SUBDIRS = . tests
include_HEADERS = urcu.h urcu-bp.h urcu-call-rcu.h urcu-defer.h \
- urcu-pointer.h urcu-qsbr.h
+ urcu-pointer.h urcu-qsbr.h urcu-flavor.h
nobase_dist_include_HEADERS = urcu/compiler.h urcu/hlist.h urcu/list.h \
urcu/rculist.h urcu/rcuhlist.h urcu/system.h urcu/futex.h \
urcu/uatomic/generic.h urcu/arch/generic.h urcu/wfstack.h \
urcu/wfqueue.h urcu/rculfstack.h urcu/rculfqueue.h \
urcu/ref.h urcu/map/*.h urcu/static/*.h urcu/cds.h \
- urcu/urcu_ref.h urcu/urcu-futex.h urcu/uatomic_arch.h
+ urcu/urcu_ref.h urcu/urcu-futex.h urcu/uatomic_arch.h \
+ urcu/rculfhash.h
nobase_nodist_include_HEADERS = urcu/arch.h urcu/uatomic.h urcu/config.h
EXTRA_DIST = $(top_srcdir)/urcu/arch/*.h $(top_srcdir)/urcu/uatomic/*.h \
gpl-2.0.txt lgpl-2.1.txt lgpl-relicensing.txt \
README LICENSE compat_arch_x86.c \
urcu-call-rcu-impl.h urcu-defer-impl.h \
+ rculfhash-internal.h \
ChangeLog API.txt \
$(top_srcdir)/tests/*.sh
COMPAT+=compat_futex.c
endif
+RCULFHASH = rculfhash.c rculfhash-mm-order.c rculfhash-mm-chunk.c \
+ rculfhash-mm-mmap.c
+
lib_LTLIBRARIES = liburcu-common.la \
liburcu.la liburcu-qsbr.la \
liburcu-mb.la liburcu-signal.la liburcu-bp.la \
liburcu_bp_la_SOURCES = urcu-bp.c urcu-pointer.c $(COMPAT)
liburcu_bp_la_LIBADD = liburcu-common.la
-liburcu_cds_la_SOURCES = rculfqueue.c rculfstack.c $(COMPAT)
+liburcu_cds_la_SOURCES = rculfqueue.c rculfstack.c $(RCULFHASH) $(COMPAT)
liburcu_cds_la_LIBADD = liburcu-common.la
pkgconfigdir = $(libdir)/pkgconfig
--- /dev/null
+#ifndef _URCU_RCULFHASH_INTERNAL_H
+#define _URCU_RCULFHASH_INTERNAL_H
+
+/*
+ * urcu/rculfhash-internal.h
+ *
+ * Internal header for Lock-Free RCU Hash Table
+ *
+ * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <urcu/rculfhash.h>
+
+#ifdef DEBUG
+#define dbg_printf(fmt, args...) printf("[debug rculfhash] " fmt, ## args)
+#else
+#define dbg_printf(fmt, args...)
+#endif
+
+#if (CAA_BITS_PER_LONG == 32)
+#define MAX_TABLE_ORDER 32
+#else
+#define MAX_TABLE_ORDER 64
+#endif
+
+#define MAX_CHUNK_TABLE (1UL << 10)
+
+#ifndef min
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+#ifndef max
+#define max(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
+struct ht_items_count;
+
+/*
+ * cds_lfht: Top-level data structure representing a lock-free hash
+ * table. Defined in the implementation file to make it be an opaque
+ * cookie to users.
+ *
+ * The fields used in fast-paths are placed near the end of the
+ * structure, because we need to have a variable-sized union to contain
+ * the mm plugin fields, which are used in the fast path.
+ */
+struct cds_lfht {
+ /* Initial configuration items */
+ unsigned long max_nr_buckets;
+ const struct cds_lfht_mm_type *mm; /* memory management plugin */
+ const struct rcu_flavor_struct *flavor; /* RCU flavor */
+
+ long count; /* global approximate item count */
+
+ /*
+ * We need to put the work threads offline (QSBR) when taking this
+ * mutex, because we use synchronize_rcu within this mutex critical
+ * section, which waits on read-side critical sections, and could
+ * therefore cause grace-period deadlock if we hold off RCU G.P.
+ * completion.
+ */
+ pthread_mutex_t resize_mutex; /* resize mutex: add/del mutex */
+ pthread_attr_t *resize_attr; /* Resize threads attributes */
+ unsigned int in_progress_resize, in_progress_destroy;
+ unsigned long resize_target;
+ int resize_initiated;
+
+ /*
+ * Variables needed for add and remove fast-paths.
+ */
+ int flags;
+ unsigned long min_alloc_buckets_order;
+ unsigned long min_nr_alloc_buckets;
+ struct ht_items_count *split_count; /* split item count */
+
+ /*
+ * Variables needed for the lookup, add and remove fast-paths.
+ */
+ unsigned long size; /* always a power of 2, shared (RCU) */
+ /*
+ * bucket_at pointer is kept here to skip the extra level of
+ * dereference needed to get to "mm" (this is a fast-path).
+ */
+ struct cds_lfht_node *(*bucket_at)(struct cds_lfht *ht,
+ unsigned long index);
+ /*
+ * Dynamic length "tbl_chunk" needs to be at the end of
+ * cds_lfht.
+ */
+ union {
+ /*
+ * Contains the per order-index-level bucket node table.
+ * The size of each bucket node table is half the number
+ * of hashes contained in this order (except for order 0).
+ * The minimum allocation buckets size parameter allows
+ * combining the bucket node arrays of the lowermost
+ * levels to improve cache locality for small index orders.
+ */
+ struct cds_lfht_node *tbl_order[MAX_TABLE_ORDER];
+
+ /*
+ * Contains the bucket node chunks. The size of each
+ * bucket node chunk is ->min_alloc_size (we avoid to
+ * allocate chunks with different size). Chunks improve
+ * cache locality for small index orders, and are more
+ * friendly with environments where allocation of large
+ * contiguous memory areas is challenging due to memory
+ * fragmentation concerns or inability to use virtual
+ * memory addressing.
+ */
+ struct cds_lfht_node *tbl_chunk[0];
+
+ /*
+ * Memory mapping with room for all possible buckets.
+ * Their memory is allocated when needed.
+ */
+ struct cds_lfht_node *tbl_mmap;
+ };
+ /*
+ * End of variables needed for the lookup, add and remove
+ * fast-paths.
+ */
+};
+
+extern unsigned int fls_ulong(unsigned long x);
+extern int get_count_order_ulong(unsigned long x);
+
+#ifdef POISON_FREE
+#define poison_free(ptr) \
+ do { \
+ if (ptr) { \
+ memset(ptr, 0x42, sizeof(*(ptr))); \
+ free(ptr); \
+ } \
+ } while (0)
+#else
+#define poison_free(ptr) free(ptr)
+#endif
+
+static inline
+struct cds_lfht *__default_alloc_cds_lfht(
+ const struct cds_lfht_mm_type *mm,
+ unsigned long cds_lfht_size,
+ unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets)
+{
+ struct cds_lfht *ht;
+
+ ht = calloc(1, cds_lfht_size);
+ assert(ht);
+
+ ht->mm = mm;
+ ht->bucket_at = mm->bucket_at;
+ ht->min_nr_alloc_buckets = min_nr_alloc_buckets;
+ ht->min_alloc_buckets_order =
+ get_count_order_ulong(min_nr_alloc_buckets);
+ ht->max_nr_buckets = max_nr_buckets;
+
+ return ht;
+}
+
+#endif /* _URCU_RCULFHASH_INTERNAL_H */
--- /dev/null
+/*
+ * rculfhash-mm-chunk.c
+ *
+ * Chunk based memory management for Lock-Free RCU Hash Table
+ *
+ * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stddef.h>
+#include <rculfhash-internal.h>
+
+static
+void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+ if (order == 0) {
+ ht->tbl_chunk[0] = calloc(ht->min_nr_alloc_buckets,
+ sizeof(struct cds_lfht_node));
+ assert(ht->tbl_chunk[0]);
+ } else if (order > ht->min_alloc_buckets_order) {
+ unsigned long i, len = 1UL << (order - 1 - ht->min_alloc_buckets_order);
+
+ for (i = len; i < 2 * len; i++) {
+ ht->tbl_chunk[i] = calloc(ht->min_nr_alloc_buckets,
+ sizeof(struct cds_lfht_node));
+ assert(ht->tbl_chunk[i]);
+ }
+ }
+ /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
+}
+
+/*
+ * cds_lfht_free_bucket_table() should be called with decreasing order.
+ * When cds_lfht_free_bucket_table(0) is called, it means the whole
+ * lfht is destroyed.
+ */
+static
+void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+ if (order == 0)
+ poison_free(ht->tbl_chunk[0]);
+ else if (order > ht->min_alloc_buckets_order) {
+ unsigned long i, len = 1UL << (order - 1 - ht->min_alloc_buckets_order);
+
+ for (i = len; i < 2 * len; i++)
+ poison_free(ht->tbl_chunk[i]);
+ }
+ /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
+}
+
+static
+struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index)
+{
+ unsigned long chunk, offset;
+
+ chunk = index >> ht->min_alloc_buckets_order;
+ offset = index & (ht->min_nr_alloc_buckets - 1);
+ return &ht->tbl_chunk[chunk][offset];
+}
+
+static
+struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets)
+{
+ unsigned long nr_chunks, cds_lfht_size;
+
+ min_nr_alloc_buckets = max(min_nr_alloc_buckets,
+ max_nr_buckets / MAX_CHUNK_TABLE);
+ nr_chunks = max_nr_buckets / min_nr_alloc_buckets;
+ cds_lfht_size = offsetof(struct cds_lfht, tbl_chunk) +
+ sizeof(struct cds_lfht_node *) * nr_chunks;
+ cds_lfht_size = max(cds_lfht_size, sizeof(struct cds_lfht));
+
+ return __default_alloc_cds_lfht(
+ &cds_lfht_mm_chunk, cds_lfht_size,
+ min_nr_alloc_buckets, max_nr_buckets);
+}
+
+const struct cds_lfht_mm_type cds_lfht_mm_chunk = {
+ .alloc_cds_lfht = alloc_cds_lfht,
+ .alloc_bucket_table = cds_lfht_alloc_bucket_table,
+ .free_bucket_table = cds_lfht_free_bucket_table,
+ .bucket_at = bucket_at,
+};
--- /dev/null
+/*
+ * rculfhash-mm-mmap.c
+ *
+ * mmap/reservation based memory management for Lock-Free RCU Hash Table
+ *
+ * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <unistd.h>
+#include <sys/mman.h>
+#include "rculfhash-internal.h"
+
+/* reserve inaccessible memory space without allocation any memory */
+static void *memory_map(size_t length)
+{
+ void *ret = mmap(NULL, length, PROT_NONE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+ assert(ret != MAP_FAILED);
+ return ret;
+}
+
+static void memory_unmap(void *ptr, size_t length)
+{
+ int ret __attribute__((unused));
+
+ ret = munmap(ptr, length);
+
+ assert(ret == 0);
+}
+
+static void memory_populate(void *ptr, size_t length)
+{
+ void *ret __attribute__((unused));
+
+ ret = mmap(ptr, length, PROT_READ | PROT_WRITE,
+ MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+ assert(ret == ptr);
+}
+
+/*
+ * Discard garbage memory and avoid system save it when try to swap it out.
+ * Make it still reserved, inaccessible.
+ */
+static void memory_discard(void *ptr, size_t length)
+{
+ void *ret __attribute__((unused));
+
+ ret = mmap(ptr, length, PROT_NONE,
+ MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+ assert(ret == ptr);
+}
+
+static
+void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+ if (order == 0) {
+ if (ht->min_nr_alloc_buckets == ht->max_nr_buckets) {
+ /* small table */
+ ht->tbl_mmap = calloc(ht->max_nr_buckets,
+ sizeof(*ht->tbl_mmap));
+ assert(ht->tbl_mmap);
+ return;
+ }
+ /* large table */
+ ht->tbl_mmap = memory_map(ht->max_nr_buckets
+ * sizeof(*ht->tbl_mmap));
+ memory_populate(ht->tbl_mmap,
+ ht->min_nr_alloc_buckets * sizeof(*ht->tbl_mmap));
+ } else if (order > ht->min_alloc_buckets_order) {
+ /* large table */
+ unsigned long len = 1UL << (order - 1);
+
+ assert(ht->min_nr_alloc_buckets < ht->max_nr_buckets);
+ memory_populate(ht->tbl_mmap + len,
+ len * sizeof(*ht->tbl_mmap));
+ }
+ /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
+}
+
+/*
+ * cds_lfht_free_bucket_table() should be called with decreasing order.
+ * When cds_lfht_free_bucket_table(0) is called, it means the whole
+ * lfht is destroyed.
+ */
+static
+void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+ if (order == 0) {
+ if (ht->min_nr_alloc_buckets == ht->max_nr_buckets) {
+ /* small table */
+ poison_free(ht->tbl_mmap);
+ return;
+ }
+ /* large table */
+ memory_unmap(ht->tbl_mmap,
+ ht->max_nr_buckets * sizeof(*ht->tbl_mmap));
+ } else if (order > ht->min_alloc_buckets_order) {
+ /* large table */
+ unsigned long len = 1UL << (order - 1);
+
+ assert(ht->min_nr_alloc_buckets < ht->max_nr_buckets);
+ memory_discard(ht->tbl_mmap + len, len * sizeof(*ht->tbl_mmap));
+ }
+ /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
+}
+
+static
+struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index)
+{
+ return &ht->tbl_mmap[index];
+}
+
+static
+struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets)
+{
+ unsigned long page_bucket_size;
+
+ page_bucket_size = getpagesize() / sizeof(struct cds_lfht_node);
+ if (max_nr_buckets <= page_bucket_size) {
+ /* small table */
+ min_nr_alloc_buckets = max_nr_buckets;
+ } else {
+ /* large table */
+ min_nr_alloc_buckets = max(min_nr_alloc_buckets,
+ page_bucket_size);
+ }
+
+ return __default_alloc_cds_lfht(
+ &cds_lfht_mm_mmap, sizeof(struct cds_lfht),
+ min_nr_alloc_buckets, max_nr_buckets);
+}
+
+const struct cds_lfht_mm_type cds_lfht_mm_mmap = {
+ .alloc_cds_lfht = alloc_cds_lfht,
+ .alloc_bucket_table = cds_lfht_alloc_bucket_table,
+ .free_bucket_table = cds_lfht_free_bucket_table,
+ .bucket_at = bucket_at,
+};
--- /dev/null
+/*
+ * rculfhash-mm-order.c
+ *
+ * Order based memory management for Lock-Free RCU Hash Table
+ *
+ * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <rculfhash-internal.h>
+
+static
+void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+ if (order == 0) {
+ ht->tbl_order[0] = calloc(ht->min_nr_alloc_buckets,
+ sizeof(struct cds_lfht_node));
+ assert(ht->tbl_order[0]);
+ } else if (order > ht->min_alloc_buckets_order) {
+ ht->tbl_order[order] = calloc(1UL << (order -1),
+ sizeof(struct cds_lfht_node));
+ assert(ht->tbl_order[order]);
+ }
+ /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
+}
+
+/*
+ * cds_lfht_free_bucket_table() should be called with decreasing order.
+ * When cds_lfht_free_bucket_table(0) is called, it means the whole
+ * lfht is destroyed.
+ */
+static
+void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+ if (order == 0)
+ poison_free(ht->tbl_order[0]);
+ else if (order > ht->min_alloc_buckets_order)
+ poison_free(ht->tbl_order[order]);
+ /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
+}
+
+static
+struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index)
+{
+ unsigned long order;
+
+ if (index < ht->min_nr_alloc_buckets) {
+ dbg_printf("bucket index %lu order 0 aridx 0\n", index);
+ return &ht->tbl_order[0][index];
+ }
+ /*
+ * equivalent to get_count_order_ulong(index + 1), but optimizes
+ * away the non-existing 0 special-case for
+ * get_count_order_ulong.
+ */
+ order = fls_ulong(index);
+ dbg_printf("bucket index %lu order %lu aridx %lu\n",
+ index, order, index & ((1UL << (order - 1)) - 1));
+ return &ht->tbl_order[order][index & ((1UL << (order - 1)) - 1)];
+}
+
+static
+struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets)
+{
+ return __default_alloc_cds_lfht(
+ &cds_lfht_mm_order, sizeof(struct cds_lfht),
+ min_nr_alloc_buckets, max_nr_buckets);
+}
+
+const struct cds_lfht_mm_type cds_lfht_mm_order = {
+ .alloc_cds_lfht = alloc_cds_lfht,
+ .alloc_bucket_table = cds_lfht_alloc_bucket_table,
+ .free_bucket_table = cds_lfht_free_bucket_table,
+ .bucket_at = bucket_at,
+};
--- /dev/null
+/*
+ * rculfhash.c
+ *
+ * Userspace RCU library - Lock-Free Resizable RCU Hash Table
+ *
+ * Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * Based on the following articles:
+ * - Ori Shalev and Nir Shavit. Split-ordered lists: Lock-free
+ * extensible hash tables. J. ACM 53, 3 (May 2006), 379-405.
+ * - Michael, M. M. High performance dynamic lock-free hash tables
+ * and list-based sets. In Proceedings of the fourteenth annual ACM
+ * symposium on Parallel algorithms and architectures, ACM Press,
+ * (2002), 73-82.
+ *
+ * Some specificities of this Lock-Free Resizable RCU Hash Table
+ * implementation:
+ *
+ * - RCU read-side critical section allows readers to perform hash
+ * table lookups and use the returned objects safely by delaying
+ * memory reclaim of a grace period.
+ * - Add and remove operations are lock-free, and do not need to
+ * allocate memory. They need to be executed within RCU read-side
+ * critical section to ensure the objects they read are valid and to
+ * deal with the cmpxchg ABA problem.
+ * - add and add_unique operations are supported. add_unique checks if
+ * the node key already exists in the hash table. It ensures no key
+ * duplicata exists.
+ * - The resize operation executes concurrently with add/remove/lookup.
+ * - Hash table nodes are contained within a split-ordered list. This
+ * list is ordered by incrementing reversed-bits-hash value.
+ * - An index of bucket nodes is kept. These bucket nodes are the hash
+ * table "buckets", and they are also chained together in the
+ * split-ordered list, which allows recursive expansion.
+ * - The resize operation for small tables only allows expanding the hash table.
+ * It is triggered automatically by detecting long chains in the add
+ * operation.
+ * - The resize operation for larger tables (and available through an
+ * API) allows both expanding and shrinking the hash table.
+ * - Split-counters are used to keep track of the number of
+ * nodes within the hash table for automatic resize triggering.
+ * - Resize operation initiated by long chain detection is executed by a
+ * call_rcu thread, which keeps lock-freedom of add and remove.
+ * - Resize operations are protected by a mutex.
+ * - The removal operation is split in two parts: first, a "removed"
+ * flag is set in the next pointer within the node to remove. Then,
+ * a "garbage collection" is performed in the bucket containing the
+ * removed node (from the start of the bucket up to the removed node).
+ * All encountered nodes with "removed" flag set in their next
+ * pointers are removed from the linked-list. If the cmpxchg used for
+ * removal fails (due to concurrent garbage-collection or concurrent
+ * add), we retry from the beginning of the bucket. This ensures that
+ * the node with "removed" flag set is removed from the hash table
+ * (not visible to lookups anymore) before the RCU read-side critical
+ * section held across removal ends. Furthermore, this ensures that
+ * the node with "removed" flag set is removed from the linked-list
+ * before its memory is reclaimed. Only the thread which removal
+ * successfully set the "removed" flag (with a cmpxchg) into a node's
+ * next pointer is considered to have succeeded its removal (and thus
+ * owns the node to reclaim). Because we garbage-collect starting from
+ * an invariant node (the start-of-bucket bucket node) up to the
+ * "removed" node (or find a reverse-hash that is higher), we are sure
+ * that a successful traversal of the chain leads to a chain that is
+ * present in the linked-list (the start node is never removed) and
+ * that is does not contain the "removed" node anymore, even if
+ * concurrent delete/add operations are changing the structure of the
+ * list concurrently.
+ * - The add operation performs gargage collection of buckets if it
+ * encounters nodes with removed flag set in the bucket where it wants
+ * to add its new node. This ensures lock-freedom of add operation by
+ * helping the remover unlink nodes from the list rather than to wait
+ * for it do to so.
+ * - A RCU "order table" indexed by log2(hash index) is copied and
+ * expanded by the resize operation. This order table allows finding
+ * the "bucket node" tables.
+ * - There is one bucket node table per hash index order. The size of
+ * each bucket node table is half the number of hashes contained in
+ * this order (except for order 0).
+ * - synchronzie_rcu is used to garbage-collect the old bucket node table.
+ * - The per-order bucket node tables contain a compact version of the
+ * hash table nodes. These tables are invariant after they are
+ * populated into the hash table.
+ *
+ * Bucket node tables:
+ *
+ * hash table hash table the last all bucket node tables
+ * order size bucket node 0 1 2 3 4 5 6(index)
+ * table size
+ * 0 1 1 1
+ * 1 2 1 1 1
+ * 2 4 2 1 1 2
+ * 3 8 4 1 1 2 4
+ * 4 16 8 1 1 2 4 8
+ * 5 32 16 1 1 2 4 8 16
+ * 6 64 32 1 1 2 4 8 16 32
+ *
+ * When growing/shrinking, we only focus on the last bucket node table
+ * which size is (!order ? 1 : (1 << (order -1))).
+ *
+ * Example for growing/shrinking:
+ * grow hash table from order 5 to 6: init the index=6 bucket node table
+ * shrink hash table from order 6 to 5: fini the index=6 bucket node table
+ *
+ * A bit of ascii art explanation:
+ *
+ * Order index is the off-by-one compare to the actual power of 2 because
+ * we use index 0 to deal with the 0 special-case.
+ *
+ * This shows the nodes for a small table ordered by reversed bits:
+ *
+ * bits reverse
+ * 0 000 000
+ * 4 100 001
+ * 2 010 010
+ * 6 110 011
+ * 1 001 100
+ * 5 101 101
+ * 3 011 110
+ * 7 111 111
+ *
+ * This shows the nodes in order of non-reversed bits, linked by
+ * reversed-bit order.
+ *
+ * order bits reverse
+ * 0 0 000 000
+ * 1 | 1 001 100 <-
+ * 2 | | 2 010 010 <- |
+ * | | | 3 011 110 | <- |
+ * 3 -> | | | 4 100 001 | |
+ * -> | | 5 101 101 |
+ * -> | 6 110 011
+ * -> 7 111 111
+ */
+
+#define _LGPL_SOURCE
+#include <stdlib.h>
+#include <errno.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "config.h"
+#include <urcu.h>
+#include <urcu-call-rcu.h>
+#include <urcu-flavor.h>
+#include <urcu/arch.h>
+#include <urcu/uatomic.h>
+#include <urcu/compiler.h>
+#include <urcu/rculfhash.h>
+#include <rculfhash-internal.h>
+#include <stdio.h>
+#include <pthread.h>
+
+/*
+ * Split-counters lazily update the global counter each 1024
+ * addition/removal. It automatically keeps track of resize required.
+ * We use the bucket length as indicator for need to expand for small
+ * tables and machines lacking per-cpu data suppport.
+ */
+#define COUNT_COMMIT_ORDER 10
+#define DEFAULT_SPLIT_COUNT_MASK 0xFUL
+#define CHAIN_LEN_TARGET 1
+#define CHAIN_LEN_RESIZE_THRESHOLD 3
+
+/*
+ * Define the minimum table size.
+ */
+#define MIN_TABLE_ORDER 0
+#define MIN_TABLE_SIZE (1UL << MIN_TABLE_ORDER)
+
+/*
+ * Minimum number of bucket nodes to touch per thread to parallelize grow/shrink.
+ */
+#define MIN_PARTITION_PER_THREAD_ORDER 12
+#define MIN_PARTITION_PER_THREAD (1UL << MIN_PARTITION_PER_THREAD_ORDER)
+
+/*
+ * The removed flag needs to be updated atomically with the pointer.
+ * It indicates that no node must attach to the node scheduled for
+ * removal, and that node garbage collection must be performed.
+ * The bucket flag does not require to be updated atomically with the
+ * pointer, but it is added as a pointer low bit flag to save space.
+ */
+#define REMOVED_FLAG (1UL << 0)
+#define BUCKET_FLAG (1UL << 1)
+#define FLAGS_MASK ((1UL << 2) - 1)
+
+/* Value of the end pointer. Should not interact with flags. */
+#define END_VALUE NULL
+
+/*
+ * ht_items_count: Split-counters counting the number of node addition
+ * and removal in the table. Only used if the CDS_LFHT_ACCOUNTING flag
+ * is set at hash table creation.
+ *
+ * These are free-running counters, never reset to zero. They count the
+ * number of add/remove, and trigger every (1 << COUNT_COMMIT_ORDER)
+ * operations to update the global counter. We choose a power-of-2 value
+ * for the trigger to deal with 32 or 64-bit overflow of the counter.
+ */
+struct ht_items_count {
+ unsigned long add, del;
+} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
+
+/*
+ * rcu_resize_work: Contains arguments passed to RCU worker thread
+ * responsible for performing lazy resize.
+ */
+struct rcu_resize_work {
+ struct rcu_head head;
+ struct cds_lfht *ht;
+};
+
+/*
+ * partition_resize_work: Contains arguments passed to worker threads
+ * executing the hash table resize on partitions of the hash table
+ * assigned to each processor's worker thread.
+ */
+struct partition_resize_work {
+ pthread_t thread_id;
+ struct cds_lfht *ht;
+ unsigned long i, start, len;
+ void (*fct)(struct cds_lfht *ht, unsigned long i,
+ unsigned long start, unsigned long len);
+};
+
+/*
+ * Algorithm to reverse bits in a word by lookup table, extended to
+ * 64-bit words.
+ * Source:
+ * http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable
+ * Originally from Public Domain.
+ */
+
+static const uint8_t BitReverseTable256[256] =
+{
+#define R2(n) (n), (n) + 2*64, (n) + 1*64, (n) + 3*64
+#define R4(n) R2(n), R2((n) + 2*16), R2((n) + 1*16), R2((n) + 3*16)
+#define R6(n) R4(n), R4((n) + 2*4 ), R4((n) + 1*4 ), R4((n) + 3*4 )
+ R6(0), R6(2), R6(1), R6(3)
+};
+#undef R2
+#undef R4
+#undef R6
+
+static
+uint8_t bit_reverse_u8(uint8_t v)
+{
+ return BitReverseTable256[v];
+}
+
+static __attribute__((unused))
+uint32_t bit_reverse_u32(uint32_t v)
+{
+ return ((uint32_t) bit_reverse_u8(v) << 24) |
+ ((uint32_t) bit_reverse_u8(v >> 8) << 16) |
+ ((uint32_t) bit_reverse_u8(v >> 16) << 8) |
+ ((uint32_t) bit_reverse_u8(v >> 24));
+}
+
+static __attribute__((unused))
+uint64_t bit_reverse_u64(uint64_t v)
+{
+ return ((uint64_t) bit_reverse_u8(v) << 56) |
+ ((uint64_t) bit_reverse_u8(v >> 8) << 48) |
+ ((uint64_t) bit_reverse_u8(v >> 16) << 40) |
+ ((uint64_t) bit_reverse_u8(v >> 24) << 32) |
+ ((uint64_t) bit_reverse_u8(v >> 32) << 24) |
+ ((uint64_t) bit_reverse_u8(v >> 40) << 16) |
+ ((uint64_t) bit_reverse_u8(v >> 48) << 8) |
+ ((uint64_t) bit_reverse_u8(v >> 56));
+}
+
+static
+unsigned long bit_reverse_ulong(unsigned long v)
+{
+#if (CAA_BITS_PER_LONG == 32)
+ return bit_reverse_u32(v);
+#else
+ return bit_reverse_u64(v);
+#endif
+}
+
+/*
+ * fls: returns the position of the most significant bit.
+ * Returns 0 if no bit is set, else returns the position of the most
+ * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
+ */
+#if defined(__i386) || defined(__x86_64)
+static inline
+unsigned int fls_u32(uint32_t x)
+{
+ int r;
+
+ asm("bsrl %1,%0\n\t"
+ "jnz 1f\n\t"
+ "movl $-1,%0\n\t"
+ "1:\n\t"
+ : "=r" (r) : "rm" (x));
+ return r + 1;
+}
+#define HAS_FLS_U32
+#endif
+
+#if defined(__x86_64)
+static inline
+unsigned int fls_u64(uint64_t x)
+{
+ long r;
+
+ asm("bsrq %1,%0\n\t"
+ "jnz 1f\n\t"
+ "movq $-1,%0\n\t"
+ "1:\n\t"
+ : "=r" (r) : "rm" (x));
+ return r + 1;
+}
+#define HAS_FLS_U64
+#endif
+
+#ifndef HAS_FLS_U64
+static __attribute__((unused))
+unsigned int fls_u64(uint64_t x)
+{
+ unsigned int r = 64;
+
+ if (!x)
+ return 0;
+
+ if (!(x & 0xFFFFFFFF00000000ULL)) {
+ x <<= 32;
+ r -= 32;
+ }
+ if (!(x & 0xFFFF000000000000ULL)) {
+ x <<= 16;
+ r -= 16;
+ }
+ if (!(x & 0xFF00000000000000ULL)) {
+ x <<= 8;
+ r -= 8;
+ }
+ if (!(x & 0xF000000000000000ULL)) {
+ x <<= 4;
+ r -= 4;
+ }
+ if (!(x & 0xC000000000000000ULL)) {
+ x <<= 2;
+ r -= 2;
+ }
+ if (!(x & 0x8000000000000000ULL)) {
+ x <<= 1;
+ r -= 1;
+ }
+ return r;
+}
+#endif
+
+#ifndef HAS_FLS_U32
+static __attribute__((unused))
+unsigned int fls_u32(uint32_t x)
+{
+ unsigned int r = 32;
+
+ if (!x)
+ return 0;
+ if (!(x & 0xFFFF0000U)) {
+ x <<= 16;
+ r -= 16;
+ }
+ if (!(x & 0xFF000000U)) {
+ x <<= 8;
+ r -= 8;
+ }
+ if (!(x & 0xF0000000U)) {
+ x <<= 4;
+ r -= 4;
+ }
+ if (!(x & 0xC0000000U)) {
+ x <<= 2;
+ r -= 2;
+ }
+ if (!(x & 0x80000000U)) {
+ x <<= 1;
+ r -= 1;
+ }
+ return r;
+}
+#endif
+
+unsigned int fls_ulong(unsigned long x)
+{
+#if (CAA_BITS_PER_LONG == 32)
+ return fls_u32(x);
+#else
+ return fls_u64(x);
+#endif
+}
+
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+int get_count_order_u32(uint32_t x)
+{
+ if (!x)
+ return -1;
+
+ return fls_u32(x - 1);
+}
+
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+int get_count_order_ulong(unsigned long x)
+{
+ if (!x)
+ return -1;
+
+ return fls_ulong(x - 1);
+}
+
+static
+void cds_lfht_resize_lazy_grow(struct cds_lfht *ht, unsigned long size, int growth);
+
+static
+void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
+ unsigned long count);
+
+static long nr_cpus_mask = -1;
+static long split_count_mask = -1;
+
+#if defined(HAVE_SYSCONF)
+static void ht_init_nr_cpus_mask(void)
+{
+ long maxcpus;
+
+ maxcpus = sysconf(_SC_NPROCESSORS_CONF);
+ if (maxcpus <= 0) {
+ nr_cpus_mask = -2;
+ return;
+ }
+ /*
+ * round up number of CPUs to next power of two, so we
+ * can use & for modulo.
+ */
+ maxcpus = 1UL << get_count_order_ulong(maxcpus);
+ nr_cpus_mask = maxcpus - 1;
+}
+#else /* #if defined(HAVE_SYSCONF) */
+static void ht_init_nr_cpus_mask(void)
+{
+ nr_cpus_mask = -2;
+}
+#endif /* #else #if defined(HAVE_SYSCONF) */
+
+static
+void alloc_split_items_count(struct cds_lfht *ht)
+{
+ struct ht_items_count *count;
+
+ if (nr_cpus_mask == -1) {
+ ht_init_nr_cpus_mask();
+ if (nr_cpus_mask < 0)
+ split_count_mask = DEFAULT_SPLIT_COUNT_MASK;
+ else
+ split_count_mask = nr_cpus_mask;
+ }
+
+ assert(split_count_mask >= 0);
+
+ if (ht->flags & CDS_LFHT_ACCOUNTING) {
+ ht->split_count = calloc(split_count_mask + 1, sizeof(*count));
+ assert(ht->split_count);
+ } else {
+ ht->split_count = NULL;
+ }
+}
+
+static
+void free_split_items_count(struct cds_lfht *ht)
+{
+ poison_free(ht->split_count);
+}
+
+#if defined(HAVE_SCHED_GETCPU)
+static
+int ht_get_split_count_index(unsigned long hash)
+{
+ int cpu;
+
+ assert(split_count_mask >= 0);
+ cpu = sched_getcpu();
+ if (caa_unlikely(cpu < 0))
+ return hash & split_count_mask;
+ else
+ return cpu & split_count_mask;
+}
+#else /* #if defined(HAVE_SCHED_GETCPU) */
+static
+int ht_get_split_count_index(unsigned long hash)
+{
+ return hash & split_count_mask;
+}
+#endif /* #else #if defined(HAVE_SCHED_GETCPU) */
+
+static
+void ht_count_add(struct cds_lfht *ht, unsigned long size, unsigned long hash)
+{
+ unsigned long split_count;
+ int index;
+ long count;
+
+ if (caa_unlikely(!ht->split_count))
+ return;
+ index = ht_get_split_count_index(hash);
+ split_count = uatomic_add_return(&ht->split_count[index].add, 1);
+ if (caa_likely(split_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))
+ return;
+ /* Only if number of add multiple of 1UL << COUNT_COMMIT_ORDER */
+
+ dbg_printf("add split count %lu\n", split_count);
+ count = uatomic_add_return(&ht->count,
+ 1UL << COUNT_COMMIT_ORDER);
+ if (caa_likely(count & (count - 1)))
+ return;
+ /* Only if global count is power of 2 */
+
+ if ((count >> CHAIN_LEN_RESIZE_THRESHOLD) < size)
+ return;
+ dbg_printf("add set global %ld\n", count);
+ cds_lfht_resize_lazy_count(ht, size,
+ count >> (CHAIN_LEN_TARGET - 1));
+}
+
+static
+void ht_count_del(struct cds_lfht *ht, unsigned long size, unsigned long hash)
+{
+ unsigned long split_count;
+ int index;
+ long count;
+
+ if (caa_unlikely(!ht->split_count))
+ return;
+ index = ht_get_split_count_index(hash);
+ split_count = uatomic_add_return(&ht->split_count[index].del, 1);
+ if (caa_likely(split_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))
+ return;
+ /* Only if number of deletes multiple of 1UL << COUNT_COMMIT_ORDER */
+
+ dbg_printf("del split count %lu\n", split_count);
+ count = uatomic_add_return(&ht->count,
+ -(1UL << COUNT_COMMIT_ORDER));
+ if (caa_likely(count & (count - 1)))
+ return;
+ /* Only if global count is power of 2 */
+
+ if ((count >> CHAIN_LEN_RESIZE_THRESHOLD) >= size)
+ return;
+ dbg_printf("del set global %ld\n", count);
+ /*
+ * Don't shrink table if the number of nodes is below a
+ * certain threshold.
+ */
+ if (count < (1UL << COUNT_COMMIT_ORDER) * (split_count_mask + 1))
+ return;
+ cds_lfht_resize_lazy_count(ht, size,
+ count >> (CHAIN_LEN_TARGET - 1));
+}
+
+static
+void check_resize(struct cds_lfht *ht, unsigned long size, uint32_t chain_len)
+{
+ unsigned long count;
+
+ if (!(ht->flags & CDS_LFHT_AUTO_RESIZE))
+ return;
+ count = uatomic_read(&ht->count);
+ /*
+ * Use bucket-local length for small table expand and for
+ * environments lacking per-cpu data support.
+ */
+ if (count >= (1UL << COUNT_COMMIT_ORDER))
+ return;
+ if (chain_len > 100)
+ dbg_printf("WARNING: large chain length: %u.\n",
+ chain_len);
+ if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD)
+ cds_lfht_resize_lazy_grow(ht, size,
+ get_count_order_u32(chain_len - (CHAIN_LEN_TARGET - 1)));
+}
+
+static
+struct cds_lfht_node *clear_flag(struct cds_lfht_node *node)
+{
+ return (struct cds_lfht_node *) (((unsigned long) node) & ~FLAGS_MASK);
+}
+
+static
+int is_removed(struct cds_lfht_node *node)
+{
+ return ((unsigned long) node) & REMOVED_FLAG;
+}
+
+static
+struct cds_lfht_node *flag_removed(struct cds_lfht_node *node)
+{
+ return (struct cds_lfht_node *) (((unsigned long) node) | REMOVED_FLAG);
+}
+
+static
+int is_bucket(struct cds_lfht_node *node)
+{
+ return ((unsigned long) node) & BUCKET_FLAG;
+}
+
+static
+struct cds_lfht_node *flag_bucket(struct cds_lfht_node *node)
+{
+ return (struct cds_lfht_node *) (((unsigned long) node) | BUCKET_FLAG);
+}
+
+static
+struct cds_lfht_node *get_end(void)
+{
+ return (struct cds_lfht_node *) END_VALUE;
+}
+
+static
+int is_end(struct cds_lfht_node *node)
+{
+ return clear_flag(node) == (struct cds_lfht_node *) END_VALUE;
+}
+
+static
+unsigned long _uatomic_xchg_monotonic_increase(unsigned long *ptr,
+ unsigned long v)
+{
+ unsigned long old1, old2;
+
+ old1 = uatomic_read(ptr);
+ do {
+ old2 = old1;
+ if (old2 >= v)
+ return old2;
+ } while ((old1 = uatomic_cmpxchg(ptr, old2, v)) != old2);
+ return old2;
+}
+
+static
+void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+ return ht->mm->alloc_bucket_table(ht, order);
+}
+
+/*
+ * cds_lfht_free_bucket_table() should be called with decreasing order.
+ * When cds_lfht_free_bucket_table(0) is called, it means the whole
+ * lfht is destroyed.
+ */
+static
+void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+ return ht->mm->free_bucket_table(ht, order);
+}
+
+static inline
+struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index)
+{
+ return ht->bucket_at(ht, index);
+}
+
+static inline
+struct cds_lfht_node *lookup_bucket(struct cds_lfht *ht, unsigned long size,
+ unsigned long hash)
+{
+ assert(size > 0);
+ return bucket_at(ht, hash & (size - 1));
+}
+
+/*
+ * Remove all logically deleted nodes from a bucket up to a certain node key.
+ */
+static
+void _cds_lfht_gc_bucket(struct cds_lfht_node *bucket, struct cds_lfht_node *node)
+{
+ struct cds_lfht_node *iter_prev, *iter, *next, *new_next;
+
+ assert(!is_bucket(bucket));
+ assert(!is_removed(bucket));
+ assert(!is_bucket(node));
+ assert(!is_removed(node));
+ for (;;) {
+ iter_prev = bucket;
+ /* We can always skip the bucket node initially */
+ iter = rcu_dereference(iter_prev->next);
+ assert(!is_removed(iter));
+ assert(iter_prev->reverse_hash <= node->reverse_hash);
+ /*
+ * We should never be called with bucket (start of chain)
+ * and logically removed node (end of path compression
+ * marker) being the actual same node. This would be a
+ * bug in the algorithm implementation.
+ */
+ assert(bucket != node);
+ for (;;) {
+ if (caa_unlikely(is_end(iter)))
+ return;
+ if (caa_likely(clear_flag(iter)->reverse_hash > node->reverse_hash))
+ return;
+ next = rcu_dereference(clear_flag(iter)->next);
+ if (caa_likely(is_removed(next)))
+ break;
+ iter_prev = clear_flag(iter);
+ iter = next;
+ }
+ assert(!is_removed(iter));
+ if (is_bucket(iter))
+ new_next = flag_bucket(clear_flag(next));
+ else
+ new_next = clear_flag(next);
+ (void) uatomic_cmpxchg(&iter_prev->next, iter, new_next);
+ }
+ return;
+}
+
+static
+int _cds_lfht_replace(struct cds_lfht *ht, unsigned long size,
+ struct cds_lfht_node *old_node,
+ struct cds_lfht_node *old_next,
+ struct cds_lfht_node *new_node)
+{
+ struct cds_lfht_node *bucket, *ret_next;
+
+ if (!old_node) /* Return -ENOENT if asked to replace NULL node */
+ return -ENOENT;
+
+ assert(!is_removed(old_node));
+ assert(!is_bucket(old_node));
+ assert(!is_removed(new_node));
+ assert(!is_bucket(new_node));
+ assert(new_node != old_node);
+ for (;;) {
+ /* Insert after node to be replaced */
+ if (is_removed(old_next)) {
+ /*
+ * Too late, the old node has been removed under us
+ * between lookup and replace. Fail.
+ */
+ return -ENOENT;
+ }
+ assert(!is_bucket(old_next));
+ assert(new_node != clear_flag(old_next));
+ new_node->next = clear_flag(old_next);
+ /*
+ * Here is the whole trick for lock-free replace: we add
+ * the replacement node _after_ the node we want to
+ * replace by atomically setting its next pointer at the
+ * same time we set its removal flag. Given that
+ * the lookups/get next use an iterator aware of the
+ * next pointer, they will either skip the old node due
+ * to the removal flag and see the new node, or use
+ * the old node, but will not see the new one.
+ */
+ ret_next = uatomic_cmpxchg(&old_node->next,
+ old_next, flag_removed(new_node));
+ if (ret_next == old_next)
+ break; /* We performed the replacement. */
+ old_next = ret_next;
+ }
+
+ /*
+ * Ensure that the old node is not visible to readers anymore:
+ * lookup for the node, and remove it (along with any other
+ * logically removed node) if found.
+ */
+ bucket = lookup_bucket(ht, size, bit_reverse_ulong(old_node->reverse_hash));
+ _cds_lfht_gc_bucket(bucket, new_node);
+
+ assert(is_removed(rcu_dereference(old_node->next)));
+ return 0;
+}
+
+/*
+ * A non-NULL unique_ret pointer uses the "add unique" (or uniquify) add
+ * mode. A NULL unique_ret allows creation of duplicate keys.
+ */
+static
+void _cds_lfht_add(struct cds_lfht *ht,
+ cds_lfht_match_fct match,
+ const void *key,
+ unsigned long size,
+ struct cds_lfht_node *node,
+ struct cds_lfht_iter *unique_ret,
+ int bucket_flag)
+{
+ struct cds_lfht_node *iter_prev, *iter, *next, *new_node, *new_next,
+ *return_node;
+ struct cds_lfht_node *bucket;
+
+ assert(!is_bucket(node));
+ assert(!is_removed(node));
+ bucket = lookup_bucket(ht, size, bit_reverse_ulong(node->reverse_hash));
+ for (;;) {
+ uint32_t chain_len = 0;
+
+ /*
+ * iter_prev points to the non-removed node prior to the
+ * insert location.
+ */
+ iter_prev = bucket;
+ /* We can always skip the bucket node initially */
+ iter = rcu_dereference(iter_prev->next);
+ assert(iter_prev->reverse_hash <= node->reverse_hash);
+ for (;;) {
+ if (caa_unlikely(is_end(iter)))
+ goto insert;
+ if (caa_likely(clear_flag(iter)->reverse_hash > node->reverse_hash))
+ goto insert;
+
+ /* bucket node is the first node of the identical-hash-value chain */
+ if (bucket_flag && clear_flag(iter)->reverse_hash == node->reverse_hash)
+ goto insert;
+
+ next = rcu_dereference(clear_flag(iter)->next);
+ if (caa_unlikely(is_removed(next)))
+ goto gc_node;
+
+ /* uniquely add */
+ if (unique_ret
+ && !is_bucket(next)
+ && clear_flag(iter)->reverse_hash == node->reverse_hash) {
+ struct cds_lfht_iter d_iter = { .node = node, .next = iter, };
+
+ /*
+ * uniquely adding inserts the node as the first
+ * node of the identical-hash-value node chain.
+ *
+ * This semantic ensures no duplicated keys
+ * should ever be observable in the table
+ * (including observe one node by one node
+ * by forward iterations)
+ */
+ cds_lfht_next_duplicate(ht, match, key, &d_iter);
+ if (!d_iter.node)
+ goto insert;
+
+ *unique_ret = d_iter;
+ return;
+ }
+
+ /* Only account for identical reverse hash once */
+ if (iter_prev->reverse_hash != clear_flag(iter)->reverse_hash
+ && !is_bucket(next))
+ check_resize(ht, size, ++chain_len);
+ iter_prev = clear_flag(iter);
+ iter = next;
+ }
+
+ insert:
+ assert(node != clear_flag(iter));
+ assert(!is_removed(iter_prev));
+ assert(!is_removed(iter));
+ assert(iter_prev != node);
+ if (!bucket_flag)
+ node->next = clear_flag(iter);
+ else
+ node->next = flag_bucket(clear_flag(iter));
+ if (is_bucket(iter))
+ new_node = flag_bucket(node);
+ else
+ new_node = node;
+ if (uatomic_cmpxchg(&iter_prev->next, iter,
+ new_node) != iter) {
+ continue; /* retry */
+ } else {
+ return_node = node;
+ goto end;
+ }
+
+ gc_node:
+ assert(!is_removed(iter));
+ if (is_bucket(iter))
+ new_next = flag_bucket(clear_flag(next));
+ else
+ new_next = clear_flag(next);
+ (void) uatomic_cmpxchg(&iter_prev->next, iter, new_next);
+ /* retry */
+ }
+end:
+ if (unique_ret) {
+ unique_ret->node = return_node;
+ /* unique_ret->next left unset, never used. */
+ }
+}
+
+static
+int _cds_lfht_del(struct cds_lfht *ht, unsigned long size,
+ struct cds_lfht_node *node,
+ int bucket_removal)
+{
+ struct cds_lfht_node *bucket, *next, *old;
+
+ if (!node) /* Return -ENOENT if asked to delete NULL node */
+ return -ENOENT;
+
+ /* logically delete the node */
+ assert(!is_bucket(node));
+ assert(!is_removed(node));
+ old = rcu_dereference(node->next);
+ do {
+ struct cds_lfht_node *new_next;
+
+ next = old;
+ if (caa_unlikely(is_removed(next)))
+ return -ENOENT;
+ if (bucket_removal)
+ assert(is_bucket(next));
+ else
+ assert(!is_bucket(next));
+ new_next = flag_removed(next);
+ old = uatomic_cmpxchg(&node->next, next, new_next);
+ } while (old != next);
+ /* We performed the (logical) deletion. */
+
+ /*
+ * Ensure that the node is not visible to readers anymore: lookup for
+ * the node, and remove it (along with any other logically removed node)
+ * if found.
+ */
+ bucket = lookup_bucket(ht, size, bit_reverse_ulong(node->reverse_hash));
+ _cds_lfht_gc_bucket(bucket, node);
+
+ assert(is_removed(rcu_dereference(node->next)));
+ return 0;
+}
+
+static
+void *partition_resize_thread(void *arg)
+{
+ struct partition_resize_work *work = arg;
+
+ work->ht->flavor->register_thread();
+ work->fct(work->ht, work->i, work->start, work->len);
+ work->ht->flavor->unregister_thread();
+ return NULL;
+}
+
+static
+void partition_resize_helper(struct cds_lfht *ht, unsigned long i,
+ unsigned long len,
+ void (*fct)(struct cds_lfht *ht, unsigned long i,
+ unsigned long start, unsigned long len))
+{
+ unsigned long partition_len;
+ struct partition_resize_work *work;
+ int thread, ret;
+ unsigned long nr_threads;
+
+ /*
+ * Note: nr_cpus_mask + 1 is always power of 2.
+ * We spawn just the number of threads we need to satisfy the minimum
+ * partition size, up to the number of CPUs in the system.
+ */
+ if (nr_cpus_mask > 0) {
+ nr_threads = min(nr_cpus_mask + 1,
+ len >> MIN_PARTITION_PER_THREAD_ORDER);
+ } else {
+ nr_threads = 1;
+ }
+ partition_len = len >> get_count_order_ulong(nr_threads);
+ work = calloc(nr_threads, sizeof(*work));
+ assert(work);
+ for (thread = 0; thread < nr_threads; thread++) {
+ work[thread].ht = ht;
+ work[thread].i = i;
+ work[thread].len = partition_len;
+ work[thread].start = thread * partition_len;
+ work[thread].fct = fct;
+ ret = pthread_create(&(work[thread].thread_id), ht->resize_attr,
+ partition_resize_thread, &work[thread]);
+ assert(!ret);
+ }
+ for (thread = 0; thread < nr_threads; thread++) {
+ ret = pthread_join(work[thread].thread_id, NULL);
+ assert(!ret);
+ }
+ free(work);
+}
+
+/*
+ * Holding RCU read lock to protect _cds_lfht_add against memory
+ * reclaim that could be performed by other call_rcu worker threads (ABA
+ * problem).
+ *
+ * When we reach a certain length, we can split this population phase over
+ * many worker threads, based on the number of CPUs available in the system.
+ * This should therefore take care of not having the expand lagging behind too
+ * many concurrent insertion threads by using the scheduler's ability to
+ * schedule bucket node population fairly with insertions.
+ */
+static
+void init_table_populate_partition(struct cds_lfht *ht, unsigned long i,
+ unsigned long start, unsigned long len)
+{
+ unsigned long j, size = 1UL << (i - 1);
+
+ assert(i > MIN_TABLE_ORDER);
+ ht->flavor->read_lock();
+ for (j = size + start; j < size + start + len; j++) {
+ struct cds_lfht_node *new_node = bucket_at(ht, j);
+
+ assert(j >= size && j < (size << 1));
+ dbg_printf("init populate: order %lu index %lu hash %lu\n",
+ i, j, j);
+ new_node->reverse_hash = bit_reverse_ulong(j);
+ _cds_lfht_add(ht, NULL, NULL, size, new_node, NULL, 1);
+ }
+ ht->flavor->read_unlock();
+}
+
+static
+void init_table_populate(struct cds_lfht *ht, unsigned long i,
+ unsigned long len)
+{
+ assert(nr_cpus_mask != -1);
+ if (nr_cpus_mask < 0 || len < 2 * MIN_PARTITION_PER_THREAD) {
+ ht->flavor->thread_online();
+ init_table_populate_partition(ht, i, 0, len);
+ ht->flavor->thread_offline();
+ return;
+ }
+ partition_resize_helper(ht, i, len, init_table_populate_partition);
+}
+
+static
+void init_table(struct cds_lfht *ht,
+ unsigned long first_order, unsigned long last_order)
+{
+ unsigned long i;
+
+ dbg_printf("init table: first_order %lu last_order %lu\n",
+ first_order, last_order);
+ assert(first_order > MIN_TABLE_ORDER);
+ for (i = first_order; i <= last_order; i++) {
+ unsigned long len;
+
+ len = 1UL << (i - 1);
+ dbg_printf("init order %lu len: %lu\n", i, len);
+
+ /* Stop expand if the resize target changes under us */
+ if (CMM_LOAD_SHARED(ht->resize_target) < (1UL << i))
+ break;
+
+ cds_lfht_alloc_bucket_table(ht, i);
+
+ /*
+ * Set all bucket nodes reverse hash values for a level and
+ * link all bucket nodes into the table.
+ */
+ init_table_populate(ht, i, len);
+
+ /*
+ * Update table size.
+ */
+ cmm_smp_wmb(); /* populate data before RCU size */
+ CMM_STORE_SHARED(ht->size, 1UL << i);
+
+ dbg_printf("init new size: %lu\n", 1UL << i);
+ if (CMM_LOAD_SHARED(ht->in_progress_destroy))
+ break;
+ }
+}
+
+/*
+ * Holding RCU read lock to protect _cds_lfht_remove against memory
+ * reclaim that could be performed by other call_rcu worker threads (ABA
+ * problem).
+ * For a single level, we logically remove and garbage collect each node.
+ *
+ * As a design choice, we perform logical removal and garbage collection on a
+ * node-per-node basis to simplify this algorithm. We also assume keeping good
+ * cache locality of the operation would overweight possible performance gain
+ * that could be achieved by batching garbage collection for multiple levels.
+ * However, this would have to be justified by benchmarks.
+ *
+ * Concurrent removal and add operations are helping us perform garbage
+ * collection of logically removed nodes. We guarantee that all logically
+ * removed nodes have been garbage-collected (unlinked) before call_rcu is
+ * invoked to free a hole level of bucket nodes (after a grace period).
+ *
+ * Logical removal and garbage collection can therefore be done in batch or on a
+ * node-per-node basis, as long as the guarantee above holds.
+ *
+ * When we reach a certain length, we can split this removal over many worker
+ * threads, based on the number of CPUs available in the system. This should
+ * take care of not letting resize process lag behind too many concurrent
+ * updater threads actively inserting into the hash table.
+ */
+static
+void remove_table_partition(struct cds_lfht *ht, unsigned long i,
+ unsigned long start, unsigned long len)
+{
+ unsigned long j, size = 1UL << (i - 1);
+
+ assert(i > MIN_TABLE_ORDER);
+ ht->flavor->read_lock();
+ for (j = size + start; j < size + start + len; j++) {
+ struct cds_lfht_node *fini_node = bucket_at(ht, j);
+
+ assert(j >= size && j < (size << 1));
+ dbg_printf("remove entry: order %lu index %lu hash %lu\n",
+ i, j, j);
+ fini_node->reverse_hash = bit_reverse_ulong(j);
+ (void) _cds_lfht_del(ht, size, fini_node, 1);
+ }
+ ht->flavor->read_unlock();
+}
+
+static
+void remove_table(struct cds_lfht *ht, unsigned long i, unsigned long len)
+{
+
+ assert(nr_cpus_mask != -1);
+ if (nr_cpus_mask < 0 || len < 2 * MIN_PARTITION_PER_THREAD) {
+ ht->flavor->thread_online();
+ remove_table_partition(ht, i, 0, len);
+ ht->flavor->thread_offline();
+ return;
+ }
+ partition_resize_helper(ht, i, len, remove_table_partition);
+}
+
+/*
+ * fini_table() is never called for first_order == 0, which is why
+ * free_by_rcu_order == 0 can be used as criterion to know if free must
+ * be called.
+ */
+static
+void fini_table(struct cds_lfht *ht,
+ unsigned long first_order, unsigned long last_order)
+{
+ long i;
+ unsigned long free_by_rcu_order = 0;
+
+ dbg_printf("fini table: first_order %lu last_order %lu\n",
+ first_order, last_order);
+ assert(first_order > MIN_TABLE_ORDER);
+ for (i = last_order; i >= first_order; i--) {
+ unsigned long len;
+
+ len = 1UL << (i - 1);
+ dbg_printf("fini order %lu len: %lu\n", i, len);
+
+ /* Stop shrink if the resize target changes under us */
+ if (CMM_LOAD_SHARED(ht->resize_target) > (1UL << (i - 1)))
+ break;
+
+ cmm_smp_wmb(); /* populate data before RCU size */
+ CMM_STORE_SHARED(ht->size, 1UL << (i - 1));
+
+ /*
+ * We need to wait for all add operations to reach Q.S. (and
+ * thus use the new table for lookups) before we can start
+ * releasing the old bucket nodes. Otherwise their lookup will
+ * return a logically removed node as insert position.
+ */
+ ht->flavor->update_synchronize_rcu();
+ if (free_by_rcu_order)
+ cds_lfht_free_bucket_table(ht, free_by_rcu_order);
+
+ /*
+ * Set "removed" flag in bucket nodes about to be removed.
+ * Unlink all now-logically-removed bucket node pointers.
+ * Concurrent add/remove operation are helping us doing
+ * the gc.
+ */
+ remove_table(ht, i, len);
+
+ free_by_rcu_order = i;
+
+ dbg_printf("fini new size: %lu\n", 1UL << i);
+ if (CMM_LOAD_SHARED(ht->in_progress_destroy))
+ break;
+ }
+
+ if (free_by_rcu_order) {
+ ht->flavor->update_synchronize_rcu();
+ cds_lfht_free_bucket_table(ht, free_by_rcu_order);
+ }
+}
+
+static
+void cds_lfht_create_bucket(struct cds_lfht *ht, unsigned long size)
+{
+ struct cds_lfht_node *prev, *node;
+ unsigned long order, len, i;
+
+ cds_lfht_alloc_bucket_table(ht, 0);
+
+ dbg_printf("create bucket: order 0 index 0 hash 0\n");
+ node = bucket_at(ht, 0);
+ node->next = flag_bucket(get_end());
+ node->reverse_hash = 0;
+
+ for (order = 1; order < get_count_order_ulong(size) + 1; order++) {
+ len = 1UL << (order - 1);
+ cds_lfht_alloc_bucket_table(ht, order);
+
+ for (i = 0; i < len; i++) {
+ /*
+ * Now, we are trying to init the node with the
+ * hash=(len+i) (which is also a bucket with the
+ * index=(len+i)) and insert it into the hash table,
+ * so this node has to be inserted after the bucket
+ * with the index=(len+i)&(len-1)=i. And because there
+ * is no other non-bucket node nor bucket node with
+ * larger index/hash inserted, so the bucket node
+ * being inserted should be inserted directly linked
+ * after the bucket node with index=i.
+ */
+ prev = bucket_at(ht, i);
+ node = bucket_at(ht, len + i);
+
+ dbg_printf("create bucket: order %lu index %lu hash %lu\n",
+ order, len + i, len + i);
+ node->reverse_hash = bit_reverse_ulong(len + i);
+
+ /* insert after prev */
+ assert(is_bucket(prev->next));
+ node->next = prev->next;
+ prev->next = flag_bucket(node);
+ }
+ }
+}
+
+struct cds_lfht *_cds_lfht_new(unsigned long init_size,
+ unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets,
+ int flags,
+ const struct cds_lfht_mm_type *mm,
+ const struct rcu_flavor_struct *flavor,
+ pthread_attr_t *attr)
+{
+ struct cds_lfht *ht;
+ unsigned long order;
+
+ /* min_nr_alloc_buckets must be power of two */
+ if (!min_nr_alloc_buckets || (min_nr_alloc_buckets & (min_nr_alloc_buckets - 1)))
+ return NULL;
+
+ /* init_size must be power of two */
+ if (!init_size || (init_size & (init_size - 1)))
+ return NULL;
+
+ /*
+ * Memory management plugin default.
+ */
+ if (!mm) {
+ if (CAA_BITS_PER_LONG > 32
+ && max_nr_buckets
+ && max_nr_buckets <= (1ULL << 32)) {
+ /*
+ * For 64-bit architectures, with max number of
+ * buckets small enough not to use the entire
+ * 64-bit memory mapping space (and allowing a
+ * fair number of hash table instances), use the
+ * mmap allocator, which is faster than the
+ * order allocator.
+ */
+ mm = &cds_lfht_mm_mmap;
+ } else {
+ /*
+ * The fallback is to use the order allocator.
+ */
+ mm = &cds_lfht_mm_order;
+ }
+ }
+
+ /* max_nr_buckets == 0 for order based mm means infinite */
+ if (mm == &cds_lfht_mm_order && !max_nr_buckets)
+ max_nr_buckets = 1UL << (MAX_TABLE_ORDER - 1);
+
+ /* max_nr_buckets must be power of two */
+ if (!max_nr_buckets || (max_nr_buckets & (max_nr_buckets - 1)))
+ return NULL;
+
+ min_nr_alloc_buckets = max(min_nr_alloc_buckets, MIN_TABLE_SIZE);
+ init_size = max(init_size, MIN_TABLE_SIZE);
+ max_nr_buckets = max(max_nr_buckets, min_nr_alloc_buckets);
+ init_size = min(init_size, max_nr_buckets);
+
+ ht = mm->alloc_cds_lfht(min_nr_alloc_buckets, max_nr_buckets);
+ assert(ht);
+ assert(ht->mm == mm);
+ assert(ht->bucket_at == mm->bucket_at);
+
+ ht->flags = flags;
+ ht->flavor = flavor;
+ ht->resize_attr = attr;
+ alloc_split_items_count(ht);
+ /* this mutex should not nest in read-side C.S. */
+ pthread_mutex_init(&ht->resize_mutex, NULL);
+ order = get_count_order_ulong(init_size);
+ ht->resize_target = 1UL << order;
+ cds_lfht_create_bucket(ht, 1UL << order);
+ ht->size = 1UL << order;
+ return ht;
+}
+
+void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
+ cds_lfht_match_fct match, const void *key,
+ struct cds_lfht_iter *iter)
+{
+ struct cds_lfht_node *node, *next, *bucket;
+ unsigned long reverse_hash, size;
+
+ reverse_hash = bit_reverse_ulong(hash);
+
+ size = rcu_dereference(ht->size);
+ bucket = lookup_bucket(ht, size, hash);
+ /* We can always skip the bucket node initially */
+ node = rcu_dereference(bucket->next);
+ node = clear_flag(node);
+ for (;;) {
+ if (caa_unlikely(is_end(node))) {
+ node = next = NULL;
+ break;
+ }
+ if (caa_unlikely(node->reverse_hash > reverse_hash)) {
+ node = next = NULL;
+ break;
+ }
+ next = rcu_dereference(node->next);
+ assert(node == clear_flag(node));
+ if (caa_likely(!is_removed(next))
+ && !is_bucket(next)
+ && node->reverse_hash == reverse_hash
+ && caa_likely(match(node, key))) {
+ break;
+ }
+ node = clear_flag(next);
+ }
+ assert(!node || !is_bucket(rcu_dereference(node->next)));
+ iter->node = node;
+ iter->next = next;
+}
+
+void cds_lfht_next_duplicate(struct cds_lfht *ht, cds_lfht_match_fct match,
+ const void *key, struct cds_lfht_iter *iter)
+{
+ struct cds_lfht_node *node, *next;
+ unsigned long reverse_hash;
+
+ node = iter->node;
+ reverse_hash = node->reverse_hash;
+ next = iter->next;
+ node = clear_flag(next);
+
+ for (;;) {
+ if (caa_unlikely(is_end(node))) {
+ node = next = NULL;
+ break;
+ }
+ if (caa_unlikely(node->reverse_hash > reverse_hash)) {
+ node = next = NULL;
+ break;
+ }
+ next = rcu_dereference(node->next);
+ if (caa_likely(!is_removed(next))
+ && !is_bucket(next)
+ && caa_likely(match(node, key))) {
+ break;
+ }
+ node = clear_flag(next);
+ }
+ assert(!node || !is_bucket(rcu_dereference(node->next)));
+ iter->node = node;
+ iter->next = next;
+}
+
+void cds_lfht_next(struct cds_lfht *ht, struct cds_lfht_iter *iter)
+{
+ struct cds_lfht_node *node, *next;
+
+ node = clear_flag(iter->next);
+ for (;;) {
+ if (caa_unlikely(is_end(node))) {
+ node = next = NULL;
+ break;
+ }
+ next = rcu_dereference(node->next);
+ if (caa_likely(!is_removed(next))
+ && !is_bucket(next)) {
+ break;
+ }
+ node = clear_flag(next);
+ }
+ assert(!node || !is_bucket(rcu_dereference(node->next)));
+ iter->node = node;
+ iter->next = next;
+}
+
+void cds_lfht_first(struct cds_lfht *ht, struct cds_lfht_iter *iter)
+{
+ /*
+ * Get next after first bucket node. The first bucket node is the
+ * first node of the linked list.
+ */
+ iter->next = bucket_at(ht, 0)->next;
+ cds_lfht_next(ht, iter);
+}
+
+void cds_lfht_add(struct cds_lfht *ht, unsigned long hash,
+ struct cds_lfht_node *node)
+{
+ unsigned long size;
+
+ node->reverse_hash = bit_reverse_ulong((unsigned long) hash);
+ size = rcu_dereference(ht->size);
+ _cds_lfht_add(ht, NULL, NULL, size, node, NULL, 0);
+ ht_count_add(ht, size, hash);
+}
+
+struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht,
+ unsigned long hash,
+ cds_lfht_match_fct match,
+ const void *key,
+ struct cds_lfht_node *node)
+{
+ unsigned long size;
+ struct cds_lfht_iter iter;
+
+ node->reverse_hash = bit_reverse_ulong((unsigned long) hash);
+ size = rcu_dereference(ht->size);
+ _cds_lfht_add(ht, match, key, size, node, &iter, 0);
+ if (iter.node == node)
+ ht_count_add(ht, size, hash);
+ return iter.node;
+}
+
+struct cds_lfht_node *cds_lfht_add_replace(struct cds_lfht *ht,
+ unsigned long hash,
+ cds_lfht_match_fct match,
+ const void *key,
+ struct cds_lfht_node *node)
+{
+ unsigned long size;
+ struct cds_lfht_iter iter;
+
+ node->reverse_hash = bit_reverse_ulong((unsigned long) hash);
+ size = rcu_dereference(ht->size);
+ for (;;) {
+ _cds_lfht_add(ht, match, key, size, node, &iter, 0);
+ if (iter.node == node) {
+ ht_count_add(ht, size, hash);
+ return NULL;
+ }
+
+ if (!_cds_lfht_replace(ht, size, iter.node, iter.next, node))
+ return iter.node;
+ }
+}
+
+int cds_lfht_replace(struct cds_lfht *ht, struct cds_lfht_iter *old_iter,
+ struct cds_lfht_node *new_node)
+{
+ unsigned long size;
+
+ size = rcu_dereference(ht->size);
+ return _cds_lfht_replace(ht, size, old_iter->node, old_iter->next,
+ new_node);
+}
+
+int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_iter *iter)
+{
+ unsigned long size, hash;
+ int ret;
+
+ size = rcu_dereference(ht->size);
+ ret = _cds_lfht_del(ht, size, iter->node, 0);
+ if (!ret) {
+ hash = bit_reverse_ulong(iter->node->reverse_hash);
+ ht_count_del(ht, size, hash);
+ }
+ return ret;
+}
+
+static
+int cds_lfht_delete_bucket(struct cds_lfht *ht)
+{
+ struct cds_lfht_node *node;
+ unsigned long order, i, size;
+
+ /* Check that the table is empty */
+ node = bucket_at(ht, 0);
+ do {
+ node = clear_flag(node)->next;
+ if (!is_bucket(node))
+ return -EPERM;
+ assert(!is_removed(node));
+ } while (!is_end(node));
+ /*
+ * size accessed without rcu_dereference because hash table is
+ * being destroyed.
+ */
+ size = ht->size;
+ /* Internal sanity check: all nodes left should be bucket */
+ for (i = 0; i < size; i++) {
+ node = bucket_at(ht, i);
+ dbg_printf("delete bucket: index %lu expected hash %lu hash %lu\n",
+ i, i, bit_reverse_ulong(node->reverse_hash));
+ assert(is_bucket(node->next));
+ }
+
+ for (order = get_count_order_ulong(size); (long)order >= 0; order--)
+ cds_lfht_free_bucket_table(ht, order);
+
+ return 0;
+}
+
+/*
+ * Should only be called when no more concurrent readers nor writers can
+ * possibly access the table.
+ */
+int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr)
+{
+ int ret;
+
+ /* Wait for in-flight resize operations to complete */
+ _CMM_STORE_SHARED(ht->in_progress_destroy, 1);
+ cmm_smp_mb(); /* Store destroy before load resize */
+ while (uatomic_read(&ht->in_progress_resize))
+ poll(NULL, 0, 100); /* wait for 100ms */
+ ret = cds_lfht_delete_bucket(ht);
+ if (ret)
+ return ret;
+ free_split_items_count(ht);
+ if (attr)
+ *attr = ht->resize_attr;
+ poison_free(ht);
+ return ret;
+}
+
+void cds_lfht_count_nodes(struct cds_lfht *ht,
+ long *approx_before,
+ unsigned long *count,
+ unsigned long *removed,
+ long *approx_after)
+{
+ struct cds_lfht_node *node, *next;
+ unsigned long nr_bucket = 0;
+
+ *approx_before = 0;
+ if (ht->split_count) {
+ int i;
+
+ for (i = 0; i < split_count_mask + 1; i++) {
+ *approx_before += uatomic_read(&ht->split_count[i].add);
+ *approx_before -= uatomic_read(&ht->split_count[i].del);
+ }
+ }
+
+ *count = 0;
+ *removed = 0;
+
+ /* Count non-bucket nodes in the table */
+ node = bucket_at(ht, 0);
+ do {
+ next = rcu_dereference(node->next);
+ if (is_removed(next)) {
+ if (!is_bucket(next))
+ (*removed)++;
+ else
+ (nr_bucket)++;
+ } else if (!is_bucket(next))
+ (*count)++;
+ else
+ (nr_bucket)++;
+ node = clear_flag(next);
+ } while (!is_end(node));
+ dbg_printf("number of bucket nodes: %lu\n", nr_bucket);
+ *approx_after = 0;
+ if (ht->split_count) {
+ int i;
+
+ for (i = 0; i < split_count_mask + 1; i++) {
+ *approx_after += uatomic_read(&ht->split_count[i].add);
+ *approx_after -= uatomic_read(&ht->split_count[i].del);
+ }
+ }
+}
+
+/* called with resize mutex held */
+static
+void _do_cds_lfht_grow(struct cds_lfht *ht,
+ unsigned long old_size, unsigned long new_size)
+{
+ unsigned long old_order, new_order;
+
+ old_order = get_count_order_ulong(old_size);
+ new_order = get_count_order_ulong(new_size);
+ dbg_printf("resize from %lu (order %lu) to %lu (order %lu) buckets\n",
+ old_size, old_order, new_size, new_order);
+ assert(new_size > old_size);
+ init_table(ht, old_order + 1, new_order);
+}
+
+/* called with resize mutex held */
+static
+void _do_cds_lfht_shrink(struct cds_lfht *ht,
+ unsigned long old_size, unsigned long new_size)
+{
+ unsigned long old_order, new_order;
+
+ new_size = max(new_size, MIN_TABLE_SIZE);
+ old_order = get_count_order_ulong(old_size);
+ new_order = get_count_order_ulong(new_size);
+ dbg_printf("resize from %lu (order %lu) to %lu (order %lu) buckets\n",
+ old_size, old_order, new_size, new_order);
+ assert(new_size < old_size);
+
+ /* Remove and unlink all bucket nodes to remove. */
+ fini_table(ht, new_order + 1, old_order);
+}
+
+
+/* called with resize mutex held */
+static
+void _do_cds_lfht_resize(struct cds_lfht *ht)
+{
+ unsigned long new_size, old_size;
+
+ /*
+ * Resize table, re-do if the target size has changed under us.
+ */
+ do {
+ assert(uatomic_read(&ht->in_progress_resize));
+ if (CMM_LOAD_SHARED(ht->in_progress_destroy))
+ break;
+ ht->resize_initiated = 1;
+ old_size = ht->size;
+ new_size = CMM_LOAD_SHARED(ht->resize_target);
+ if (old_size < new_size)
+ _do_cds_lfht_grow(ht, old_size, new_size);
+ else if (old_size > new_size)
+ _do_cds_lfht_shrink(ht, old_size, new_size);
+ ht->resize_initiated = 0;
+ /* write resize_initiated before read resize_target */
+ cmm_smp_mb();
+ } while (ht->size != CMM_LOAD_SHARED(ht->resize_target));
+}
+
+static
+unsigned long resize_target_grow(struct cds_lfht *ht, unsigned long new_size)
+{
+ return _uatomic_xchg_monotonic_increase(&ht->resize_target, new_size);
+}
+
+static
+void resize_target_update_count(struct cds_lfht *ht,
+ unsigned long count)
+{
+ count = max(count, MIN_TABLE_SIZE);
+ count = min(count, ht->max_nr_buckets);
+ uatomic_set(&ht->resize_target, count);
+}
+
+void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size)
+{
+ resize_target_update_count(ht, new_size);
+ CMM_STORE_SHARED(ht->resize_initiated, 1);
+ ht->flavor->thread_offline();
+ pthread_mutex_lock(&ht->resize_mutex);
+ _do_cds_lfht_resize(ht);
+ pthread_mutex_unlock(&ht->resize_mutex);
+ ht->flavor->thread_online();
+}
+
+static
+void do_resize_cb(struct rcu_head *head)
+{
+ struct rcu_resize_work *work =
+ caa_container_of(head, struct rcu_resize_work, head);
+ struct cds_lfht *ht = work->ht;
+
+ ht->flavor->thread_offline();
+ pthread_mutex_lock(&ht->resize_mutex);
+ _do_cds_lfht_resize(ht);
+ pthread_mutex_unlock(&ht->resize_mutex);
+ ht->flavor->thread_online();
+ poison_free(work);
+ cmm_smp_mb(); /* finish resize before decrement */
+ uatomic_dec(&ht->in_progress_resize);
+}
+
+static
+void __cds_lfht_resize_lazy_launch(struct cds_lfht *ht)
+{
+ struct rcu_resize_work *work;
+
+ /* Store resize_target before read resize_initiated */
+ cmm_smp_mb();
+ if (!CMM_LOAD_SHARED(ht->resize_initiated)) {
+ uatomic_inc(&ht->in_progress_resize);
+ cmm_smp_mb(); /* increment resize count before load destroy */
+ if (CMM_LOAD_SHARED(ht->in_progress_destroy)) {
+ uatomic_dec(&ht->in_progress_resize);
+ return;
+ }
+ work = malloc(sizeof(*work));
+ work->ht = ht;
+ ht->flavor->update_call_rcu(&work->head, do_resize_cb);
+ CMM_STORE_SHARED(ht->resize_initiated, 1);
+ }
+}
+
+static
+void cds_lfht_resize_lazy_grow(struct cds_lfht *ht, unsigned long size, int growth)
+{
+ unsigned long target_size = size << growth;
+
+ target_size = min(target_size, ht->max_nr_buckets);
+ if (resize_target_grow(ht, target_size) >= target_size)
+ return;
+
+ __cds_lfht_resize_lazy_launch(ht);
+}
+
+/*
+ * We favor grow operations over shrink. A shrink operation never occurs
+ * if a grow operation is queued for lazy execution. A grow operation
+ * cancels any pending shrink lazy execution.
+ */
+static
+void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
+ unsigned long count)
+{
+ if (!(ht->flags & CDS_LFHT_AUTO_RESIZE))
+ return;
+ count = max(count, MIN_TABLE_SIZE);
+ count = min(count, ht->max_nr_buckets);
+ if (count == size)
+ return; /* Already the right size, no resize needed */
+ if (count > size) { /* lazy grow */
+ if (resize_target_grow(ht, count) >= count)
+ return;
+ } else { /* lazy shrink */
+ for (;;) {
+ unsigned long s;
+
+ s = uatomic_cmpxchg(&ht->resize_target, size, count);
+ if (s == size)
+ break; /* no resize needed */
+ if (s > size)
+ return; /* growing is/(was just) in progress */
+ if (s <= count)
+ return; /* some other thread do shrink */
+ size = s;
+ }
+ }
+ __cds_lfht_resize_lazy_launch(ht);
+}
test_urcu_bp test_urcu_bp_dynamic_link test_cycles_per_loop \
test_urcu_lfq test_urcu_wfq test_urcu_lfs test_urcu_wfs \
test_urcu_wfq_dynlink test_urcu_wfs_dynlink \
- test_urcu_lfq_dynlink test_urcu_lfs_dynlink
+ test_urcu_lfq_dynlink test_urcu_lfs_dynlink test_urcu_hash
noinst_HEADERS = rcutorture.h
if COMPAT_ARCH
test_urcu_wfs_dynlink_CFLAGS = -DDYNAMIC_LINK_TEST $(AM_CFLAGS)
test_urcu_wfs_dynlink_LDADD = $(URCU_COMMON_LIB)
+test_urcu_hash_SOURCES = test_urcu_hash.c $(COMPAT)
+test_urcu_hash_CFLAGS = -DRCU_QSBR $(AM_CFLAGS)
+test_urcu_hash_LDADD = $(URCU_QSBR_LIB) $(URCU_CDS_LIB)
+
urcutorture.c: api.h
check-am:
--- /dev/null
+/*
+ * test_urcu_hash.c
+ *
+ * Userspace RCU library - test program
+ *
+ * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <assert.h>
+#include <sched.h>
+#include <errno.h>
+
+#ifdef __linux__
+#include <syscall.h>
+#endif
+
+#define DEFAULT_HASH_SIZE 32
+#define DEFAULT_MIN_ALLOC_SIZE 1
+#define DEFAULT_RAND_POOL 1000000
+
+#define TEST_HASH_SEED 0x42UL
+
+/* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
+#define CACHE_LINE_SIZE 4096
+
+/* hardcoded number of CPUs */
+#define NR_CPUS 16384
+
+#ifdef POISON_FREE
+#define poison_free(ptr) \
+ do { \
+ memset(ptr, 0x42, sizeof(*(ptr))); \
+ free(ptr); \
+ } while (0)
+#else
+#define poison_free(ptr) free(ptr)
+#endif
+
+
+
+#if defined(_syscall0)
+_syscall0(pid_t, gettid)
+#elif defined(__NR_gettid)
+static inline pid_t gettid(void)
+{
+ return syscall(__NR_gettid);
+}
+#else
+#warning "use pid as tid"
+static inline pid_t gettid(void)
+{
+ return getpid();
+}
+#endif
+
+#ifndef DYNAMIC_LINK_TEST
+#define _LGPL_SOURCE
+#else
+#define debug_yield_read()
+#endif
+#include <urcu-qsbr.h>
+#include <urcu/rculfhash.h>
+#include <urcu-call-rcu.h>
+
+struct wr_count {
+ unsigned long update_ops;
+ unsigned long add;
+ unsigned long add_exist;
+ unsigned long remove;
+};
+
+static unsigned int __thread rand_lookup;
+static unsigned long __thread nr_add;
+static unsigned long __thread nr_addexist;
+static unsigned long __thread nr_del;
+static unsigned long __thread nr_delnoent;
+static unsigned long __thread lookup_fail;
+static unsigned long __thread lookup_ok;
+
+static struct cds_lfht *test_ht;
+
+struct test_data {
+ int a;
+ int b;
+};
+
+struct lfht_test_node {
+ struct cds_lfht_node node;
+ void *key;
+ unsigned int key_len;
+ /* cache-cold for iteration */
+ struct rcu_head head;
+};
+
+static inline struct lfht_test_node *
+to_test_node(struct cds_lfht_node *node)
+{
+ return caa_container_of(node, struct lfht_test_node, node);
+}
+
+static inline
+void lfht_test_node_init(struct lfht_test_node *node, void *key,
+ size_t key_len)
+{
+ cds_lfht_node_init(&node->node);
+ node->key = key;
+ node->key_len = key_len;
+}
+
+static inline struct lfht_test_node *
+cds_lfht_iter_get_test_node(struct cds_lfht_iter *iter)
+{
+ return to_test_node(cds_lfht_iter_get_node(iter));
+}
+
+static volatile int test_go, test_stop;
+
+static unsigned long wdelay;
+
+static unsigned long duration;
+
+/* read-side C.S. duration, in loops */
+static unsigned long rduration;
+
+static unsigned long init_hash_size = DEFAULT_HASH_SIZE;
+static unsigned long min_hash_alloc_size = DEFAULT_MIN_ALLOC_SIZE;
+static unsigned long max_hash_buckets_size = (1UL << 20);
+static unsigned long init_populate;
+static int opt_auto_resize;
+static int add_only, add_unique, add_replace;
+static const struct cds_lfht_mm_type *memory_backend;
+
+static unsigned long init_pool_offset, lookup_pool_offset, write_pool_offset;
+static unsigned long init_pool_size = DEFAULT_RAND_POOL,
+ lookup_pool_size = DEFAULT_RAND_POOL,
+ write_pool_size = DEFAULT_RAND_POOL;
+static int validate_lookup;
+
+static int count_pipe[2];
+
+static inline void loop_sleep(unsigned long l)
+{
+ while(l-- != 0)
+ caa_cpu_relax();
+}
+
+static int verbose_mode;
+
+#define printf_verbose(fmt, args...) \
+ do { \
+ if (verbose_mode) \
+ printf(fmt, ## args); \
+ } while (0)
+
+static unsigned int cpu_affinities[NR_CPUS];
+static unsigned int next_aff = 0;
+static int use_affinity = 0;
+
+pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static void set_affinity(void)
+{
+ cpu_set_t mask;
+ int cpu;
+ int ret;
+
+ if (!use_affinity)
+ return;
+
+ ret = pthread_mutex_lock(&affinity_mutex);
+ if (ret) {
+ perror("Error in pthread mutex lock");
+ exit(-1);
+ }
+ cpu = cpu_affinities[next_aff++];
+ ret = pthread_mutex_unlock(&affinity_mutex);
+ if (ret) {
+ perror("Error in pthread mutex unlock");
+ exit(-1);
+ }
+ CPU_ZERO(&mask);
+ CPU_SET(cpu, &mask);
+ sched_setaffinity(0, sizeof(mask), &mask);
+}
+
+static enum {
+ AR_RANDOM = 0,
+ AR_ADD = 1,
+ AR_REMOVE = -1,
+} addremove; /* 1: add, -1 remove, 0: random */
+
+static
+void sigusr1_handler(int signo)
+{
+ switch (addremove) {
+ case AR_ADD:
+ printf("Add/Remove: random.\n");
+ addremove = AR_RANDOM;
+ break;
+ case AR_RANDOM:
+ printf("Add/Remove: remove only.\n");
+ addremove = AR_REMOVE;
+ break;
+ case AR_REMOVE:
+ printf("Add/Remove: add only.\n");
+ addremove = AR_ADD;
+ break;
+ }
+}
+
+static
+void sigusr2_handler(int signo)
+{
+ char msg[1] = { 0x42 };
+ ssize_t ret;
+
+ do {
+ ret = write(count_pipe[1], msg, 1); /* wakeup thread */
+ } while (ret == -1L && errno == EINTR);
+}
+
+/*
+ * returns 0 if test should end.
+ */
+static int test_duration_write(void)
+{
+ return !test_stop;
+}
+
+static int test_duration_read(void)
+{
+ return !test_stop;
+}
+
+static unsigned long long __thread nr_writes;
+static unsigned long long __thread nr_reads;
+
+static unsigned int nr_readers;
+static unsigned int nr_writers;
+
+pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+void rcu_copy_mutex_lock(void)
+{
+ int ret;
+ ret = pthread_mutex_lock(&rcu_copy_mutex);
+ if (ret) {
+ perror("Error in pthread mutex lock");
+ exit(-1);
+ }
+}
+
+void rcu_copy_mutex_unlock(void)
+{
+ int ret;
+
+ ret = pthread_mutex_unlock(&rcu_copy_mutex);
+ if (ret) {
+ perror("Error in pthread mutex unlock");
+ exit(-1);
+ }
+}
+
+/*
+ * Hash function
+ * Source: http://burtleburtle.net/bob/c/lookup3.c
+ * Originally Public Domain
+ */
+
+#define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k))))
+
+#define mix(a, b, c) \
+do { \
+ a -= c; a ^= rot(c, 4); c += b; \
+ b -= a; b ^= rot(a, 6); a += c; \
+ c -= b; c ^= rot(b, 8); b += a; \
+ a -= c; a ^= rot(c, 16); c += b; \
+ b -= a; b ^= rot(a, 19); a += c; \
+ c -= b; c ^= rot(b, 4); b += a; \
+} while (0)
+
+#define final(a, b, c) \
+{ \
+ c ^= b; c -= rot(b, 14); \
+ a ^= c; a -= rot(c, 11); \
+ b ^= a; b -= rot(a, 25); \
+ c ^= b; c -= rot(b, 16); \
+ a ^= c; a -= rot(c, 4);\
+ b ^= a; b -= rot(a, 14); \
+ c ^= b; c -= rot(b, 24); \
+}
+
+static __attribute__((unused))
+uint32_t hash_u32(
+ const uint32_t *k, /* the key, an array of uint32_t values */
+ size_t length, /* the length of the key, in uint32_ts */
+ uint32_t initval) /* the previous hash, or an arbitrary value */
+{
+ uint32_t a, b, c;
+
+ /* Set up the internal state */
+ a = b = c = 0xdeadbeef + (((uint32_t) length) << 2) + initval;
+
+ /*----------------------------------------- handle most of the key */
+ while (length > 3) {
+ a += k[0];
+ b += k[1];
+ c += k[2];
+ mix(a, b, c);
+ length -= 3;
+ k += 3;
+ }
+
+ /*----------------------------------- handle the last 3 uint32_t's */
+ switch (length) { /* all the case statements fall through */
+ case 3: c += k[2];
+ case 2: b += k[1];
+ case 1: a += k[0];
+ final(a, b, c);
+ case 0: /* case 0: nothing left to add */
+ break;
+ }
+ /*---------------------------------------------- report the result */
+ return c;
+}
+
+static
+void hashword2(
+ const uint32_t *k, /* the key, an array of uint32_t values */
+ size_t length, /* the length of the key, in uint32_ts */
+ uint32_t *pc, /* IN: seed OUT: primary hash value */
+ uint32_t *pb) /* IN: more seed OUT: secondary hash value */
+{
+ uint32_t a, b, c;
+
+ /* Set up the internal state */
+ a = b = c = 0xdeadbeef + ((uint32_t) (length << 2)) + *pc;
+ c += *pb;
+
+ /*----------------------------------------- handle most of the key */
+ while (length > 3) {
+ a += k[0];
+ b += k[1];
+ c += k[2];
+ mix(a, b, c);
+ length -= 3;
+ k += 3;
+ }
+
+ /*----------------------------------- handle the last 3 uint32_t's */
+ switch (length) { /* all the case statements fall through */
+ case 3: c += k[2];
+ case 2: b += k[1];
+ case 1: a += k[0];
+ final(a, b, c);
+ case 0: /* case 0: nothing left to add */
+ break;
+ }
+ /*---------------------------------------------- report the result */
+ *pc = c;
+ *pb = b;
+}
+
+#if (CAA_BITS_PER_LONG == 32)
+static
+unsigned long test_hash(const void *_key, size_t length, unsigned long seed)
+{
+ unsigned int key = (unsigned int) _key;
+
+ assert(length == sizeof(unsigned int));
+ return hash_u32(&key, 1, seed);
+}
+#else
+static
+unsigned long test_hash(const void *_key, size_t length, unsigned long seed)
+{
+ union {
+ uint64_t v64;
+ uint32_t v32[2];
+ } v;
+ union {
+ uint64_t v64;
+ uint32_t v32[2];
+ } key;
+
+ assert(length == sizeof(unsigned long));
+ v.v64 = (uint64_t) seed;
+ key.v64 = (uint64_t) _key;
+ hashword2(key.v32, 2, &v.v32[0], &v.v32[1]);
+ return v.v64;
+}
+#endif
+
+static
+unsigned long test_compare(const void *key1, size_t key1_len,
+ const void *key2, size_t key2_len)
+{
+ if (caa_unlikely(key1_len != key2_len))
+ return -1;
+ assert(key1_len == sizeof(unsigned long));
+ if (key1 == key2)
+ return 0;
+ else
+ return 1;
+}
+
+static
+int test_match(struct cds_lfht_node *node, const void *key)
+{
+ struct lfht_test_node *test_node = to_test_node(node);
+
+ return !test_compare(test_node->key, test_node->key_len,
+ key, sizeof(unsigned long));
+}
+
+static inline
+void cds_lfht_test_lookup(struct cds_lfht *ht, void *key, size_t key_len,
+ struct cds_lfht_iter *iter)
+{
+ assert(key_len == sizeof(unsigned long));
+
+ cds_lfht_lookup(ht, test_hash(key, key_len, TEST_HASH_SEED),
+ test_match, key, iter);
+}
+
+void *thr_count(void *arg)
+{
+ printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
+ "counter", pthread_self(), (unsigned long)gettid());
+
+ rcu_register_thread();
+
+ for (;;) {
+ unsigned long count, removed;
+ long approx_before, approx_after;
+ ssize_t len;
+ char buf[1];
+
+ rcu_thread_offline();
+ len = read(count_pipe[0], buf, 1);
+ rcu_thread_online();
+ if (caa_unlikely(!test_duration_read()))
+ break;
+ if (len != 1)
+ continue;
+ /* Accounting */
+ printf("Counting nodes... ");
+ fflush(stdout);
+ rcu_read_lock();
+ cds_lfht_count_nodes(test_ht, &approx_before, &count, &removed,
+ &approx_after);
+ rcu_read_unlock();
+ printf("done.\n");
+ printf("Approximation before node accounting: %ld nodes.\n",
+ approx_before);
+ printf("Accounting of nodes in the hash table: "
+ "%lu nodes + %lu logically removed.\n",
+ count, removed);
+ printf("Approximation after node accounting: %ld nodes.\n",
+ approx_after);
+ }
+ rcu_unregister_thread();
+ return NULL;
+}
+
+void *thr_reader(void *_count)
+{
+ unsigned long long *count = _count;
+ struct lfht_test_node *node;
+ struct cds_lfht_iter iter;
+
+ printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
+ "reader", pthread_self(), (unsigned long)gettid());
+
+ set_affinity();
+
+ rcu_register_thread();
+
+ while (!test_go)
+ {
+ }
+ cmm_smp_mb();
+
+ for (;;) {
+ rcu_read_lock();
+ cds_lfht_test_lookup(test_ht,
+ (void *)(((unsigned long) rand_r(&rand_lookup) % lookup_pool_size) + lookup_pool_offset),
+ sizeof(void *), &iter);
+ node = cds_lfht_iter_get_test_node(&iter);
+ if (node == NULL) {
+ if (validate_lookup) {
+ printf("[ERROR] Lookup cannot find initial node.\n");
+ exit(-1);
+ }
+ lookup_fail++;
+ } else {
+ lookup_ok++;
+ }
+ debug_yield_read();
+ if (caa_unlikely(rduration))
+ loop_sleep(rduration);
+ rcu_read_unlock();
+ nr_reads++;
+ if (caa_unlikely(!test_duration_read()))
+ break;
+ if (caa_unlikely((nr_reads & ((1 << 10) - 1)) == 0))
+ rcu_quiescent_state();
+ }
+
+ rcu_unregister_thread();
+
+ *count = nr_reads;
+ printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
+ "reader", pthread_self(), (unsigned long)gettid());
+ printf_verbose("readid : %lx, lookupfail %lu, lookupok %lu\n",
+ pthread_self(), lookup_fail, lookup_ok);
+ return ((void*)1);
+
+}
+
+static
+void free_node_cb(struct rcu_head *head)
+{
+ struct lfht_test_node *node =
+ caa_container_of(head, struct lfht_test_node, head);
+ free(node);
+}
+
+void *thr_writer(void *_count)
+{
+ struct lfht_test_node *node;
+ struct cds_lfht_node *ret_node;
+ struct cds_lfht_iter iter;
+ struct wr_count *count = _count;
+ int ret;
+
+ printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
+ "writer", pthread_self(), (unsigned long)gettid());
+
+ set_affinity();
+
+ rcu_register_thread();
+
+ while (!test_go)
+ {
+ }
+ cmm_smp_mb();
+
+ for (;;) {
+ if ((addremove == AR_ADD || add_only)
+ || (addremove == AR_RANDOM && rand_r(&rand_lookup) & 1)) {
+ node = malloc(sizeof(struct lfht_test_node));
+ lfht_test_node_init(node,
+ (void *)(((unsigned long) rand_r(&rand_lookup) % write_pool_size) + write_pool_offset),
+ sizeof(void *));
+ rcu_read_lock();
+ if (add_unique) {
+ ret_node = cds_lfht_add_unique(test_ht,
+ test_hash(node->key, node->key_len, TEST_HASH_SEED),
+ test_match, node->key, &node->node);
+ } else {
+ if (add_replace)
+ ret_node = cds_lfht_add_replace(test_ht,
+ test_hash(node->key, node->key_len, TEST_HASH_SEED),
+ test_match, node->key, &node->node);
+ else
+ cds_lfht_add(test_ht,
+ test_hash(node->key, node->key_len, TEST_HASH_SEED),
+ &node->node);
+ }
+ rcu_read_unlock();
+ if (add_unique && ret_node != &node->node) {
+ free(node);
+ nr_addexist++;
+ } else {
+ if (add_replace && ret_node) {
+ call_rcu(&to_test_node(ret_node)->head,
+ free_node_cb);
+ nr_addexist++;
+ } else {
+ nr_add++;
+ }
+ }
+ } else {
+ /* May delete */
+ rcu_read_lock();
+ cds_lfht_test_lookup(test_ht,
+ (void *)(((unsigned long) rand_r(&rand_lookup) % write_pool_size) + write_pool_offset),
+ sizeof(void *), &iter);
+ ret = cds_lfht_del(test_ht, &iter);
+ rcu_read_unlock();
+ if (ret == 0) {
+ node = cds_lfht_iter_get_test_node(&iter);
+ call_rcu(&node->head, free_node_cb);
+ nr_del++;
+ } else
+ nr_delnoent++;
+ }
+#if 0
+ //if (nr_writes % 100000 == 0) {
+ if (nr_writes % 1000 == 0) {
+ rcu_read_lock();
+ if (rand_r(&rand_lookup) & 1) {
+ ht_resize(test_ht, 1);
+ } else {
+ ht_resize(test_ht, -1);
+ }
+ rcu_read_unlock();
+ }
+#endif //0
+ nr_writes++;
+ if (caa_unlikely(!test_duration_write()))
+ break;
+ if (caa_unlikely(wdelay))
+ loop_sleep(wdelay);
+ if (caa_unlikely((nr_writes & ((1 << 10) - 1)) == 0))
+ rcu_quiescent_state();
+ }
+
+ rcu_unregister_thread();
+
+ printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
+ "writer", pthread_self(), (unsigned long)gettid());
+ printf_verbose("info id %lx: nr_add %lu, nr_addexist %lu, nr_del %lu, "
+ "nr_delnoent %lu\n", pthread_self(), nr_add,
+ nr_addexist, nr_del, nr_delnoent);
+ count->update_ops = nr_writes;
+ count->add = nr_add;
+ count->add_exist = nr_addexist;
+ count->remove = nr_del;
+ return ((void*)2);
+}
+
+static int populate_hash(void)
+{
+ struct lfht_test_node *node;
+ struct cds_lfht_node *ret_node;
+
+ if (!init_populate)
+ return 0;
+
+ if ((add_unique || add_replace) && init_populate * 10 > init_pool_size) {
+ printf("WARNING: required to populate %lu nodes (-k), but random "
+"pool is quite small (%lu values) and we are in add_unique (-u) or add_replace (-s) mode. Try with a "
+"larger random pool (-p option). This may take a while...\n", init_populate, init_pool_size);
+ }
+
+ while (nr_add < init_populate) {
+ node = malloc(sizeof(struct lfht_test_node));
+ lfht_test_node_init(node,
+ (void *)(((unsigned long) rand_r(&rand_lookup) % init_pool_size) + init_pool_offset),
+ sizeof(void *));
+ rcu_read_lock();
+ if (add_unique) {
+ ret_node = cds_lfht_add_unique(test_ht,
+ test_hash(node->key, node->key_len, TEST_HASH_SEED),
+ test_match, node->key, &node->node);
+ } else {
+ if (add_replace)
+ ret_node = cds_lfht_add_replace(test_ht,
+ test_hash(node->key, node->key_len, TEST_HASH_SEED),
+ test_match, node->key, &node->node);
+ else
+ cds_lfht_add(test_ht,
+ test_hash(node->key, node->key_len, TEST_HASH_SEED),
+ &node->node);
+ }
+ rcu_read_unlock();
+ if (add_unique && ret_node != &node->node) {
+ free(node);
+ nr_addexist++;
+ } else {
+ if (add_replace && ret_node) {
+ call_rcu(&to_test_node(ret_node)->head, free_node_cb);
+ nr_addexist++;
+ } else {
+ nr_add++;
+ }
+ }
+ nr_writes++;
+ }
+ return 0;
+}
+
+static
+void test_delete_all_nodes(struct cds_lfht *ht)
+{
+ struct cds_lfht_iter iter;
+ struct lfht_test_node *node;
+ unsigned long count = 0;
+
+ cds_lfht_for_each_entry(ht, &iter, node, node) {
+ int ret;
+
+ ret = cds_lfht_del(test_ht, &iter);
+ assert(!ret);
+ call_rcu(&node->head, free_node_cb);
+ count++;
+ }
+ printf("deleted %lu nodes.\n", count);
+}
+
+void show_usage(int argc, char **argv)
+{
+ printf("Usage : %s nr_readers nr_writers duration (s)\n", argv[0]);
+#ifdef DEBUG_YIELD
+ printf(" [-r] [-w] (yield reader and/or writer)\n");
+#endif
+ printf(" [-d delay] (writer period (us))\n");
+ printf(" [-c duration] (reader C.S. duration (in loops))\n");
+ printf(" [-v] (verbose output)\n");
+ printf(" [-a cpu#] [-a cpu#]... (affinity)\n");
+ printf(" [-h size] (initial number of buckets)\n");
+ printf(" [-m size] (minimum number of allocated buckets)\n");
+ printf(" [-n size] (maximum number of buckets)\n");
+ printf(" [not -u nor -s] Add entries (supports redundant keys).\n");
+ printf(" [-u] Uniquify add (no redundant keys).\n");
+ printf(" [-s] Replace (swap) entries.\n");
+ printf(" [-i] Add only (no removal).\n");
+ printf(" [-k nr_nodes] Number of nodes to insert initially.\n");
+ printf(" [-A] Automatically resize hash table.\n");
+ printf(" [-B order|chunk|mmap] Specify the memory backend.\n");
+ printf(" [-R offset] Lookup pool offset.\n");
+ printf(" [-S offset] Write pool offset.\n");
+ printf(" [-T offset] Init pool offset.\n");
+ printf(" [-M size] Lookup pool size.\n");
+ printf(" [-N size] Write pool size.\n");
+ printf(" [-O size] Init pool size.\n");
+ printf(" [-V] Validate lookups of init values (use with filled init pool, same lookup range, with different write range).\n");
+ printf("\n\n");
+}
+
+int main(int argc, char **argv)
+{
+ int err;
+ pthread_t *tid_reader, *tid_writer;
+ pthread_t tid_count;
+ void *tret;
+ unsigned long long *count_reader;
+ struct wr_count *count_writer;
+ unsigned long long tot_reads = 0, tot_writes = 0,
+ tot_add = 0, tot_add_exist = 0, tot_remove = 0;
+ unsigned long count, removed;
+ long approx_before, approx_after;
+ int i, a, ret;
+ struct sigaction act;
+ unsigned int remain;
+
+ if (argc < 4) {
+ show_usage(argc, argv);
+ return -1;
+ }
+
+ err = sscanf(argv[1], "%u", &nr_readers);
+ if (err != 1) {
+ show_usage(argc, argv);
+ return -1;
+ }
+
+ err = sscanf(argv[2], "%u", &nr_writers);
+ if (err != 1) {
+ show_usage(argc, argv);
+ return -1;
+ }
+
+ err = sscanf(argv[3], "%lu", &duration);
+ if (err != 1) {
+ show_usage(argc, argv);
+ return -1;
+ }
+
+ for (i = 4; i < argc; i++) {
+ if (argv[i][0] != '-')
+ continue;
+ switch (argv[i][1]) {
+#ifdef DEBUG_YIELD
+ case 'r':
+ yield_active |= YIELD_READ;
+ break;
+ case 'w':
+ yield_active |= YIELD_WRITE;
+ break;
+#endif
+ case 'a':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ return -1;
+ }
+ a = atoi(argv[++i]);
+ cpu_affinities[next_aff++] = a;
+ use_affinity = 1;
+ printf_verbose("Adding CPU %d affinity\n", a);
+ break;
+ case 'c':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ return -1;
+ }
+ rduration = atol(argv[++i]);
+ break;
+ case 'd':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ return -1;
+ }
+ wdelay = atol(argv[++i]);
+ break;
+ case 'v':
+ verbose_mode = 1;
+ break;
+ case 'h':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ return -1;
+ }
+ init_hash_size = atol(argv[++i]);
+ break;
+ case 'm':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ return -1;
+ }
+ min_hash_alloc_size = atol(argv[++i]);
+ break;
+ case 'n':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ return -1;
+ }
+ max_hash_buckets_size = atol(argv[++i]);
+ break;
+ case 'u':
+ if (add_replace) {
+ printf("Please specify at most one of -s or -u.\n");
+ exit(-1);
+ }
+ add_unique = 1;
+ break;
+ case 's':
+ if (add_unique) {
+ printf("Please specify at most one of -s or -u.\n");
+ exit(-1);
+ }
+ add_replace = 1;
+ break;
+ case 'i':
+ add_only = 1;
+ break;
+ case 'k':
+ init_populate = atol(argv[++i]);
+ break;
+ case 'A':
+ opt_auto_resize = 1;
+ break;
+ case 'B':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ return -1;
+ }
+ i++;
+ if (!strcmp("order", argv[i]))
+ memory_backend = &cds_lfht_mm_order;
+ else if (!strcmp("chunk", argv[i]))
+ memory_backend = &cds_lfht_mm_chunk;
+ else if (!strcmp("mmap", argv[i]))
+ memory_backend = &cds_lfht_mm_mmap;
+ else {
+ printf("Please specify memory backend with order|chunk|mmap.\n");
+ exit(-1);
+ }
+ break;
+ case 'R':
+ lookup_pool_offset = atol(argv[++i]);
+ break;
+ case 'S':
+ write_pool_offset = atol(argv[++i]);
+ break;
+ case 'T':
+ init_pool_offset = atol(argv[++i]);
+ break;
+ case 'M':
+ lookup_pool_size = atol(argv[++i]);
+ break;
+ case 'N':
+ write_pool_size = atol(argv[++i]);
+ break;
+ case 'O':
+ init_pool_size = atol(argv[++i]);
+ break;
+ case 'V':
+ validate_lookup = 1;
+ break;
+
+ }
+ }
+
+ /* Check if hash size is power of 2 */
+ if (init_hash_size && init_hash_size & (init_hash_size - 1)) {
+ printf("Error: Initial number of buckets (%lu) is not a power of 2.\n",
+ init_hash_size);
+ return -1;
+ }
+
+ if (min_hash_alloc_size && min_hash_alloc_size & (min_hash_alloc_size - 1)) {
+ printf("Error: Minimum number of allocated buckets (%lu) is not a power of 2.\n",
+ min_hash_alloc_size);
+ return -1;
+ }
+
+ if (max_hash_buckets_size && max_hash_buckets_size & (max_hash_buckets_size - 1)) {
+ printf("Error: Maximum number of buckets (%lu) is not a power of 2.\n",
+ max_hash_buckets_size);
+ return -1;
+ }
+
+ memset(&act, 0, sizeof(act));
+ ret = sigemptyset(&act.sa_mask);
+ if (ret == -1) {
+ perror("sigemptyset");
+ return -1;
+ }
+ act.sa_handler = sigusr1_handler;
+ act.sa_flags = SA_RESTART;
+ ret = sigaction(SIGUSR1, &act, NULL);
+ if (ret == -1) {
+ perror("sigaction");
+ return -1;
+ }
+
+ ret = pipe(count_pipe);
+ if (ret == -1) {
+ perror("pipe");
+ return -1;
+ }
+
+ /* spawn counter thread */
+ err = pthread_create(&tid_count, NULL, thr_count,
+ NULL);
+ if (err != 0)
+ exit(1);
+
+ act.sa_handler = sigusr2_handler;
+ act.sa_flags = SA_RESTART;
+ ret = sigaction(SIGUSR2, &act, NULL);
+ if (ret == -1) {
+ perror("sigaction");
+ return -1;
+ }
+
+ printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
+ duration, nr_readers, nr_writers);
+ printf_verbose("Writer delay : %lu loops.\n", wdelay);
+ printf_verbose("Reader duration : %lu loops.\n", rduration);
+ printf_verbose("Mode:%s%s.\n",
+ add_only ? " add only" : " add/remove",
+ add_unique ? " uniquify" : ( add_replace ? " replace" : " insert"));
+ printf_verbose("Initial number of buckets: %lu buckets.\n", init_hash_size);
+ printf_verbose("Minimum number of allocated buckets: %lu buckets.\n", min_hash_alloc_size);
+ printf_verbose("Maximum number of buckets: %lu buckets.\n", max_hash_buckets_size);
+ printf_verbose("Init pool size offset %lu size %lu.\n",
+ init_pool_offset, init_pool_size);
+ printf_verbose("Lookup pool size offset %lu size %lu.\n",
+ lookup_pool_offset, lookup_pool_size);
+ printf_verbose("Update pool size offset %lu size %lu.\n",
+ write_pool_offset, write_pool_size);
+ printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
+ "main", pthread_self(), (unsigned long)gettid());
+
+ tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
+ tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
+ count_reader = malloc(sizeof(*count_reader) * nr_readers);
+ count_writer = malloc(sizeof(*count_writer) * nr_writers);
+
+ err = create_all_cpu_call_rcu_data(0);
+ assert(!err);
+
+ if (memory_backend) {
+ test_ht = _cds_lfht_new(init_hash_size, min_hash_alloc_size,
+ max_hash_buckets_size,
+ (opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0) |
+ CDS_LFHT_ACCOUNTING, memory_backend,
+ &rcu_flavor, NULL);
+ } else {
+ test_ht = cds_lfht_new(init_hash_size, min_hash_alloc_size,
+ max_hash_buckets_size,
+ (opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0) |
+ CDS_LFHT_ACCOUNTING, NULL);
+ }
+
+ /*
+ * Hash Population needs to be seen as a RCU reader
+ * thread from the point of view of resize.
+ */
+ rcu_register_thread();
+ ret = populate_hash();
+ assert(!ret);
+
+ rcu_thread_offline();
+
+ next_aff = 0;
+
+ for (i = 0; i < nr_readers; i++) {
+ err = pthread_create(&tid_reader[i], NULL, thr_reader,
+ &count_reader[i]);
+ if (err != 0)
+ exit(1);
+ }
+ for (i = 0; i < nr_writers; i++) {
+ err = pthread_create(&tid_writer[i], NULL, thr_writer,
+ &count_writer[i]);
+ if (err != 0)
+ exit(1);
+ }
+
+ cmm_smp_mb();
+
+ test_go = 1;
+
+ remain = duration;
+ do {
+ remain = sleep(remain);
+ } while (remain > 0);
+
+ test_stop = 1;
+
+ for (i = 0; i < nr_readers; i++) {
+ err = pthread_join(tid_reader[i], &tret);
+ if (err != 0)
+ exit(1);
+ tot_reads += count_reader[i];
+ }
+ for (i = 0; i < nr_writers; i++) {
+ err = pthread_join(tid_writer[i], &tret);
+ if (err != 0)
+ exit(1);
+ tot_writes += count_writer[i].update_ops;
+ tot_add += count_writer[i].add;
+ tot_add_exist += count_writer[i].add_exist;
+ tot_remove += count_writer[i].remove;
+ }
+
+ /* teardown counter thread */
+ act.sa_handler = SIG_IGN;
+ act.sa_flags = SA_RESTART;
+ ret = sigaction(SIGUSR2, &act, NULL);
+ if (ret == -1) {
+ perror("sigaction");
+ return -1;
+ }
+ {
+ char msg[1] = { 0x42 };
+ ssize_t ret;
+
+ do {
+ ret = write(count_pipe[1], msg, 1); /* wakeup thread */
+ } while (ret == -1L && errno == EINTR);
+ }
+ err = pthread_join(tid_count, &tret);
+ if (err != 0)
+ exit(1);
+
+ fflush(stdout);
+ rcu_thread_online();
+ rcu_read_lock();
+ printf("Counting nodes... ");
+ cds_lfht_count_nodes(test_ht, &approx_before, &count, &removed,
+ &approx_after);
+ printf("done.\n");
+ test_delete_all_nodes(test_ht);
+ rcu_read_unlock();
+ rcu_thread_offline();
+ if (count || removed) {
+ printf("Approximation before node accounting: %ld nodes.\n",
+ approx_before);
+ printf("Nodes deleted from hash table before destroy: "
+ "%lu nodes + %lu logically removed.\n",
+ count, removed);
+ printf("Approximation after node accounting: %ld nodes.\n",
+ approx_after);
+ }
+ ret = cds_lfht_destroy(test_ht, NULL);
+ if (ret)
+ printf_verbose("final delete aborted\n");
+ else
+ printf_verbose("final delete success\n");
+ printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
+ tot_writes);
+ printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
+ "nr_writers %3u "
+ "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu "
+ "nr_add %12llu nr_add_fail %12llu nr_remove %12llu nr_leaked %12lld\n",
+ argv[0], duration, nr_readers, rduration,
+ nr_writers, wdelay, tot_reads, tot_writes,
+ tot_reads + tot_writes, tot_add, tot_add_exist, tot_remove,
+ (long long) tot_add + init_populate - tot_remove - count);
+ rcu_unregister_thread();
+ free_all_cpu_call_rcu_data();
+ free(tid_reader);
+ free(tid_writer);
+ free(count_reader);
+ free(count_writer);
+ return 0;
+}
return uatomic_cmpxchg(p, old, _new);
}
+DEFINE_RCU_FLAVOR()
+
#include "urcu-call-rcu-impl.h"
#include "urcu-defer-impl.h"
#include <urcu-call-rcu.h>
#include <urcu-defer.h>
+#include <urcu-flavor.h>
#endif /* _URCU_BP_H */
--- /dev/null
+#ifndef _URCU_FLAVOR_H
+#define _URCU_FLAVOR_H
+
+/*
+ * urcu-flavor.h
+ *
+ * Userspace RCU header - rcu flavor declarations
+ *
+ * Copyright (c) 2011 Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct rcu_flavor_struct {
+ void (*read_lock)(void);
+ void (*read_unlock)(void);
+ void (*read_quiescent_state)(void);
+ void (*update_call_rcu)(struct rcu_head *head,
+ void (*func)(struct rcu_head *head));
+ void (*update_synchronize_rcu)(void);
+ void (*update_defer_rcu)(void (*fct)(void *p), void *p);
+
+ void (*thread_offline)(void);
+ void (*thread_online)(void);
+ void (*register_thread)(void);
+ void (*unregister_thread)(void);
+};
+
+#define DEFINE_RCU_FLAVOR() \
+const struct rcu_flavor_struct rcu_flavor = { \
+ .read_lock = rcu_read_lock, \
+ .read_unlock = rcu_read_unlock, \
+ .read_quiescent_state = rcu_quiescent_state, \
+ .update_call_rcu = call_rcu, \
+ .update_synchronize_rcu = synchronize_rcu, \
+ .update_defer_rcu = defer_rcu, \
+ .thread_offline = rcu_thread_offline, \
+ .thread_online = rcu_thread_online, \
+ .register_thread = rcu_register_thread, \
+ .unregister_thread = rcu_unregister_thread,\
+};
+
+extern const struct rcu_flavor_struct rcu_flavor;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _URCU_FLAVOR_H */
*/
}
+DEFINE_RCU_FLAVOR()
+
#include "urcu-call-rcu-impl.h"
#include "urcu-defer-impl.h"
#include <urcu-call-rcu.h>
#include <urcu-defer.h>
+#include <urcu-flavor.h>
#endif /* _URCU_QSBR_H */
#endif /* #ifdef RCU_SIGNAL */
+DEFINE_RCU_FLAVOR()
+
#include "urcu-call-rcu-impl.h"
#include "urcu-defer-impl.h"
#include <urcu-call-rcu.h>
#include <urcu-defer.h>
+#include <urcu-flavor.h>
#endif /* _URCU_H */
#include <urcu/rculist.h>
#include <urcu/rculfqueue.h>
#include <urcu/rculfstack.h>
+#include <urcu/rculfhash.h>
#include <urcu/wfqueue.h>
#include <urcu/wfstack.h>
--- /dev/null
+#ifndef _KCOMPAT_JHASH_H
+#define _KCOMPAT_JHASH_H
+
+/* jhash.h: Jenkins hash support.
+ *
+ * Copyright (C) 1996 Bob Jenkins (bob_jenkins@burtleburtle.net)
+ *
+ * http://burtleburtle.net/bob/hash/
+ *
+ * These are the credits from Bob's sources:
+ *
+ * lookup2.c, by Bob Jenkins, December 1996, Public Domain.
+ * hash(), hash2(), hash3, and mix() are externally useful functions.
+ * Routines to test the hash are included if SELF_TEST is defined.
+ * You can use this free for any purpose. It has no warranty.
+ *
+ * Copyright (C) 2003 David S. Miller (davem@redhat.com)
+ *
+ * I've modified Bob's hash to be useful in the Linux kernel, and
+ * any bugs present are surely my fault. -DaveM
+ */
+
+#include <stdint.h>
+
+typedef uint8_t u8;
+typedef uint32_t u32;
+
+/* NOTE: Arguments are modified. */
+#define __jhash_mix(a, b, c) \
+{ \
+ a -= b; a -= c; a ^= (c>>13); \
+ b -= c; b -= a; b ^= (a<<8); \
+ c -= a; c -= b; c ^= (b>>13); \
+ a -= b; a -= c; a ^= (c>>12); \
+ b -= c; b -= a; b ^= (a<<16); \
+ c -= a; c -= b; c ^= (b>>5); \
+ a -= b; a -= c; a ^= (c>>3); \
+ b -= c; b -= a; b ^= (a<<10); \
+ c -= a; c -= b; c ^= (b>>15); \
+}
+
+/* The golden ration: an arbitrary value */
+#define JHASH_GOLDEN_RATIO 0x9e3779b9
+
+/* The most generic version, hashes an arbitrary sequence
+ * of bytes. No alignment or length assumptions are made about
+ * the input key.
+ */
+static inline u32 jhash(const void *key, u32 length, u32 initval)
+{
+ u32 a, b, c, len;
+ const u8 *k = key;
+
+ len = length;
+ a = b = JHASH_GOLDEN_RATIO;
+ c = initval;
+
+ while (len >= 12) {
+ a += (k[0] +((u32)k[1]<<8) +((u32)k[2]<<16) +((u32)k[3]<<24));
+ b += (k[4] +((u32)k[5]<<8) +((u32)k[6]<<16) +((u32)k[7]<<24));
+ c += (k[8] +((u32)k[9]<<8) +((u32)k[10]<<16)+((u32)k[11]<<24));
+
+ __jhash_mix(a,b,c);
+
+ k += 12;
+ len -= 12;
+ }
+
+ c += length;
+ switch (len) {
+ case 11: c += ((u32)k[10]<<24);
+ case 10: c += ((u32)k[9]<<16);
+ case 9 : c += ((u32)k[8]<<8);
+ case 8 : b += ((u32)k[7]<<24);
+ case 7 : b += ((u32)k[6]<<16);
+ case 6 : b += ((u32)k[5]<<8);
+ case 5 : b += k[4];
+ case 4 : a += ((u32)k[3]<<24);
+ case 3 : a += ((u32)k[2]<<16);
+ case 2 : a += ((u32)k[1]<<8);
+ case 1 : a += k[0];
+ };
+
+ __jhash_mix(a,b,c);
+
+ return c;
+}
+
+#endif /* _KCOMPAT_JHASH_H */
#define rcu_defer_barrier rcu_defer_barrier_bp
#define rcu_defer_barrier_thread rcu_defer_barrier_thread_bp
+#define rcu_flavor rcu_flavor_bp
+
#endif /* _URCU_BP_MAP_H */
#define rcu_defer_barrier rcu_defer_barrier_qsbr
#define rcu_defer_barrier_thread rcu_defer_barrier_thread_qsbr
+#define rcu_flavor rcu_flavor_qsbr
+
#endif /* _URCU_QSBR_MAP_H */
#define rcu_defer_barrier rcu_defer_barrier_memb
#define rcu_defer_barrier_thread rcu_defer_barrier_thread_memb
+#define rcu_flavor rcu_flavor_memb
+
#elif defined(RCU_SIGNAL)
#define rcu_read_lock rcu_read_lock_sig
#define rcu_defer_barrier rcu_defer_barrier_sig
#define rcu_defer_barrier_thread rcu_defer_barrier_thread_sig
+#define rcu_flavor rcu_flavor_sig
+
#elif defined(RCU_MB)
#define rcu_read_lock rcu_read_lock_mb
#define rcu_defer_barrier rcu_defer_barrier_mb
#define rcu_defer_barrier_thread rcu_defer_barrier_thread_mb
+#define rcu_flavor rcu_flavor_mb
+
#else
#error "Undefined selection"
--- /dev/null
+#ifndef _URCU_RCULFHASH_H
+#define _URCU_RCULFHASH_H
+
+/*
+ * urcu/rculfhash.h
+ *
+ * Userspace RCU library - Lock-Free RCU Hash Table
+ *
+ * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Include this file _after_ including your URCU flavor.
+ */
+
+#include <stdint.h>
+#include <urcu/compiler.h>
+#include <urcu-call-rcu.h>
+#include <urcu-flavor.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * cds_lfht_node: Contains the next pointers and reverse-hash
+ * value required for lookup and traversal of the hash table.
+ *
+ * struct cds_lfht_node should be aligned on 4-bytes boundaries because
+ * the two lower bits are used as flags.
+ *
+ * struct cds_lfht_node can be embedded into a structure (as a field).
+ * caa_container_of() can be used to get the structure from the struct
+ * cds_lfht_node after a lookup.
+ *
+ * The structure which embeds it typically holds the key (or key-value
+ * pair) of the object. The caller code is responsible for calculation
+ * of the hash value for cds_lfht APIs.
+ */
+struct cds_lfht_node {
+ struct cds_lfht_node *next; /* ptr | BUCKET_FLAG | REMOVED_FLAG */
+ unsigned long reverse_hash;
+} __attribute__((aligned(4)));
+
+/* cds_lfht_iter: Used to track state while traversing a hash chain. */
+struct cds_lfht_iter {
+ struct cds_lfht_node *node, *next;
+};
+
+static inline
+struct cds_lfht_node *cds_lfht_iter_get_node(struct cds_lfht_iter *iter)
+{
+ return iter->node;
+}
+
+struct cds_lfht;
+
+/*
+ * Caution !
+ * Ensure reader and writer threads are registered as urcu readers.
+ */
+
+typedef int (*cds_lfht_match_fct)(struct cds_lfht_node *node, const void *key);
+
+/*
+ * cds_lfht_node_init - initialize a hash table node
+ * @node: the node to initialize.
+ *
+ * This function is kept to be eventually used for debugging purposes
+ * (detection of memory corruption).
+ */
+static inline
+void cds_lfht_node_init(struct cds_lfht_node *node)
+{
+}
+
+/*
+ * Hash table creation flags.
+ */
+enum {
+ CDS_LFHT_AUTO_RESIZE = (1U << 0),
+ CDS_LFHT_ACCOUNTING = (1U << 1),
+};
+
+struct cds_lfht_mm_type {
+ struct cds_lfht *(*alloc_cds_lfht)(unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets);
+ void (*alloc_bucket_table)(struct cds_lfht *ht, unsigned long order);
+ void (*free_bucket_table)(struct cds_lfht *ht, unsigned long order);
+ struct cds_lfht_node *(*bucket_at)(struct cds_lfht *ht,
+ unsigned long index);
+};
+
+extern const struct cds_lfht_mm_type cds_lfht_mm_order;
+extern const struct cds_lfht_mm_type cds_lfht_mm_chunk;
+extern const struct cds_lfht_mm_type cds_lfht_mm_mmap;
+
+/*
+ * _cds_lfht_new - API used by cds_lfht_new wrapper. Do not use directly.
+ */
+struct cds_lfht *_cds_lfht_new(unsigned long init_size,
+ unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets,
+ int flags,
+ const struct cds_lfht_mm_type *mm,
+ const struct rcu_flavor_struct *flavor,
+ pthread_attr_t *attr);
+
+/*
+ * cds_lfht_new - allocate a hash table.
+ * @init_size: number of buckets to allocate initially. Must be power of two.
+ * @min_nr_alloc_buckets: the minimum number of allocated buckets.
+ * (must be power of two)
+ * @max_nr_buckets: the maximum number of hash table buckets allowed.
+ * (must be power of two)
+ * @flags: hash table creation flags (can be combined with bitwise or: '|').
+ * 0: no flags.
+ * CDS_LFHT_AUTO_RESIZE: automatically resize hash table.
+ * CDS_LFHT_ACCOUNTING: count the number of node addition
+ * and removal in the table
+ * @attr: optional resize worker thread attributes. NULL for default.
+ *
+ * Return NULL on error.
+ * Note: the RCU flavor must be already included before the hash table header.
+ *
+ * The programmer is responsible for ensuring that resize operation has a
+ * priority equal to hash table updater threads. It should be performed by
+ * specifying the appropriate priority in the pthread "attr" argument, and,
+ * for CDS_LFHT_AUTO_RESIZE, by ensuring that call_rcu worker threads also have
+ * this priority level. Having lower priority for call_rcu and resize threads
+ * does not pose any correctness issue, but the resize operations could be
+ * starved by updates, thus leading to long hash table bucket chains.
+ * Threads calling this API are NOT required to be registered RCU read-side
+ * threads. It can be called very early.(before rcu is initialized ...etc.)
+ */
+static inline
+struct cds_lfht *cds_lfht_new(unsigned long init_size,
+ unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets,
+ int flags,
+ pthread_attr_t *attr)
+{
+ return _cds_lfht_new(init_size, min_nr_alloc_buckets, max_nr_buckets,
+ flags, NULL, &rcu_flavor, attr);
+}
+
+/*
+ * cds_lfht_destroy - destroy a hash table.
+ * @ht: the hash table to destroy.
+ * @attr: (output) resize worker thread attributes, as received by cds_lfht_new.
+ * The caller will typically want to free this pointer if dynamically
+ * allocated. The attr point can be NULL if the caller does not
+ * need to be informed of the value passed to cds_lfht_new().
+ *
+ * Return 0 on success, negative error value on error.
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
+
+/*
+ * cds_lfht_count_nodes - count the number of nodes in the hash table.
+ * @ht: the hash table.
+ * @split_count_before: Sample the node count split-counter before traversal.
+ * @count: Traverse the hash table, count the number of nodes observed.
+ * @removed: Number of logically removed nodes observed during traversal.
+ * @split_count_after: Sample the node count split-counter after traversal.
+ *
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+void cds_lfht_count_nodes(struct cds_lfht *ht,
+ long *split_count_before,
+ unsigned long *count,
+ unsigned long *removed,
+ long *split_count_after);
+
+/*
+ * cds_lfht_lookup - lookup a node by key.
+ * @ht: the hash table.
+ * @hash: the key hash.
+ * @match: the key match function.
+ * @key: the current node key.
+ * @iter: Node, if found (output). *iter->node set to NULL if not found.
+ *
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
+ cds_lfht_match_fct match, const void *key,
+ struct cds_lfht_iter *iter);
+
+/*
+ * cds_lfht_next_duplicate - get the next item with same key (after a lookup).
+ * @ht: the hash table.
+ * @match: the key match function.
+ * @key: the current node key.
+ * @iter: Node, if found (output). *iter->node set to NULL if not found.
+ *
+ * Uses an iterator initialized by a lookup.
+ * Sets *iter-node to the following node with same key.
+ * Sets *iter->node to NULL if no following node exists with same key.
+ * RCU read-side lock must be held across cds_lfht_lookup and
+ * cds_lfht_next calls, and also between cds_lfht_next calls using the
+ * node returned by a previous cds_lfht_next.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+void cds_lfht_next_duplicate(struct cds_lfht *ht,
+ cds_lfht_match_fct match, const void *key,
+ struct cds_lfht_iter *iter);
+
+/*
+ * cds_lfht_first - get the first node in the table.
+ * @ht: the hash table.
+ * @iter: First node, if exists (output). *iter->node set to NULL if not found.
+ *
+ * Output in "*iter". *iter->node set to NULL if table is empty.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+void cds_lfht_first(struct cds_lfht *ht, struct cds_lfht_iter *iter);
+
+/*
+ * cds_lfht_next - get the next node in the table.
+ * @ht: the hash table.
+ * @iter: Next node, if exists (output). *iter->node set to NULL if not found.
+ *
+ * Input/Output in "*iter". *iter->node set to NULL if *iter was
+ * pointing to the last table node.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+void cds_lfht_next(struct cds_lfht *ht, struct cds_lfht_iter *iter);
+
+/*
+ * cds_lfht_add - add a node to the hash table.
+ * @ht: the hash table.
+ * @hash: the key hash.
+ * @node: the node to add.
+ *
+ * This function supports adding redundant keys into the table.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+void cds_lfht_add(struct cds_lfht *ht, unsigned long hash,
+ struct cds_lfht_node *node);
+
+/*
+ * cds_lfht_add_unique - add a node to hash table, if key is not present.
+ * @ht: the hash table.
+ * @hash: the node's hash.
+ * @match: the key match function.
+ * @key: the node's key.
+ * @node: the node to try adding.
+ *
+ * Return the node added upon success.
+ * Return the unique node already present upon failure. If
+ * cds_lfht_add_unique fails, the node passed as parameter should be
+ * freed by the caller.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ *
+ * The semantic of this function is that if only this function is used
+ * to add keys into the table, no duplicated keys should ever be
+ * observable in the table. The same guarantee apply for combination of
+ * add_unique and add_replace (see below).
+ */
+struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht,
+ unsigned long hash,
+ cds_lfht_match_fct match,
+ const void *key,
+ struct cds_lfht_node *node);
+
+/*
+ * cds_lfht_add_replace - replace or add a node within hash table.
+ * @ht: the hash table.
+ * @hash: the node's hash.
+ * @match: the key match function.
+ * @key: the node's key.
+ * @node: the node to add.
+ *
+ * Return the node replaced upon success. If no node matching the key
+ * was present, return NULL, which also means the operation succeeded.
+ * This replacement operation should never fail.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ * After successful replacement, a grace period must be waited for before
+ * freeing the memory reserved for the returned node.
+ *
+ * The semantic of replacement vs lookups is the following: if lookups
+ * are performed between a key unique insertion and its removal, we
+ * guarantee that the lookups and get next will always find exactly one
+ * instance of the key if it is replaced concurrently with the lookups.
+ *
+ * Providing this semantic allows us to ensure that replacement-only
+ * schemes will never generate duplicated keys. It also allows us to
+ * guarantee that a combination of add_replace and add_unique updates
+ * will never generate duplicated keys.
+ */
+struct cds_lfht_node *cds_lfht_add_replace(struct cds_lfht *ht,
+ unsigned long hash,
+ cds_lfht_match_fct match,
+ const void *key,
+ struct cds_lfht_node *node);
+
+/*
+ * cds_lfht_replace - replace a node pointer to by iter within hash table.
+ * @ht: the hash table.
+ * @old_iter: the iterator position of the node to replace.
+ * @now_node: the new node to try using for replacement.
+ *
+ * Return 0 if replacement is successful, negative value otherwise.
+ * Replacing a NULL old node or an already removed node will fail with a
+ * negative value.
+ * Old node can be looked up with cds_lfht_lookup and cds_lfht_next.
+ * RCU read-side lock must be held between lookup and replacement.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ * After successful replacement, a grace period must be waited for before
+ * freeing the memory reserved for the old node (which can be accessed
+ * with cds_lfht_iter_get_node).
+ *
+ * The semantic of replacement vs lookups is the following: if lookups
+ * are performed between a key unique insertion and its removal, we
+ * guarantee that the lookups and get next will always find exactly one
+ * instance of the key if it is replaced concurrently with the lookups.
+ *
+ * Providing this semantic allows us to ensure that replacement-only
+ * schemes will never generate duplicated keys. It also allows us to
+ * guarantee that a combination of add_replace and add_unique updates
+ * will never generate duplicated keys.
+ */
+int cds_lfht_replace(struct cds_lfht *ht, struct cds_lfht_iter *old_iter,
+ struct cds_lfht_node *new_node);
+
+/*
+ * cds_lfht_del - remove node pointed to by iterator from hash table.
+ * @ht: the hash table.
+ * @iter: the iterator position of the node to delete.
+ *
+ * Return 0 if the node is successfully removed, negative value
+ * otherwise.
+ * Replacing a NULL node or an already removed node will fail with a
+ * negative value.
+ * Node can be looked up with cds_lfht_lookup and cds_lfht_next.
+ * cds_lfht_iter_get_node.
+ * RCU read-side lock must be held between lookup and removal.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ * After successful removal, a grace period must be waited for before
+ * freeing the memory reserved for old node (which can be accessed with
+ * cds_lfht_iter_get_node).
+ */
+int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_iter *iter);
+
+/*
+ * cds_lfht_resize - Force a hash table resize
+ * @ht: the hash table.
+ * @new_size: update to this hash table size.
+ *
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size);
+
+/*
+ * Note: cds_lfht_for_each are safe for element removal during
+ * iteration.
+ */
+#define cds_lfht_for_each(ht, iter, node) \
+ for (cds_lfht_first(ht, iter), \
+ node = cds_lfht_iter_get_node(iter); \
+ node != NULL; \
+ cds_lfht_next(ht, iter), \
+ node = cds_lfht_iter_get_node(iter))
+
+#define cds_lfht_for_each_duplicate(ht, hash, match, key, iter, node) \
+ for (cds_lfht_lookup(ht, hash, match, key, iter), \
+ node = cds_lfht_iter_get_node(iter); \
+ node != NULL; \
+ cds_lfht_next_duplicate(ht, match, key, iter), \
+ node = cds_lfht_iter_get_node(iter))
+
+#define cds_lfht_for_each_entry(ht, iter, pos, member) \
+ for (cds_lfht_first(ht, iter), \
+ pos = caa_container_of(cds_lfht_iter_get_node(iter), \
+ typeof(*(pos)), member); \
+ &(pos)->member != NULL; \
+ cds_lfht_next(ht, iter), \
+ pos = caa_container_of(cds_lfht_iter_get_node(iter), \
+ typeof(*(pos)), member))
+
+#define cds_lfht_for_each_entry_duplicate(ht, hash, match, key, \
+ iter, pos, member) \
+ for (cds_lfht_lookup(ht, hash, match, key, iter), \
+ pos = caa_container_of(cds_lfht_iter_get_node(iter), \
+ typeof(*(pos)), member); \
+ &(pos)->member != NULL; \
+ cds_lfht_next_duplicate(ht, match, key, iter), \
+ pos = caa_container_of(cds_lfht_iter_get_node(iter), \
+ typeof(*(pos)), member))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _URCU_RCULFHASH_H */
projects / urcu.git / commitdiff
