[urcu.git] / rculfhash-internal.h

#ifndef _URCU_RCULFHASH_INTERNAL_H
#define _URCU_RCULFHASH_INTERNAL_H

/*
 * urcu/rculfhash-internal.h
 *
 * Internal header for Lock-Free RCU Hash Table
 *
 * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <urcu/rculfhash.h>

#ifdef DEBUG
#define dbg_printf(fmt, args...)     printf("[debug rculfhash] " fmt, ## args)
#else
#define dbg_printf(fmt, args...)
#endif

#if (CAA_BITS_PER_LONG == 32)
#define MAX_TABLE_ORDER			32
#else
#define MAX_TABLE_ORDER			64
#endif

#define MAX_CHUNK_TABLE			(1UL << 10)

#ifndef min
#define min(a, b)	((a) < (b) ? (a) : (b))
#endif

#ifndef max
#define max(a, b)	((a) > (b) ? (a) : (b))
#endif

struct ht_items_count;

/*
 * cds_lfht: Top-level data structure representing a lock-free hash
 * table. Defined in the implementation file to make it be an opaque
 * cookie to users.
 */
struct cds_lfht {
	/*
	 * Variables needed for the lookup, add and remove fast-paths.
	 */
	unsigned long size;	/* always a power of 2, shared (RCU) */
	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;
	};
	/*
	 * 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);
	/*
	 * End of variables needed for lookup fast-path.
	 */

	struct ht_items_count *split_count;	/* split item count */
	/*
	 * End of variables needed for add/remove fast-path.
	 */

	/* Initial configuration items */
	int flags;
	unsigned long min_alloc_buckets_order;
	unsigned long min_nr_alloc_buckets;
	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;
};

extern unsigned int fls_ulong(unsigned long x);
extern int get_count_order_ulong(unsigned long x);

#ifdef POISON_FREE
#define poison_free(ptr)					\
	do {							\
		if (ptr) {					\
			memset(ptr, 0x42, sizeof(*(ptr)));	\
			free(ptr);				\
		}						\
	} while (0)
#else
#define poison_free(ptr)	free(ptr)
#endif

#endif /* _URCU_RCULFHASH_INTERNAL_H */
Commit	Line	Data
0b6aa001 LJ	1	#ifndef _URCU_RCULFHASH_INTERNAL_H
	2	#define _URCU_RCULFHASH_INTERNAL_H
	3
	4	/*
	5	* urcu/rculfhash-internal.h
	6	*
	7	* Internal header for Lock-Free RCU Hash Table
	8	*
	9	* Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	* Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
	11	*
	12	* This library is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU Lesser General Public
	14	* License as published by the Free Software Foundation; either
	15	* version 2.1 of the License, or (at your option) any later version.
	16	*
	17	* This library is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	20	* Lesser General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU Lesser General Public
	23	* License along with this library; if not, write to the Free Software
	24	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	25	*/
	26
	27	#include <urcu/rculfhash.h>
	28
	29	#ifdef DEBUG
	30	#define dbg_printf(fmt, args...) printf("[debug rculfhash] " fmt, ## args)
	31	#else
	32	#define dbg_printf(fmt, args...)
	33	#endif
	34
	35	#if (CAA_BITS_PER_LONG == 32)
	36	#define MAX_TABLE_ORDER 32
	37	#else
	38	#define MAX_TABLE_ORDER 64
	39	#endif
	40
308d1cb3 LJ	41	#define MAX_CHUNK_TABLE (1UL << 10)
308d1cb3 LJ	42
0b6aa001 LJ	43	#ifndef min
	44	#define min(a, b) ((a) < (b) ? (a) : (b))
	45	#endif
	46
	47	#ifndef max
	48	#define max(a, b) ((a) > (b) ? (a) : (b))
	49	#endif
	50
	51	struct ht_items_count;
	52
	53	/*
	54	* cds_lfht: Top-level data structure representing a lock-free hash
	55	* table. Defined in the implementation file to make it be an opaque
	56	* cookie to users.
	57	*/
	58	struct cds_lfht {
0b6aa001	59	/*
3fd3f554	60	* Variables needed for the lookup, add and remove fast-paths.
0b6aa001	61	*/
3fd3f554	62	unsigned long size; /* always a power of 2, shared (RCU) */
0b6aa001 LJ	63	union {
	64	/*
	65	* Contains the per order-index-level bucket node table.
	66	* The size of each bucket node table is half the number
	67	* of hashes contained in this order (except for order 0).
	68	* The minimum allocation buckets size parameter allows
	69	* combining the bucket node arrays of the lowermost
	70	* levels to improve cache locality for small index orders.
	71	*/
	72	struct cds_lfht_node *tbl_order[MAX_TABLE_ORDER];
308d1cb3 LJ	73
	74	/*
	75	* Contains the bucket node chunks. The size of each
	76	* bucket node chunk is ->min_alloc_size (we avoid to
	77	* allocate chunks with different size). Chunks improve
	78	* cache locality for small index orders, and are more
	79	* friendly with environments where allocation of large
	80	* contiguous memory areas is challenging due to memory
	81	* fragmentation concerns or inability to use virtual
	82	* memory addressing.
	83	*/
	84	struct cds_lfht_node *tbl_chunk[0];
b0b55251 LJ	85
	86	/*
	87	* Memory mapping with room for all possible buckets.
	88	* Their memory is allocated when needed.
	89	*/
	90	struct cds_lfht_node *tbl_mmap;
0b6aa001	91	};
3fd3f554 MD	92	/*
	93	* bucket_at pointer is kept here to skip the extra level of
	94	* dereference needed to get to "mm" (this is a fast-path).
	95	*/
	96	struct cds_lfht_node (bucket_at)(struct cds_lfht *ht,
	97	unsigned long index);
	98	/*
	99	* End of variables needed for lookup fast-path.
	100	*/
	101
	102	struct ht_items_count split_count; / split item count */
	103	/*
	104	* End of variables needed for add/remove fast-path.
	105	*/
	106
	107	/* Initial configuration items */
	108	int flags;
	109	unsigned long min_alloc_buckets_order;
	110	unsigned long min_nr_alloc_buckets;
	111	unsigned long max_nr_buckets;
	112	const struct cds_lfht_mm_type mm; / memory management plugin */
	113	const struct rcu_flavor_struct flavor; / RCU flavor */
	114
	115	long count; /* global approximate item count */
	116
	117	/*
	118	* We need to put the work threads offline (QSBR) when taking this
	119	* mutex, because we use synchronize_rcu within this mutex critical
	120	* section, which waits on read-side critical sections, and could
	121	* therefore cause grace-period deadlock if we hold off RCU G.P.
	122	* completion.
	123	*/
	124	pthread_mutex_t resize_mutex; /* resize mutex: add/del mutex */
	125	pthread_attr_t resize_attr; / Resize threads attributes */
	126	unsigned int in_progress_resize, in_progress_destroy;
	127	unsigned long resize_target;
	128	int resize_initiated;
0b6aa001 LJ	129	};
	130
	131	extern unsigned int fls_ulong(unsigned long x);
	132	extern int get_count_order_ulong(unsigned long x);
	133
	134	#ifdef POISON_FREE
	135	#define poison_free(ptr) \
	136	do { \
	137	if (ptr) { \
	138	memset(ptr, 0x42, sizeof(*(ptr))); \
	139	free(ptr); \
	140	} \
	141	} while (0)
	142	#else
	143	#define poison_free(ptr) free(ptr)
	144	#endif
	145
	146	#endif /* _URCU_RCULFHASH_INTERNAL_H */