[fio.git] / smalloc.c

/*
 * simple memory allocator, backed by mmap() so that it hands out memory
 * that can be shared across processes and threads
 */
#include <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <limits.h>

#include "mutex.h"

#define MP_SAFE			/* define to make thread safe */
#define SMALLOC_REDZONE		/* define to detect memory corruption */

#define SMALLOC_BPB	32	/* block size, bytes-per-bit in bitmap */
#define SMALLOC_BPI	(sizeof(unsigned int) * 8)
#define SMALLOC_BPL	(SMALLOC_BPB * SMALLOC_BPI)

#define INITIAL_SIZE	1024*1024	/* new pool size */
#define MAX_POOLS	4		/* maximum number of pools to setup */

#define SMALLOC_PRE_RED		0xdeadbeefU
#define SMALLOC_POST_RED	0x5aa55aa5U

unsigned int smalloc_pool_size = INITIAL_SIZE;

struct pool {
	struct fio_mutex *lock;			/* protects this pool */
	void *map;				/* map of blocks */
	unsigned int *bitmap;			/* blocks free/busy map */
	unsigned int free_blocks;		/* free blocks */
	unsigned int nr_blocks;			/* total blocks */
	unsigned int next_non_full;
	int fd;					/* memory backing fd */
	char file[PATH_MAX];			/* filename for fd */
	unsigned int mmap_size;
};

struct block_hdr {
	unsigned int size;
#ifdef SMALLOC_REDZONE
	unsigned int prered;
#endif
};

static struct pool mp[MAX_POOLS];
static unsigned int nr_pools;
static unsigned int last_pool;
static struct fio_mutex *lock;

static inline void pool_lock(struct pool *pool)
{
	if (pool->lock)
		fio_mutex_down(pool->lock);
}

static inline void pool_unlock(struct pool *pool)
{
	if (pool->lock)
		fio_mutex_up(pool->lock);
}

static inline void global_read_lock(void)
{
	if (lock)
		fio_mutex_down_read(lock);
}

static inline void global_read_unlock(void)
{
	if (lock)
		fio_mutex_up_read(lock);
}

static inline void global_write_lock(void)
{
	if (lock)
		fio_mutex_down_write(lock);
}

static inline void global_write_unlock(void)
{
	if (lock)
		fio_mutex_up_write(lock);
}

static inline int ptr_valid(struct pool *pool, void *ptr)
{
	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;

	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
}

static inline unsigned int size_to_blocks(unsigned int size)
{
	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
}

static int blocks_iter(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, unsigned int nr_blocks,
		       int (*func)(unsigned int *map, unsigned int mask))
{

	while (nr_blocks) {
		unsigned int this_blocks, mask;
		unsigned int *map;

		if (pool_idx >= pool->nr_blocks)
			return 0;

		map = &pool->bitmap[pool_idx];

		this_blocks = nr_blocks;
		if (this_blocks + idx > SMALLOC_BPI) {
			this_blocks = SMALLOC_BPI - idx;
			idx = SMALLOC_BPI - this_blocks;
		}

		if (this_blocks == SMALLOC_BPI)
			mask = -1U;
		else
			mask = ((1U << this_blocks) - 1) << idx;

		if (!func(map, mask))
			return 0;

		nr_blocks -= this_blocks;
		idx = 0;
		pool_idx++;
	}

	return 1;
}

static int mask_cmp(unsigned int *map, unsigned int mask)
{
	return !(*map & mask);
}

static int mask_clear(unsigned int *map, unsigned int mask)
{
	assert((*map & mask) == mask);
	*map &= ~mask;
	return 1;
}

static int mask_set(unsigned int *map, unsigned int mask)
{
	assert(!(*map & mask));
	*map |= mask;
	return 1;
}

static int blocks_free(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, unsigned int nr_blocks)
{
	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
}

static void set_blocks(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, unsigned int nr_blocks)
{
	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
}

static void clear_blocks(struct pool *pool, unsigned int pool_idx,
			 unsigned int idx, unsigned int nr_blocks)
{
	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
}

static inline int __ffs(int word)
{
	int r = 0;

	if (!(word & 0xffff)) {
		word >>= 16;
		r += 16;
	}
	if (!(word & 0xff)) {
		word >>= 8;
		r += 8;
	}
	if (!(word & 0xf)) {
		word >>= 4;
		r += 4;
	}
	if (!(word & 3)) {
		word >>= 2;
		r += 2;
	}
	if (!(word & 1)) {
		word >>= 1;
		r += 1;
	}

	return r;
}

static int find_next_zero(int word, int start)
{
	assert(word != -1U);
	word >>= (start + 1);
	return __ffs(~word) + start + 1;
}

static int add_pool(struct pool *pool, unsigned int alloc_size)
{
	void *ptr;
	int fd, bitmap_blocks;

	strcpy(pool->file, "/tmp/.fio_smalloc.XXXXXX");
	fd = mkstemp(pool->file);
	if (fd < 0)
		goto out_close;

#ifdef SMALLOC_REDZONE
	alloc_size += sizeof(unsigned int);
#endif
	alloc_size += sizeof(struct block_hdr);
	if (alloc_size < INITIAL_SIZE)
		alloc_size = INITIAL_SIZE;

	/* round up to nearest full number of blocks */
	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	bitmap_blocks = alloc_size / SMALLOC_BPL;
	alloc_size += bitmap_blocks * sizeof(unsigned int);
	pool->mmap_size = alloc_size;
	
	pool->nr_blocks = bitmap_blocks;
	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;

	if (ftruncate(fd, alloc_size) < 0)
		goto out_unlink;

	ptr = mmap(NULL, alloc_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	if (ptr == MAP_FAILED)
		goto out_unlink;

	memset(ptr, 0, alloc_size);
	pool->map = ptr;
	pool->bitmap = (void *) ptr + (pool->nr_blocks * SMALLOC_BPL);

#ifdef MP_SAFE
	pool->lock = fio_mutex_init(1);
	if (!pool->lock)
		goto out_unlink;
#endif

	pool->fd = fd;

	global_write_lock();
	nr_pools++;
	global_write_unlock();
	return 0;
out_unlink:
	fprintf(stderr, "smalloc: failed adding pool\n");
	if (pool->map)
		munmap(pool->map, pool->mmap_size);
	unlink(pool->file);
out_close:
	if (fd >= 0)
		close(fd);
	return 1;
}

void sinit(void)
{
	int ret;

#ifdef MP_SAFE
	lock = fio_mutex_rw_init();
#endif
	ret = add_pool(&mp[0], INITIAL_SIZE);
	assert(!ret);
}

static void cleanup_pool(struct pool *pool)
{
	unlink(pool->file);
	close(pool->fd);
	munmap(pool->map, pool->mmap_size);

	if (pool->lock)
		fio_mutex_remove(pool->lock);
}

void scleanup(void)
{
	unsigned int i;

	for (i = 0; i < nr_pools; i++)
		cleanup_pool(&mp[i]);

	if (lock)
		fio_mutex_remove(lock);
}

#ifdef SMALLOC_REDZONE
static void fill_redzone(struct block_hdr *hdr)
{
	unsigned int *postred = (void *) hdr + hdr->size - sizeof(unsigned int);

	hdr->prered = SMALLOC_PRE_RED;
	*postred = SMALLOC_POST_RED;
}

static void sfree_check_redzone(struct block_hdr *hdr)
{
	unsigned int *postred = (void *) hdr + hdr->size - sizeof(unsigned int);

	if (hdr->prered != SMALLOC_PRE_RED) {
		fprintf(stderr, "smalloc pre redzone destroyed!\n");
		fprintf(stderr, "  ptr=%p, prered=%x, expected %x\n",
				hdr, hdr->prered, SMALLOC_PRE_RED);
		assert(0);
	}
	if (*postred != SMALLOC_POST_RED) {
		fprintf(stderr, "smalloc post redzone destroyed!\n");
		fprintf(stderr, "  ptr=%p, postred=%x, expected %x\n",
				hdr, *postred, SMALLOC_POST_RED);
		assert(0);
	}
}
#else
static void fill_redzone(struct block_hdr *hdr)
{
}

static void sfree_check_redzone(struct block_hdr *hdr)
{
}
#endif

static void sfree_pool(struct pool *pool, void *ptr)
{
	struct block_hdr *hdr;
	unsigned int i, idx;
	unsigned long offset;

	if (!ptr)
		return;

	ptr -= sizeof(*hdr);
	hdr = ptr;

	assert(ptr_valid(pool, ptr));

	sfree_check_redzone(hdr);

	offset = ptr - pool->map;
	i = offset / SMALLOC_BPL;
	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;

	pool_lock(pool);
	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	if (i < pool->next_non_full)
		pool->next_non_full = i;
	pool->free_blocks += size_to_blocks(hdr->size);
	pool_unlock(pool);
}

void sfree(void *ptr)
{
	struct pool *pool = NULL;
	unsigned int i;

	if (!ptr)
		return;

	global_read_lock();

	for (i = 0; i < nr_pools; i++) {
		if (ptr_valid(&mp[i], ptr)) {
			pool = &mp[i];
			break;
		}
	}

	global_read_unlock();

	assert(pool);
	sfree_pool(pool, ptr);
}

static void *__smalloc_pool(struct pool *pool, unsigned int size)
{
	unsigned int nr_blocks;
	unsigned int i;
	unsigned int offset;
	unsigned int last_idx;
	void *ret = NULL;

	pool_lock(pool);

	nr_blocks = size_to_blocks(size);
	if (nr_blocks > pool->free_blocks)
		goto fail;

	i = pool->next_non_full;
	last_idx = 0;
	offset = -1U;
	while (i < pool->nr_blocks) {
		unsigned int idx;

		if (pool->bitmap[i] == -1U) {
			i++;
			pool->next_non_full = i;
			last_idx = 0;
			continue;
		}

		idx = find_next_zero(pool->bitmap[i], last_idx);
		if (!blocks_free(pool, i, idx, nr_blocks)) {
			idx += nr_blocks;
			if (idx < SMALLOC_BPI)
				last_idx = idx;
			else {
				last_idx = 0;
				while (idx >= SMALLOC_BPI) {
					i++;
					idx -= SMALLOC_BPI;
				}
			}
			continue;
		}
		set_blocks(pool, i, idx, nr_blocks);
		offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
		break;
	}

	if (i < pool->nr_blocks) {
		pool->free_blocks -= nr_blocks;
		ret = pool->map + offset;
	}
fail:
	pool_unlock(pool);
	return ret;
}

static void *smalloc_pool(struct pool *pool, unsigned int size)
{
	unsigned int alloc_size = size + sizeof(struct block_hdr);
	void *ptr;

#ifdef SMALLOC_REDZONE
	alloc_size += sizeof(unsigned int);
#endif

	ptr = __smalloc_pool(pool, alloc_size);
	if (ptr) {
		struct block_hdr *hdr = ptr;

		hdr->size = alloc_size;
		fill_redzone(hdr);

		ptr += sizeof(*hdr);
		memset(ptr, 0, size);
	}

	return ptr;
}

void *smalloc(unsigned int size)
{
	unsigned int i;

	global_read_lock();
	i = last_pool;

	do {
		for (; i < nr_pools; i++) {
			void *ptr = smalloc_pool(&mp[i], size);

			if (ptr) {
				last_pool = i;
				global_read_unlock();
				return ptr;
			}
		}
		if (last_pool) {
			last_pool = 0;
			continue;
		}

		if (nr_pools + 1 > MAX_POOLS)
			break;
		else {
			i = nr_pools;
			global_read_unlock();
			if (add_pool(&mp[nr_pools], size))
				goto out;
			global_read_lock();
		}
	} while (1);

	global_read_unlock();
out:
	return NULL;
}

char *smalloc_strdup(const char *str)
{
	char *ptr;

	ptr = smalloc(strlen(str) + 1);
	strcpy(ptr, str);
	return ptr;
}
Commit	Line	Data
	1	/*
	2	* simple memory allocator, backed by mmap() so that it hands out memory
	3	* that can be shared across processes and threads
	4	*/
	5	#include <sys/mman.h>
	6	#include <stdio.h>
	7	#include <stdlib.h>
	8	#include <assert.h>
	9	#include <string.h>
	10	#include <unistd.h>
	11	#include <sys/types.h>
	12	#include <limits.h>
	13
	14	#include "mutex.h"
	15
	16	#define MP_SAFE /* define to make thread safe */
	17	#define SMALLOC_REDZONE /* define to detect memory corruption */
	18
	19	#define SMALLOC_BPB 32 /* block size, bytes-per-bit in bitmap */
	20	#define SMALLOC_BPI (sizeof(unsigned int) * 8)
	21	#define SMALLOC_BPL (SMALLOC_BPB * SMALLOC_BPI)
	22
	23	#define INITIAL_SIZE 10241024 / new pool size */
	24	#define MAX_POOLS 4 /* maximum number of pools to setup */
	25
	26	#define SMALLOC_PRE_RED 0xdeadbeefU
	27	#define SMALLOC_POST_RED 0x5aa55aa5U
	28
	29	unsigned int smalloc_pool_size = INITIAL_SIZE;
	30
	31	struct pool {
	32	struct fio_mutex lock; / protects this pool */
	33	void map; / map of blocks */
	34	unsigned int bitmap; / blocks free/busy map */
	35	unsigned int free_blocks; /* free blocks */
	36	unsigned int nr_blocks; /* total blocks */
	37	unsigned int next_non_full;
	38	int fd; /* memory backing fd */
	39	char file[PATH_MAX]; /* filename for fd */
	40	unsigned int mmap_size;
	41	};
	42
	43	struct block_hdr {
	44	unsigned int size;
	45	#ifdef SMALLOC_REDZONE
	46	unsigned int prered;
	47	#endif
	48	};
	49
	50	static struct pool mp[MAX_POOLS];
	51	static unsigned int nr_pools;
	52	static unsigned int last_pool;
	53	static struct fio_mutex *lock;
	54
	55	static inline void pool_lock(struct pool *pool)
	56	{
	57	if (pool->lock)
	58	fio_mutex_down(pool->lock);
	59	}
	60
	61	static inline void pool_unlock(struct pool *pool)
	62	{
	63	if (pool->lock)
	64	fio_mutex_up(pool->lock);
	65	}
	66
	67	static inline void global_read_lock(void)
	68	{
	69	if (lock)
	70	fio_mutex_down_read(lock);
	71	}
	72
	73	static inline void global_read_unlock(void)
	74	{
	75	if (lock)
	76	fio_mutex_up_read(lock);
	77	}
	78
	79	static inline void global_write_lock(void)
	80	{
	81	if (lock)
	82	fio_mutex_down_write(lock);
	83	}
	84
	85	static inline void global_write_unlock(void)
	86	{
	87	if (lock)
	88	fio_mutex_up_write(lock);
	89	}
	90
	91	static inline int ptr_valid(struct pool pool, void ptr)
	92	{
	93	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
	94
	95	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
	96	}
	97
	98	static inline unsigned int size_to_blocks(unsigned int size)
	99	{
	100	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
	101	}
	102
	103	static int blocks_iter(struct pool *pool, unsigned int pool_idx,
	104	unsigned int idx, unsigned int nr_blocks,
	105	int (func)(unsigned int map, unsigned int mask))
	106	{
	107
	108	while (nr_blocks) {
	109	unsigned int this_blocks, mask;
	110	unsigned int *map;
	111
	112	if (pool_idx >= pool->nr_blocks)
	113	return 0;
	114
	115	map = &pool->bitmap[pool_idx];
	116
	117	this_blocks = nr_blocks;
	118	if (this_blocks + idx > SMALLOC_BPI) {
	119	this_blocks = SMALLOC_BPI - idx;
	120	idx = SMALLOC_BPI - this_blocks;
	121	}
	122
	123	if (this_blocks == SMALLOC_BPI)
	124	mask = -1U;
	125	else
	126	mask = ((1U << this_blocks) - 1) << idx;
	127
	128	if (!func(map, mask))
	129	return 0;
	130
	131	nr_blocks -= this_blocks;
	132	idx = 0;
	133	pool_idx++;
	134	}
	135
	136	return 1;
	137	}
	138
	139	static int mask_cmp(unsigned int *map, unsigned int mask)
	140	{
	141	return !(*map & mask);
	142	}
	143
	144	static int mask_clear(unsigned int *map, unsigned int mask)
	145	{
	146	assert((*map & mask) == mask);
	147	*map &= ~mask;
	148	return 1;
	149	}
	150
	151	static int mask_set(unsigned int *map, unsigned int mask)
	152	{
	153	assert(!(*map & mask));
	154	*map \|= mask;
	155	return 1;
	156	}
	157
	158	static int blocks_free(struct pool *pool, unsigned int pool_idx,
	159	unsigned int idx, unsigned int nr_blocks)
	160	{
	161	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
	162	}
	163
	164	static void set_blocks(struct pool *pool, unsigned int pool_idx,
	165	unsigned int idx, unsigned int nr_blocks)
	166	{
	167	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
	168	}
	169
	170	static void clear_blocks(struct pool *pool, unsigned int pool_idx,
	171	unsigned int idx, unsigned int nr_blocks)
	172	{
	173	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
	174	}
	175
	176	static inline int __ffs(int word)
	177	{
	178	int r = 0;
	179
	180	if (!(word & 0xffff)) {
	181	word >>= 16;
	182	r += 16;
	183	}
	184	if (!(word & 0xff)) {
	185	word >>= 8;
	186	r += 8;
	187	}
	188	if (!(word & 0xf)) {
	189	word >>= 4;
	190	r += 4;
	191	}
	192	if (!(word & 3)) {
	193	word >>= 2;
	194	r += 2;
	195	}
	196	if (!(word & 1)) {
	197	word >>= 1;
	198	r += 1;
	199	}
	200
	201	return r;
	202	}
	203
	204	static int find_next_zero(int word, int start)
	205	{
	206	assert(word != -1U);
	207	word >>= (start + 1);
	208	return __ffs(~word) + start + 1;
	209	}
	210
	211	static int add_pool(struct pool *pool, unsigned int alloc_size)
	212	{
	213	void *ptr;
	214	int fd, bitmap_blocks;
	215
	216	strcpy(pool->file, "/tmp/.fio_smalloc.XXXXXX");
	217	fd = mkstemp(pool->file);
	218	if (fd < 0)
	219	goto out_close;
	220
	221	#ifdef SMALLOC_REDZONE
	222	alloc_size += sizeof(unsigned int);
	223	#endif
	224	alloc_size += sizeof(struct block_hdr);
	225	if (alloc_size < INITIAL_SIZE)
	226	alloc_size = INITIAL_SIZE;
	227
	228	/* round up to nearest full number of blocks */
	229	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	230	bitmap_blocks = alloc_size / SMALLOC_BPL;
	231	alloc_size += bitmap_blocks * sizeof(unsigned int);
	232	pool->mmap_size = alloc_size;
	233
	234	pool->nr_blocks = bitmap_blocks;
	235	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
	236
	237	if (ftruncate(fd, alloc_size) < 0)
	238	goto out_unlink;
	239
	240	ptr = mmap(NULL, alloc_size, PROT_READ\|PROT_WRITE, MAP_SHARED, fd, 0);
	241	if (ptr == MAP_FAILED)
	242	goto out_unlink;
	243
	244	memset(ptr, 0, alloc_size);
	245	pool->map = ptr;
	246	pool->bitmap = (void ) ptr + (pool->nr_blocks SMALLOC_BPL);
	247
	248	#ifdef MP_SAFE
	249	pool->lock = fio_mutex_init(1);
	250	if (!pool->lock)
	251	goto out_unlink;
	252	#endif
	253
	254	pool->fd = fd;
	255
	256	global_write_lock();
	257	nr_pools++;
	258	global_write_unlock();
	259	return 0;
	260	out_unlink:
	261	fprintf(stderr, "smalloc: failed adding pool\n");
	262	if (pool->map)
	263	munmap(pool->map, pool->mmap_size);
	264	unlink(pool->file);
	265	out_close:
	266	if (fd >= 0)
	267	close(fd);
	268	return 1;
	269	}
	270
	271	void sinit(void)
	272	{
	273	int ret;
	274
	275	#ifdef MP_SAFE
	276	lock = fio_mutex_rw_init();
	277	#endif
	278	ret = add_pool(&mp[0], INITIAL_SIZE);
	279	assert(!ret);
	280	}
	281
	282	static void cleanup_pool(struct pool *pool)
	283	{
	284	unlink(pool->file);
	285	close(pool->fd);
	286	munmap(pool->map, pool->mmap_size);
	287
	288	if (pool->lock)
	289	fio_mutex_remove(pool->lock);
	290	}
	291
	292	void scleanup(void)
	293	{
	294	unsigned int i;
	295
	296	for (i = 0; i < nr_pools; i++)
	297	cleanup_pool(&mp[i]);
	298
	299	if (lock)
	300	fio_mutex_remove(lock);
	301	}
	302
	303	#ifdef SMALLOC_REDZONE
	304	static void fill_redzone(struct block_hdr *hdr)
	305	{
	306	unsigned int postred = (void ) hdr + hdr->size - sizeof(unsigned int);
	307
	308	hdr->prered = SMALLOC_PRE_RED;
	309	*postred = SMALLOC_POST_RED;
	310	}
	311
	312	static void sfree_check_redzone(struct block_hdr *hdr)
	313	{
	314	unsigned int postred = (void ) hdr + hdr->size - sizeof(unsigned int);
	315
	316	if (hdr->prered != SMALLOC_PRE_RED) {
	317	fprintf(stderr, "smalloc pre redzone destroyed!\n");
	318	fprintf(stderr, " ptr=%p, prered=%x, expected %x\n",
	319	hdr, hdr->prered, SMALLOC_PRE_RED);
	320	assert(0);
	321	}
	322	if (*postred != SMALLOC_POST_RED) {
	323	fprintf(stderr, "smalloc post redzone destroyed!\n");
	324	fprintf(stderr, " ptr=%p, postred=%x, expected %x\n",
	325	hdr, *postred, SMALLOC_POST_RED);
	326	assert(0);
	327	}
	328	}
	329	#else
	330	static void fill_redzone(struct block_hdr *hdr)
	331	{
	332	}
	333
	334	static void sfree_check_redzone(struct block_hdr *hdr)
	335	{
	336	}
	337	#endif
	338
	339	static void sfree_pool(struct pool pool, void ptr)
	340	{
	341	struct block_hdr *hdr;
	342	unsigned int i, idx;
	343	unsigned long offset;
	344
	345	if (!ptr)
	346	return;
	347
	348	ptr -= sizeof(*hdr);
	349	hdr = ptr;
	350
	351	assert(ptr_valid(pool, ptr));
	352
	353	sfree_check_redzone(hdr);
	354
	355	offset = ptr - pool->map;
	356	i = offset / SMALLOC_BPL;
	357	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
	358
	359	pool_lock(pool);
	360	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	361	if (i < pool->next_non_full)
	362	pool->next_non_full = i;
	363	pool->free_blocks += size_to_blocks(hdr->size);
	364	pool_unlock(pool);
	365	}
	366
	367	void sfree(void *ptr)
	368	{
	369	struct pool *pool = NULL;
	370	unsigned int i;
	371
	372	if (!ptr)
	373	return;
	374
	375	global_read_lock();
	376
	377	for (i = 0; i < nr_pools; i++) {
	378	if (ptr_valid(&mp[i], ptr)) {
	379	pool = &mp[i];
	380	break;
	381	}
	382	}
	383
	384	global_read_unlock();
	385
	386	assert(pool);
	387	sfree_pool(pool, ptr);
	388	}
	389
	390	static void __smalloc_pool(struct pool pool, unsigned int size)
	391	{
	392	unsigned int nr_blocks;
	393	unsigned int i;
	394	unsigned int offset;
	395	unsigned int last_idx;
	396	void *ret = NULL;
	397
	398	pool_lock(pool);
	399
	400	nr_blocks = size_to_blocks(size);
	401	if (nr_blocks > pool->free_blocks)
	402	goto fail;
	403
	404	i = pool->next_non_full;
	405	last_idx = 0;
	406	offset = -1U;
	407	while (i < pool->nr_blocks) {
	408	unsigned int idx;
	409
	410	if (pool->bitmap[i] == -1U) {
	411	i++;
	412	pool->next_non_full = i;
	413	last_idx = 0;
	414	continue;
	415	}
	416
	417	idx = find_next_zero(pool->bitmap[i], last_idx);
	418	if (!blocks_free(pool, i, idx, nr_blocks)) {
	419	idx += nr_blocks;
	420	if (idx < SMALLOC_BPI)
	421	last_idx = idx;
	422	else {
	423	last_idx = 0;
	424	while (idx >= SMALLOC_BPI) {
	425	i++;
	426	idx -= SMALLOC_BPI;
	427	}
	428	}
	429	continue;
	430	}
	431	set_blocks(pool, i, idx, nr_blocks);
	432	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	433	break;
	434	}
	435
	436	if (i < pool->nr_blocks) {
	437	pool->free_blocks -= nr_blocks;
	438	ret = pool->map + offset;
	439	}
	440	fail:
	441	pool_unlock(pool);
	442	return ret;
	443	}
	444
	445	static void smalloc_pool(struct pool pool, unsigned int size)
	446	{
	447	unsigned int alloc_size = size + sizeof(struct block_hdr);
	448	void *ptr;
	449
	450	#ifdef SMALLOC_REDZONE
	451	alloc_size += sizeof(unsigned int);
	452	#endif
	453
	454	ptr = __smalloc_pool(pool, alloc_size);
	455	if (ptr) {
	456	struct block_hdr *hdr = ptr;
	457
	458	hdr->size = alloc_size;
	459	fill_redzone(hdr);
	460
	461	ptr += sizeof(*hdr);
	462	memset(ptr, 0, size);
	463	}
	464
	465	return ptr;
	466	}
	467
	468	void *smalloc(unsigned int size)
	469	{
	470	unsigned int i;
	471
	472	global_read_lock();
	473	i = last_pool;
	474
	475	do {
	476	for (; i < nr_pools; i++) {
	477	void *ptr = smalloc_pool(&mp[i], size);
	478
	479	if (ptr) {
	480	last_pool = i;
	481	global_read_unlock();
	482	return ptr;
	483	}
	484	}
	485	if (last_pool) {
	486	last_pool = 0;
	487	continue;
	488	}
	489
	490	if (nr_pools + 1 > MAX_POOLS)
	491	break;
	492	else {
	493	i = nr_pools;
	494	global_read_unlock();
	495	if (add_pool(&mp[nr_pools], size))
	496	goto out;
	497	global_read_lock();
	498	}
	499	} while (1);
	500
	501	global_read_unlock();
	502	out:
	503	return NULL;
	504	}
	505
	506	char smalloc_strdup(const char str)
	507	{
	508	char *ptr;
	509
	510	ptr = smalloc(strlen(str) + 1);
	511	strcpy(ptr, str);
	512	return ptr;
	513	}