[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"
#include "arch/arch.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	128		/* 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 int find_next_zero(int word, int start)
{
	assert(word != -1U);
	word >>= (start + 1);
	return ffz(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;

	nr_pools++;
	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_write_lock();
	i = last_pool;

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

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

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

out:
	global_write_unlock();
	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
6548f47f	14	#include "mutex.h"
b3268b92	15	#include "arch/arch.h"
d24c33a4	16
6548f47f	17	#define MP_SAFE /* define to make thread safe */
55f6491d	18	#define SMALLOC_REDZONE /* define to detect memory corruption */
d24c33a4	19
ec996e9c JA	20	#define SMALLOC_BPB 32 /* block size, bytes-per-bit in bitmap */
	21	#define SMALLOC_BPI (sizeof(unsigned int) * 8)
	22	#define SMALLOC_BPL (SMALLOC_BPB * SMALLOC_BPI)
	23
	24	#define INITIAL_SIZE 10241024 / new pool size */
68857686	25	#define MAX_POOLS 128 /* maximum number of pools to setup */
d24c33a4	26
55f6491d JA	27	#define SMALLOC_PRE_RED 0xdeadbeefU
55f6491d JA	28	#define SMALLOC_POST_RED 0x5aa55aa5U
55f6491d	29
2b386d25 JA	30	unsigned int smalloc_pool_size = INITIAL_SIZE;
2b386d25 JA	31
d24c33a4	32	struct pool {
6548f47f	33	struct fio_mutex lock; / protects this pool */
d24c33a4	34	void map; / map of blocks */
ec996e9c JA	35	unsigned int bitmap; / blocks free/busy map */
	36	unsigned int free_blocks; /* free blocks */
	37	unsigned int nr_blocks; /* total blocks */
	38	unsigned int next_non_full;
d24c33a4 JA	39	int fd; /* memory backing fd */
d24c33a4 JA	40	char file[PATH_MAX]; /* filename for fd */
ec996e9c JA	41	unsigned int mmap_size;
	42	};
	43
	44	struct block_hdr {
	45	unsigned int size;
	46	#ifdef SMALLOC_REDZONE
	47	unsigned int prered;
	48	#endif
d24c33a4 JA	49	};
	50
	51	static struct pool mp[MAX_POOLS];
	52	static unsigned int nr_pools;
	53	static unsigned int last_pool;
6548f47f	54	static struct fio_mutex *lock;
d24c33a4	55
d24c33a4 JA	56	static inline void pool_lock(struct pool *pool)
d24c33a4 JA	57	{
6548f47f JA	58	if (pool->lock)
6548f47f JA	59	fio_mutex_down(pool->lock);
d24c33a4 JA	60	}
	61
	62	static inline void pool_unlock(struct pool *pool)
	63	{
6548f47f JA	64	if (pool->lock)
6548f47f JA	65	fio_mutex_up(pool->lock);
d24c33a4 JA	66	}
d24c33a4 JA	67
65864cf7	68	static inline void global_read_lock(void)
d24c33a4	69	{
6548f47f JA	70	if (lock)
6548f47f JA	71	fio_mutex_down_read(lock);
d24c33a4 JA	72	}
d24c33a4 JA	73
65864cf7	74	static inline void global_read_unlock(void)
d24c33a4	75	{
6548f47f JA	76	if (lock)
6548f47f JA	77	fio_mutex_up_read(lock);
65864cf7 JA	78	}
	79
	80	static inline void global_write_lock(void)
	81	{
6548f47f JA	82	if (lock)
6548f47f JA	83	fio_mutex_down_write(lock);
65864cf7 JA	84	}
	85
	86	static inline void global_write_unlock(void)
	87	{
6548f47f JA	88	if (lock)
6548f47f JA	89	fio_mutex_up_write(lock);
d24c33a4 JA	90	}
d24c33a4 JA	91
d24c33a4 JA	92	static inline int ptr_valid(struct pool pool, void ptr)
d24c33a4 JA	93	{
dcb69098	94	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
ec996e9c JA	95
ec996e9c JA	96	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
d24c33a4 JA	97	}
d24c33a4 JA	98
808e9ea8 JA	99	static inline unsigned int size_to_blocks(unsigned int size)
	100	{
	101	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
	102	}
	103
dcb69098 JA	104	static int blocks_iter(struct pool *pool, unsigned int pool_idx,
dcb69098 JA	105	unsigned int idx, unsigned int nr_blocks,
ec996e9c	106	int (func)(unsigned int map, unsigned int mask))
d24c33a4	107	{
dcb69098	108
ec996e9c JA	109	while (nr_blocks) {
ec996e9c JA	110	unsigned int this_blocks, mask;
dcb69098 JA	111	unsigned int *map;
	112
	113	if (pool_idx >= pool->nr_blocks)
	114	return 0;
	115
	116	map = &pool->bitmap[pool_idx];
ec996e9c JA	117
	118	this_blocks = nr_blocks;
	119	if (this_blocks + idx > SMALLOC_BPI) {
	120	this_blocks = SMALLOC_BPI - idx;
	121	idx = SMALLOC_BPI - this_blocks;
	122	}
	123
	124	if (this_blocks == SMALLOC_BPI)
	125	mask = -1U;
	126	else
	127	mask = ((1U << this_blocks) - 1) << idx;
	128
	129	if (!func(map, mask))
	130	return 0;
	131
	132	nr_blocks -= this_blocks;
	133	idx = 0;
dcb69098	134	pool_idx++;
ec996e9c JA	135	}
	136
	137	return 1;
d24c33a4 JA	138	}
d24c33a4 JA	139
ec996e9c	140	static int mask_cmp(unsigned int *map, unsigned int mask)
d24c33a4	141	{
ec996e9c	142	return !(*map & mask);
d24c33a4 JA	143	}
d24c33a4 JA	144
ec996e9c	145	static int mask_clear(unsigned int *map, unsigned int mask)
d24c33a4	146	{
dcb69098	147	assert((*map & mask) == mask);
ec996e9c JA	148	*map &= ~mask;
ec996e9c JA	149	return 1;
d24c33a4 JA	150	}
d24c33a4 JA	151
ec996e9c	152	static int mask_set(unsigned int *map, unsigned int mask)
d24c33a4	153	{
dcb69098	154	assert(!(*map & mask));
ec996e9c JA	155	*map \|= mask;
ec996e9c JA	156	return 1;
d24c33a4 JA	157	}
d24c33a4 JA	158
dcb69098 JA	159	static int blocks_free(struct pool *pool, unsigned int pool_idx,
dcb69098 JA	160	unsigned int idx, unsigned int nr_blocks)
d24c33a4	161	{
dcb69098	162	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
d24c33a4 JA	163	}
d24c33a4 JA	164
dcb69098 JA	165	static void set_blocks(struct pool *pool, unsigned int pool_idx,
dcb69098 JA	166	unsigned int idx, unsigned int nr_blocks)
d24c33a4	167	{
dcb69098	168	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
d24c33a4 JA	169	}
d24c33a4 JA	170
dcb69098 JA	171	static void clear_blocks(struct pool *pool, unsigned int pool_idx,
dcb69098 JA	172	unsigned int idx, unsigned int nr_blocks)
d24c33a4	173	{
dcb69098	174	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
d24c33a4 JA	175	}
d24c33a4 JA	176
ec996e9c JA	177	static int find_next_zero(int word, int start)
	178	{
	179	assert(word != -1U);
	180	word >>= (start + 1);
b3268b92	181	return ffz(word) + start + 1;
d24c33a4 JA	182	}
d24c33a4 JA	183
adf57099	184	static int add_pool(struct pool *pool, unsigned int alloc_size)
d24c33a4	185	{
d24c33a4	186	void *ptr;
ec996e9c JA	187	int fd, bitmap_blocks;
ec996e9c JA	188
d24c33a4 JA	189	strcpy(pool->file, "/tmp/.fio_smalloc.XXXXXX");
	190	fd = mkstemp(pool->file);
	191	if (fd < 0)
	192	goto out_close;
	193
55f6491d	194	#ifdef SMALLOC_REDZONE
ec996e9c	195	alloc_size += sizeof(unsigned int);
55f6491d	196	#endif
ec996e9c JA	197	alloc_size += sizeof(struct block_hdr);
	198	if (alloc_size < INITIAL_SIZE)
	199	alloc_size = INITIAL_SIZE;
	200
	201	/* round up to nearest full number of blocks */
	202	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	203	bitmap_blocks = alloc_size / SMALLOC_BPL;
	204	alloc_size += bitmap_blocks * sizeof(unsigned int);
	205	pool->mmap_size = alloc_size;
55f6491d	206
ec996e9c JA	207	pool->nr_blocks = bitmap_blocks;
ec996e9c JA	208	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
adf57099	209
ec996e9c	210	if (ftruncate(fd, alloc_size) < 0)
d24c33a4 JA	211	goto out_unlink;
d24c33a4 JA	212
ec996e9c	213	ptr = mmap(NULL, alloc_size, PROT_READ\|PROT_WRITE, MAP_SHARED, fd, 0);
d24c33a4 JA	214	if (ptr == MAP_FAILED)
	215	goto out_unlink;
	216
ec996e9c JA	217	memset(ptr, 0, alloc_size);
	218	pool->map = ptr;
	219	pool->bitmap = (void ) ptr + (pool->nr_blocks SMALLOC_BPL);
d24c33a4	220
6548f47f JA	221	#ifdef MP_SAFE
6548f47f JA	222	pool->lock = fio_mutex_init(1);
d24c33a4 JA	223	if (!pool->lock)
d24c33a4 JA	224	goto out_unlink;
6548f47f	225	#endif
d24c33a4 JA	226
	227	pool->fd = fd;
	228
d24c33a4 JA	229	nr_pools++;
	230	return 0;
	231	out_unlink:
ec996e9c	232	fprintf(stderr, "smalloc: failed adding pool\n");
d24c33a4	233	if (pool->map)
ec996e9c	234	munmap(pool->map, pool->mmap_size);
d24c33a4 JA	235	unlink(pool->file);
	236	out_close:
	237	if (fd >= 0)
	238	close(fd);
	239	return 1;
	240	}
	241
	242	void sinit(void)
	243	{
4d4e80f2	244	int ret;
d24c33a4	245
6548f47f JA	246	#ifdef MP_SAFE
	247	lock = fio_mutex_rw_init();
	248	#endif
adf57099	249	ret = add_pool(&mp[0], INITIAL_SIZE);
d24c33a4 JA	250	assert(!ret);
	251	}
	252
	253	static void cleanup_pool(struct pool *pool)
	254	{
	255	unlink(pool->file);
	256	close(pool->fd);
ec996e9c	257	munmap(pool->map, pool->mmap_size);
6548f47f JA	258
	259	if (pool->lock)
	260	fio_mutex_remove(pool->lock);
d24c33a4 JA	261	}
	262
	263	void scleanup(void)
	264	{
	265	unsigned int i;
	266
	267	for (i = 0; i < nr_pools; i++)
	268	cleanup_pool(&mp[i]);
	269
6548f47f JA	270	if (lock)
6548f47f JA	271	fio_mutex_remove(lock);
d24c33a4 JA	272	}
d24c33a4 JA	273
89da54e8	274	#ifdef SMALLOC_REDZONE
ec996e9c	275	static void fill_redzone(struct block_hdr *hdr)
55f6491d	276	{
ec996e9c	277	unsigned int postred = (void ) hdr + hdr->size - sizeof(unsigned int);
55f6491d	278
ec996e9c JA	279	hdr->prered = SMALLOC_PRE_RED;
ec996e9c JA	280	*postred = SMALLOC_POST_RED;
ec996e9c	281	}
55f6491d	282
ec996e9c JA	283	static void sfree_check_redzone(struct block_hdr *hdr)
ec996e9c JA	284	{
ec996e9c JA	285	unsigned int postred = (void ) hdr + hdr->size - sizeof(unsigned int);
	286
	287	if (hdr->prered != SMALLOC_PRE_RED) {
55f6491d JA	288	fprintf(stderr, "smalloc pre redzone destroyed!\n");
55f6491d JA	289	fprintf(stderr, " ptr=%p, prered=%x, expected %x\n",
ec996e9c	290	hdr, hdr->prered, SMALLOC_PRE_RED);
55f6491d JA	291	assert(0);
	292	}
	293	if (*postred != SMALLOC_POST_RED) {
	294	fprintf(stderr, "smalloc post redzone destroyed!\n");
	295	fprintf(stderr, " ptr=%p, postred=%x, expected %x\n",
ec996e9c	296	hdr, *postred, SMALLOC_POST_RED);
55f6491d JA	297	assert(0);
55f6491d JA	298	}
89da54e8 JA	299	}
	300	#else
	301	static void fill_redzone(struct block_hdr *hdr)
	302	{
55f6491d JA	303	}
55f6491d JA	304
89da54e8 JA	305	static void sfree_check_redzone(struct block_hdr *hdr)
	306	{
	307	}
	308	#endif
	309
d24c33a4 JA	310	static void sfree_pool(struct pool pool, void ptr)
d24c33a4 JA	311	{
ec996e9c	312	struct block_hdr *hdr;
179446e0	313	unsigned int i, idx;
ec996e9c	314	unsigned long offset;
d24c33a4 JA	315
	316	if (!ptr)
	317	return;
	318
ec996e9c JA	319	ptr -= sizeof(*hdr);
ec996e9c JA	320	hdr = ptr;
55f6491d	321
d24c33a4 JA	322	assert(ptr_valid(pool, ptr));
d24c33a4 JA	323
ec996e9c	324	sfree_check_redzone(hdr);
d24c33a4	325
ec996e9c JA	326	offset = ptr - pool->map;
	327	i = offset / SMALLOC_BPL;
	328	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
d24c33a4	329
ec996e9c	330	pool_lock(pool);
dcb69098	331	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
ec996e9c JA	332	if (i < pool->next_non_full)
ec996e9c JA	333	pool->next_non_full = i;
179446e0	334	pool->free_blocks += size_to_blocks(hdr->size);
d24c33a4 JA	335	pool_unlock(pool);
	336	}
	337
	338	void sfree(void *ptr)
	339	{
	340	struct pool *pool = NULL;
	341	unsigned int i;
	342
8e5732e5 JA	343	if (!ptr)
	344	return;
	345
65864cf7	346	global_read_lock();
d24c33a4 JA	347
	348	for (i = 0; i < nr_pools; i++) {
	349	if (ptr_valid(&mp[i], ptr)) {
	350	pool = &mp[i];
	351	break;
	352	}
	353	}
	354
65864cf7	355	global_read_unlock();
d24c33a4 JA	356
	357	assert(pool);
	358	sfree_pool(pool, ptr);
	359	}
	360
55f6491d	361	static void __smalloc_pool(struct pool pool, unsigned int size)
d24c33a4	362	{
ec996e9c JA	363	unsigned int nr_blocks;
	364	unsigned int i;
	365	unsigned int offset;
	366	unsigned int last_idx;
	367	void *ret = NULL;
d24c33a4	368
d24c33a4	369	pool_lock(pool);
179446e0 JA	370
179446e0 JA	371	nr_blocks = size_to_blocks(size);
ec996e9c	372	if (nr_blocks > pool->free_blocks)
8e5732e5	373	goto fail;
5ec10eaa	374
ec996e9c JA	375	i = pool->next_non_full;
	376	last_idx = 0;
	377	offset = -1U;
	378	while (i < pool->nr_blocks) {
	379	unsigned int idx;
d24c33a4	380
ec996e9c JA	381	if (pool->bitmap[i] == -1U) {
	382	i++;
	383	pool->next_non_full = i;
	384	last_idx = 0;
	385	continue;
	386	}
d24c33a4	387
ec996e9c	388	idx = find_next_zero(pool->bitmap[i], last_idx);
dcb69098	389	if (!blocks_free(pool, i, idx, nr_blocks)) {
ec996e9c JA	390	idx += nr_blocks;
	391	if (idx < SMALLOC_BPI)
	392	last_idx = idx;
	393	else {
	394	last_idx = 0;
	395	while (idx >= SMALLOC_BPI) {
	396	i++;
	397	idx -= SMALLOC_BPI;
	398	}
	399	}
	400	continue;
d24c33a4	401	}
dcb69098	402	set_blocks(pool, i, idx, nr_blocks);
ec996e9c JA	403	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	404	break;
	405	}
	406
	407	if (i < pool->nr_blocks) {
	408	pool->free_blocks -= nr_blocks;
	409	ret = pool->map + offset;
d24c33a4	410	}
ec996e9c	411	fail:
d24c33a4	412	pool_unlock(pool);
ec996e9c	413	return ret;
d24c33a4 JA	414	}
d24c33a4 JA	415
55f6491d JA	416	static void smalloc_pool(struct pool pool, unsigned int size)
55f6491d JA	417	{
89da54e8	418	unsigned int alloc_size = size + sizeof(struct block_hdr);
55f6491d JA	419	void *ptr;
55f6491d JA	420
ec996e9c JA	421	#ifdef SMALLOC_REDZONE
	422	alloc_size += sizeof(unsigned int);
	423	#endif
	424
	425	ptr = __smalloc_pool(pool, alloc_size);
89da54e8 JA	426	if (ptr) {
89da54e8 JA	427	struct block_hdr *hdr = ptr;
55f6491d	428
89da54e8 JA	429	hdr->size = alloc_size;
89da54e8 JA	430	fill_redzone(hdr);
55f6491d	431
89da54e8 JA	432	ptr += sizeof(*hdr);
	433	memset(ptr, 0, size);
	434	}
ec996e9c	435
55f6491d	436	return ptr;
55f6491d JA	437	}
55f6491d JA	438
d24c33a4 JA	439	void *smalloc(unsigned int size)
	440	{
	441	unsigned int i;
	442
d1271dc1	443	global_write_lock();
d24c33a4 JA	444	i = last_pool;
	445
	446	do {
	447	for (; i < nr_pools; i++) {
	448	void *ptr = smalloc_pool(&mp[i], size);
	449
	450	if (ptr) {
	451	last_pool = i;
d1271dc1	452	global_write_unlock();
d24c33a4 JA	453	return ptr;
	454	}
	455	}
	456	if (last_pool) {
	457	last_pool = 0;
	458	continue;
	459	}
	460
ec996e9c	461	if (nr_pools + 1 > MAX_POOLS)
d24c33a4 JA	462	break;
	463	else {
	464	i = nr_pools;
adf57099	465	if (add_pool(&mp[nr_pools], size))
65864cf7	466	goto out;
d24c33a4 JA	467	}
	468	} while (1);
	469
65864cf7	470	out:
d1271dc1	471	global_write_unlock();
d24c33a4 JA	472	return NULL;
	473	}
	474
	475	char smalloc_strdup(const char str)
	476	{
	477	char *ptr;
	478
	479	ptr = smalloc(strlen(str) + 1);
	480	strcpy(ptr, str);
	481	return ptr;
	482	}