset].entry);
+}
+
+static CK_CC_INLINE const void **
+ck_rhs_entry_addr(struct ck_rhs_map *map, long offset)
+{
+
+	if (map->read_mostly)
+		return (&map->entries.no_entries.entries[offset]);
+	else
+		return (&map->entries.descs[offset].entry);
+}
+
+static CK_CC_INLINE struct ck_rhs_entry_desc *
+ck_rhs_desc(struct ck_rhs_map *map, long offset)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		return ((struct ck_rhs_entry_desc *)(void *)&map->entries.no_entries.descs[offset]);
+	else
+		return (&map->entries.descs[offset]);
+}
+
+static CK_CC_INLINE void
+ck_rhs_wanted_inc(struct ck_rhs_map *map, long offset)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		map->entries.no_entries.descs[offset].wanted++;
+	else
+		map->entries.descs[offset].wanted++;
+}
+
+static CK_CC_INLINE unsigned int
+ck_rhs_probes(struct ck_rhs_map *map, long offset)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		return (map->entries.no_entries.descs[offset].probes);
+	else
+		return (map->entries.descs[offset].probes);
+}
+
+static CK_CC_INLINE void
+ck_rhs_set_probes(struct ck_rhs_map *map, long offset, unsigned int value)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		map->entries.no_entries.descs[offset].probes = value;
+	else
+		map->entries.descs[offset].probes = value;
+}
+
+static CK_CC_INLINE CK_RHS_WORD
+ck_rhs_probe_bound(struct ck_rhs_map *map, long offset)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		return (map->entries.no_entries.descs[offset].probe_bound);
+	else
+		return (map->entries.descs[offset].probe_bound);
+}
+
+static CK_CC_INLINE CK_RHS_WORD *
+ck_rhs_probe_bound_addr(struct ck_rhs_map *map, long offset)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		return (&map->entries.no_entries.descs[offset].probe_bound);
+	else
+		return (&map->entries.descs[offset].probe_bound);
+}
+
+
+static CK_CC_INLINE bool
+ck_rhs_in_rh(struct ck_rhs_map *map, long offset)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		return (map->entries.no_entries.descs[offset].in_rh);
+	else
+		return (map->entries.descs[offset].in_rh);
+}
+
+static CK_CC_INLINE void
+ck_rhs_set_rh(struct ck_rhs_map *map, long offset)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		map->entries.no_entries.descs[offset].in_rh = true;
+	else
+		map->entries.descs[offset].in_rh = true;
+}
+
+static CK_CC_INLINE void
+ck_rhs_unset_rh(struct ck_rhs_map *map, long offset)
+{
+
+	if (CK_CC_UNLIKELY(map->read_mostly))
+		map->entries.no_entries.descs[offset].in_rh = false;
+	else
+		map->entries.descs[offset].in_rh = false;
+}
+
+
+#define CK_RHS_DEFAULT_LOAD_FACTOR	50
+
+static ck_rhs_probe_cb_t ck_rhs_map_probe;
+static ck_rhs_probe_cb_t ck_rhs_map_probe_rm;
+
+bool
+ck_rhs_set_load_factor(struct ck_rhs *hs, unsigned int load_factor)
+{
+	struct ck_rhs_map *map = hs->map;
+
+	if (load_factor == 0 || load_factor > 100)
+		return false;
+
+	hs->load_factor = load_factor;
+	map->max_entries = (map->capacity * (unsigned long)hs->load_factor) / 100;
+	while (map->n_entries > map->max_entries) {
+		if (ck_rhs_grow(hs, map->capacity << 1) == false)
+			return false;
+		map = hs->map;
+	}
+	return true;
+}
+
+void
+ck_rhs_iterator_init(struct ck_rhs_iterator *iterator)
+{
+
+	iterator->cursor = NULL;
+	iterator->offset = 0;
+	return;
+}
+
+bool
+ck_rhs_next(struct ck_rhs *hs, struct ck_rhs_iterator *i, void **key)
+{
+	struct ck_rhs_map *map = hs->map;
+	void *value;
+
+	if (i->offset >= map->capacity)
+		return false;
+
+	do {
+		value = CK_CC_DECONST_PTR(ck_rhs_entry(map, i->offset));
+		if (value != CK_RHS_EMPTY) {
+#ifdef CK_RHS_PP
+			if (hs->mode & CK_RHS_MODE_OBJECT)
+				value = CK_RHS_VMA(value);
+#endif
+			i->offset++;
+			*key = value;
+			return true;
+		}
+	} while (++i->offset < map->capacity);
+
+	return false;
+}
+
+void
+ck_rhs_stat(struct ck_rhs *hs, struct ck_rhs_stat *st)
+{
+	struct ck_rhs_map *map = hs->map;
+
+	st->n_entries = map->n_entries;
+	st->probe_maximum = map->probe_maximum;
+	return;
+}
+
+unsigned long
+ck_rhs_count(struct ck_rhs *hs)
+{
+
+	return hs->map->n_entries;
+}
+
+static void
+ck_rhs_map_destroy(struct ck_malloc *m, struct ck_rhs_map *map, bool defer)
+{
+
+	m->free(map, map->size, defer);
+	return;
+}
+
+void
+ck_rhs_destroy(struct ck_rhs *hs)
+{
+
+	ck_rhs_map_destroy(hs->m, hs->map, false);
+	return;
+}
+
+static struct ck_rhs_map *
+ck_rhs_map_create(struct ck_rhs *hs, unsigned long entries)
+{
+	struct ck_rhs_map *map;
+	unsigned long size, n_entries, limit;
+
+	n_entries = ck_internal_power_2(entries);
+	if (n_entries < CK_RHS_PROBE_L1)
+		n_entries = CK_RHS_PROBE_L1;
+
+	if (hs->mode & CK_RHS_MODE_READ_MOSTLY)
+		size = sizeof(struct ck_rhs_map) +
+		    (sizeof(void *) * n_entries +
+		     sizeof(struct ck_rhs_no_entry_desc) * n_entries +
+		     2 * CK_MD_CACHELINE - 1);
+	else
+		size = sizeof(struct ck_rhs_map) +
+		    (sizeof(struct ck_rhs_entry_desc) * n_entries +
+		     CK_MD_CACHELINE - 1);
+	map = hs->m->malloc(size);
+	if (map == NULL)
+		return NULL;
+	map->read_mostly = !!(hs->mode & CK_RHS_MODE_READ_MOSTLY);
+
+	map->size = size;
+	/* We should probably use a more intelligent heuristic for default probe length. */
+	limit = ck_internal_max(n_entries >> (CK_RHS_PROBE_L1_SHIFT + 2), CK_RHS_PROBE_L1_DEFAULT);
+	if (limit > UINT_MAX)
+		limit = UINT_MAX;
+
+	map->probe_limit = (unsigned int)limit;
+	map->probe_maximum = 0;
+	map->capacity = n_entries;
+	map->step = ck_internal_bsf(n_entries);
+	map->mask = n_entries - 1;
+	map->n_entries = 0;
+
+	map->max_entries = (map->capacity * (unsigned long)hs->load_factor) / 100;
+	/* Align map allocation to cache line. */
+	if (map->read_mostly) {
+		map->entries.no_entries.entries = (void *)(((uintptr_t)&map[1] +
+		    CK_MD_CACHELINE - 1) & ~(CK_MD_CACHELINE - 1));
+		map->entries.no_entries.descs = (void *)(((uintptr_t)map->entries.no_entries.entries + (sizeof(void *) * n_entries) + CK_MD_CACHELINE - 1) &~ (CK_MD_CACHELINE - 1));
+		memset(map->entries.no_entries.entries, 0,
+		    sizeof(void *) * n_entries);
+		memset(map->entries.no_entries.descs, 0,
+		    sizeof(struct ck_rhs_no_entry_desc) * n_entries);
+		map->offset_mask = (CK_MD_CACHELINE / sizeof(void *)) - 1;
+		map->probe_func = ck_rhs_map_probe_rm;
+
+	} else {
+		map->entries.descs = (void *)(((uintptr_t)&map[1] +
+		    CK_MD_CACHELINE - 1) & ~(CK_MD_CACHELINE - 1));
+		memset(map->entries.descs, 0, sizeof(struct ck_rhs_entry_desc) * n_entries);
+		map->offset_mask = (CK_MD_CACHELINE / sizeof(struct ck_rhs_entry_desc)) - 1;
+		map->probe_func = ck_rhs_map_probe;
+	}
+	memset(map->generation, 0, sizeof map->generation);
+
+	/* Commit entries purge with respect to map publication. */
+	ck_pr_fence_store();
+	return map;
+}
+
+bool
+ck_rhs_reset_size(struct ck_rhs *hs, unsigned long capacity)
+{
+	struct ck_rhs_map *map, *previous;
+
+	previous = hs->map;
+	map = ck_rhs_map_create(hs, capacity);
+	if (map == NULL)
+		return false;
+
+	ck_pr_store_ptr(&hs->map, map);
+	ck_rhs_map_destroy(hs->m, previous, true);
+	return true;
+}
+
+bool
+ck_rhs_reset(struct ck_rhs *hs)
+{
+	struct ck_rhs_map *previous;
+
+	previous = hs->map;
+	return ck_rhs_reset_size(hs, previous->capacity);
+}
+
+static inline unsigned long
+ck_rhs_map_probe_next(struct ck_rhs_map *map,
+    unsigned long offset,
+    unsigned long probes)
+{
+
+	if (probes & map->offset_mask) {
+		offset = (offset &~ map->offset_mask) +
+		    ((offset + 1) & map->offset_mask);
+		return offset;
+	} else
+		return (offset + probes) & map->mask;
+}
+
+static inline unsigned long
+ck_rhs_map_probe_prev(struct ck_rhs_map *map, unsigned long offset,
+    unsigned long probes)
+{
+
+	if (probes & map->offset_mask) {
+		offset = (offset &~ map->offset_mask) + ((offset - 1) &
+		    map->offset_mask);
+		return offset;
+	} else
+		return ((offset - probes) & map->mask);
+}
+
+
+static inline void
+ck_rhs_map_bound_set(struct ck_rhs_map *m,
+    unsigned long h,
+    unsigned long n_probes)
+{
+	unsigned long offset = h & m->mask;
+	struct ck_rhs_entry_desc *desc;
+
+	if (n_probes > m->probe_maximum)
+		ck_pr_store_uint(&m->probe_maximum, n_probes);
+	if (!(m->read_mostly)) {
+		desc = &m->entries.descs[offset];
+
+		if (desc->probe_bound < n_probes) {
+			if (n_probes > CK_RHS_WORD_MAX)
+				n_probes = CK_RHS_WORD_MAX;
+
+			CK_RHS_STORE(&desc->probe_bound, n_probes);
+			ck_pr_fence_store();
+		}
+	}
+
+	return;
+}
+
+static inline unsigned int
+ck_rhs_map_bound_get(struct ck_rhs_map *m, unsigned long h)
+{
+	unsigned long offset = h & m->mask;
+	unsigned int r = CK_RHS_WORD_MAX;
+
+	if (m->read_mostly)
+		r = ck_pr_load_uint(&m->probe_maximum);
+	else {
+		r = CK_RHS_LOAD(&m->entries.descs[offset].probe_bound);
+		if (r == CK_RHS_WORD_MAX)
+			r = ck_pr_load_uint(&m->probe_maximum);
+	}
+	return r;
+}
+
+bool
+ck_rhs_grow(struct ck_rhs *hs,
+    unsigned long capacity)
+{
+	struct ck_rhs_map *map, *update;
+	const void *previous, *prev_saved;
+	unsigned long k, offset, probes;
+
+restart:
+	map = hs->map;
+	if (map->capacity > capacity)
+		return false;
+
+	update = ck_rhs_map_create(hs, capacity);
+	if (update == NULL)
+		return false;
+
+	for (k = 0; k < map->capacity; k++) {
+		unsigned long h;
+
+		prev_saved = previous = ck_rhs_entry(map, k);
+		if (previous == CK_RHS_EMPTY)
+			continue;
+
+#ifdef CK_RHS_PP
+		if (hs->mode & CK_RHS_MODE_OBJECT)
+			previous = CK_RHS_VMA(previous);
+#endif
+
+		h = hs->hf(previous, hs->seed);
+		offset = h & update->mask;
+		probes = 0;
+
+		for (;;) {
+			const void **cursor = ck_rhs_entry_addr(update, offset);
+
+			if (probes++ == update->probe_limit) {
+				/*
+				 * We have hit the probe limit, map needs to be even larger.
+				 */
+				ck_rhs_map_destroy(hs->m, update, false);
+				capacity <<= 1;
+				goto restart;
+			}
+
+			if (CK_CC_LIKELY(*cursor == CK_RHS_EMPTY)) {
+				*cursor = prev_saved;
+				update->n_entries++;
+				ck_rhs_set_probes(update, offset, probes);
+				ck_rhs_map_bound_set(update, h, probes);
+				break;
+			} else if (ck_rhs_probes(update, offset) < probes) {
+				const void *tmp = prev_saved;
+				unsigned int old_probes;
+				prev_saved = previous = *cursor;
+#ifdef CK_RHS_PP
+				if (hs->mode & CK_RHS_MODE_OBJECT)
+					previous = CK_RHS_VMA(previous);
+#endif
+				*cursor = tmp;
+				ck_rhs_map_bound_set(update, h, probes);
+				h = hs->hf(previous, hs->seed);
+				old_probes = ck_rhs_probes(update, offset);
+				ck_rhs_set_probes(update, offset, probes);
+				probes = old_probes - 1;
+				continue;
+			}
+			ck_rhs_wanted_inc(update, offset);
+			offset = ck_rhs_map_probe_next(update, offset,  probes);
+		}
+
+	}
+
+	ck_pr_fence_store();
+	ck_pr_store_ptr(&hs->map, update);
+	ck_rhs_map_destroy(hs->m, map, true);
+	return true;
+}
+
+bool
+ck_rhs_rebuild(struct ck_rhs *hs)
+{
+
+	return ck_rhs_grow(hs, hs->map->capacity);
+}
+
+static long
+ck_rhs_map_probe_rm(struct ck_rhs *hs,
+    struct ck_rhs_map *map,
+    unsigned long *n_probes,
+    long *priority,
+    unsigned long h,
+    const void *key,
+    const void **object,
+    unsigned long probe_limit,
+    enum ck_rhs_probe_behavior behavior)
+{
+	const void *k;
+	const void *compare;
+	long pr = -1;
+	unsigned long offset, probes, opl;
+
+#ifdef CK_RHS_PP
+	/* If we are storing object pointers, then we may leverage pointer packing. */
+	unsigned long hv = 0;
+
+	if (hs->mode & CK_RHS_MODE_OBJECT) {
+		hv = (h >> 25) & CK_RHS_KEY_MASK;
+		compare = CK_RHS_VMA(key);
+	} else {
+		compare = key;
+	}
+#else
+	compare = key;
+#endif
+ 	*object = NULL;
+	if (behavior != CK_RHS_PROBE_ROBIN_HOOD) {
+		probes = 0;
+		offset = h & map->mask;
+	} else {
+		/* Restart from the bucket we were previously in */
+		probes = *n_probes;
+		offset = ck_rhs_map_probe_next(map, *priority,
+		    probes);
+	}
+	opl = probe_limit;
+
+	for (;;) {
+		if (probes++ == probe_limit) {
+			if (probe_limit == opl || pr != -1) {
+				k = CK_RHS_EMPTY;
+				goto leave;
+			}
+			/*
+			 * If no eligible slot has been found yet, continue probe
+			 * sequence with original probe limit.
+			 */
+			probe_limit = opl;
+		}
+		k = ck_pr_load_ptr(&map->entries.no_entries.entries[offset]);
+		if (k == CK_RHS_EMPTY)
+			goto leave;
+
+		if (behavior != CK_RHS_PROBE_NO_RH) {
+			struct ck_rhs_entry_desc *desc = (void *)&map->entries.no_entries.descs[offset];
+
+			if (pr == -1 &&
+			    desc->in_rh == false && desc->probes < probes) {
+				pr = offset;
+				*n_probes = probes;
+
+				if (behavior == CK_RHS_PROBE_RH ||
+				    behavior == CK_RHS_PROBE_ROBIN_HOOD) {
+					k = CK_RHS_EMPTY;
+					goto leave;
+				}
+			}
+		}
+
+		if (behavior != CK_RHS_PROBE_ROBIN_HOOD) {
+#ifdef CK_RHS_PP
+			if (hs->mode & CK_RHS_MODE_OBJECT) {
+				if (((uintptr_t)k >> CK_MD_VMA_BITS) != hv) {
+					offset = ck_rhs_map_probe_next(map, offset, probes);
+					continue;
+				}
+
+				k = CK_RHS_VMA(k);
+			}
+#endif
+
+			if (k == compare)
+				goto leave;
+
+			if (hs->compare == NULL) {
+				offset = ck_rhs_map_probe_next(map, offset, probes);
+				continue;
+			}
+
+			if (hs->compare(k, key) == true)
+				goto leave;
+		}
+		offset = ck_rhs_map_probe_next(map, offset, probes);
+	}
+leave:
+	if (probes > probe_limit) {
+		offset = -1;
+	} else {
+		*object = k;
+	}
+
+	if (pr == -1)
+		*n_probes = probes;
+
+	*priority = pr;
+	return offset;
+}
+
+static long
+ck_rhs_map_probe(struct ck_rhs *hs,
+    struct ck_rhs_map *map,
+    unsigned long *n_probes,
+    long *priority,
+    unsigned long h,
+    const void *key,
+    const void **object,
+    unsigned long probe_limit,
+    enum ck_rhs_probe_behavior behavior)
+{
+	const void *k;
+	const void *compare;
+	long pr = -1;
+	unsigned long offset, probes, opl;
+
+#ifdef CK_RHS_PP
+	/* If we are storing object pointers, then we may leverage pointer packing. */
+	unsigned long hv = 0;
+
+	if (hs->mode & CK_RHS_MODE_OBJECT) {
+		hv = (h >> 25) & CK_RHS_KEY_MASK;
+		compare = CK_RHS_VMA(key);
+	} else {
+		compare = key;
+	}
+#else
+	compare = key;
+#endif
+
+ 	*object = NULL;
+	if (behavior != CK_RHS_PROBE_ROBIN_HOOD) {
+		probes = 0;
+		offset = h & map->mask;
+	} else {
+		/* Restart from the bucket we were previously in */
+		probes = *n_probes;
+		offset = ck_rhs_map_probe_next(map, *priority,
+		    probes);
+	}
+	opl = probe_limit;
+	if (behavior == CK_RHS_PROBE_INSERT)
+		probe_limit = ck_rhs_map_bound_get(map, h);
+
+	for (;;) {
+		if (probes++ == probe_limit) {
+			if (probe_limit == opl || pr != -1) {
+				k = CK_RHS_EMPTY;
+				goto leave;
+			}
+			/*
+			 * If no eligible slot has been found yet, continue probe
+			 * sequence with original probe limit.
+			 */
+			probe_limit = opl;
+		}
+		k = ck_pr_load_ptr(&map->entries.descs[offset].entry);
+		if (k == CK_RHS_EMPTY)
+			goto leave;
+		if ((behavior != CK_RHS_PROBE_NO_RH)) {
+			struct ck_rhs_entry_desc *desc = &map->entries.descs[offset];
+
+			if (pr == -1 &&
+			    desc->in_rh == false && desc->probes < probes) {
+				pr = offset;
+				*n_probes = probes;
+
+				if (behavior == CK_RHS_PROBE_RH ||
+				    behavior == CK_RHS_PROBE_ROBIN_HOOD) {
+					k = CK_RHS_EMPTY;
+					goto leave;
+				}
+			}
+		}
+
+		if (behavior != CK_RHS_PROBE_ROBIN_HOOD) {
+#ifdef CK_RHS_PP
+			if (hs->mode & CK_RHS_MODE_OBJECT) {
+				if (((uintptr_t)k >> CK_MD_VMA_BITS) != hv) {
+					offset = ck_rhs_map_probe_next(map, offset, probes);
+					continue;
+				}
+
+				k = CK_RHS_VMA(k);
+			}
+#endif
+
+			if (k == compare)
+				goto leave;
+
+			if (hs->compare == NULL) {
+				offset = ck_rhs_map_probe_next(map, offset, probes);
+				continue;
+			}
+
+			if (hs->compare(k, key) == true)
+				goto leave;
+		}
+		offset = ck_rhs_map_probe_next(map, offset, probes);
+	}
+leave:
+	if (probes > probe_limit) {
+		offset = -1;
+	} else {
+		*object = k;
+	}
+
+	if (pr == -1)
+		*n_probes = probes;
+
+	*priority = pr;
+	return offset;
+}
+
+static inline const void *
+ck_rhs_marshal(unsigned int mode, const void *key, unsigned long h)
+{
+#ifdef CK_RHS_PP
+	const void *insert;
+
+	if (mode & CK_RHS_MODE_OBJECT) {
+		insert = (void *)((uintptr_t)CK_RHS_VMA(key) | ((h >> 25) << CK_MD_VMA_BITS));
+	} else {
+		insert = key;
+	}
+
+	return insert;
+#else
+	(void)mode;
+	(void)h;
+
+	return key;
+#endif
+}
+
+bool
+ck_rhs_gc(struct ck_rhs *hs)
+{
+	unsigned long i;
+	struct ck_rhs_map *map = hs->map;
+
+	unsigned int max_probes = 0;
+	for (i = 0; i < map->capacity; i++) {
+		if (ck_rhs_probes(map, i) > max_probes)
+			max_probes = ck_rhs_probes(map, i);
+	}
+	map->probe_maximum = max_probes;
+	return true;
+}
+
+static void
+ck_rhs_add_wanted(struct ck_rhs *hs, long end_offset, long old_slot,
+	unsigned long h)
+{
+	struct ck_rhs_map *map = hs->map;
+	long offset;
+	unsigned int probes = 1;
+	bool found_slot = false;
+	struct ck_rhs_entry_desc *desc;
+
+	offset = h & map->mask;
+
+	if (old_slot == -1)
+		found_slot = true;
+	while (offset != end_offset) {
+		if (offset == old_slot)
+			found_slot = true;
+		if (found_slot) {
+			desc = ck_rhs_desc(map, offset);
+			if (desc->wanted < CK_RHS_MAX_WANTED)
+				desc->wanted++;
+		}
+		offset = ck_rhs_map_probe_next(map, offset, probes);
+		probes++;
+	}
+}
+
+static unsigned long
+ck_rhs_remove_wanted(struct ck_rhs *hs, long offset, long limit)
+{
+	struct ck_rhs_map *map = hs->map;
+	int probes = ck_rhs_probes(map, offset);
+	bool do_remove = true;
+	struct ck_rhs_entry_desc *desc;
+
+	while (probes > 1) {
+		probes--;
+		offset = ck_rhs_map_probe_prev(map, offset, probes);
+		if (offset == limit)
+			do_remove = false;
+		if (do_remove) {
+			desc = ck_rhs_desc(map, offset);
+			if (desc->wanted != CK_RHS_MAX_WANTED)
+				desc->wanted--;
+		}
+	}
+	return offset;
+}
+
+static long
+ck_rhs_get_first_offset(struct ck_rhs_map *map, unsigned long offset, unsigned int probes)
+{
+	while (probes > (unsigned long)map->offset_mask + 1) {
+		offset -= ((probes - 1) &~ map->offset_mask);
+		offset &= map->mask;
+		offset = (offset &~ map->offset_mask) +
+		    ((offset - map->offset_mask) & map->offset_mask);
+		probes -= map->offset_mask + 1;
+	}
+	return ((offset &~ map->offset_mask) + ((offset - (probes - 1)) & map->offset_mask));
+}
+
+#define CK_RHS_MAX_RH	512
+
+static int
+ck_rhs_put_robin_hood(struct ck_rhs *hs,
+    long orig_slot, struct ck_rhs_entry_desc *desc)
+{
+	long slot, first;
+	const void *object, *insert;
+	unsigned long n_probes;
+	struct ck_rhs_map *map;
+	unsigned long h = 0;
+	long prev;
+	void *key;
+	long prevs[CK_RHS_MAX_RH];
+	unsigned int prevs_nb = 0;
+	unsigned int i;
+
+	map = hs->map;
+	first = orig_slot;
+	n_probes = desc->probes;
+restart:
+	key = CK_CC_DECONST_PTR(ck_rhs_entry(map, first));
+	insert = key;
+#ifdef CK_RHS_PP
+	if (hs->mode & CK_RHS_MODE_OBJECT)
+	    key = CK_RHS_VMA(key);
+#endif
+	orig_slot = first;
+	ck_rhs_set_rh(map, orig_slot);
+
+	slot = map->probe_func(hs, map, &n_probes, &first, h, key, &object,
+	    map->probe_limit, prevs_nb == CK_RHS_MAX_RH ?
+	    CK_RHS_PROBE_NO_RH : CK_RHS_PROBE_ROBIN_HOOD);
+
+	if (slot == -1 && first == -1) {
+		if (ck_rhs_grow(hs, map->capacity << 1) == false) {
+			desc->in_rh = false;
+
+			for (i = 0; i < prevs_nb; i++)
+				ck_rhs_unset_rh(map, prevs[i]);
+
+			return -1;
+		}
+
+		return 1;
+	}
+
+	if (first != -1) {
+		desc = ck_rhs_desc(map, first);
+		int old_probes = desc->probes;
+
+		desc->probes = n_probes;
+		h = ck_rhs_get_first_offset(map, first, n_probes);
+		ck_rhs_map_bound_set(map, h, n_probes);
+		prev = orig_slot;
+		prevs[prevs_nb++] = prev;
+		n_probes = old_probes;
+		goto restart;
+	} else {
+		/* An empty slot was found. */
+		h =  ck_rhs_get_first_offset(map, slot, n_probes);
+		ck_rhs_map_bound_set(map, h, n_probes);
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, slot), insert);
+		ck_pr_inc_uint(&map->generation[h & CK_RHS_G_MASK]);
+		ck_pr_fence_atomic_store();
+		ck_rhs_set_probes(map, slot, n_probes);
+		desc->in_rh = 0;
+		ck_rhs_add_wanted(hs, slot, orig_slot, h);
+	}
+	while (prevs_nb > 0) {
+		prev = prevs[--prevs_nb];
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, orig_slot),
+		    ck_rhs_entry(map, prev));
+		h = ck_rhs_get_first_offset(map, orig_slot,
+		    desc->probes);
+		ck_rhs_add_wanted(hs, orig_slot, prev, h);
+		ck_pr_inc_uint(&map->generation[h & CK_RHS_G_MASK]);
+		ck_pr_fence_atomic_store();
+		orig_slot = prev;
+		desc->in_rh = false;
+		desc = ck_rhs_desc(map, orig_slot);
+	}
+	return 0;
+}
+
+static void
+ck_rhs_do_backward_shift_delete(struct ck_rhs *hs, long slot)
+{
+	struct ck_rhs_map *map = hs->map;
+	struct ck_rhs_entry_desc *desc, *new_desc = NULL;
+	unsigned long h;
+
+	desc = ck_rhs_desc(map, slot);
+	h = ck_rhs_remove_wanted(hs, slot, -1);
+	while (desc->wanted > 0) {
+		unsigned long offset = 0, tmp_offset;
+		unsigned long wanted_probes = 1;
+		unsigned int probe = 0;
+		unsigned int max_probes;
+
+		/* Find a successor */
+		while (wanted_probes < map->probe_maximum) {
+			probe = wanted_probes;
+			offset = ck_rhs_map_probe_next(map, slot, probe);
+			while (probe < map->probe_maximum) {
+				new_desc = ck_rhs_desc(map, offset);
+				if (new_desc->probes == probe + 1)
+					break;
+				probe++;
+				offset = ck_rhs_map_probe_next(map, offset,
+				    probe);
+			}
+			if (probe < map->probe_maximum)
+				break;
+			wanted_probes++;
+		}
+		if (!(wanted_probes < map->probe_maximum)) {
+			desc->wanted = 0;
+			break;
+		}
+		desc->probes = wanted_probes;
+		h = ck_rhs_remove_wanted(hs, offset, slot);
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, slot),
+		    ck_rhs_entry(map, offset));
+		ck_pr_inc_uint(&map->generation[h & CK_RHS_G_MASK]);
+		ck_pr_fence_atomic_store();
+		if (wanted_probes < CK_RHS_WORD_MAX) {
+			struct ck_rhs_entry_desc *hdesc = ck_rhs_desc(map, h);
+			if (hdesc->wanted == 1)
+				CK_RHS_STORE(&hdesc->probe_bound,
+				    wanted_probes);
+			else if (hdesc->probe_bound == CK_RHS_WORD_MAX ||
+			    hdesc->probe_bound == new_desc->probes) {
+				probe++;
+				if (hdesc->probe_bound == CK_RHS_WORD_MAX)
+					max_probes = map->probe_maximum;
+				else {
+					max_probes = hdesc->probe_bound;
+					max_probes--;
+				}
+				tmp_offset = ck_rhs_map_probe_next(map, offset,
+				    probe);
+				while (probe < max_probes) {
+					if (h == (unsigned long)ck_rhs_get_first_offset(map, tmp_offset, probe))
+						break;
+					probe++;
+					tmp_offset = ck_rhs_map_probe_next(map, tmp_offset, probe);
+				}
+				if (probe == max_probes)
+					CK_RHS_STORE(&hdesc->probe_bound,
+					    wanted_probes);
+			}
+		}
+		if (desc->wanted < CK_RHS_MAX_WANTED)
+			desc->wanted--;
+		slot = offset;
+		desc = new_desc;
+	}
+	ck_pr_store_ptr(ck_rhs_entry_addr(map, slot), CK_RHS_EMPTY);
+	if ((desc->probes - 1) < CK_RHS_WORD_MAX)
+		CK_RHS_STORE(ck_rhs_probe_bound_addr(map, h),
+		    desc->probes - 1);
+	desc->probes = 0;
+}
+
+bool
+ck_rhs_fas(struct ck_rhs *hs,
+    unsigned long h,
+    const void *key,
+    void **previous)
+{
+	long slot, first;
+	const void *object;
+	const void *insert;
+	unsigned long n_probes;
+	struct ck_rhs_map *map = hs->map;
+	struct ck_rhs_entry_desc *desc, *desc2;
+
+	*previous = NULL;
+restart:
+	slot = map->probe_func(hs, map, &n_probes, &first, h, key, &object,
+	    ck_rhs_map_bound_get(map, h), CK_RHS_PROBE);
+
+	/* Replacement semantics presume existence. */
+	if (object == NULL)
+		return false;
+
+	insert = ck_rhs_marshal(hs->mode, key, h);
+
+	if (first != -1) {
+		int ret;
+
+		desc = ck_rhs_desc(map, slot);
+		desc2 = ck_rhs_desc(map, first);
+		desc->in_rh = true;
+		ret = ck_rhs_put_robin_hood(hs, first, desc2);
+		desc->in_rh = false;
+		if (CK_CC_UNLIKELY(ret == 1))
+			goto restart;
+		else if (CK_CC_UNLIKELY(ret != 0))
+			return false;
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, first), insert);
+		ck_pr_inc_uint(&map->generation[h & CK_RHS_G_MASK]);
+		ck_pr_fence_atomic_store();
+		desc2->probes = n_probes;
+		ck_rhs_add_wanted(hs, first, -1, h);
+		ck_rhs_do_backward_shift_delete(hs, slot);
+	} else {
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, slot), insert);
+		ck_rhs_set_probes(map, slot, n_probes);
+	}
+	*previous = CK_CC_DECONST_PTR(object);
+	return true;
+}
+
+/*
+ * An apply function takes two arguments. The first argument is a pointer to a
+ * pre-existing object. The second argument is a pointer to the fifth argument
+ * passed to ck_hs_apply. If a non-NULL pointer is passed to the first argument
+ * and the return value of the apply function is NULL, then the pre-existing
+ * value is deleted. If the return pointer is the same as the one passed to the
+ * apply function then no changes are made to the hash table.  If the first
+ * argument is non-NULL and the return pointer is different than that passed to
+ * the apply function, then the pre-existing value is replaced. For
+ * replacement, it is required that the value itself is identical to the
+ * previous value.
+ */
+bool
+ck_rhs_apply(struct ck_rhs *hs,
+    unsigned long h,
+    const void *key,
+    ck_rhs_apply_fn_t *fn,
+    void *cl)
+{
+	const void *insert;
+	const void  *object, *delta = false;
+	unsigned long n_probes;
+	long slot, first;
+	struct ck_rhs_map *map;
+	bool delta_set = false;
+
+restart:
+	map = hs->map;
+
+	slot = map->probe_func(hs, map, &n_probes, &first, h, key, &object, map->probe_limit, CK_RHS_PROBE_INSERT);
+	if (slot == -1 && first == -1) {
+		if (ck_rhs_grow(hs, map->capacity << 1) == false)
+			return false;
+
+		goto restart;
+	}
+	if (!delta_set) {
+		delta = fn(CK_CC_DECONST_PTR(object), cl);
+		delta_set = true;
+	}
+
+	if (delta == NULL) {
+		/*
+		 * The apply function has requested deletion. If the object doesn't exist,
+		 * then exit early.
+		 */
+		if (CK_CC_UNLIKELY(object == NULL))
+			return true;
+
+		/* Otherwise, delete it. */
+		ck_rhs_do_backward_shift_delete(hs, slot);
+		return true;
+	}
+
+	/* The apply function has not requested hash set modification so exit early. */
+	if (delta == object)
+		return true;
+
+	/* A modification or insertion has been requested. */
+	ck_rhs_map_bound_set(map, h, n_probes);
+
+	insert = ck_rhs_marshal(hs->mode, delta, h);
+	if (first != -1) {
+		/*
+		 * This follows the same semantics as ck_hs_set, please refer to that
+		 * function for documentation.
+		 */
+		struct ck_rhs_entry_desc *desc = NULL, *desc2;
+		if (slot != -1) {
+			desc = ck_rhs_desc(map, slot);
+			desc->in_rh = true;
+		}
+		desc2 = ck_rhs_desc(map, first);
+		int ret = ck_rhs_put_robin_hood(hs, first, desc2);
+		if (slot != -1)
+			desc->in_rh = false;
+
+		if (CK_CC_UNLIKELY(ret == 1))
+			goto restart;
+		if (CK_CC_UNLIKELY(ret == -1))
+			return false;
+		/* If an earlier bucket was found, then store entry there. */
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, first), insert);
+		desc2->probes = n_probes;
+		/*
+		 * If a duplicate key was found, then delete it after
+		 * signaling concurrent probes to restart. Optionally,
+		 * it is possible to install tombstone after grace
+		 * period if we can guarantee earlier position of
+		 * duplicate key.
+		 */
+		ck_rhs_add_wanted(hs, first, -1, h);
+		if (object != NULL) {
+			ck_pr_inc_uint(&map->generation[h & CK_RHS_G_MASK]);
+			ck_pr_fence_atomic_store();
+			ck_rhs_do_backward_shift_delete(hs, slot);
+		}
+	} else {
+		/*
+		 * If we are storing into same slot, then atomic store is sufficient
+		 * for replacement.
+		 */
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, slot), insert);
+		ck_rhs_set_probes(map, slot, n_probes);
+		if (object == NULL)
+			ck_rhs_add_wanted(hs, slot, -1, h);
+	}
+
+	if (object == NULL) {
+		map->n_entries++;
+		if ((map->n_entries ) > map->max_entries)
+			ck_rhs_grow(hs, map->capacity << 1);
+	}
+	return true;
+}
+
+bool
+ck_rhs_set(struct ck_rhs *hs,
+    unsigned long h,
+    const void *key,
+    void **previous)
+{
+	long slot, first;
+	const void *object;
+	const void *insert;
+	unsigned long n_probes;
+	struct ck_rhs_map *map;
+
+	*previous = NULL;
+
+restart:
+	map = hs->map;
+
+	slot = map->probe_func(hs, map, &n_probes, &first, h, key, &object, map->probe_limit, CK_RHS_PROBE_INSERT);
+	if (slot == -1 && first == -1) {
+		if (ck_rhs_grow(hs, map->capacity << 1) == false)
+			return false;
+
+		goto restart;
+	}
+	ck_rhs_map_bound_set(map, h, n_probes);
+	insert = ck_rhs_marshal(hs->mode, key, h);
+
+	if (first != -1) {
+		struct ck_rhs_entry_desc *desc = NULL, *desc2;
+		if (slot != -1) {
+			desc = ck_rhs_desc(map, slot);
+			desc->in_rh = true;
+		}
+		desc2 = ck_rhs_desc(map, first);
+		int ret = ck_rhs_put_robin_hood(hs, first, desc2);
+		if (slot != -1)
+			desc->in_rh = false;
+
+		if (CK_CC_UNLIKELY(ret == 1))
+			goto restart;
+		if (CK_CC_UNLIKELY(ret == -1))
+			return false;
+		/* If an earlier bucket was found, then store entry there. */
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, first), insert);
+		desc2->probes = n_probes;
+		/*
+		 * If a duplicate key was found, then delete it after
+		 * signaling concurrent probes to restart. Optionally,
+		 * it is possible to install tombstone after grace
+		 * period if we can guarantee earlier position of
+		 * duplicate key.
+		 */
+		ck_rhs_add_wanted(hs, first, -1, h);
+		if (object != NULL) {
+			ck_pr_inc_uint(&map->generation[h & CK_RHS_G_MASK]);
+			ck_pr_fence_atomic_store();
+			ck_rhs_do_backward_shift_delete(hs, slot);
+		}
+
+	} else {
+		/*
+		 * If we are storing into same slot, then atomic store is sufficient
+		 * for replacement.
+		 */
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, slot), insert);
+		ck_rhs_set_probes(map, slot, n_probes);
+		if (object == NULL)
+			ck_rhs_add_wanted(hs, slot, -1, h);
+	}
+
+	if (object == NULL) {
+		map->n_entries++;
+		if ((map->n_entries ) > map->max_entries)
+			ck_rhs_grow(hs, map->capacity << 1);
+	}
+
+	*previous = CK_CC_DECONST_PTR(object);
+	return true;
+}
+
+static bool
+ck_rhs_put_internal(struct ck_rhs *hs,
+    unsigned long h,
+    const void *key,
+    enum ck_rhs_probe_behavior behavior)
+{
+	long slot, first;
+	const void *object;
+	const void *insert;
+	unsigned long n_probes;
+	struct ck_rhs_map *map;
+
+restart:
+	map = hs->map;
+
+	slot = map->probe_func(hs, map, &n_probes, &first, h, key, &object,
+	    map->probe_limit, behavior);
+
+	if (slot == -1 && first == -1) {
+		if (ck_rhs_grow(hs, map->capacity << 1) == false)
+			return false;
+
+		goto restart;
+	}
+
+	/* Fail operation if a match was found. */
+	if (object != NULL)
+		return false;
+
+	ck_rhs_map_bound_set(map, h, n_probes);
+	insert = ck_rhs_marshal(hs->mode, key, h);
+
+	if (first != -1) {
+		struct ck_rhs_entry_desc *desc = ck_rhs_desc(map, first);
+		int ret = ck_rhs_put_robin_hood(hs, first, desc);
+		if (CK_CC_UNLIKELY(ret == 1))
+			return ck_rhs_put_internal(hs, h, key, behavior);
+		else if (CK_CC_UNLIKELY(ret == -1))
+			return false;
+		/* Insert key into first bucket in probe sequence. */
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, first), insert);
+		desc->probes = n_probes;
+		ck_rhs_add_wanted(hs, first, -1, h);
+	} else {
+		/* An empty slot was found. */
+		ck_pr_store_ptr(ck_rhs_entry_addr(map, slot), insert);
+		ck_rhs_set_probes(map, slot, n_probes);
+		ck_rhs_add_wanted(hs, slot, -1, h);
+	}
+
+	map->n_entries++;
+	if ((map->n_entries ) > map->max_entries)
+		ck_rhs_grow(hs, map->capacity << 1);
+	return true;
+}
+
+bool
+ck_rhs_put(struct ck_rhs *hs,
+    unsigned long h,
+    const void *key)
+{
+
+	return ck_rhs_put_internal(hs, h, key, CK_RHS_PROBE_INSERT);
+}
+
+bool
+ck_rhs_put_unique(struct ck_rhs *hs,
+    unsigned long h,
+    const void *key)
+{
+
+	return ck_rhs_put_internal(hs, h, key, CK_RHS_PROBE_RH);
+}
+
+void *
+ck_rhs_get(struct ck_rhs *hs,
+    unsigned long h,
+    const void *key)
+{
+	long first;
+	const void *object;
+	struct ck_rhs_map *map;
+	unsigned long n_probes;
+	unsigned int g, g_p, probe;
+	unsigned int *generation;
+
+	do {
+		map = ck_pr_load_ptr(&hs->map);
+		generation = &map->generation[h & CK_RHS_G_MASK];
+		g = ck_pr_load_uint(generation);
+		probe  = ck_rhs_map_bound_get(map, h);
+		ck_pr_fence_load();
+
+		first = -1;
+		map->probe_func(hs, map, &n_probes, &first, h, key, &object, probe, CK_RHS_PROBE_NO_RH);
+
+		ck_pr_fence_load();
+		g_p = ck_pr_load_uint(generation);
+	} while (g != g_p);
+
+	return CK_CC_DECONST_PTR(object);
+}
+
+void *
+ck_rhs_remove(struct ck_rhs *hs,
+    unsigned long h,
+    const void *key)
+{
+	long slot, first;
+	const void *object;
+	struct ck_rhs_map *map = hs->map;
+	unsigned long n_probes;
+
+	slot = map->probe_func(hs, map, &n_probes, &first, h, key, &object,
+	    ck_rhs_map_bound_get(map, h), CK_RHS_PROBE_NO_RH);
+	if (object == NULL)
+		return NULL;
+
+	map->n_entries--;
+	ck_rhs_do_backward_shift_delete(hs, slot);
+	return CK_CC_DECONST_PTR(object);
+}
+
+bool
+ck_rhs_move(struct ck_rhs *hs,
+    struct ck_rhs *source,
+    ck_rhs_hash_cb_t *hf,
+    ck_rhs_compare_cb_t *compare,
+    struct ck_malloc *m)
+{
+
+	if (m == NULL || m->malloc == NULL || m->free == NULL || hf == NULL)
+		return false;
+
+	hs->mode = source->mode;
+	hs->seed = source->seed;
+	hs->map = source->map;
+	hs->load_factor = source->load_factor;
+	hs->m = m;
+	hs->hf = hf;
+	hs->compare = compare;
+	return true;
+}
+
+bool
+ck_rhs_init(struct ck_rhs *hs,
+    unsigned int mode,
+    ck_rhs_hash_cb_t *hf,
+    ck_rhs_compare_cb_t *compare,
+    struct ck_malloc *m,
+    unsigned long n_entries,
+    unsigned long seed)
+{
+
+	if (m == NULL || m->malloc == NULL || m->free == NULL || hf == NULL)
+		return false;
+
+	hs->m = m;
+	hs->mode = mode;
+	hs->seed = seed;
+	hs->hf = hf;
+	hs->compare = compare;
+	hs->load_factor = CK_RHS_DEFAULT_LOAD_FACTOR;
+
+	hs->map = ck_rhs_map_create(hs, n_entries);
+	return hs->map != NULL;
+}