X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=rculfhash-mm-mmap.c;fp=rculfhash-mm-mmap.c;h=0000000000000000000000000000000000000000;hp=3cc3fa01c9d5ed5c16888ae8f02fb85ae65cf1de;hb=6893800a4d1cc14dff0395ddcd660a5138db183d;hpb=a59f39055b5ecb77b68cf78b9839aa9e8e4ec332 diff --git a/rculfhash-mm-mmap.c b/rculfhash-mm-mmap.c deleted file mode 100644 index 3cc3fa0..0000000 --- a/rculfhash-mm-mmap.c +++ /dev/null @@ -1,160 +0,0 @@ -/* - * rculfhash-mm-mmap.c - * - * mmap/reservation based memory management for Lock-Free RCU Hash Table - * - * Copyright 2011 - Lai Jiangshan - * - * 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 -#include -#include "rculfhash-internal.h" - -#ifndef MAP_ANONYMOUS -#define MAP_ANONYMOUS MAP_ANON -#endif - -/* reserve inaccessible memory space without allocation any memory */ -static void *memory_map(size_t length) -{ - void *ret = mmap(NULL, length, PROT_NONE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - - assert(ret != MAP_FAILED); - return ret; -} - -static void memory_unmap(void *ptr, size_t length) -{ - int ret __attribute__((unused)); - - ret = munmap(ptr, length); - - assert(ret == 0); -} - -static void memory_populate(void *ptr, size_t length) -{ - void *ret __attribute__((unused)); - - ret = mmap(ptr, length, PROT_READ | PROT_WRITE, - MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - - assert(ret == ptr); -} - -/* - * Discard garbage memory and avoid system save it when try to swap it out. - * Make it still reserved, inaccessible. - */ -static void memory_discard(void *ptr, size_t length) -{ - void *ret __attribute__((unused)); - - ret = mmap(ptr, length, PROT_NONE, - MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - - assert(ret == ptr); -} - -static -void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order) -{ - if (order == 0) { - if (ht->min_nr_alloc_buckets == ht->max_nr_buckets) { - /* small table */ - ht->tbl_mmap = calloc(ht->max_nr_buckets, - sizeof(*ht->tbl_mmap)); - assert(ht->tbl_mmap); - return; - } - /* large table */ - ht->tbl_mmap = memory_map(ht->max_nr_buckets - * sizeof(*ht->tbl_mmap)); - memory_populate(ht->tbl_mmap, - ht->min_nr_alloc_buckets * sizeof(*ht->tbl_mmap)); - } else if (order > ht->min_alloc_buckets_order) { - /* large table */ - unsigned long len = 1UL << (order - 1); - - assert(ht->min_nr_alloc_buckets < ht->max_nr_buckets); - memory_populate(ht->tbl_mmap + len, - len * sizeof(*ht->tbl_mmap)); - } - /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */ -} - -/* - * cds_lfht_free_bucket_table() should be called with decreasing order. - * When cds_lfht_free_bucket_table(0) is called, it means the whole - * lfht is destroyed. - */ -static -void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order) -{ - if (order == 0) { - if (ht->min_nr_alloc_buckets == ht->max_nr_buckets) { - /* small table */ - poison_free(ht->tbl_mmap); - return; - } - /* large table */ - memory_unmap(ht->tbl_mmap, - ht->max_nr_buckets * sizeof(*ht->tbl_mmap)); - } else if (order > ht->min_alloc_buckets_order) { - /* large table */ - unsigned long len = 1UL << (order - 1); - - assert(ht->min_nr_alloc_buckets < ht->max_nr_buckets); - memory_discard(ht->tbl_mmap + len, len * sizeof(*ht->tbl_mmap)); - } - /* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */ -} - -static -struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index) -{ - return &ht->tbl_mmap[index]; -} - -static -struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets, - unsigned long max_nr_buckets) -{ - unsigned long page_bucket_size; - - page_bucket_size = getpagesize() / sizeof(struct cds_lfht_node); - if (max_nr_buckets <= page_bucket_size) { - /* small table */ - min_nr_alloc_buckets = max_nr_buckets; - } else { - /* large table */ - min_nr_alloc_buckets = max(min_nr_alloc_buckets, - page_bucket_size); - } - - return __default_alloc_cds_lfht( - &cds_lfht_mm_mmap, sizeof(struct cds_lfht), - min_nr_alloc_buckets, max_nr_buckets); -} - -const struct cds_lfht_mm_type cds_lfht_mm_mmap = { - .alloc_cds_lfht = alloc_cds_lfht, - .alloc_bucket_table = cds_lfht_alloc_bucket_table, - .free_bucket_table = cds_lfht_free_bucket_table, - .bucket_at = bucket_at, -};