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shared: split mempool implementation from hashmaps

This commit is contained in:
Michal Schmidt 2014-08-12 23:35:23 +02:00
parent 1e43061b67
commit b3dcf58e28
4 changed files with 164 additions and 81 deletions
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2
Makefile.am
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@ -768,6 +768,8 @@ libsystemd_shared_la_SOURCES = \
src/shared/time-util.h \
src/shared/locale-util.c \
src/shared/locale-util.h \
src/shared/mempool.c \
src/shared/mempool.h \
src/shared/hashmap.c \
src/shared/hashmap.h \
src/shared/siphash24.c \

101
src/shared/hashmap.c
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@ -28,6 +28,7 @@
#include "hashmap.h"
#include "macro.h"
#include "siphash24.h"
#include "mempool.h"
#define INITIAL_N_BUCKETS 31
@ -50,82 +51,21 @@ struct Hashmap {
bool from_pool:1;
};
struct pool {
struct pool *next;
unsigned n_tiles;
unsigned n_used;
struct hashmap_tile {
Hashmap h;
struct hashmap_entry *initial_buckets[INITIAL_N_BUCKETS];
};
static struct pool *first_hashmap_pool = NULL;
static void *first_hashmap_tile = NULL;
static struct pool *first_entry_pool = NULL;
static void *first_entry_tile = NULL;
static void* allocate_tile(struct pool **first_pool, void **first_tile, size_t tile_size, unsigned at_least) {
unsigned i;
/* When a tile is released we add it to the list and simply
* place the next pointer at its offset 0. */
assert(tile_size >= sizeof(void*));
assert(at_least > 0);
if (*first_tile) {
void *r;
r = *first_tile;
*first_tile = * (void**) (*first_tile);
return r;
}
if (_unlikely_(!*first_pool) || _unlikely_((*first_pool)->n_used >= (*first_pool)->n_tiles)) {
unsigned n;
size_t size;
struct pool *p;
n = *first_pool ? (*first_pool)->n_tiles : 0;
n = MAX(at_least, n * 2);
size = PAGE_ALIGN(ALIGN(sizeof(struct pool)) + n*tile_size);
n = (size - ALIGN(sizeof(struct pool))) / tile_size;
p = malloc(size);
if (!p)
return NULL;
p->next = *first_pool;
p->n_tiles = n;
p->n_used = 0;
*first_pool = p;
}
i = (*first_pool)->n_used++;
return ((uint8_t*) (*first_pool)) + ALIGN(sizeof(struct pool)) + i*tile_size;
}
static void deallocate_tile(void **first_tile, void *p) {
* (void**) p = *first_tile;
*first_tile = p;
}
static DEFINE_MEMPOOL(hashmap_pool, struct hashmap_tile, 8);
static DEFINE_MEMPOOL(hashmap_entry_pool, struct hashmap_entry, 64);
#ifdef VALGRIND
static void drop_pool(struct pool *p) {
while (p) {
struct pool *n;
n = p->next;
free(p);
p = n;
}
}
__attribute__((destructor)) static void cleanup_pool(void) {
__attribute__((destructor)) static void cleanup_pools(void) {
/* Be nice to valgrind */
drop_pool(first_hashmap_pool);
drop_pool(first_entry_pool);
mempool_drop(&hashmap_entry_pool);
mempool_drop(&hashmap_pool);
}
#endif
@ -223,33 +163,32 @@ static void get_hash_key(uint8_t hash_key[HASH_KEY_SIZE], bool reuse_is_ok) {
Hashmap *hashmap_new(const struct hash_ops *hash_ops) {
bool b;
struct hashmap_tile *ht;
Hashmap *h;
size_t size;
b = is_main_thread();
size = ALIGN(sizeof(Hashmap)) + INITIAL_N_BUCKETS * sizeof(struct hashmap_entry*);
if (b) {
h = allocate_tile(&first_hashmap_pool, &first_hashmap_tile, size, 8);
if (!h)
ht = mempool_alloc_tile(&hashmap_pool);
if (!ht)
return NULL;
memzero(h, size);
memzero(ht, sizeof(struct hashmap_tile));
} else {
h = malloc0(size);
ht = malloc0(sizeof(struct hashmap_tile));
if (!h)
if (!ht)
return NULL;
}
h = &ht->h;
h->hash_ops = hash_ops ? hash_ops : &trivial_hash_ops;
h->n_buckets = INITIAL_N_BUCKETS;
h->n_entries = 0;
h->iterate_list_head = h->iterate_list_tail = NULL;
h->buckets = (struct hashmap_entry**) ((uint8_t*) h + ALIGN(sizeof(Hashmap)));
h->buckets = ht->initial_buckets;
h->from_pool = b;
@ -339,7 +278,7 @@ static void remove_entry(Hashmap *h, struct hashmap_entry *e) {
unlink_entry(h, e, hash);
if (h->from_pool)
deallocate_tile(&first_entry_tile, e);
mempool_free_tile(&hashmap_entry_pool, e);
else
free(e);
}
@ -357,7 +296,7 @@ void hashmap_free(Hashmap*h) {
free(h->buckets);
if (h->from_pool)
deallocate_tile(&first_hashmap_tile, h);
mempool_free_tile(&hashmap_pool, container_of(h, struct hashmap_tile, h));
else
free(h);
}
@ -497,7 +436,7 @@ static int __hashmap_put(Hashmap *h, const void *key, void *value, unsigned hash
hash = bucket_hash(h, key);
if (h->from_pool)
e = allocate_tile(&first_entry_pool, &first_entry_tile, sizeof(struct hashmap_entry), 64U);
e = mempool_alloc_tile(&hashmap_entry_pool);
else
e = new(struct hashmap_entry, 1);

94
src/shared/mempool.c Normal file
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@ -0,0 +1,94 @@
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010-2014 Lennart Poettering
Copyright 2014 Michal Schmidt
systemd 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.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include "mempool.h"
#include "macro.h"
#include "util.h"
struct pool {
struct pool *next;
unsigned n_tiles;
unsigned n_used;
};
void* mempool_alloc_tile(struct mempool *mp) {
unsigned i;
/* When a tile is released we add it to the list and simply
* place the next pointer at its offset 0. */
assert(mp->tile_size >= sizeof(void*));
assert(mp->at_least > 0);
if (mp->freelist) {
void *r;
r = mp->freelist;
mp->freelist = * (void**) mp->freelist;
return r;
}
if (_unlikely_(!mp->first_pool) ||
_unlikely_(mp->first_pool->n_used >= mp->first_pool->n_tiles)) {
unsigned n;
size_t size;
struct pool *p;
n = mp->first_pool ? mp->first_pool->n_tiles : 0;
n = MAX(mp->at_least, n * 2);
size = PAGE_ALIGN(ALIGN(sizeof(struct pool)) + n*mp->tile_size);
n = (size - ALIGN(sizeof(struct pool))) / mp->tile_size;
p = malloc(size);
if (!p)
return NULL;
p->next = mp->first_pool;
p->n_tiles = n;
p->n_used = 0;
mp->first_pool = p;
}
i = mp->first_pool->n_used++;
return ((uint8_t*) mp->first_pool) + ALIGN(sizeof(struct pool)) + i*mp->tile_size;
}
void mempool_free_tile(struct mempool *mp, void *p) {
* (void**) p = mp->freelist;
mp->freelist = p;
}
#ifdef VALGRIND
void mempool_drop(struct mempool *mp) {
struct pool *p = mp->first_pool;
while (p) {
struct pool *n;
n = p->next;
free(p);
p = n;
}
}
#endif

48
src/shared/mempool.h Normal file
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@ -0,0 +1,48 @@
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
#pragma once
/***
This file is part of systemd.
Copyright 2011-2014 Lennart Poettering
Copyright 2014 Michal Schmidt
systemd 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.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <stddef.h>
struct pool;
struct mempool {
struct pool *first_pool;
void *freelist;
size_t tile_size;
unsigned at_least;
};
void* mempool_alloc_tile(struct mempool *mp);
void mempool_free_tile(struct mempool *mp, void *p);
#define DEFINE_MEMPOOL(pool_name, tile_type, alloc_at_least) \
struct mempool pool_name = { \
.tile_size = sizeof(tile_type), \
.at_least = alloc_at_least, \
}
#ifdef VALGRIND
void mempool_drop(struct mempool *mp);
#endif