Adding upstream version 0.6.0.upstream/0.6.0

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

1 files changed, 941 insertions, 0 deletions

diff --git a/src/ck_hs.c b/src/ck_hs.c
new file mode 100644
index 0000000..31510ec
--- /dev/null
+++ b/src/ck_hs.c
@@ -0,0 +1,941 @@
+/*
+ * 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_hs.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_HS_PROBE_L1_SHIFT
+#define CK_HS_PROBE_L1_SHIFT 3ULL
+#endif /* CK_HS_PROBE_L1_SHIFT */
+
+#define CK_HS_PROBE_L1 (1 << CK_HS_PROBE_L1_SHIFT)
+#define CK_HS_PROBE_L1_MASK (CK_HS_PROBE_L1 - 1)
+
+#ifndef CK_HS_PROBE_L1_DEFAULT
+#define CK_HS_PROBE_L1_DEFAULT CK_MD_CACHELINE
+#endif
+
+#define CK_HS_VMA_MASK ((uintptr_t)((1ULL << CK_MD_VMA_BITS) - 1))
+#define CK_HS_VMA(x)	\
+	((void *)((uintptr_t)(x) & CK_HS_VMA_MASK))
+
+#define CK_HS_EMPTY     NULL
+#define CK_HS_TOMBSTONE ((void *)~(uintptr_t)0)
+#define CK_HS_G		(2)
+#define CK_HS_G_MASK	(CK_HS_G - 1)
+
+#if defined(CK_F_PR_LOAD_8) && defined(CK_F_PR_STORE_8)
+#define CK_HS_WORD          uint8_t
+#define CK_HS_WORD_MAX	    UINT8_MAX
+#define CK_HS_STORE(x, y)   ck_pr_store_8(x, y)
+#define CK_HS_LOAD(x)       ck_pr_load_8(x)
+#elif defined(CK_F_PR_LOAD_16) && defined(CK_F_PR_STORE_16)
+#define CK_HS_WORD          uint16_t
+#define CK_HS_WORD_MAX	    UINT16_MAX
+#define CK_HS_STORE(x, y)   ck_pr_store_16(x, y)
+#define CK_HS_LOAD(x)       ck_pr_load_16(x)
+#elif defined(CK_F_PR_LOAD_32) && defined(CK_F_PR_STORE_32)
+#define CK_HS_WORD          uint32_t
+#define CK_HS_WORD_MAX	    UINT32_MAX
+#define CK_HS_STORE(x, y)   ck_pr_store_32(x, y)
+#define CK_HS_LOAD(x)       ck_pr_load_32(x)
+#else
+#error "ck_hs is not supported on your platform."
+#endif
+
+enum ck_hs_probe_behavior {
+	CK_HS_PROBE = 0,	/* Default behavior. */
+	CK_HS_PROBE_TOMBSTONE,	/* Short-circuit on tombstone. */
+	CK_HS_PROBE_INSERT	/* Short-circuit on probe bound if tombstone found. */
+};
+
+struct ck_hs_map {
+	unsigned int generation[CK_HS_G];
+	unsigned int probe_maximum;
+	unsigned long mask;
+	unsigned long step;
+	unsigned int probe_limit;
+	unsigned int tombstones;
+	unsigned long n_entries;
+	unsigned long capacity;
+	unsigned long size;
+	CK_HS_WORD *probe_bound;
+	const void **entries;
+};
+
+static inline void
+ck_hs_map_signal(struct ck_hs_map *map, unsigned long h)
+{
+
+	h &= CK_HS_G_MASK;
+	ck_pr_store_uint(&map->generation[h],
+	    map->generation[h] + 1);
+	ck_pr_fence_store();
+	return;
+}
+
+void
+ck_hs_iterator_init(struct ck_hs_iterator *iterator)
+{
+
+	iterator->cursor = NULL;
+	iterator->offset = 0;
+	return;
+}
+
+bool
+ck_hs_next(struct ck_hs *hs, struct ck_hs_iterator *i, void **key)
+{
+	struct ck_hs_map *map = hs->map;
+	void *value;
+
+	if (i->offset >= map->capacity)
+		return false;
+
+	do {
+		value = CK_CC_DECONST_PTR(map->entries[i->offset]);
+		if (value != CK_HS_EMPTY && value != CK_HS_TOMBSTONE) {
+#ifdef CK_HS_PP
+			if (hs->mode & CK_HS_MODE_OBJECT)
+				value = CK_HS_VMA(value);
+#endif
+			i->offset++;
+			*key = value;
+			return true;
+		}
+	} while (++i->offset < map->capacity);
+
+	return false;
+}
+
+void
+ck_hs_stat(struct ck_hs *hs, struct ck_hs_stat *st)
+{
+	struct ck_hs_map *map = hs->map;
+
+	st->n_entries = map->n_entries;
+	st->tombstones = map->tombstones;
+	st->probe_maximum = map->probe_maximum;
+	return;
+}
+
+unsigned long
+ck_hs_count(struct ck_hs *hs)
+{
+
+	return hs->map->n_entries;
+}
+
+static void
+ck_hs_map_destroy(struct ck_malloc *m, struct ck_hs_map *map, bool defer)
+{
+
+	m->free(map, map->size, defer);
+	return;
+}
+
+void
+ck_hs_destroy(struct ck_hs *hs)
+{
+
+	ck_hs_map_destroy(hs->m, hs->map, false);
+	return;
+}
+
+static struct ck_hs_map *
+ck_hs_map_create(struct ck_hs *hs, unsigned long entries)
+{
+	struct ck_hs_map *map;
+	unsigned long size, n_entries, prefix, limit;
+
+	n_entries = ck_internal_power_2(entries);
+	if (n_entries < CK_HS_PROBE_L1)
+		n_entries = CK_HS_PROBE_L1;
+
+	size = sizeof(struct ck_hs_map) + (sizeof(void *) * n_entries + CK_MD_CACHELINE - 1);
+
+	if (hs->mode & CK_HS_MODE_DELETE) {
+		prefix = sizeof(CK_HS_WORD) * n_entries;
+		size += prefix;
+	} else {
+		prefix = 0;
+	}
+
+	map = hs->m->malloc(size);
+	if (map == NULL)
+		return NULL;
+
+	map->size = size;
+
+	/* We should probably use a more intelligent heuristic for default probe length. */
+	limit = ck_internal_max(n_entries >> (CK_HS_PROBE_L1_SHIFT + 2), CK_HS_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;
+
+	/* Align map allocation to cache line. */
+	map->entries = (void *)(((uintptr_t)&map[1] + prefix +
+	    CK_MD_CACHELINE - 1) & ~(CK_MD_CACHELINE - 1));
+
+	memset(map->entries, 0, sizeof(void *) * n_entries);
+	memset(map->generation, 0, sizeof map->generation);
+
+	if (hs->mode & CK_HS_MODE_DELETE) {
+		map->probe_bound = (CK_HS_WORD *)&map[1];
+		memset(map->probe_bound, 0, prefix);
+	} else {
+		map->probe_bound = NULL;
+	}
+
+	/* Commit entries purge with respect to map publication. */
+	ck_pr_fence_store();
+	return map;
+}
+
+bool
+ck_hs_reset_size(struct ck_hs *hs, unsigned long capacity)
+{
+	struct ck_hs_map *map, *previous;
+
+	previous = hs->map;
+	map = ck_hs_map_create(hs, capacity);
+	if (map == NULL)
+		return false;
+
+	ck_pr_store_ptr(&hs->map, map);
+	ck_hs_map_destroy(hs->m, previous, true);
+	return true;
+}
+
+bool
+ck_hs_reset(struct ck_hs *hs)
+{
+	struct ck_hs_map *previous;
+
+	previous = hs->map;
+	return ck_hs_reset_size(hs, previous->capacity);
+}
+
+static inline unsigned long
+ck_hs_map_probe_next(struct ck_hs_map *map,
+    unsigned long offset,
+    unsigned long h,
+    unsigned long level,
+    unsigned long probes)
+{
+	unsigned long r, stride;
+
+	r = (h >> map->step) >> level;
+	stride = (r & ~CK_HS_PROBE_L1_MASK) << 1 | (r & CK_HS_PROBE_L1_MASK);
+
+	return (offset + (probes >> CK_HS_PROBE_L1_SHIFT) +
+	    (stride | CK_HS_PROBE_L1)) & map->mask;
+}
+
+static inline void
+ck_hs_map_bound_set(struct ck_hs_map *m,
+    unsigned long h,
+    unsigned long n_probes)
+{
+	unsigned long offset = h & m->mask;
+
+	if (n_probes > m->probe_maximum)
+		ck_pr_store_uint(&m->probe_maximum, n_probes);
+
+	if (m->probe_bound != NULL && m->probe_bound[offset] < n_probes) {
+		if (n_probes > CK_HS_WORD_MAX)
+			n_probes = CK_HS_WORD_MAX;
+
+		CK_HS_STORE(&m->probe_bound[offset], n_probes);
+		ck_pr_fence_store();
+	}
+
+	return;
+}
+
+static inline unsigned int
+ck_hs_map_bound_get(struct ck_hs_map *m, unsigned long h)
+{
+	unsigned long offset = h & m->mask;
+	unsigned int r = CK_HS_WORD_MAX;
+
+	if (m->probe_bound != NULL) {
+		r = CK_HS_LOAD(&m->probe_bound[offset]);
+		if (r == CK_HS_WORD_MAX)
+			r = ck_pr_load_uint(&m->probe_maximum);
+	} else {
+		r = ck_pr_load_uint(&m->probe_maximum);
+	}
+
+	return r;
+}
+
+bool
+ck_hs_grow(struct ck_hs *hs,
+    unsigned long capacity)
+{
+	struct ck_hs_map *map, *update;
+	unsigned long k, i, j, offset, probes;
+	const void *previous, **bucket;
+
+restart:
+	map = hs->map;
+	if (map->capacity > capacity)
+		return false;
+
+	update = ck_hs_map_create(hs, capacity);
+	if (update == NULL)
+		return false;
+
+	for (k = 0; k < map->capacity; k++) {
+		unsigned long h;
+
+		previous = map->entries[k];
+		if (previous == CK_HS_EMPTY || previous == CK_HS_TOMBSTONE)
+			continue;
+
+#ifdef CK_HS_PP
+		if (hs->mode & CK_HS_MODE_OBJECT)
+			previous = CK_HS_VMA(previous);
+#endif
+
+		h = hs->hf(previous, hs->seed);
+		offset = h & update->mask;
+		i = probes = 0;
+
+		for (;;) {
+			bucket = (const void **)((uintptr_t)&update->entries[offset] & ~(CK_MD_CACHELINE - 1));
+
+			for (j = 0; j < CK_HS_PROBE_L1; j++) {
+				const void **cursor = bucket + ((j + offset) & (CK_HS_PROBE_L1 - 1));
+
+				if (probes++ == update->probe_limit)
+					break;
+
+				if (CK_CC_LIKELY(*cursor == CK_HS_EMPTY)) {
+					*cursor = map->entries[k];
+					update->n_entries++;
+
+					ck_hs_map_bound_set(update, h, probes);
+					break;
+				}
+			}
+
+			if (j < CK_HS_PROBE_L1)
+				break;
+
+			offset = ck_hs_map_probe_next(update, offset, h, i++, probes);
+		}
+
+		if (probes > update->probe_limit) {
+			/*
+			 * We have hit the probe limit, map needs to be even larger.
+			 */
+			ck_hs_map_destroy(hs->m, update, false);
+			capacity <<= 1;
+			goto restart;
+		}
+	}
+
+	ck_pr_fence_store();
+	ck_pr_store_ptr(&hs->map, update);
+	ck_hs_map_destroy(hs->m, map, true);
+	return true;
+}
+
+static void
+ck_hs_map_postinsert(struct ck_hs *hs, struct ck_hs_map *map)
+{
+
+	map->n_entries++;
+	if ((map->n_entries << 1) > map->capacity)
+		ck_hs_grow(hs, map->capacity << 1);
+
+	return;
+}
+
+bool
+ck_hs_rebuild(struct ck_hs *hs)
+{
+
+	return ck_hs_grow(hs, hs->map->capacity);
+}
+
+static const void **
+ck_hs_map_probe(struct ck_hs *hs,
+    struct ck_hs_map *map,
+    unsigned long *n_probes,
+    const void ***priority,
+    unsigned long h,
+    const void *key,
+    const void **object,
+    unsigned long probe_limit,
+    enum ck_hs_probe_behavior behavior)
+{
+	const void **bucket, **cursor, *k, *compare;
+	const void **pr = NULL;
+	unsigned long offset, j, i, probes, opl;
+
+#ifdef CK_HS_PP
+	/* If we are storing object pointers, then we may leverage pointer packing. */
+	unsigned long hv = 0;
+
+	if (hs->mode & CK_HS_MODE_OBJECT) {
+		hv = (h >> 25) & CK_HS_KEY_MASK;
+		compare = CK_HS_VMA(key);
+	} else {
+		compare = key;
+	}
+#else
+	compare = key;
+#endif
+
+	offset = h & map->mask;
+	*object = NULL;
+	i = probes = 0;
+
+	opl = probe_limit;
+	if (behavior == CK_HS_PROBE_INSERT)
+		probe_limit = ck_hs_map_bound_get(map, h);
+
+	for (;;) {
+		bucket = (const void **)((uintptr_t)&map->entries[offset] & ~(CK_MD_CACHELINE - 1));
+
+		for (j = 0; j < CK_HS_PROBE_L1; j++) {
+			cursor = bucket + ((j + offset) & (CK_HS_PROBE_L1 - 1));
+
+			if (probes++ == probe_limit) {
+				if (probe_limit == opl || pr != NULL) {
+					k = CK_HS_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(cursor);
+			if (k == CK_HS_EMPTY)
+				goto leave;
+
+			if (k == CK_HS_TOMBSTONE) {
+				if (pr == NULL) {
+					pr = cursor;
+					*n_probes = probes;
+
+					if (behavior == CK_HS_PROBE_TOMBSTONE) {
+						k = CK_HS_EMPTY;
+						goto leave;
+					}
+				}
+
+				continue;
+			}
+
+#ifdef CK_HS_PP
+			if (hs->mode & CK_HS_MODE_OBJECT) {
+				if (((uintptr_t)k >> CK_MD_VMA_BITS) != hv)
+					continue;
+
+				k = CK_HS_VMA(k);
+			}
+#endif
+
+			if (k == compare)
+				goto leave;
+
+			if (hs->compare == NULL)
+				continue;
+
+			if (hs->compare(k, key) == true)
+				goto leave;
+		}
+
+		offset = ck_hs_map_probe_next(map, offset, h, i++, probes);
+	}
+
+leave:
+	if (probes > probe_limit) {
+		cursor = NULL;
+	} else {
+		*object = k;
+	}
+
+	if (pr == NULL)
+		*n_probes = probes;
+
+	*priority = pr;
+	return cursor;
+}
+
+static inline const void *
+ck_hs_marshal(unsigned int mode, const void *key, unsigned long h)
+{
+#ifdef CK_HS_PP
+	const void *insert;
+
+	if (mode & CK_HS_MODE_OBJECT) {
+		insert = (void *)((uintptr_t)CK_HS_VMA(key) |
+		    ((h >> 25) << CK_MD_VMA_BITS));
+	} else {
+		insert = key;
+	}
+
+	return insert;
+#else
+	(void)mode;
+	(void)h;
+
+	return key;
+#endif
+}
+
+bool
+ck_hs_gc(struct ck_hs *hs, unsigned long cycles, unsigned long seed)
+{
+	unsigned long size = 0;
+	unsigned long i;
+	struct ck_hs_map *map = hs->map;
+	unsigned int maximum;
+	CK_HS_WORD *bounds = NULL;
+
+	if (map->n_entries == 0) {
+		ck_pr_store_uint(&map->probe_maximum, 0);
+		if (map->probe_bound != NULL)
+			memset(map->probe_bound, 0, sizeof(CK_HS_WORD) * map->capacity);
+
+		return true;
+	}
+
+	if (cycles == 0) {
+		maximum = 0;
+
+		if (map->probe_bound != NULL) {
+			size = sizeof(CK_HS_WORD) * map->capacity;
+			bounds = hs->m->malloc(size);
+			if (bounds == NULL)
+				return false;
+
+			memset(bounds, 0, size);
+		}
+	} else {
+		maximum = map->probe_maximum;
+	}
+
+	for (i = 0; i < map->capacity; i++) {
+		const void **first, *object, **slot, *entry;
+		unsigned long n_probes, offset, h;
+
+		entry = map->entries[(i + seed) & map->mask];
+		if (entry == CK_HS_EMPTY || entry == CK_HS_TOMBSTONE)
+			continue;
+
+#ifdef CK_HS_PP
+		if (hs->mode & CK_HS_MODE_OBJECT)
+			entry = CK_HS_VMA(entry);
+#endif
+
+		h = hs->hf(entry, hs->seed);
+		offset = h & map->mask;
+
+		slot = ck_hs_map_probe(hs, map, &n_probes, &first, h, entry, &object,
+		    ck_hs_map_bound_get(map, h), CK_HS_PROBE);
+
+		if (first != NULL) {
+			const void *insert = ck_hs_marshal(hs->mode, entry, h);
+
+			ck_pr_store_ptr(first, insert);
+			ck_hs_map_signal(map, h);
+			ck_pr_store_ptr(slot, CK_HS_TOMBSTONE);
+		}
+
+		if (cycles == 0) {
+			if (n_probes > maximum)
+				maximum = n_probes;
+
+			if (n_probes > CK_HS_WORD_MAX)
+				n_probes = CK_HS_WORD_MAX;
+
+			if (bounds != NULL && n_probes > bounds[offset])
+				bounds[offset] = n_probes;
+		} else if (--cycles == 0)
+			break;
+	}
+
+	/*
+	 * The following only apply to garbage collection involving
+	 * a full scan of all entries.
+	 */
+	if (maximum != map->probe_maximum)
+		ck_pr_store_uint(&map->probe_maximum, maximum);
+
+	if (bounds != NULL) {
+		for (i = 0; i < map->capacity; i++)
+			CK_HS_STORE(&map->probe_bound[i], bounds[i]);
+
+		hs->m->free(bounds, size, false);
+	}
+
+	return true;
+}
+
+bool
+ck_hs_fas(struct ck_hs *hs,
+    unsigned long h,
+    const void *key,
+    void **previous)
+{
+	const void **slot, **first, *object, *insert;
+	struct ck_hs_map *map = hs->map;
+	unsigned long n_probes;
+
+	*previous = NULL;
+	slot = ck_hs_map_probe(hs, map, &n_probes, &first, h, key, &object,
+	    ck_hs_map_bound_get(map, h), CK_HS_PROBE);
+
+	/* Replacement semantics presume existence. */
+	if (object == NULL)
+		return false;
+
+	insert = ck_hs_marshal(hs->mode, key, h);
+
+	if (first != NULL) {
+		ck_pr_store_ptr(first, insert);
+		ck_hs_map_signal(map, h);
+		ck_pr_store_ptr(slot, CK_HS_TOMBSTONE);
+	} else {
+		ck_pr_store_ptr(slot, insert);
+	}
+
+	*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_hs_apply(struct ck_hs *hs,
+    unsigned long h,
+    const void *key,
+    ck_hs_apply_fn_t *fn,
+    void *cl)
+{
+	const void **slot, **first, *object, *delta, *insert;
+	unsigned long n_probes;
+	struct ck_hs_map *map;
+
+restart:
+	map = hs->map;
+
+	slot = ck_hs_map_probe(hs, map, &n_probes, &first, h, key, &object, map->probe_limit, CK_HS_PROBE_INSERT);
+	if (slot == NULL && first == NULL) {
+		if (ck_hs_grow(hs, map->capacity << 1) == false)
+			return false;
+
+		goto restart;
+	}
+
+	delta = fn(CK_CC_DECONST_PTR(object), cl);
+	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, mark slot as deleted. */
+		ck_pr_store_ptr(slot, CK_HS_TOMBSTONE);
+		map->n_entries--;
+		map->tombstones++;
+		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_hs_map_bound_set(map, h, n_probes);
+
+	insert = ck_hs_marshal(hs->mode, delta, h);
+	if (first != NULL) {
+		/*
+		 * This follows the same semantics as ck_hs_set, please refer to that
+		 * function for documentation.
+		 */
+		ck_pr_store_ptr(first, insert);
+
+		if (object != NULL) {
+			ck_hs_map_signal(map, h);
+			ck_pr_store_ptr(slot, CK_HS_TOMBSTONE);
+		}
+	} else {
+		/*
+		 * If we are storing into same slot, then atomic store is sufficient
+		 * for replacement.
+		 */
+		ck_pr_store_ptr(slot, insert);
+	}
+
+	if (object == NULL)
+		ck_hs_map_postinsert(hs, map);
+
+	return true;
+}
+
+bool
+ck_hs_set(struct ck_hs *hs,
+    unsigned long h,
+    const void *key,
+    void **previous)
+{
+	const void **slot, **first, *object, *insert;
+	unsigned long n_probes;
+	struct ck_hs_map *map;
+
+	*previous = NULL;
+
+restart:
+	map = hs->map;
+
+	slot = ck_hs_map_probe(hs, map, &n_probes, &first, h, key, &object, map->probe_limit, CK_HS_PROBE_INSERT);
+	if (slot == NULL && first == NULL) {
+		if (ck_hs_grow(hs, map->capacity << 1) == false)
+			return false;
+
+		goto restart;
+	}
+
+	ck_hs_map_bound_set(map, h, n_probes);
+	insert = ck_hs_marshal(hs->mode, key, h);
+
+	if (first != NULL) {
+		/* If an earlier bucket was found, then store entry there. */
+		ck_pr_store_ptr(first, insert);
+
+		/*
+		 * 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.
+		 */
+		if (object != NULL) {
+			ck_hs_map_signal(map, h);
+			ck_pr_store_ptr(slot, CK_HS_TOMBSTONE);
+		}
+	} else {
+		/*
+		 * If we are storing into same slot, then atomic store is sufficient
+		 * for replacement.
+		 */
+		ck_pr_store_ptr(slot, insert);
+	}
+
+	if (object == NULL)
+		ck_hs_map_postinsert(hs, map);
+
+	*previous = CK_CC_DECONST_PTR(object);
+	return true;
+}
+
+CK_CC_INLINE static bool
+ck_hs_put_internal(struct ck_hs *hs,
+    unsigned long h,
+    const void *key,
+    enum ck_hs_probe_behavior behavior)
+{
+	const void **slot, **first, *object, *insert;
+	unsigned long n_probes;
+	struct ck_hs_map *map;
+
+restart:
+	map = hs->map;
+
+	slot = ck_hs_map_probe(hs, map, &n_probes, &first, h, key, &object,
+	    map->probe_limit, behavior);
+
+	if (slot == NULL && first == NULL) {
+		if (ck_hs_grow(hs, map->capacity << 1) == false)
+			return false;
+
+		goto restart;
+	}
+
+	/* Fail operation if a match was found. */
+	if (object != NULL)
+		return false;
+
+	ck_hs_map_bound_set(map, h, n_probes);
+	insert = ck_hs_marshal(hs->mode, key, h);
+
+	if (first != NULL) {
+		/* Insert key into first bucket in probe sequence. */
+		ck_pr_store_ptr(first, insert);
+	} else {
+		/* An empty slot was found. */
+		ck_pr_store_ptr(slot, insert);
+	}
+
+	ck_hs_map_postinsert(hs, map);
+	return true;
+}
+
+bool
+ck_hs_put(struct ck_hs *hs,
+    unsigned long h,
+    const void *key)
+{
+
+	return ck_hs_put_internal(hs, h, key, CK_HS_PROBE_INSERT);
+}
+
+bool
+ck_hs_put_unique(struct ck_hs *hs,
+    unsigned long h,
+    const void *key)
+{
+
+	return ck_hs_put_internal(hs, h, key, CK_HS_PROBE_TOMBSTONE);
+}
+
+void *
+ck_hs_get(struct ck_hs *hs,
+    unsigned long h,
+    const void *key)
+{
+	const void **first, *object;
+	struct ck_hs_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_HS_G_MASK];
+		g = ck_pr_load_uint(generation);
+		probe  = ck_hs_map_bound_get(map, h);
+		ck_pr_fence_load();
+
+		ck_hs_map_probe(hs, map, &n_probes, &first, h, key, &object, probe, CK_HS_PROBE);
+
+		ck_pr_fence_load();
+		g_p = ck_pr_load_uint(generation);
+	} while (g != g_p);
+
+	return CK_CC_DECONST_PTR(object);
+}
+
+void *
+ck_hs_remove(struct ck_hs *hs,
+    unsigned long h,
+    const void *key)
+{
+	const void **slot, **first, *object;
+	struct ck_hs_map *map = hs->map;
+	unsigned long n_probes;
+
+	slot = ck_hs_map_probe(hs, map, &n_probes, &first, h, key, &object,
+	    ck_hs_map_bound_get(map, h), CK_HS_PROBE);
+	if (object == NULL)
+		return NULL;
+
+	ck_pr_store_ptr(slot, CK_HS_TOMBSTONE);
+	map->n_entries--;
+	map->tombstones++;
+	return CK_CC_DECONST_PTR(object);
+}
+
+bool
+ck_hs_move(struct ck_hs *hs,
+    struct ck_hs *source,
+    ck_hs_hash_cb_t *hf,
+    ck_hs_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->m = m;
+	hs->hf = hf;
+	hs->compare = compare;
+	return true;
+}
+
+bool
+ck_hs_init(struct ck_hs *hs,
+    unsigned int mode,
+    ck_hs_hash_cb_t *hf,
+    ck_hs_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->map = ck_hs_map_create(hs, n_entries);
+	return hs->map != NULL;
+}