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mirror of git://sourceware.org/git/lvm2.git synced 2024-12-29 15:22:30 +03:00
lvm2/libdm/mm/pool-fast.c
Zdenek Kabelac dbc71dc05e gcc: cleanup some sign warnings
When comparing unsigned with int, the comparision is made
as 'unsigned' type, so make it rather explicit which type
is being compared.
2016-02-23 12:25:25 +01:00

364 lines
7.9 KiB
C

/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved.
*
* This file is part of the device-mapper userspace tools.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifdef VALGRIND_POOL
#include "memcheck.h"
#endif
#include "dmlib.h"
#include <stddef.h> /* For musl libc */
#include <malloc.h>
struct chunk {
char *begin, *end;
struct chunk *prev;
} __attribute__((aligned(8)));
struct dm_pool {
struct dm_list list;
struct chunk *chunk, *spare_chunk; /* spare_chunk is a one entry free
list to stop 'bobbling' */
const char *name;
size_t chunk_size;
size_t object_len;
unsigned object_alignment;
int locked;
long crc;
};
static void _align_chunk(struct chunk *c, unsigned alignment);
static struct chunk *_new_chunk(struct dm_pool *p, size_t s);
static void _free_chunk(struct chunk *c);
/* by default things come out aligned for doubles */
#define DEFAULT_ALIGNMENT __alignof__ (double)
struct dm_pool *dm_pool_create(const char *name, size_t chunk_hint)
{
size_t new_size = 1024;
struct dm_pool *p = dm_zalloc(sizeof(*p));
if (!p) {
log_error("Couldn't create memory pool %s (size %"
PRIsize_t ")", name, sizeof(*p));
return 0;
}
p->name = name;
/* round chunk_hint up to the next power of 2 */
p->chunk_size = chunk_hint + sizeof(struct chunk);
while (new_size < p->chunk_size)
new_size <<= 1;
p->chunk_size = new_size;
pthread_mutex_lock(&_dm_pools_mutex);
dm_list_add(&_dm_pools, &p->list);
pthread_mutex_unlock(&_dm_pools_mutex);
return p;
}
void dm_pool_destroy(struct dm_pool *p)
{
struct chunk *c, *pr;
_free_chunk(p->spare_chunk);
c = p->chunk;
while (c) {
pr = c->prev;
_free_chunk(c);
c = pr;
}
pthread_mutex_lock(&_dm_pools_mutex);
dm_list_del(&p->list);
pthread_mutex_unlock(&_dm_pools_mutex);
dm_free(p);
}
void *dm_pool_alloc(struct dm_pool *p, size_t s)
{
return dm_pool_alloc_aligned(p, s, DEFAULT_ALIGNMENT);
}
void *dm_pool_alloc_aligned(struct dm_pool *p, size_t s, unsigned alignment)
{
struct chunk *c = p->chunk;
void *r;
/* realign begin */
if (c)
_align_chunk(c, alignment);
/* have we got room ? */
if (!c || (c->begin > c->end) || ((c->end - c->begin) < (int) s)) {
/* allocate new chunk */
size_t needed = s + alignment + sizeof(struct chunk);
c = _new_chunk(p, (needed > p->chunk_size) ?
needed : p->chunk_size);
if (!c)
return_NULL;
_align_chunk(c, alignment);
}
r = c->begin;
c->begin += s;
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_UNDEFINED(r, s);
#endif
return r;
}
void dm_pool_empty(struct dm_pool *p)
{
struct chunk *c;
for (c = p->chunk; c && c->prev; c = c->prev)
;
if (c)
dm_pool_free(p, (char *) (c + 1));
}
void dm_pool_free(struct dm_pool *p, void *ptr)
{
struct chunk *c = p->chunk;
while (c) {
if (((char *) c < (char *) ptr) &&
((char *) c->end > (char *) ptr)) {
c->begin = ptr;
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_NOACCESS(c->begin, c->end - c->begin);
#endif
break;
}
if (p->spare_chunk)
_free_chunk(p->spare_chunk);
c->begin = (char *) (c + 1);
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_NOACCESS(c->begin, c->end - c->begin);
#endif
p->spare_chunk = c;
c = c->prev;
}
if (!c)
log_error(INTERNAL_ERROR "pool_free asked to free pointer "
"not in pool");
else
p->chunk = c;
}
int dm_pool_begin_object(struct dm_pool *p, size_t hint)
{
struct chunk *c = p->chunk;
const size_t align = DEFAULT_ALIGNMENT;
p->object_len = 0;
p->object_alignment = align;
if (c)
_align_chunk(c, align);
if (!c || (c->begin > c->end) || ((c->end - c->begin) < (int) hint)) {
/* allocate a new chunk */
c = _new_chunk(p,
hint > (p->chunk_size - sizeof(struct chunk)) ?
hint + sizeof(struct chunk) + align :
p->chunk_size);
if (!c)
return 0;
_align_chunk(c, align);
}
return 1;
}
int dm_pool_grow_object(struct dm_pool *p, const void *extra, size_t delta)
{
struct chunk *c = p->chunk, *nc;
if (!delta)
delta = strlen(extra);
if ((c->end - (c->begin + p->object_len)) < (int) delta) {
/* move into a new chunk */
if (p->object_len + delta > (p->chunk_size / 2))
nc = _new_chunk(p, (p->object_len + delta) * 2);
else
nc = _new_chunk(p, p->chunk_size);
if (!nc)
return 0;
_align_chunk(p->chunk, p->object_alignment);
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_UNDEFINED(p->chunk->begin, p->object_len);
#endif
memcpy(p->chunk->begin, c->begin, p->object_len);
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_NOACCESS(c->begin, p->object_len);
#endif
c = p->chunk;
}
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_UNDEFINED(p->chunk->begin + p->object_len, delta);
#endif
memcpy(c->begin + p->object_len, extra, delta);
p->object_len += delta;
return 1;
}
void *dm_pool_end_object(struct dm_pool *p)
{
struct chunk *c = p->chunk;
void *r = c->begin;
c->begin += p->object_len;
p->object_len = 0u;
p->object_alignment = DEFAULT_ALIGNMENT;
return r;
}
void dm_pool_abandon_object(struct dm_pool *p)
{
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_NOACCESS(p->chunk, p->object_len);
#endif
p->object_len = 0;
p->object_alignment = DEFAULT_ALIGNMENT;
}
static void _align_chunk(struct chunk *c, unsigned alignment)
{
c->begin += alignment - ((unsigned long) c->begin & (alignment - 1));
}
static struct chunk *_new_chunk(struct dm_pool *p, size_t s)
{
struct chunk *c;
if (p->spare_chunk &&
((p->spare_chunk->end - p->spare_chunk->begin) >= (ptrdiff_t)s)) {
/* reuse old chunk */
c = p->spare_chunk;
p->spare_chunk = 0;
} else {
#ifdef DEBUG_ENFORCE_POOL_LOCKING
if (!pagesize) {
pagesize = getpagesize(); /* lvm_pagesize(); */
pagesize_mask = pagesize - 1;
}
/*
* Allocate page aligned size so malloc could work.
* Otherwise page fault would happen from pool unrelated
* memory writes of internal malloc pointers.
*/
# define aligned_malloc(s) (posix_memalign((void**)&c, pagesize, \
ALIGN_ON_PAGE(s)) == 0)
#else
# define aligned_malloc(s) (c = dm_malloc(s))
#endif /* DEBUG_ENFORCE_POOL_LOCKING */
if (!aligned_malloc(s)) {
#undef aligned_malloc
log_error("Out of memory. Requested %" PRIsize_t
" bytes.", s);
return NULL;
}
c->begin = (char *) (c + 1);
c->end = (char *) c + s;
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_NOACCESS(c->begin, c->end - c->begin);
#endif
}
c->prev = p->chunk;
p->chunk = c;
return c;
}
static void _free_chunk(struct chunk *c)
{
#ifdef VALGRIND_POOL
# ifdef DEBUG_MEM
if (c)
VALGRIND_MAKE_MEM_UNDEFINED(c + 1, c->end - (char *) (c + 1));
# endif
#endif
#ifdef DEBUG_ENFORCE_POOL_LOCKING
/* since DEBUG_MEM is using own memory list */
free(c); /* for posix_memalign() */
#else
dm_free(c);
#endif
}
/**
* Calc crc/hash from pool's memory chunks with internal pointers
*/
static long _pool_crc(const struct dm_pool *p)
{
long crc_hash = 0;
#ifndef DEBUG_ENFORCE_POOL_LOCKING
const struct chunk *c;
const long *ptr, *end;
for (c = p->chunk; c; c = c->prev) {
end = (const long *) (c->begin < c->end ? (long) c->begin & ~7: (long) c->end);
ptr = (const long *) c;
#ifdef VALGRIND_POOL
VALGRIND_MAKE_MEM_DEFINED(ptr, (end - ptr) * sizeof(*end));
#endif
while (ptr < end) {
crc_hash += *ptr++;
crc_hash += (crc_hash << 10);
crc_hash ^= (crc_hash >> 6);
}
}
#endif /* DEBUG_ENFORCE_POOL_LOCKING */
return crc_hash;
}
static int _pool_protect(struct dm_pool *p, int prot)
{
#ifdef DEBUG_ENFORCE_POOL_LOCKING
struct chunk *c;
for (c = p->chunk; c; c = c->prev) {
if (mprotect(c, (size_t) ((c->end - (char *) c) - 1), prot) != 0) {
log_sys_error("mprotect", "");
return 0;
}
}
#endif
return 1;
}