+// SPDX-FileCopyrightText: 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+// SPDX-FileCopyrightText: 2011 Lai Jiangshan <laijs@cn.fujitsu.com>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
#ifndef _URCU_RCULFHASH_H
#define _URCU_RCULFHASH_H
/*
- * urcu/rculfhash.h
- *
* Userspace RCU library - Lock-Free RCU Hash Table
*
- * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
* For use with URCU_API_MAP (API mapping of liburcu), include this file
* _after_ including your URCU flavor.
*/
+#include <urcu/config.h>
#include <stdint.h>
#include <pthread.h>
#include <urcu/compiler.h>
extern "C" {
#endif
+struct cds_lfht;
+
/*
* cds_lfht_node: Contains the next pointers and reverse-hash
* value required for lookup and traversal of the hash table.
/* cds_lfht_iter: Used to track state while traversing a hash chain. */
struct cds_lfht_iter {
struct cds_lfht_node *node, *next;
+ /*
+ * For debugging purposes, build both API users and rculfhash
+ * library with CDS_LFHT_ITER_DEBUG defined. This enables extra
+ * consistency checks for calls to a cds_lfht_next() or
+ * cds_lfht_next_duplicate() after the iterator has been
+ * re-purposed to iterate on a different hash table. This is a
+ * common programming mistake when performing hash table lookup
+ * nested in a hash table traversal.
+ */
+#ifdef CONFIG_CDS_LFHT_ITER_DEBUG
+ struct cds_lfht *lfht;
+#endif
+};
+
+/*
+ * cds_lfht_alloc: Callbacks if we want to use custom memory allocator.
+ */
+struct cds_lfht_alloc {
+ void *(*malloc)(void *state, size_t size);
+ void *(*calloc)(void *state, size_t nmemb, size_t size);
+ void *(*realloc)(void *state, void *ptr, size_t size);
+ void *(*aligned_alloc)(void *state, size_t alignment, size_t size);
+ void (*free)(void *state, void *ptr);
+ void *state;
};
static inline
return iter->node;
}
-struct cds_lfht;
struct rcu_flavor_struct;
/*
* (detection of memory corruption).
*/
static inline
-void cds_lfht_node_init(struct cds_lfht_node *node)
+void cds_lfht_node_init(struct cds_lfht_node *node __attribute__((unused)))
{
}
+/*
+ * cds_lfht_node_init_deleted - initialize a hash table node to "removed" state
+ * @node: the node to initialize.
+ *
+ * Initialize the node such that cds_lfht_is_node_deleted() can be used
+ * on the node before it is added to a hash table.
+ */
+extern
+void cds_lfht_node_init_deleted(struct cds_lfht_node *node);
+
/*
* Hash table creation flags.
*/
struct cds_lfht_mm_type {
struct cds_lfht *(*alloc_cds_lfht)(unsigned long min_nr_alloc_buckets,
- unsigned long max_nr_buckets);
+ unsigned long max_nr_buckets, const struct cds_lfht_alloc *alloc);
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,
const struct rcu_flavor_struct *flavor,
pthread_attr_t *attr);
+/*
+ * _cds_lfht_new_with_alloc - API used by cds_lfht_new_with_flavor_alloc.
+ */
+extern
+struct cds_lfht *_cds_lfht_new_with_alloc(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,
+ const struct cds_lfht_alloc *alloc,
+ pthread_attr_t *attr);
+
/*
* cds_lfht_new_flavor - allocate a hash table tied to a RCU flavor.
* @init_size: number of buckets to allocate initially. Must be power of two.
flags, NULL, flavor, attr);
}
+/*
+ * cds_lfht_new_with_flavor_alloc - allocate a hash table tied to a RCU flavor.
+ * @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, 0 is accepted, means
+ * "infinite")
+ * @flavor: flavor of liburcu to use to synchronize the hash table
+ * @alloc: Custom memory allocator for hash table memory management.
+ * NULL for default. If a custom allocator is used, then
+ * the whole interface of struct cds_lfht_alloc must be implemented.
+ * @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_with_flavor_alloc(unsigned long init_size,
+ unsigned long min_nr_alloc_buckets,
+ unsigned long max_nr_buckets,
+ int flags,
+ const struct rcu_flavor_struct *flavor,
+ const struct cds_lfht_alloc *alloc,
+ pthread_attr_t *attr)
+{
+ return _cds_lfht_new_with_alloc(init_size, min_nr_alloc_buckets, max_nr_buckets,
+ flags, NULL, flavor, alloc, attr);
+}
+
#ifdef URCU_API_MAP
/*
*
* Return 0 on success, negative error value on error.
+ * Threads calling this API need to be registered RCU read-side threads.
+ *
* Prior to liburcu 0.10:
- * - 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. It should *not* be called from a call_rcu thread
* context neither.
*
* Starting from liburcu 0.10, rculfhash implements its own worker
- * thread to handle resize operations, which removes RCU requirements on
- * cds_lfht_destroy.
+ * thread to handle resize operations, which removes the above RCU
+ * read-side critical section requirement on cds_lfht_destroy.
*/
extern
int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
* This function does not issue any memory barrier.
*/
extern
-int cds_lfht_is_node_deleted(struct cds_lfht_node *node);
+int cds_lfht_is_node_deleted(const struct cds_lfht_node *node);
/*
* cds_lfht_resize - Force a hash table resize
cds_lfht_next_duplicate(ht, match, key, iter), \
node = cds_lfht_iter_get_node(iter))
+#define cds_lfht_entry(ptr, type, member) \
+ caa_container_of_check_null(ptr, type, member)
+
#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; \
+ pos = cds_lfht_entry(cds_lfht_iter_get_node(iter), \
+ __typeof__(*(pos)), member); \
+ pos != NULL; \
cds_lfht_next(ht, iter), \
- pos = caa_container_of(cds_lfht_iter_get_node(iter), \
- __typeof__(*(pos)), member))
+ pos = cds_lfht_entry(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; \
+ pos = cds_lfht_entry(cds_lfht_iter_get_node(iter), \
+ __typeof__(*(pos)), member); \
+ pos != NULL; \
cds_lfht_next_duplicate(ht, match, key, iter), \
- pos = caa_container_of(cds_lfht_iter_get_node(iter), \
- __typeof__(*(pos)), member))
+ pos = cds_lfht_entry(cds_lfht_iter_get_node(iter), \
+ __typeof__(*(pos)), member))
#ifdef __cplusplus
}