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

		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;
		map++;
	}

	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)
{
	*map &= ~mask;
	return 1;
}

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

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

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

static void clear_blocks(unsigned int *map, unsigned int idx,
			 unsigned int nr_blocks)
{
	blocks_iter(map, 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);
}

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

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

static void sfree_check_redzone(struct block_hdr *hdr)
{
#ifdef SMALLOC_REDZONE
	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);
	}
#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->bitmap[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->bitmap[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->bitmap[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)
{
	struct block_hdr *hdr;
	unsigned int alloc_size;
	void *ptr;

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

	ptr = __smalloc_pool(pool, alloc_size);
	if (!ptr) {
		printf("failed allocating %u\n", alloc_size);
		return NULL;
	}

	hdr = ptr;
	hdr->size = alloc_size;
	ptr += sizeof(*hdr);

	fill_redzone(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
d24c33a4 JA	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
1f37f636	16	#define MP_SAFE /* define to make thread safe */
55f6491d	17	#define SMALLOC_REDZONE /* define to detect memory corruption */
d24c33a4	18
ec996e9c JA	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 */
c5dda9e3	24	#define MAX_POOLS 4 /* maximum number of pools to setup */
d24c33a4	25
55f6491d JA	26	#define SMALLOC_PRE_RED 0xdeadbeefU
55f6491d JA	27	#define SMALLOC_POST_RED 0x5aa55aa5U
55f6491d	28
2b386d25 JA	29	unsigned int smalloc_pool_size = INITIAL_SIZE;
2b386d25 JA	30
d24c33a4 JA	31	struct pool {
	32	struct fio_mutex lock; / protects this pool */
	33	void map; / map of blocks */
ec996e9c JA	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;
d24c33a4 JA	38	int fd; /* memory backing fd */
d24c33a4 JA	39	char file[PATH_MAX]; /* filename for fd */
ec996e9c JA	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
d24c33a4 JA	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
d24c33a4 JA	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
65864cf7	67	static inline void global_read_lock(void)
d24c33a4 JA	68	{
d24c33a4 JA	69	if (lock)
65864cf7	70	fio_mutex_down_read(lock);
d24c33a4 JA	71	}
d24c33a4 JA	72
65864cf7	73	static inline void global_read_unlock(void)
d24c33a4 JA	74	{
d24c33a4 JA	75	if (lock)
65864cf7 JA	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);
d24c33a4 JA	89	}
d24c33a4 JA	90
d24c33a4 JA	91	static inline int ptr_valid(struct pool pool, void ptr)
d24c33a4 JA	92	{
ec996e9c JA	93	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
	94
	95	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
d24c33a4 JA	96	}
d24c33a4 JA	97
808e9ea8 JA	98	static inline unsigned int size_to_blocks(unsigned int size)
	99	{
	100	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
	101	}
	102
ec996e9c JA	103	static int blocks_iter(unsigned int *map, unsigned int idx,
	104	unsigned int nr_blocks,
	105	int (func)(unsigned int map, unsigned int mask))
d24c33a4	106	{
ec996e9c JA	107	while (nr_blocks) {
	108	unsigned int this_blocks, mask;
	109
	110	this_blocks = nr_blocks;
	111	if (this_blocks + idx > SMALLOC_BPI) {
	112	this_blocks = SMALLOC_BPI - idx;
	113	idx = SMALLOC_BPI - this_blocks;
	114	}
	115
	116	if (this_blocks == SMALLOC_BPI)
	117	mask = -1U;
	118	else
	119	mask = ((1U << this_blocks) - 1) << idx;
	120
	121	if (!func(map, mask))
	122	return 0;
	123
	124	nr_blocks -= this_blocks;
	125	idx = 0;
	126	map++;
	127	}
	128
	129	return 1;
d24c33a4 JA	130	}
d24c33a4 JA	131
ec996e9c	132	static int mask_cmp(unsigned int *map, unsigned int mask)
d24c33a4	133	{
ec996e9c	134	return !(*map & mask);
d24c33a4 JA	135	}
d24c33a4 JA	136
ec996e9c	137	static int mask_clear(unsigned int *map, unsigned int mask)
d24c33a4	138	{
ec996e9c JA	139	*map &= ~mask;
ec996e9c JA	140	return 1;
d24c33a4 JA	141	}
d24c33a4 JA	142
ec996e9c	143	static int mask_set(unsigned int *map, unsigned int mask)
d24c33a4	144	{
ec996e9c JA	145	*map \|= mask;
ec996e9c JA	146	return 1;
d24c33a4 JA	147	}
d24c33a4 JA	148
ec996e9c JA	149	static int blocks_free(unsigned int *map, unsigned int idx,
ec996e9c JA	150	unsigned int nr_blocks)
d24c33a4	151	{
ec996e9c	152	return blocks_iter(map, idx, nr_blocks, mask_cmp);
d24c33a4 JA	153	}
d24c33a4 JA	154
ec996e9c JA	155	static void set_blocks(unsigned int *map, unsigned int idx,
ec996e9c JA	156	unsigned int nr_blocks)
d24c33a4	157	{
ec996e9c	158	blocks_iter(map, idx, nr_blocks, mask_set);
d24c33a4 JA	159	}
d24c33a4 JA	160
ec996e9c JA	161	static void clear_blocks(unsigned int *map, unsigned int idx,
ec996e9c JA	162	unsigned int nr_blocks)
d24c33a4	163	{
ec996e9c	164	blocks_iter(map, idx, nr_blocks, mask_clear);
d24c33a4 JA	165	}
d24c33a4 JA	166
ec996e9c	167	static inline int __ffs(int word)
d24c33a4	168	{
ec996e9c	169	int r = 0;
d24c33a4	170
ec996e9c JA	171	if (!(word & 0xffff)) {
	172	word >>= 16;
	173	r += 16;
	174	}
	175	if (!(word & 0xff)) {
	176	word >>= 8;
	177	r += 8;
	178	}
	179	if (!(word & 0xf)) {
	180	word >>= 4;
	181	r += 4;
	182	}
	183	if (!(word & 3)) {
	184	word >>= 2;
	185	r += 2;
	186	}
	187	if (!(word & 1)) {
	188	word >>= 1;
	189	r += 1;
d24c33a4 JA	190	}
d24c33a4 JA	191
ec996e9c JA	192	return r;
	193	}
	194
	195	static int find_next_zero(int word, int start)
	196	{
	197	assert(word != -1U);
	198	word >>= (start + 1);
	199	return __ffs(~word) + start + 1;
d24c33a4 JA	200	}
d24c33a4 JA	201
adf57099	202	static int add_pool(struct pool *pool, unsigned int alloc_size)
d24c33a4	203	{
d24c33a4	204	void *ptr;
ec996e9c JA	205	int fd, bitmap_blocks;
ec996e9c JA	206
d24c33a4 JA	207	strcpy(pool->file, "/tmp/.fio_smalloc.XXXXXX");
	208	fd = mkstemp(pool->file);
	209	if (fd < 0)
	210	goto out_close;
	211
55f6491d	212	#ifdef SMALLOC_REDZONE
ec996e9c	213	alloc_size += sizeof(unsigned int);
55f6491d	214	#endif
ec996e9c JA	215	alloc_size += sizeof(struct block_hdr);
	216	if (alloc_size < INITIAL_SIZE)
	217	alloc_size = INITIAL_SIZE;
	218
	219	/* round up to nearest full number of blocks */
	220	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	221	bitmap_blocks = alloc_size / SMALLOC_BPL;
	222	alloc_size += bitmap_blocks * sizeof(unsigned int);
	223	pool->mmap_size = alloc_size;
55f6491d	224
ec996e9c JA	225	pool->nr_blocks = bitmap_blocks;
ec996e9c JA	226	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
adf57099	227
ec996e9c	228	if (ftruncate(fd, alloc_size) < 0)
d24c33a4 JA	229	goto out_unlink;
d24c33a4 JA	230
ec996e9c	231	ptr = mmap(NULL, alloc_size, PROT_READ\|PROT_WRITE, MAP_SHARED, fd, 0);
d24c33a4 JA	232	if (ptr == MAP_FAILED)
	233	goto out_unlink;
	234
ec996e9c JA	235	memset(ptr, 0, alloc_size);
	236	pool->map = ptr;
	237	pool->bitmap = (void ) ptr + (pool->nr_blocks SMALLOC_BPL);
d24c33a4 JA	238
	239	#ifdef MP_SAFE
	240	pool->lock = fio_mutex_init(1);
	241	if (!pool->lock)
	242	goto out_unlink;
	243	#endif
	244
	245	pool->fd = fd;
	246
65864cf7	247	global_write_lock();
d24c33a4	248	nr_pools++;
65864cf7	249	global_write_unlock();
d24c33a4 JA	250	return 0;
d24c33a4 JA	251	out_unlink:
ec996e9c	252	fprintf(stderr, "smalloc: failed adding pool\n");
d24c33a4	253	if (pool->map)
ec996e9c	254	munmap(pool->map, pool->mmap_size);
d24c33a4 JA	255	unlink(pool->file);
	256	out_close:
	257	if (fd >= 0)
	258	close(fd);
	259	return 1;
	260	}
	261
	262	void sinit(void)
	263	{
4d4e80f2	264	int ret;
d24c33a4 JA	265
d24c33a4 JA	266	#ifdef MP_SAFE
9c5b5290	267	lock = fio_mutex_rw_init();
d24c33a4	268	#endif
adf57099	269	ret = add_pool(&mp[0], INITIAL_SIZE);
d24c33a4 JA	270	assert(!ret);
	271	}
	272
	273	static void cleanup_pool(struct pool *pool)
	274	{
	275	unlink(pool->file);
	276	close(pool->fd);
ec996e9c	277	munmap(pool->map, pool->mmap_size);
d24c33a4 JA	278
	279	if (pool->lock)
	280	fio_mutex_remove(pool->lock);
	281	}
	282
	283	void scleanup(void)
	284	{
	285	unsigned int i;
	286
	287	for (i = 0; i < nr_pools; i++)
	288	cleanup_pool(&mp[i]);
	289
	290	if (lock)
	291	fio_mutex_remove(lock);
	292	}
	293
ec996e9c	294	static void fill_redzone(struct block_hdr *hdr)
55f6491d JA	295	{
55f6491d JA	296	#ifdef SMALLOC_REDZONE
ec996e9c	297	unsigned int postred = (void ) hdr + hdr->size - sizeof(unsigned int);
55f6491d	298
ec996e9c JA	299	hdr->prered = SMALLOC_PRE_RED;
	300	*postred = SMALLOC_POST_RED;
	301	#endif
	302	}
55f6491d	303
ec996e9c JA	304	static void sfree_check_redzone(struct block_hdr *hdr)
	305	{
	306	#ifdef SMALLOC_REDZONE
	307	unsigned int postred = (void ) hdr + hdr->size - sizeof(unsigned int);
	308
	309	if (hdr->prered != SMALLOC_PRE_RED) {
55f6491d JA	310	fprintf(stderr, "smalloc pre redzone destroyed!\n");
55f6491d JA	311	fprintf(stderr, " ptr=%p, prered=%x, expected %x\n",
ec996e9c	312	hdr, hdr->prered, SMALLOC_PRE_RED);
55f6491d JA	313	assert(0);
	314	}
	315	if (*postred != SMALLOC_POST_RED) {
	316	fprintf(stderr, "smalloc post redzone destroyed!\n");
	317	fprintf(stderr, " ptr=%p, postred=%x, expected %x\n",
ec996e9c	318	hdr, *postred, SMALLOC_POST_RED);
55f6491d JA	319	assert(0);
	320	}
	321	#endif
	322	}
	323
d24c33a4 JA	324	static void sfree_pool(struct pool pool, void ptr)
d24c33a4 JA	325	{
ec996e9c	326	struct block_hdr *hdr;
179446e0	327	unsigned int i, idx;
ec996e9c	328	unsigned long offset;
d24c33a4 JA	329
	330	if (!ptr)
	331	return;
	332
ec996e9c JA	333	ptr -= sizeof(*hdr);
ec996e9c JA	334	hdr = ptr;
55f6491d	335
d24c33a4 JA	336	assert(ptr_valid(pool, ptr));
d24c33a4 JA	337
ec996e9c	338	sfree_check_redzone(hdr);
d24c33a4	339
ec996e9c JA	340	offset = ptr - pool->map;
	341	i = offset / SMALLOC_BPL;
	342	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
d24c33a4	343
ec996e9c	344	pool_lock(pool);
179446e0	345	clear_blocks(&pool->bitmap[i], idx, size_to_blocks(hdr->size));
ec996e9c JA	346	if (i < pool->next_non_full)
ec996e9c JA	347	pool->next_non_full = i;
179446e0	348	pool->free_blocks += size_to_blocks(hdr->size);
d24c33a4 JA	349	pool_unlock(pool);
	350	}
	351
	352	void sfree(void *ptr)
	353	{
	354	struct pool *pool = NULL;
	355	unsigned int i;
	356
8e5732e5 JA	357	if (!ptr)
	358	return;
	359
65864cf7	360	global_read_lock();
d24c33a4 JA	361
	362	for (i = 0; i < nr_pools; i++) {
	363	if (ptr_valid(&mp[i], ptr)) {
	364	pool = &mp[i];
	365	break;
	366	}
	367	}
	368
65864cf7	369	global_read_unlock();
d24c33a4 JA	370
	371	assert(pool);
	372	sfree_pool(pool, ptr);
	373	}
	374
55f6491d	375	static void __smalloc_pool(struct pool pool, unsigned int size)
d24c33a4	376	{
ec996e9c JA	377	unsigned int nr_blocks;
	378	unsigned int i;
	379	unsigned int offset;
	380	unsigned int last_idx;
	381	void *ret = NULL;
d24c33a4	382
d24c33a4	383	pool_lock(pool);
179446e0 JA	384
179446e0 JA	385	nr_blocks = size_to_blocks(size);
ec996e9c	386	if (nr_blocks > pool->free_blocks)
8e5732e5	387	goto fail;
5ec10eaa	388
ec996e9c JA	389	i = pool->next_non_full;
	390	last_idx = 0;
	391	offset = -1U;
	392	while (i < pool->nr_blocks) {
	393	unsigned int idx;
d24c33a4	394
ec996e9c JA	395	if (pool->bitmap[i] == -1U) {
	396	i++;
	397	pool->next_non_full = i;
	398	last_idx = 0;
	399	continue;
	400	}
d24c33a4	401
ec996e9c JA	402	idx = find_next_zero(pool->bitmap[i], last_idx);
	403	if (!blocks_free(&pool->bitmap[i], idx, nr_blocks)) {
	404	idx += nr_blocks;
	405	if (idx < SMALLOC_BPI)
	406	last_idx = idx;
	407	else {
	408	last_idx = 0;
	409	while (idx >= SMALLOC_BPI) {
	410	i++;
	411	idx -= SMALLOC_BPI;
	412	}
	413	}
	414	continue;
d24c33a4	415	}
ec996e9c JA	416	set_blocks(&pool->bitmap[i], idx, nr_blocks);
	417	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	418	break;
	419	}
	420
	421	if (i < pool->nr_blocks) {
	422	pool->free_blocks -= nr_blocks;
	423	ret = pool->map + offset;
d24c33a4	424	}
ec996e9c	425	fail:
d24c33a4	426	pool_unlock(pool);
ec996e9c	427	return ret;
d24c33a4 JA	428	}
d24c33a4 JA	429
55f6491d JA	430	static void smalloc_pool(struct pool pool, unsigned int size)
55f6491d JA	431	{
ec996e9c JA	432	struct block_hdr *hdr;
ec996e9c JA	433	unsigned int alloc_size;
55f6491d JA	434	void *ptr;
55f6491d JA	435
ec996e9c JA	436	alloc_size = size + sizeof(*hdr);
	437	#ifdef SMALLOC_REDZONE
	438	alloc_size += sizeof(unsigned int);
	439	#endif
	440
	441	ptr = __smalloc_pool(pool, alloc_size);
	442	if (!ptr) {
	443	printf("failed allocating %u\n", alloc_size);
55f6491d	444	return NULL;
ec996e9c	445	}
55f6491d	446
ec996e9c JA	447	hdr = ptr;
	448	hdr->size = alloc_size;
	449	ptr += sizeof(*hdr);
55f6491d	450
ec996e9c JA	451	fill_redzone(hdr);
	452
	453	memset(ptr, 0, size);
55f6491d	454	return ptr;
55f6491d JA	455	}
55f6491d JA	456
d24c33a4 JA	457	void *smalloc(unsigned int size)
	458	{
	459	unsigned int i;
	460
65864cf7	461	global_read_lock();
d24c33a4 JA	462	i = last_pool;
	463
	464	do {
	465	for (; i < nr_pools; i++) {
	466	void *ptr = smalloc_pool(&mp[i], size);
	467
	468	if (ptr) {
	469	last_pool = i;
65864cf7	470	global_read_unlock();
d24c33a4 JA	471	return ptr;
	472	}
	473	}
	474	if (last_pool) {
	475	last_pool = 0;
	476	continue;
	477	}
	478
ec996e9c	479	if (nr_pools + 1 > MAX_POOLS)
d24c33a4 JA	480	break;
	481	else {
	482	i = nr_pools;
65864cf7	483	global_read_unlock();
adf57099	484	if (add_pool(&mp[nr_pools], size))
65864cf7 JA	485	goto out;
65864cf7 JA	486	global_read_lock();
d24c33a4 JA	487	}
	488	} while (1);
	489
65864cf7 JA	490	global_read_unlock();
65864cf7 JA	491	out:
d24c33a4 JA	492	return NULL;
	493	}
	494
	495	char smalloc_strdup(const char str)
	496	{
	497	char *ptr;
	498
	499	ptr = smalloc(strlen(str) + 1);
	500	strcpy(ptr, str);
	501	return ptr;
	502	}