src/rculfhash-mm-order.c

   1 // SPDX-FileCopyrightText: 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   2 // SPDX-FileCopyrightText: 2011 Lai Jiangshan <laijs@cn.fujitsu.com>
   3 //
   4 // SPDX-License-Identifier: LGPL-2.1-or-later
   5
   6 /*
   7  * Order based memory management for Lock-Free RCU Hash Table
   8  */
   9
  10 #include <urcu/assert.h>
  11 #include "rculfhash-internal.h"
  12
  13 static
  14 void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order)
  15 {
  16         if (order == 0) {
  17                 ht->tbl_order[0] = ht->alloc->calloc(ht->alloc->state,
  18                         ht->min_nr_alloc_buckets, sizeof(struct cds_lfht_node));
  19                 urcu_posix_assert(ht->tbl_order[0]);
  20         } else if (order > ht->min_alloc_buckets_order) {
  21                 ht->tbl_order[order] = ht->alloc->calloc(ht->alloc->state,
  22                         1UL << (order -1), sizeof(struct cds_lfht_node));
  23                 urcu_posix_assert(ht->tbl_order[order]);
  24         }
  25         /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
  26 }
  27
  28 /*
  29  * cds_lfht_free_bucket_table() should be called with decreasing order.
  30  * When cds_lfht_free_bucket_table(0) is called, it means the whole
  31  * lfht is destroyed.
  32  */
  33 static
  34 void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order)
  35 {
  36         if (order == 0)
  37                 poison_free(ht->alloc, ht->tbl_order[0]);
  38         else if (order > ht->min_alloc_buckets_order)
  39                 poison_free(ht->alloc, ht->tbl_order[order]);
  40         /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
  41 }
  42
  43 static
  44 struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index)
  45 {
  46         unsigned long order;
  47
  48         if (index < ht->min_nr_alloc_buckets) {
  49                 dbg_printf("bucket index %lu order 0 aridx 0\n", index);
  50                 return &ht->tbl_order[0][index];
  51         }
  52         /*
  53          * equivalent to cds_lfht_get_count_order_ulong(index + 1), but
  54          * optimizes away the non-existing 0 special-case for
  55          * cds_lfht_get_count_order_ulong.
  56          */
  57         order = cds_lfht_fls_ulong(index);
  58         dbg_printf("bucket index %lu order %lu aridx %lu\n",
  59                    index, order, index & ((1UL << (order - 1)) - 1));
  60         return &ht->tbl_order[order][index & ((1UL << (order - 1)) - 1)];
  61 }
  62
  63 static
  64 struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets,
  65                 unsigned long max_nr_buckets, const struct cds_lfht_alloc *alloc)
  66 {
  67         return __default_alloc_cds_lfht(
  68                         &cds_lfht_mm_order, alloc, sizeof(struct cds_lfht),
  69                         min_nr_alloc_buckets, max_nr_buckets);
  70 }
  71
  72 const struct cds_lfht_mm_type cds_lfht_mm_order = {
  73         .alloc_cds_lfht = alloc_cds_lfht,
  74         .alloc_bucket_table = cds_lfht_alloc_bucket_table,
  75         .free_bucket_table = cds_lfht_free_bucket_table,
  76         .bucket_at = bucket_at,
  77 };