[lttng-dev] [PATCH lttng-tools 2/2] Cleanup: remove duplicated implementation of rculfhash
Jérémie Galarneau
jeremie.galarneau at efficios.com
Mon Sep 21 11:29:04 EDT 2015
Delightfully merged in master and stable-2.7 :-)
Thanks!
Jérémie
On Thu, Sep 17, 2015 at 12:48 PM, Mathieu Desnoyers
<mathieu.desnoyers at efficios.com> wrote:
> lttng-tools features a duplicated copy of Userspace RCU rculfhash due to
> interaction issues between runas clone() and internal libc mutexes.
>
> Now that the runas implementation has been changed to use fork() and a
> worker process, we don't need this work-around anymore. Remove the
> duplicated rculfhash to lessen the maintenance burden.
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> ---
> src/common/hashtable/Makefile.am | 7 +-
> src/common/hashtable/hashtable.h | 3 +-
> src/common/hashtable/rculfhash-internal.h | 184 ---
> src/common/hashtable/rculfhash-mm-chunk.c | 99 --
> src/common/hashtable/rculfhash-mm-mmap.c | 162 ---
> src/common/hashtable/rculfhash-mm-order.c | 92 --
> src/common/hashtable/rculfhash.c | 2035 -----------------------------
> src/common/hashtable/rculfhash.h | 480 -------
> src/common/hashtable/urcu-flavor.h | 65 -
> 9 files changed, 2 insertions(+), 3125 deletions(-)
> delete mode 100644 src/common/hashtable/rculfhash-internal.h
> delete mode 100644 src/common/hashtable/rculfhash-mm-chunk.c
> delete mode 100644 src/common/hashtable/rculfhash-mm-mmap.c
> delete mode 100644 src/common/hashtable/rculfhash-mm-order.c
> delete mode 100644 src/common/hashtable/rculfhash.c
> delete mode 100644 src/common/hashtable/rculfhash.h
> delete mode 100644 src/common/hashtable/urcu-flavor.h
>
> diff --git a/src/common/hashtable/Makefile.am b/src/common/hashtable/Makefile.am
> index 021f01c..765f649 100644
> --- a/src/common/hashtable/Makefile.am
> +++ b/src/common/hashtable/Makefile.am
> @@ -4,11 +4,6 @@ noinst_LTLIBRARIES = libhashtable.la
>
> libhashtable_la_SOURCES = hashtable.c hashtable.h \
> utils.c utils.h \
> - rculfhash-internal.h urcu-flavor.h \
> - rculfhash.h rculfhash.c \
> - rculfhash-mm-chunk.c \
> - rculfhash-mm-mmap.c \
> - rculfhash-mm-order.c \
> hashtable-symbols.h
>
> -libhashtable_la_LIBADD = -lurcu-common -lurcu
> +libhashtable_la_LIBADD = -lurcu-common -lurcu -lurcu-cds
> diff --git a/src/common/hashtable/hashtable.h b/src/common/hashtable/hashtable.h
> index 826e120..cf758c0 100644
> --- a/src/common/hashtable/hashtable.h
> +++ b/src/common/hashtable/hashtable.h
> @@ -21,8 +21,7 @@
> #include <urcu.h>
> #include <stdint.h>
>
> -#include "rculfhash.h"
> -#include "rculfhash-internal.h"
> +#include <urcu/rculfhash.h>
>
> extern unsigned long lttng_ht_seed;
>
> diff --git a/src/common/hashtable/rculfhash-internal.h b/src/common/hashtable/rculfhash-internal.h
> deleted file mode 100644
> index e3a59ba..0000000
> --- a/src/common/hashtable/rculfhash-internal.h
> +++ /dev/null
> @@ -1,184 +0,0 @@
> -#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 at efficios.com>
> - * Copyright 2011 - Lai Jiangshan <laijs at 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 <stdio.h>
> -
> -#include "rculfhash.h"
> -
> -#ifdef DEBUG
> -#define dbg_printf(fmt, args...) printf("[debug rculfhash] " fmt, ## args)
> -#else
> -#define dbg_printf(fmt, args...) \
> -do { \
> - /* do nothing but check printf format */ \
> - if (0) \
> - printf("[debug rculfhash] " fmt, ## args); \
> -} while (0)
> -#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 cds_lfht_fls_ulong(unsigned long x);
> -extern int cds_lfht_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 =
> - cds_lfht_get_count_order_ulong(min_nr_alloc_buckets);
> - ht->max_nr_buckets = max_nr_buckets;
> -
> - return ht;
> -}
> -
> -#endif /* _URCU_RCULFHASH_INTERNAL_H */
> diff --git a/src/common/hashtable/rculfhash-mm-chunk.c b/src/common/hashtable/rculfhash-mm-chunk.c
> deleted file mode 100644
> index 2e4e049..0000000
> --- a/src/common/hashtable/rculfhash-mm-chunk.c
> +++ /dev/null
> @@ -1,99 +0,0 @@
> -/*
> - * rculfhash-mm-chunk.c
> - *
> - * Chunk based memory management for Lock-Free RCU Hash Table
> - *
> - * Copyright 2011 - Lai Jiangshan <laijs at 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
> - */
> -
> -#define _GNU_SOURCE
> -#define _LGPL_SOURCE
> -#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,
> -};
> diff --git a/src/common/hashtable/rculfhash-mm-mmap.c b/src/common/hashtable/rculfhash-mm-mmap.c
> deleted file mode 100644
> index cd415db..0000000
> --- a/src/common/hashtable/rculfhash-mm-mmap.c
> +++ /dev/null
> @@ -1,162 +0,0 @@
> -/*
> - * rculfhash-mm-mmap.c
> - *
> - * mmap/reservation based memory management for Lock-Free RCU Hash Table
> - *
> - * Copyright 2011 - Lai Jiangshan <laijs at 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
> - */
> -
> -#define _GNU_SOURCE
> -#define _LGPL_SOURCE
> -#include <unistd.h>
> -#include <sys/mman.h>
> -#include "rculfhash-internal.h"
> -
> -#ifndef MAP_ANONYMOUS
> -#define MAP_ANONYMOUS MAP_ANON
> -#endif
> -
> -/* 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,
> -};
> diff --git a/src/common/hashtable/rculfhash-mm-order.c b/src/common/hashtable/rculfhash-mm-order.c
> deleted file mode 100644
> index 0ce98d7..0000000
> --- a/src/common/hashtable/rculfhash-mm-order.c
> +++ /dev/null
> @@ -1,92 +0,0 @@
> -/*
> - * rculfhash-mm-order.c
> - *
> - * Order based memory management for Lock-Free RCU Hash Table
> - *
> - * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> - * Copyright 2011 - Lai Jiangshan <laijs at 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
> - */
> -
> -#define _GNU_SOURCE
> -#define _LGPL_SOURCE
> -#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 cds_lfht_get_count_order_ulong(index + 1), but
> - * optimizes away the non-existing 0 special-case for
> - * cds_lfht_get_count_order_ulong.
> - */
> - order = cds_lfht_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,
> -};
> diff --git a/src/common/hashtable/rculfhash.c b/src/common/hashtable/rculfhash.c
> deleted file mode 100644
> index 9baf407..0000000
> --- a/src/common/hashtable/rculfhash.c
> +++ /dev/null
> @@ -1,2035 +0,0 @@
> -/*
> - * rculfhash.c
> - *
> - * Userspace RCU library - Lock-Free Resizable RCU Hash Table
> - *
> - * Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> - * Copyright 2011 - Lai Jiangshan <laijs at 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, as well as traversals, and use the returned objects
> - * safely by allowing memory reclaim to take place only after 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 not to
> - * populate a duplicate key if the node key already exists in the hash
> - * table.
> - * - The resize operation executes concurrently with
> - * add/add_unique/add_replace/remove/lookup/traversal.
> - * - 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". These buckets are internal nodes that allow to
> - * perform a fast hash lookup, similarly to a skip list. These
> - * buckets are chained together in the split-ordered list, which
> - * allows recursive expansion by inserting new buckets between the
> - * existing buckets. The split-ordered list allows adding new buckets
> - * between existing buckets as the table needs to grow.
> - * - 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. After setting the "removal" flag,
> - * only the thread which removal is the first to set the "removal
> - * owner" flag (with an xchg) 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 it does not
> - * contain the "removed" node anymore, even if concurrent delete/add
> - * operations are changing the structure of the list concurrently.
> - * - The add operations perform garbage collection of buckets if they
> - * encounter nodes with removed flag set in the bucket where they want
> - * to add their 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.
> - * - There are three memory backends for the hash table buckets: the
> - * "order table", the "chunks", and the "mmap".
> - * - These bucket containers contain a compact version of the hash table
> - * nodes.
> - * - The RCU "order table":
> - * - has a first level table indexed by log2(hash index) which 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).
> - * - The RCU "chunks" is best suited for close interaction with a page
> - * allocator. It uses a linear array as index to "chunks" containing
> - * each the same number of buckets.
> - * - The RCU "mmap" memory backend uses a single memory map to hold
> - * all buckets.
> - * - synchronize_rcu is used to garbage-collect the old bucket node table.
> - *
> - * Ordering Guarantees:
> - *
> - * To discuss these guarantees, we first define "read" operation as any
> - * of the the basic cds_lfht_lookup, cds_lfht_next_duplicate,
> - * cds_lfht_first, cds_lfht_next operation, as well as
> - * cds_lfht_add_unique (failure).
> - *
> - * We define "read traversal" operation as any of the following
> - * group of operations
> - * - cds_lfht_lookup followed by iteration with cds_lfht_next_duplicate
> - * (and/or cds_lfht_next, although less common).
> - * - cds_lfht_add_unique (failure) followed by iteration with
> - * cds_lfht_next_duplicate (and/or cds_lfht_next, although less
> - * common).
> - * - cds_lfht_first followed iteration with cds_lfht_next (and/or
> - * cds_lfht_next_duplicate, although less common).
> - *
> - * We define "write" operations as any of cds_lfht_add,
> - * cds_lfht_add_unique (success), cds_lfht_add_replace, cds_lfht_del.
> - *
> - * When cds_lfht_add_unique succeeds (returns the node passed as
> - * parameter), it acts as a "write" operation. When cds_lfht_add_unique
> - * fails (returns a node different from the one passed as parameter), it
> - * acts as a "read" operation. A cds_lfht_add_unique failure is a
> - * cds_lfht_lookup "read" operation, therefore, any ordering guarantee
> - * referring to "lookup" imply any of "lookup" or cds_lfht_add_unique
> - * (failure).
> - *
> - * We define "prior" and "later" node as nodes observable by reads and
> - * read traversals respectively before and after a write or sequence of
> - * write operations.
> - *
> - * Hash-table operations are often cascaded, for example, the pointer
> - * returned by a cds_lfht_lookup() might be passed to a cds_lfht_next(),
> - * whose return value might in turn be passed to another hash-table
> - * operation. This entire cascaded series of operations must be enclosed
> - * by a pair of matching rcu_read_lock() and rcu_read_unlock()
> - * operations.
> - *
> - * The following ordering guarantees are offered by this hash table:
> - *
> - * A.1) "read" after "write": if there is ordering between a write and a
> - * later read, then the read is guaranteed to see the write or some
> - * later write.
> - * A.2) "read traversal" after "write": given that there is dependency
> - * ordering between reads in a "read traversal", if there is
> - * ordering between a write and the first read of the traversal,
> - * then the "read traversal" is guaranteed to see the write or
> - * some later write.
> - * B.1) "write" after "read": if there is ordering between a read and a
> - * later write, then the read will never see the write.
> - * B.2) "write" after "read traversal": given that there is dependency
> - * ordering between reads in a "read traversal", if there is
> - * ordering between the last read of the traversal and a later
> - * write, then the "read traversal" will never see the write.
> - * C) "write" while "read traversal": if a write occurs during a "read
> - * traversal", the traversal may, or may not, see the write.
> - * D.1) "write" after "write": if there is ordering between a write and
> - * a later write, then the later write is guaranteed to see the
> - * effects of the first write.
> - * D.2) Concurrent "write" pairs: The system will assign an arbitrary
> - * order to any pair of concurrent conflicting writes.
> - * Non-conflicting writes (for example, to different keys) are
> - * unordered.
> - * E) If a grace period separates a "del" or "replace" operation
> - * and a subsequent operation, then that subsequent operation is
> - * guaranteed not to see the removed item.
> - * F) Uniqueness guarantee: given a hash table that does not contain
> - * duplicate items for a given key, there will only be one item in
> - * the hash table after an arbitrary sequence of add_unique and/or
> - * add_replace operations. Note, however, that a pair of
> - * concurrent read operations might well access two different items
> - * with that key.
> - * G.1) If a pair of lookups for a given key are ordered (e.g. by a
> - * memory barrier), then the second lookup will return the same
> - * node as the previous lookup, or some later node.
> - * G.2) A "read traversal" that starts after the end of a prior "read
> - * traversal" (ordered by memory barriers) is guaranteed to see the
> - * same nodes as the previous traversal, or some later nodes.
> - * G.3) Concurrent "read" pairs: concurrent reads are unordered. For
> - * example, if a pair of reads to the same key run concurrently
> - * with an insertion of that same key, the reads remain unordered
> - * regardless of their return values. In other words, you cannot
> - * rely on the values returned by the reads to deduce ordering.
> - *
> - * Progress guarantees:
> - *
> - * * Reads are wait-free. These operations always move forward in the
> - * hash table linked list, and this list has no loop.
> - * * Writes are lock-free. Any retry loop performed by a write operation
> - * is triggered by progress made within another update operation.
> - *
> - * 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:
> - *
> - * The order index is the off-by-one compared 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
> -#define _GNU_SOURCE
> -#include <stdlib.h>
> -#include <errno.h>
> -#include <assert.h>
> -#include <stdio.h>
> -#include <stdint.h>
> -#include <string.h>
> -#include <sched.h>
> -
> -#include "config.h"
> -#include <urcu.h>
> -#include <urcu-call-rcu.h>
> -#include <urcu/arch.h>
> -#include <urcu/uatomic.h>
> -#include <urcu/compiler.h>
> -#include <stdio.h>
> -#include <pthread.h>
> -
> -#include "rculfhash.h"
> -#include "rculfhash-internal.h"
> -#include "urcu-flavor.h"
> -
> -#include <common/common.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.
> - * The "removal owner" flag is used to detect which of the "del"
> - * operation that has set the "removed flag" gets to return the removed
> - * node to its caller. Note that the replace operation does not need to
> - * iteract with the "removal owner" flag, because it validates that
> - * the "removed" flag is not set before performing its cmpxchg.
> - */
> -#define REMOVED_FLAG (1UL << 0)
> -#define BUCKET_FLAG (1UL << 1)
> -#define REMOVAL_OWNER_FLAG (1UL << 2)
> -#define FLAGS_MASK ((1UL << 3) - 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 cds_lfht_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 cds_lfht_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 cds_lfht_get_count_order_ulong(unsigned long x)
> -{
> - if (!x)
> - return -1;
> -
> - return cds_lfht_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;
> -static int split_count_order = -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 << cds_lfht_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;
> - split_count_order =
> - cds_lfht_get_count_order_ulong(split_count_mask + 1);
> - }
> -
> - 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) && !defined(VALGRIND)
> -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 + split_count_order)))
> - return;
> - if (chain_len > 100)
> - dbg_printf("WARNING: large chain length: %u.\n",
> - chain_len);
> - if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD) {
> - int growth;
> -
> - /*
> - * Ideal growth calculated based on chain length.
> - */
> - growth = cds_lfht_get_count_order_u32(chain_len
> - - (CHAIN_LEN_TARGET - 1));
> - if ((ht->flags & CDS_LFHT_ACCOUNTING)
> - && (size << growth)
> - >= (1UL << (COUNT_COMMIT_ORDER
> - + split_count_order))) {
> - /*
> - * If ideal growth expands the hash table size
> - * beyond the "small hash table" sizes, use the
> - * maximum small hash table size to attempt
> - * expanding the hash table. This only applies
> - * when node accounting is available, otherwise
> - * the chain length is used to expand the hash
> - * table in every case.
> - */
> - growth = COUNT_COMMIT_ORDER + split_count_order
> - - cds_lfht_get_count_order_ulong(size);
> - if (growth <= 0)
> - return;
> - }
> - cds_lfht_resize_lazy_grow(ht, size, growth);
> - }
> -}
> -
> -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
> -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
> -int is_removal_owner(struct cds_lfht_node *node)
> -{
> - return ((unsigned long) node) & REMOVAL_OWNER_FLAG;
> -}
> -
> -static
> -struct cds_lfht_node *flag_removal_owner(struct cds_lfht_node *node)
> -{
> - return (struct cds_lfht_node *) (((unsigned long) node) | REMOVAL_OWNER_FLAG);
> -}
> -
> -static
> -struct cds_lfht_node *flag_removed_or_removal_owner(struct cds_lfht_node *node)
> -{
> - return (struct cds_lfht_node *) (((unsigned long) node) | REMOVED_FLAG | REMOVAL_OWNER_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);
> - }
> -}
> -
> -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(old_next == clear_flag(old_next));
> - assert(new_node != old_next);
> - /*
> - * REMOVAL_OWNER flag is _NEVER_ set before the REMOVED
> - * flag. It is either set atomically at the same time
> - * (replace) or after (del).
> - */
> - assert(!is_removal_owner(old_next));
> - new_node->next = 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.
> - * This is a replacement of a node with another node
> - * that has the same value: we are therefore not
> - * removing a value from the hash table. We set both the
> - * REMOVED and REMOVAL_OWNER flags atomically so we own
> - * the node after successful cmpxchg.
> - */
> - ret_next = uatomic_cmpxchg(&old_node->next,
> - old_next, flag_removed_or_removal_owner(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(CMM_LOAD_SHARED(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,
> - unsigned long hash,
> - 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, 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 traversing the table node by
> - * 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)
> -{
> - struct cds_lfht_node *bucket, *next;
> -
> - if (!node) /* Return -ENOENT if asked to delete NULL node */
> - return -ENOENT;
> -
> - /* logically delete the node */
> - assert(!is_bucket(node));
> - assert(!is_removed(node));
> - assert(!is_removal_owner(node));
> -
> - /*
> - * We are first checking if the node had previously been
> - * logically removed (this check is not atomic with setting the
> - * logical removal flag). Return -ENOENT if the node had
> - * previously been removed.
> - */
> - next = CMM_LOAD_SHARED(node->next); /* next is not dereferenced */
> - if (caa_unlikely(is_removed(next)))
> - return -ENOENT;
> - assert(!is_bucket(next));
> - /*
> - * The del operation semantic guarantees a full memory barrier
> - * before the uatomic_or atomic commit of the deletion flag.
> - */
> - cmm_smp_mb__before_uatomic_or();
> - /*
> - * We set the REMOVED_FLAG unconditionally. Note that there may
> - * be more than one concurrent thread setting this flag.
> - * Knowing which wins the race will be known after the garbage
> - * collection phase, stay tuned!
> - */
> - uatomic_or(&node->next, REMOVED_FLAG);
> - /* 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(CMM_LOAD_SHARED(node->next)));
> - /*
> - * Last phase: atomically exchange node->next with a version
> - * having "REMOVAL_OWNER_FLAG" set. If the returned node->next
> - * pointer did _not_ have "REMOVAL_OWNER_FLAG" set, we now own
> - * the node and win the removal race.
> - * It is interesting to note that all "add" paths are forbidden
> - * to change the next pointer starting from the point where the
> - * REMOVED_FLAG is set, so here using a read, followed by a
> - * xchg() suffice to guarantee that the xchg() will ever only
> - * set the "REMOVAL_OWNER_FLAG" (or change nothing if the flag
> - * was already set).
> - */
> - if (!is_removal_owner(uatomic_xchg(&node->next,
> - flag_removal_owner(node->next))))
> - return 0;
> - else
> - return -ENOENT;
> -}
> -
> -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 >> cds_lfht_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, j, 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_bucket = bucket_at(ht, j);
> - struct cds_lfht_node *parent_bucket = bucket_at(ht, j - size);
> -
> - assert(j >= size && j < (size << 1));
> - dbg_printf("remove entry: order %lu index %lu hash %lu\n",
> - i, j, j);
> - /* Set the REMOVED_FLAG to freeze the ->next for gc */
> - uatomic_or(&fini_bucket->next, REMOVED_FLAG);
> - _cds_lfht_gc_bucket(parent_bucket, fini_bucket);
> - }
> - 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 < cds_lfht_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 = cds_lfht_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(CMM_LOAD_SHARED(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(CMM_LOAD_SHARED(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(CMM_LOAD_SHARED(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(hash);
> - size = rcu_dereference(ht->size);
> - _cds_lfht_add(ht, hash, 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(hash);
> - size = rcu_dereference(ht->size);
> - _cds_lfht_add(ht, hash, 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(hash);
> - size = rcu_dereference(ht->size);
> - for (;;) {
> - _cds_lfht_add(ht, hash, 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,
> - unsigned long hash,
> - cds_lfht_match_fct match,
> - const void *key,
> - struct cds_lfht_node *new_node)
> -{
> - unsigned long size;
> -
> - new_node->reverse_hash = bit_reverse_ulong(hash);
> - if (!old_iter->node)
> - return -ENOENT;
> - if (caa_unlikely(old_iter->node->reverse_hash != new_node->reverse_hash))
> - return -EINVAL;
> - if (caa_unlikely(!match(old_iter->node, key)))
> - return -EINVAL;
> - 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_node *node)
> -{
> - unsigned long size, hash;
> - int ret;
> -
> - size = rcu_dereference(ht->size);
> - ret = _cds_lfht_del(ht, size, node);
> - if (!ret) {
> - hash = bit_reverse_ulong(node->reverse_hash);
> - ht_count_del(ht, size, hash);
> - }
> - return ret;
> -}
> -
> -int cds_lfht_is_node_deleted(struct cds_lfht_node *node)
> -{
> - return is_removed(CMM_LOAD_SHARED(node->next));
> -}
> -
> -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 buckets */
> - 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 = cds_lfht_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;
> -#ifdef rcu_read_ongoing_mb
> - int was_online;
> -#endif
> -
> - /* Wait for in-flight resize operations to complete */
> - _CMM_STORE_SHARED(ht->in_progress_destroy, 1);
> - cmm_smp_mb(); /* Store destroy before load resize */
> -#ifdef rcu_read_ongoing_mb
> - was_online = ht->flavor->read_ongoing();
> - if (was_online)
> - ht->flavor->thread_offline();
> - /* Calling with RCU read-side held is an error. */
> - if (ht->flavor->read_ongoing()) {
> - ret = -EINVAL;
> - if (was_online)
> - ht->flavor->thread_online();
> - goto end;
> - }
> -#endif
> - while (uatomic_read(&ht->in_progress_resize))
> - (void) 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);
> -#ifdef rcu_read_ongoing_mb
> -end:
> -#endif
> - return ret;
> -}
> -
> -void cds_lfht_count_nodes(struct cds_lfht *ht,
> - long *approx_before,
> - unsigned long *count,
> - long *approx_after)
> -{
> - struct cds_lfht_node *node, *next;
> - unsigned long nr_bucket = 0, nr_removed = 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;
> -
> - /* 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))
> - (nr_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 logically removed nodes: %lu\n", nr_removed);
> - 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 = cds_lfht_get_count_order_ulong(old_size);
> - new_order = cds_lfht_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 = cds_lfht_get_count_order_ulong(old_size);
> - new_order = cds_lfht_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)
> -{
> -#ifdef rcu_read_ongoing_mb
> - int was_online;
> -
> - was_online = ht->flavor->read_ongoing();
> - if (was_online)
> - ht->flavor->thread_offline();
> - /* Calling with RCU read-side held is an error. */
> - if (ht->flavor->read_ongoing()) {
> - static int print_once;
> -
> - if (!CMM_LOAD_SHARED(print_once))
> - fprintf(stderr, "[error] rculfhash: cds_lfht_resize "
> - "called with RCU read-side lock held.\n");
> - CMM_STORE_SHARED(print_once, 1);
> - assert(0);
> - goto end;
> - }
> -#endif
> - resize_target_update_count(ht, new_size);
> - CMM_STORE_SHARED(ht->resize_initiated, 1);
> - pthread_mutex_lock(&ht->resize_mutex);
> - _do_cds_lfht_resize(ht);
> - pthread_mutex_unlock(&ht->resize_mutex);
> -#ifdef rcu_read_ongoing_mb
> -end:
> - if (was_online)
> - ht->flavor->thread_online();
> -#endif
> -}
> -
> -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 = zmalloc(sizeof(*work));
> - if (work == NULL) {
> - dbg_printf("error allocating resize work, bailing out\n");
> - uatomic_dec(&ht->in_progress_resize);
> - return;
> - }
> - 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);
> -}
> diff --git a/src/common/hashtable/rculfhash.h b/src/common/hashtable/rculfhash.h
> deleted file mode 100644
> index adb5d9d..0000000
> --- a/src/common/hashtable/rculfhash.h
> +++ /dev/null
> @@ -1,480 +0,0 @@
> -#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 at efficios.com>
> - * Copyright 2011 - Lai Jiangshan <laijs at 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 "hashtable-symbols.h"
> -
> -#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 8-bytes boundaries because
> - * the three lower bits are used as flags. It is worth noting that the
> - * information contained within these three bits could be represented on
> - * two bits by re-using the same bit for REMOVAL_OWNER_FLAG and
> - * BUCKET_FLAG. This can be done if we ensure that no iterator nor
> - * updater check the BUCKET_FLAG after it detects that the REMOVED_FLAG
> - * is set. Given the minimum size of struct cds_lfht_node is 8 bytes on
> - * 32-bit architectures, we choose to go for simplicity and reserve
> - * three bits.
> - *
> - * 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 | REMOVAL_OWNER_FLAG | BUCKET_FLAG | REMOVED_FLAG */
> - unsigned long reverse_hash;
> -} __attribute__((aligned(8)));
> -
> -/* 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 cds_lfht_new are NOT required to be registered RCU
> - * read-side threads. It can be called very early. (e.g. before RCU is
> - * initialized)
> - */
> -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.
> - * cds_lfht_destroy should *not* be called from a RCU read-side critical
> - * section.
> - */
> -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.
> - * @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,
> - 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.
> - * This function acts as a rcu_dereference() to read the node pointer.
> - */
> -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 iterator.
> - * @ht: the hash table.
> - * @match: the key match function.
> - * @key: the current node key.
> - * @iter: input: current iterator.
> - * output: node, if found. *iter->node set to NULL if not found.
> - *
> - * Uses an iterator initialized by a lookup or traversal. Important: the
> - * iterator _needs_ to be initialized before calling
> - * cds_lfht_next_duplicate.
> - * 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.
> - * This function acts as a rcu_dereference() to read the node pointer.
> - */
> -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.
> - * This function acts as a rcu_dereference() to read the node pointer.
> - */
> -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: input: current iterator.
> - * output: next node, if exists. *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.
> - * This function acts as a rcu_dereference() to read the node pointer.
> - */
> -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.
> - * This function issues a full memory barrier before and after its
> - * atomic commit.
> - */
> -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. In this case, the caller does NOT need to wait
> - * for a grace period before freeing the node.
> - * 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).
> - *
> - * Upon success, this function issues a full memory barrier before and
> - * after its atomic commit. Upon failure, this function acts like a
> - * simple lookup operation: it acts as a rcu_dereference() to read the
> - * node pointer. The failure case does not guarantee any other memory
> - * barrier.
> - */
> -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 and traversals is the
> - * following: if lookups and traversals are performed between a key
> - * unique insertion and its removal, we guarantee that the lookups and
> - * traversals 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.
> - *
> - * This function issues a full memory barrier before and after its
> - * atomic commit.
> - */
> -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 pointed to by iter within hash table.
> - * @ht: the hash table.
> - * @old_iter: the iterator position of the node to replace.
> - * @hash: the node's hash.
> - * @match: the key match function.
> - * @key: the node's key.
> - * @new_node: the new node to use as replacement.
> - *
> - * Return 0 if replacement is successful, negative value otherwise.
> - * Replacing a NULL old node or an already removed node will fail with
> - * -ENOENT.
> - * If the hash or value of the node to replace and the new node differ,
> - * this function returns -EINVAL without proceeding to the replacement.
> - * 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 same as
> - * cds_lfht_add_replace().
> - *
> - * Upon success, this function issues a full memory barrier before and
> - * after its atomic commit. Upon failure, this function does not issue
> - * any memory barrier.
> - */
> -int cds_lfht_replace(struct cds_lfht *ht,
> - struct cds_lfht_iter *old_iter,
> - unsigned long hash,
> - cds_lfht_match_fct match,
> - const void *key,
> - struct cds_lfht_node *new_node);
> -
> -/*
> - * cds_lfht_del - remove node pointed to by iterator from hash table.
> - * @ht: the hash table.
> - * @node: the node to delete.
> - *
> - * Return 0 if the node is successfully removed, negative value
> - * otherwise.
> - * Deleting 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,
> - * followed by use of 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).
> - * Upon success, this function issues a full memory barrier before and
> - * after its atomic commit. Upon failure, this function does not issue
> - * any memory barrier.
> - */
> -int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_node *node);
> -
> -/*
> - * cds_lfht_is_node_deleted - query whether a node is removed from hash table.
> - *
> - * Return non-zero if the node is deleted from the hash table, 0
> - * otherwise.
> - * Node can be looked up with cds_lfht_lookup and cds_lfht_next,
> - * followed by use of cds_lfht_iter_get_node.
> - * RCU read-side lock must be held between lookup and call to this
> - * function.
> - * Call with rcu_read_lock held.
> - * Threads calling this API need to be registered RCU read-side threads.
> - * This function does not issue any memory barrier.
> - */
> -int cds_lfht_is_node_deleted(struct cds_lfht_node *node);
> -
> -/*
> - * 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.
> - * This function does not (necessarily) issue memory barriers.
> - * cds_lfht_resize should *not* be called from a RCU read-side critical
> - * section.
> - */
> -void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size);
> -
> -/*
> - * Note: it is safe to perform element removal (del), replacement, or
> - * any hash table update operation during any of the following hash
> - * table traversals.
> - * These functions act as rcu_dereference() to read the node pointers.
> - */
> -#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); \
> - cds_lfht_iter_get_node(iter) != 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); \
> - cds_lfht_iter_get_node(iter) != 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 */
> diff --git a/src/common/hashtable/urcu-flavor.h b/src/common/hashtable/urcu-flavor.h
> deleted file mode 100644
> index 9af4d0e..0000000
> --- a/src/common/hashtable/urcu-flavor.h
> +++ /dev/null
> @@ -1,65 +0,0 @@
> -#ifndef _URCU_FLAVOR_H
> -#define _URCU_FLAVOR_H
> -
> -/*
> - * urcu-flavor.h
> - *
> - * Userspace RCU header - rcu flavor declarations
> - *
> - * Copyright (c) 2011 Lai Jiangshan <laijs at 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(x) \
> -const struct rcu_flavor_struct x = { \
> - .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 */
> --
> 2.1.4
>
--
Jérémie Galarneau
EfficiOS Inc.
http://www.efficios.com
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