X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=rculfhash.c;h=6c648f17da8a939d22894067eb1cc8c24620a8e0;hp=18cead30cce6d015064ab965e96a552b6237fb9b;hb=c0b8a8653e108be201ae8d1ca9918461c97d45ed;hpb=7b17c13e2d72075cb69de724b9845e5a2b8826e9 diff --git a/rculfhash.c b/rculfhash.c index 18cead3..6c648f1 100644 --- a/rculfhash.c +++ b/rculfhash.c @@ -165,15 +165,10 @@ #include #include #include +#include #include #include -#ifdef DEBUG -#define dbg_printf(fmt, args...) printf("[debug rculfhash] " fmt, ## args) -#else -#define dbg_printf(fmt, args...) -#endif - /* * Split-counters lazily update the global counter each 1024 * addition/removal. It automatically keeps track of resize required. @@ -191,26 +186,12 @@ #define MIN_TABLE_ORDER 0 #define MIN_TABLE_SIZE (1UL << MIN_TABLE_ORDER) -#if (CAA_BITS_PER_LONG == 32) -#define MAX_TABLE_ORDER 32 -#else -#define MAX_TABLE_ORDER 64 -#endif - /* * 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) -#ifndef min -#define min(a, b) ((a) < (b) ? (a) : (b)) -#endif - -#ifndef max -#define max(a, b) ((a) > (b) ? (a) : (b)) -#endif - /* * The removed flag needs to be updated atomically with the pointer. * It indicates that no node must attach to the node scheduled for @@ -239,52 +220,6 @@ struct ht_items_count { unsigned long add, del; } __attribute__((aligned(CAA_CACHE_LINE_SIZE))); -/* - * rcu_table: Contains the size and desired new size if a resize - * operation is in progress, as well as the statically-sized array of - * bucket table pointers. - */ -struct rcu_table { - unsigned long size; /* always a power of 2, shared (RCU) */ - unsigned long resize_target; - int resize_initiated; - - /* - * 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 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[MAX_TABLE_ORDER]; -}; - -/* - * 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 { - struct rcu_table t; - unsigned long min_alloc_buckets_order; - unsigned long min_nr_alloc_buckets; - unsigned long max_nr_buckets; - int flags; - /* - * 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 */ - unsigned int in_progress_resize, in_progress_destroy; - const struct rcu_flavor_struct *flavor; - pthread_attr_t *resize_attr; /* Resize threads attributes */ - long count; /* global approximate item count */ - struct ht_items_count *split_count; /* split item count */ -}; - /* * rcu_resize_work: Contains arguments passed to RCU worker thread * responsible for performing lazy resize. @@ -307,15 +242,6 @@ struct partition_resize_work { unsigned long start, unsigned long len); }; -static -void _cds_lfht_add(struct cds_lfht *ht, - cds_lfht_match_fct match, - const void *key, - unsigned long size, - struct cds_lfht_node *node, - struct cds_lfht_iter *unique_ret, - int bucket); - /* * Algorithm to reverse bits in a word by lookup table, extended to * 64-bit words. @@ -512,18 +438,6 @@ int get_count_order_ulong(unsigned long x) return fls_ulong(x - 1); } -#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 void cds_lfht_resize_lazy_grow(struct cds_lfht *ht, unsigned long size, int growth); @@ -613,26 +527,28 @@ 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_unlikely(!(split_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) { - long count; - - dbg_printf("add split count %lu\n", split_count); - count = uatomic_add_return(&ht->count, - 1UL << COUNT_COMMIT_ORDER); - /* If power of 2 */ - if (!(count & (count - 1))) { - 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)); - } - } + 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 @@ -640,32 +556,34 @@ 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_unlikely(!(split_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) { - long count; - - dbg_printf("del split count %lu\n", split_count); - count = uatomic_add_return(&ht->count, - -(1UL << COUNT_COMMIT_ORDER)); - /* If power of 2 */ - if (!(count & (count - 1))) { - 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)); - } - } + 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 @@ -750,16 +668,7 @@ unsigned long _uatomic_xchg_monotonic_increase(unsigned long *ptr, static void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order) { - if (order == 0) { - ht->t.tbl[0] = calloc(ht->min_nr_alloc_buckets, - sizeof(struct cds_lfht_node)); - assert(ht->t.tbl[0]); - } else if (order > ht->min_alloc_buckets_order) { - ht->t.tbl[order] = calloc(1UL << (order -1), - sizeof(struct cds_lfht_node)); - assert(ht->t.tbl[order]); - } - /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */ + return ht->mm->alloc_bucket_table(ht, order); } /* @@ -770,32 +679,13 @@ void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order) static void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order) { - if (order == 0) - poison_free(ht->t.tbl[0]); - else if (order > ht->min_alloc_buckets_order) - poison_free(ht->t.tbl[order]); - /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */ + return ht->mm->free_bucket_table(ht, order); } static inline struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index) { - unsigned long order; - - if ((__builtin_constant_p(index) && index == 0) - || index < ht->min_nr_alloc_buckets) { - dbg_printf("bucket index %lu order 0 aridx 0\n", index); - return &ht->t.tbl[0][index]; - } - /* - * equivalent to get_count_order_ulong(index + 1), but optimizes - * away the non-existing 0 special-case for - * get_count_order_ulong. - */ - order = fls_ulong(index); - dbg_printf("bucket index %lu order %lu aridx %lu\n", - index, order, index & ((1UL << (order - 1)) - 1)); - return &ht->t.tbl[order][index & ((1UL << (order - 1)) - 1)]; + return ht->bucket_at(ht, index); } static inline @@ -1177,7 +1067,7 @@ void init_table(struct cds_lfht *ht, dbg_printf("init order %lu len: %lu\n", i, len); /* Stop expand if the resize target changes under us */ - if (CMM_LOAD_SHARED(ht->t.resize_target) < (1UL << i)) + if (CMM_LOAD_SHARED(ht->resize_target) < (1UL << i)) break; cds_lfht_alloc_bucket_table(ht, i); @@ -1192,7 +1082,7 @@ void init_table(struct cds_lfht *ht, * Update table size. */ cmm_smp_wmb(); /* populate data before RCU size */ - CMM_STORE_SHARED(ht->t.size, 1UL << i); + CMM_STORE_SHARED(ht->size, 1UL << i); dbg_printf("init new size: %lu\n", 1UL << i); if (CMM_LOAD_SHARED(ht->in_progress_destroy)) @@ -1259,6 +1149,11 @@ void remove_table(struct cds_lfht *ht, unsigned long i, unsigned long len) 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) @@ -1276,11 +1171,11 @@ void fini_table(struct cds_lfht *ht, dbg_printf("fini order %lu len: %lu\n", i, len); /* Stop shrink if the resize target changes under us */ - if (CMM_LOAD_SHARED(ht->t.resize_target) > (1UL << (i - 1))) + if (CMM_LOAD_SHARED(ht->resize_target) > (1UL << (i - 1))) break; cmm_smp_wmb(); /* populate data before RCU size */ - CMM_STORE_SHARED(ht->t.size, 1UL << (i - 1)); + CMM_STORE_SHARED(ht->size, 1UL << (i - 1)); /* * We need to wait for all add operations to reach Q.S. (and @@ -1361,6 +1256,7 @@ 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) { @@ -1375,7 +1271,8 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_size, if (!init_size || (init_size & (init_size - 1))) return NULL; - if (!max_nr_buckets) + /* 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 */ @@ -1386,8 +1283,12 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_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 = calloc(1, sizeof(struct cds_lfht)); + + 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; @@ -1395,12 +1296,9 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_size, /* this mutex should not nest in read-side C.S. */ pthread_mutex_init(&ht->resize_mutex, NULL); order = get_count_order_ulong(init_size); - ht->t.resize_target = 1UL << order; - ht->min_nr_alloc_buckets = min_nr_alloc_buckets; - ht->min_alloc_buckets_order = get_count_order_ulong(min_nr_alloc_buckets); - ht->max_nr_buckets = max_nr_buckets; + ht->resize_target = 1UL << order; cds_lfht_create_bucket(ht, 1UL << order); - ht->t.size = 1UL << order; + ht->size = 1UL << order; return ht; } @@ -1413,7 +1311,7 @@ void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash, reverse_hash = bit_reverse_ulong(hash); - size = rcu_dereference(ht->t.size); + size = rcu_dereference(ht->size); bucket = lookup_bucket(ht, size, hash); /* We can always skip the bucket node initially */ node = rcu_dereference(bucket->next); @@ -1513,7 +1411,7 @@ void cds_lfht_add(struct cds_lfht *ht, unsigned long hash, unsigned long size; node->reverse_hash = bit_reverse_ulong((unsigned long) hash); - size = rcu_dereference(ht->t.size); + size = rcu_dereference(ht->size); _cds_lfht_add(ht, NULL, NULL, size, node, NULL, 0); ht_count_add(ht, size, hash); } @@ -1528,7 +1426,7 @@ struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht, struct cds_lfht_iter iter; node->reverse_hash = bit_reverse_ulong((unsigned long) hash); - size = rcu_dereference(ht->t.size); + size = rcu_dereference(ht->size); _cds_lfht_add(ht, match, key, size, node, &iter, 0); if (iter.node == node) ht_count_add(ht, size, hash); @@ -1545,7 +1443,7 @@ struct cds_lfht_node *cds_lfht_add_replace(struct cds_lfht *ht, struct cds_lfht_iter iter; node->reverse_hash = bit_reverse_ulong((unsigned long) hash); - size = rcu_dereference(ht->t.size); + size = rcu_dereference(ht->size); for (;;) { _cds_lfht_add(ht, match, key, size, node, &iter, 0); if (iter.node == node) { @@ -1563,7 +1461,7 @@ int cds_lfht_replace(struct cds_lfht *ht, struct cds_lfht_iter *old_iter, { unsigned long size; - size = rcu_dereference(ht->t.size); + size = rcu_dereference(ht->size); return _cds_lfht_replace(ht, size, old_iter->node, old_iter->next, new_node); } @@ -1573,7 +1471,7 @@ int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_iter *iter) unsigned long size, hash; int ret; - size = rcu_dereference(ht->t.size); + size = rcu_dereference(ht->size); ret = _cds_lfht_del(ht, size, iter->node, 0); if (!ret) { hash = bit_reverse_ulong(iter->node->reverse_hash); @@ -1600,7 +1498,7 @@ int cds_lfht_delete_bucket(struct cds_lfht *ht) * size accessed without rcu_dereference because hash table is * being destroyed. */ - size = ht->t.size; + size = ht->size; /* Internal sanity check: all nodes left should be bucket */ for (i = 0; i < size; i++) { node = bucket_at(ht, i); @@ -1734,23 +1632,23 @@ void _do_cds_lfht_resize(struct cds_lfht *ht) assert(uatomic_read(&ht->in_progress_resize)); if (CMM_LOAD_SHARED(ht->in_progress_destroy)) break; - ht->t.resize_initiated = 1; - old_size = ht->t.size; - new_size = CMM_LOAD_SHARED(ht->t.resize_target); + 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->t.resize_initiated = 0; + ht->resize_initiated = 0; /* write resize_initiated before read resize_target */ cmm_smp_mb(); - } while (ht->t.size != CMM_LOAD_SHARED(ht->t.resize_target)); + } 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->t.resize_target, new_size); + return _uatomic_xchg_monotonic_increase(&ht->resize_target, new_size); } static @@ -1759,13 +1657,13 @@ void resize_target_update_count(struct cds_lfht *ht, { count = max(count, MIN_TABLE_SIZE); count = min(count, ht->max_nr_buckets); - uatomic_set(&ht->t.resize_target, count); + uatomic_set(&ht->resize_target, count); } void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size) { resize_target_update_count(ht, new_size); - CMM_STORE_SHARED(ht->t.resize_initiated, 1); + CMM_STORE_SHARED(ht->resize_initiated, 1); ht->flavor->thread_offline(); pthread_mutex_lock(&ht->resize_mutex); _do_cds_lfht_resize(ht); @@ -1797,7 +1695,7 @@ void __cds_lfht_resize_lazy_launch(struct cds_lfht *ht) /* Store resize_target before read resize_initiated */ cmm_smp_mb(); - if (!CMM_LOAD_SHARED(ht->t.resize_initiated)) { + 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)) { @@ -1807,7 +1705,7 @@ void __cds_lfht_resize_lazy_launch(struct cds_lfht *ht) work = malloc(sizeof(*work)); work->ht = ht; ht->flavor->update_call_rcu(&work->head, do_resize_cb); - CMM_STORE_SHARED(ht->t.resize_initiated, 1); + CMM_STORE_SHARED(ht->resize_initiated, 1); } } @@ -1845,7 +1743,7 @@ void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size, for (;;) { unsigned long s; - s = uatomic_cmpxchg(&ht->t.resize_target, size, count); + s = uatomic_cmpxchg(&ht->resize_target, size, count); if (s == size) break; /* no resize needed */ if (s > size)