src/rculfhash-mm-chunk.c

   1 // SPDX-FileCopyrightText: 2011 Lai Jiangshan <laijs@cn.fujitsu.com>
   2 //
   3 // SPDX-License-Identifier: LGPL-2.1-or-later
   4
   5 /*
   6  * Chunk based memory management for Lock-Free RCU Hash Table
   7  */
   8
   9 #include <stddef.h>
  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_chunk[0] = ht->alloc->calloc(ht->alloc->state,
  18                         ht->min_nr_alloc_buckets, sizeof(struct cds_lfht_node));
  19                 urcu_posix_assert(ht->tbl_chunk[0]);
  20         } else if (order > ht->min_alloc_buckets_order) {
  21                 unsigned long i, len = 1UL << (order - 1 - ht->min_alloc_buckets_order);
  22
  23                 for (i = len; i < 2 * len; i++) {
  24                         ht->tbl_chunk[i] = ht->alloc->calloc(ht->alloc->state,
  25                                 ht->min_nr_alloc_buckets, sizeof(struct cds_lfht_node));
  26                         urcu_posix_assert(ht->tbl_chunk[i]);
  27                 }
  28         }
  29         /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
  30 }
  31
  32 /*
  33  * cds_lfht_free_bucket_table() should be called with decreasing order.
  34  * When cds_lfht_free_bucket_table(0) is called, it means the whole
  35  * lfht is destroyed.
  36  */
  37 static
  38 void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order)
  39 {
  40         if (order == 0)
  41                 poison_free(ht->alloc, ht->tbl_chunk[0]);
  42         else if (order > ht->min_alloc_buckets_order) {
  43                 unsigned long i, len = 1UL << (order - 1 - ht->min_alloc_buckets_order);
  44
  45                 for (i = len; i < 2 * len; i++)
  46                         poison_free(ht->alloc, ht->tbl_chunk[i]);
  47         }
  48         /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
  49 }
  50
  51 static
  52 struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index)
  53 {
  54         unsigned long chunk, offset;
  55
  56         chunk = index >> ht->min_alloc_buckets_order;
  57         offset = index & (ht->min_nr_alloc_buckets - 1);
  58         return &ht->tbl_chunk[chunk][offset];
  59 }
  60
  61 static
  62 struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets,
  63                 unsigned long max_nr_buckets, const struct cds_lfht_alloc *alloc)
  64 {
  65         unsigned long nr_chunks, cds_lfht_size;
  66
  67         min_nr_alloc_buckets = max(min_nr_alloc_buckets,
  68                                 max_nr_buckets / MAX_CHUNK_TABLE);
  69         nr_chunks = max_nr_buckets / min_nr_alloc_buckets;
  70         cds_lfht_size = offsetof(struct cds_lfht, tbl_chunk) +
  71                         sizeof(struct cds_lfht_node *) * nr_chunks;
  72         cds_lfht_size = max(cds_lfht_size, sizeof(struct cds_lfht));
  73
  74         return __default_alloc_cds_lfht(
  75                         &cds_lfht_mm_chunk, alloc, cds_lfht_size,
  76                         min_nr_alloc_buckets, max_nr_buckets);
  77 }
  78
  79 const struct cds_lfht_mm_type cds_lfht_mm_chunk = {
  80         .alloc_cds_lfht = alloc_cds_lfht,
  81         .alloc_bucket_table = cds_lfht_alloc_bucket_table,
  82         .free_bucket_table = cds_lfht_free_bucket_table,
  83         .bucket_at = bucket_at,
  84 };