[rsync/rsync.git] / lib / pool_alloc.c

#include "rsync.h"

#define POOL_DEF_EXTENT	(32 * 1024)

#define POOL_QALIGN_P2	(1<<16)

struct alloc_pool
{
	size_t			size;		/* extent size		*/
	size_t			quantum;	/* allocation quantum	*/
	struct pool_extent	*extents;	/* top extent is "live" */
	void			(*bomb)();	/* function to call if
						 * malloc fails		*/
	int			flags;

	/* statistical data */
	unsigned long		e_created;	/* extents created	*/
	unsigned long		e_freed;	/* extents destroyed	*/
	int64			n_allocated;	/* calls to alloc	*/
	int64			n_freed;	/* calls to free	*/
	int64			b_allocated;	/* cum. bytes allocated	*/
	int64			b_freed;	/* cum. bytes freed	*/
};

struct pool_extent
{
	void			*start;		/* starting address	*/
	size_t			free;		/* free bytecount	*/
	size_t			bound;		/* trapped free bytes	*/
	struct pool_extent	*next;
};

struct align_test {
	uchar foo;
	union {
	    int64 i;
	    void *p;
	} bar;
};

#define MINALIGN	offsetof(struct align_test, bar)

/* Temporarily cast a void* var into a char* var when adding an offset (to
 * keep some compilers from complaining about the pointer arithmetic). */
#define PTR_ADD(b,o)	( (void*) ((char*)(b) + (o)) )

alloc_pool_t
pool_create(size_t size, size_t quantum, void (*bomb)(const char *), int flags)
{
	struct alloc_pool *pool;

	if (!(pool = new0(struct alloc_pool)))
		return NULL;

	if ((MINALIGN & (MINALIGN - 1)) != 0) {
		if (bomb)
			(*bomb)("Compiler error: MINALIGN is not a power of 2\n");
		return NULL;
	}

	if (!size)
		size = POOL_DEF_EXTENT;
	if (!quantum)
		quantum = MINALIGN;

	if (flags & POOL_INTERN) {
		if (size <= sizeof (struct pool_extent))
			size = quantum;
		else
			size -= sizeof (struct pool_extent);
		flags |= POOL_PREPEND;
	}

	if (quantum <= 1)
		flags &= ~(POOL_QALIGN | POOL_QALIGN_P2);
	else if (flags & POOL_QALIGN) {
		if (size % quantum)
			size += quantum - size % quantum;
		/* If quantum is a power of 2, we'll avoid using modulus. */
		if (!(quantum & (quantum - 1)))
			flags |= POOL_QALIGN_P2;
	}

	pool->size = size;
	pool->quantum = quantum;
	pool->bomb = bomb;
	pool->flags = flags;

	return pool;
}

void
pool_destroy(alloc_pool_t p)
{
	struct alloc_pool *pool = (struct alloc_pool *) p;
	struct pool_extent *cur, *next;

	if (!pool)
		return;

	for (cur = pool->extents; cur; cur = next) {
		next = cur->next;
		if (pool->flags & POOL_PREPEND)
			free(cur->start - sizeof (struct pool_extent));
		else {
			free(cur->start);
			free(cur);
		}
	}

	free(pool);
}

void *
pool_alloc(alloc_pool_t p, size_t len, const char *bomb_msg)
{
	struct alloc_pool *pool = (struct alloc_pool *) p;
	if (!pool)
		return NULL;

	if (!len)
		len = pool->quantum;
	else if (pool->flags & POOL_QALIGN_P2) {
		if (len & (pool->quantum - 1))
			len += pool->quantum - (len & (pool->quantum - 1));
	} else if (pool->flags & POOL_QALIGN) {
		if (len % pool->quantum)
			len += pool->quantum - len % pool->quantum;
	}

	if (len > pool->size)
		goto bomb_out;

	if (!pool->extents || len > pool->extents->free) {
		void *start;
		size_t asize;
		struct pool_extent *ext;

		asize = pool->size;
		if (pool->flags & POOL_PREPEND)
			asize += sizeof (struct pool_extent);

		if (!(start = new_array(char, asize)))
			goto bomb_out;

		if (pool->flags & POOL_CLEAR)
			memset(start, 0, asize);

		if (pool->flags & POOL_PREPEND) {
			ext = start;
			start += sizeof (struct pool_extent);
		} else if (!(ext = new(struct pool_extent)))
			goto bomb_out;
		ext->start = start;
		ext->free = pool->size;
		ext->bound = 0;
		ext->next = pool->extents;
		pool->extents = ext;

		pool->e_created++;
	}

	pool->n_allocated++;
	pool->b_allocated += len;

	pool->extents->free -= len;

	return PTR_ADD(pool->extents->start, pool->extents->free);

  bomb_out:
	if (pool->bomb)
		(*pool->bomb)(bomb_msg);
	return NULL;
}

/* This function allows you to declare memory in the pool that you are done
 * using.  If you free all the memory in a pool's extent, that extent will
 * be freed. */
void
pool_free(alloc_pool_t p, size_t len, void *addr)
{
	struct alloc_pool *pool = (struct alloc_pool *)p;
	struct pool_extent *cur, *prev;

	if (!pool)
		return;

	if (!len)
		len = pool->quantum;
	else if (pool->flags & POOL_QALIGN_P2) {
		if (len & (pool->quantum - 1))
			len += pool->quantum - (len & (pool->quantum - 1));
	} else if (pool->flags & POOL_QALIGN) {
		if (len % pool->quantum)
			len += pool->quantum - len % pool->quantum;
	}

	pool->n_freed++;
	pool->b_freed += len;

	for (prev = NULL, cur = pool->extents; cur; prev = cur, cur = cur->next) {
		if (addr >= cur->start
		    && addr < PTR_ADD(cur->start, pool->size))
			break;
	}
	if (!cur)
		return;

	if (!prev) {
		/* The "live" extent is kept ready for more allocations. */
		if (cur->free + cur->bound + len >= pool->size) {
			if (pool->flags & POOL_CLEAR) {
				memset(PTR_ADD(cur->start, cur->free), 0,
				       pool->size - cur->free);
			}
			cur->free = pool->size;
			cur->bound = 0;
		} else if (addr == PTR_ADD(cur->start, cur->free)) {
			if (pool->flags & POOL_CLEAR)
				memset(addr, 0, len);
			cur->free += len;
		} else
			cur->bound += len;
	} else {
		cur->bound += len;

		if (cur->free + cur->bound >= pool->size) {
			prev->next = cur->next;
			if (pool->flags & POOL_PREPEND)
				free(cur->start - sizeof (struct pool_extent));
			else {
				free(cur->start);
				free(cur);
			}
			pool->e_freed++;
		} else if (prev != pool->extents) {
			/* Move the extent to be the first non-live extent. */
			prev->next = cur->next;
			cur->next = pool->extents->next;
			pool->extents->next = cur;
		}
	}
}

/* This allows you to declare that the given address marks the edge of some
 * pool memory that is no longer needed.  Any extents that hold only data
 * older than the boundary address are freed.  NOTE: You MUST NOT USE BOTH
 * pool_free() and pool_free_old() on the same pool!! */
void
pool_free_old(alloc_pool_t p, void *addr)
{
	struct alloc_pool *pool = (struct alloc_pool *)p;
	struct pool_extent *cur, *prev, *next;

	if (!pool || !addr)
		return;

	for (prev = NULL, cur = pool->extents; cur; prev = cur, cur = cur->next) {
		if (addr >= cur->start
		    && addr < PTR_ADD(cur->start, pool->size))
			break;
	}
	if (!cur)
		return;

	if (addr == PTR_ADD(cur->start, cur->free)) {
		if (prev) {
			prev->next = NULL;
			next = cur;
		} else {
			/* The most recent live extent can just be reset. */
			if (pool->flags & POOL_CLEAR)
				memset(addr, 0, pool->size - cur->free);
			cur->free = pool->size;
			cur->bound = 0;
			next = cur->next;
			cur->next = NULL;
		}
	} else {
		next = cur->next;
		cur->next = NULL;
	}

	while ((cur = next) != NULL) {
		next = cur->next;
		if (pool->flags & POOL_PREPEND)
			free(cur->start - sizeof (struct pool_extent));
		else {
			free(cur->start);
			free(cur);
		}
		pool->e_freed++;
	}
}

/* If the current extent doesn't have "len" free space in it, mark it as full
 * so that the next alloc will start a new extent.  If len is (size_t)-1, this
 * bump will always occur.  The function returns a boundary address that can
 * be used with pool_free_old(), or a NULL if no memory is allocated. */
void *
pool_boundary(alloc_pool_t p, size_t len)
{
	struct alloc_pool *pool = (struct alloc_pool *)p;
	struct pool_extent *cur;

	if (!pool || !pool->extents)
		return NULL;

	cur = pool->extents;

	if (cur->free < len) {
		cur->bound += cur->free;
		cur->free = 0;
	}

	return PTR_ADD(cur->start, cur->free);
}

#define FDPRINT(label, value) \
	snprintf(buf, sizeof buf, label, value), \
	write(fd, buf, strlen(buf))

#define FDEXTSTAT(ext) \
	snprintf(buf, sizeof buf, "  %12ld  %5ld\n", \
		(long) ext->free, \
		(long) ext->bound), \
	write(fd, buf, strlen(buf))

void
pool_stats(alloc_pool_t p, int fd, int summarize)
{
	struct alloc_pool *pool = (struct alloc_pool *) p;
	struct pool_extent *cur;
	char buf[BUFSIZ];

	if (!pool)
		return;

	FDPRINT("  Extent size:       %12ld\n",	(long)	pool->size);
	FDPRINT("  Alloc quantum:     %12ld\n",	(long)	pool->quantum);
	FDPRINT("  Extents created:   %12ld\n",		pool->e_created);
	FDPRINT("  Extents freed:     %12ld\n",		pool->e_freed);
	FDPRINT("  Alloc count:       %12.0f\n", (double) pool->n_allocated);
	FDPRINT("  Free Count:        %12.0f\n", (double) pool->n_freed);
	FDPRINT("  Bytes allocated:   %12.0f\n", (double) pool->b_allocated);
	FDPRINT("  Bytes freed:       %12.0f\n", (double) pool->b_freed);

	if (summarize)
		return;

	if (!pool->extents)
		return;

	write(fd, "\n", 1);

	for (cur = pool->extents; cur; cur = cur->next)
		FDEXTSTAT(cur);
}
Commit	Line	Data
7efdcf32 S	1	#include "rsync.h"
	2
	3	#define POOL_DEF_EXTENT (32 * 1024)
	4
51ce67d5 WD	5	#define POOL_QALIGN_P2 (1<<16)
51ce67d5 WD	6
7efdcf32 S	7	struct alloc_pool
	8	{
	9	size_t size; /* extent size */
	10	size_t quantum; /* allocation quantum */
676e6041	11	struct pool_extent extents; / top extent is "live" */
e3d27df4	12	void (bomb)(); / function to call if
7efdcf32 S	13	* malloc fails */
	14	int flags;
	15
	16	/* statistical data */
	17	unsigned long e_created; /* extents created */
51ce67d5	18	unsigned long e_freed; /* extents destroyed */
707415d4 WD	19	int64 n_allocated; /* calls to alloc */
	20	int64 n_freed; /* calls to free */
	21	int64 b_allocated; /* cum. bytes allocated */
	22	int64 b_freed; /* cum. bytes freed */
7efdcf32 S	23	};
	24
	25	struct pool_extent
	26	{
	27	void start; / starting address */
	28	size_t free; /* free bytecount */
51ce67d5	29	size_t bound; /* trapped free bytes */
7efdcf32 S	30	struct pool_extent *next;
	31	};
	32
4d4df3cd	33	struct align_test {
51ce67d5 WD	34	uchar foo;
	35	union {
	36	int64 i;
	37	void *p;
	38	} bar;
4d4df3cd WD	39	};
	40
	41	#define MINALIGN offsetof(struct align_test, bar)
7efdcf32	42
71b291d7 WD	43	/* Temporarily cast a void* var into a char* var when adding an offset (to
	44	* keep some compilers from complaining about the pointer arithmetic). */
	45	#define PTR_ADD(b,o) ( (void) ((char)(b) + (o)) )
	46
7efdcf32	47	alloc_pool_t
4a19c3b2	48	pool_create(size_t size, size_t quantum, void (bomb)(const char ), int flags)
7efdcf32	49	{
51ce67d5	50	struct alloc_pool *pool;
7efdcf32	51
51ce67d5 WD	52	if (!(pool = new0(struct alloc_pool)))
	53	return NULL;
	54
	55	if ((MINALIGN & (MINALIGN - 1)) != 0) {
	56	if (bomb)
	57	(*bomb)("Compiler error: MINALIGN is not a power of 2\n");
	58	return NULL;
	59	}
	60
	61	if (!size)
	62	size = POOL_DEF_EXTENT;
	63	if (!quantum)
	64	quantum = MINALIGN;
7efdcf32	65
a0f70237	66	if (flags & POOL_INTERN) {
51ce67d5 WD	67	if (size <= sizeof (struct pool_extent))
	68	size = quantum;
	69	else
	70	size -= sizeof (struct pool_extent);
	71	flags \|= POOL_PREPEND;
7efdcf32	72	}
51ce67d5 WD	73
	74	if (quantum <= 1)
	75	flags &= ~(POOL_QALIGN \| POOL_QALIGN_P2);
	76	else if (flags & POOL_QALIGN) {
	77	if (size % quantum)
	78	size += quantum - size % quantum;
	79	/* If quantum is a power of 2, we'll avoid using modulus. */
	80	if (!(quantum & (quantum - 1)))
	81	flags \|= POOL_QALIGN_P2;
	82	}
	83
	84	pool->size = size;
	85	pool->quantum = quantum;
7efdcf32 S	86	pool->bomb = bomb;
	87	pool->flags = flags;
	88
	89	return pool;
	90	}
	91
	92	void
	93	pool_destroy(alloc_pool_t p)
	94	{
	95	struct alloc_pool pool = (struct alloc_pool ) p;
51ce67d5	96	struct pool_extent cur, next;
7efdcf32 S	97
	98	if (!pool)
	99	return;
	100
676e6041	101	for (cur = pool->extents; cur; cur = next) {
7efdcf32	102	next = cur->next;
51ce67d5 WD	103	if (pool->flags & POOL_PREPEND)
	104	free(cur->start - sizeof (struct pool_extent));
	105	else {
	106	free(cur->start);
7efdcf32	107	free(cur);
51ce67d5	108	}
7efdcf32	109	}
51ce67d5	110
7efdcf32 S	111	free(pool);
	112	}
	113
be20dc34	114	void *
3fac8ca8	115	pool_alloc(alloc_pool_t p, size_t len, const char *bomb_msg)
7efdcf32 S	116	{
	117	struct alloc_pool pool = (struct alloc_pool ) p;
	118	if (!pool)
15f85b1f	119	return NULL;
7efdcf32 S	120
	121	if (!len)
	122	len = pool->quantum;
51ce67d5 WD	123	else if (pool->flags & POOL_QALIGN_P2) {
	124	if (len & (pool->quantum - 1))
	125	len += pool->quantum - (len & (pool->quantum - 1));
	126	} else if (pool->flags & POOL_QALIGN) {
	127	if (len % pool->quantum)
	128	len += pool->quantum - len % pool->quantum;
	129	}
7efdcf32 S	130
7efdcf32 S	131	if (len > pool->size)
3fac8ca8	132	goto bomb_out;
7efdcf32	133
676e6041	134	if (!pool->extents \|\| len > pool->extents->free) {
51ce67d5 WD	135	void *start;
51ce67d5 WD	136	size_t asize;
e3d27df4	137	struct pool_extent *ext;
7efdcf32	138
7efdcf32	139	asize = pool->size;
51ce67d5	140	if (pool->flags & POOL_PREPEND)
7efdcf32 S	141	asize += sizeof (struct pool_extent);
7efdcf32 S	142
e3d27df4	143	if (!(start = new_array(char, asize)))
3fac8ca8	144	goto bomb_out;
7efdcf32 S	145
7efdcf32 S	146	if (pool->flags & POOL_CLEAR)
51ce67d5	147	memset(start, 0, asize);
7efdcf32	148
51ce67d5 WD	149	if (pool->flags & POOL_PREPEND) {
	150	ext = start;
	151	start += sizeof (struct pool_extent);
	152	} else if (!(ext = new(struct pool_extent)))
3fac8ca8	153	goto bomb_out;
e3d27df4	154	ext->start = start;
51ce67d5 WD	155	ext->free = pool->size;
51ce67d5 WD	156	ext->bound = 0;
676e6041 WD	157	ext->next = pool->extents;
676e6041 WD	158	pool->extents = ext;
7efdcf32 S	159
	160	pool->e_created++;
	161	}
	162
	163	pool->n_allocated++;
	164	pool->b_allocated += len;
	165
676e6041	166	pool->extents->free -= len;
7efdcf32	167
676e6041	168	return PTR_ADD(pool->extents->start, pool->extents->free);
7efdcf32	169
3fac8ca8	170	bomb_out:
7efdcf32	171	if (pool->bomb)
3fac8ca8	172	(*pool->bomb)(bomb_msg);
7efdcf32 S	173	return NULL;
	174	}
	175
e3d27df4 WD	176	/* This function allows you to declare memory in the pool that you are done
	177	* using. If you free all the memory in a pool's extent, that extent will
	178	* be freed. */
7efdcf32 S	179	void
	180	pool_free(alloc_pool_t p, size_t len, void *addr)
	181	{
e3d27df4 WD	182	struct alloc_pool pool = (struct alloc_pool )p;
e3d27df4 WD	183	struct pool_extent cur, prev;
7efdcf32 S	184
	185	if (!pool)
	186	return;
	187
	188	if (!len)
	189	len = pool->quantum;
51ce67d5 WD	190	else if (pool->flags & POOL_QALIGN_P2) {
	191	if (len & (pool->quantum - 1))
	192	len += pool->quantum - (len & (pool->quantum - 1));
	193	} else if (pool->flags & POOL_QALIGN) {
	194	if (len % pool->quantum)
	195	len += pool->quantum - len % pool->quantum;
	196	}
7efdcf32	197
7efdcf32 S	198	pool->n_freed++;
	199	pool->b_freed += len;
	200
676e6041 WD	201	for (prev = NULL, cur = pool->extents; cur; prev = cur, cur = cur->next) {
	202	if (addr >= cur->start
	203	&& addr < PTR_ADD(cur->start, pool->size))
	204	break;
	205	}
	206	if (!cur)
	207	return;
	208
	209	if (!prev) {
	210	/* The "live" extent is kept ready for more allocations. */
	211	if (cur->free + cur->bound + len >= pool->size) {
e3d27df4 WD	212	if (pool->flags & POOL_CLEAR) {
	213	memset(PTR_ADD(cur->start, cur->free), 0,
	214	pool->size - cur->free);
	215	}
7efdcf32 S	216	cur->free = pool->size;
7efdcf32 S	217	cur->bound = 0;
676e6041 WD	218	} else if (addr == PTR_ADD(cur->start, cur->free)) {
	219	if (pool->flags & POOL_CLEAR)
	220	memset(addr, 0, len);
	221	cur->free += len;
	222	} else
	223	cur->bound += len;
	224	} else {
	225	cur->bound += len;
	226
	227	if (cur->free + cur->bound >= pool->size) {
	228	prev->next = cur->next;
51ce67d5 WD	229	if (pool->flags & POOL_PREPEND)
	230	free(cur->start - sizeof (struct pool_extent));
	231	else {
	232	free(cur->start);
676e6041	233	free(cur);
51ce67d5	234	}
676e6041 WD	235	pool->e_freed++;
	236	} else if (prev != pool->extents) {
	237	/* Move the extent to be the first non-live extent. */
	238	prev->next = cur->next;
	239	cur->next = pool->extents->next;
	240	pool->extents->next = cur;
7efdcf32	241	}
7efdcf32	242	}
676e6041 WD	243	}
	244
	245	/* This allows you to declare that the given address marks the edge of some
	246	* pool memory that is no longer needed. Any extents that hold only data
	247	* older than the boundary address are freed. NOTE: You MUST NOT USE BOTH
	248	* pool_free() and pool_free_old() on the same pool!! */
	249	void
	250	pool_free_old(alloc_pool_t p, void *addr)
	251	{
	252	struct alloc_pool pool = (struct alloc_pool )p;
	253	struct pool_extent cur, prev, *next;
	254
8b498b9f	255	if (!pool \|\| !addr)
676e6041 WD	256	return;
	257
	258	for (prev = NULL, cur = pool->extents; cur; prev = cur, cur = cur->next) {
7efdcf32	259	if (addr >= cur->start
04575bca	260	&& addr < PTR_ADD(cur->start, pool->size))
7efdcf32 S	261	break;
	262	}
	263	if (!cur)
	264	return;
	265
676e6041 WD	266	if (addr == PTR_ADD(cur->start, cur->free)) {
	267	if (prev) {
	268	prev->next = NULL;
	269	next = cur;
	270	} else {
676e6041 WD	271	/* The most recent live extent can just be reset. */
	272	if (pool->flags & POOL_CLEAR)
	273	memset(addr, 0, pool->size - cur->free);
	274	cur->free = pool->size;
	275	cur->bound = 0;
676e6041	276	next = cur->next;
65a22a5f	277	cur->next = NULL;
676e6041 WD	278	}
	279	} else {
	280	next = cur->next;
	281	cur->next = NULL;
	282	}
7efdcf32	283
676e6041 WD	284	while ((cur = next) != NULL) {
676e6041 WD	285	next = cur->next;
51ce67d5 WD	286	if (pool->flags & POOL_PREPEND)
	287	free(cur->start - sizeof (struct pool_extent));
	288	else {
	289	free(cur->start);
7efdcf32	290	free(cur);
51ce67d5	291	}
7efdcf32 S	292	pool->e_freed++;
7efdcf32 S	293	}
7efdcf32 S	294	}
7efdcf32 S	295
676e6041 WD	296	/* If the current extent doesn't have "len" free space in it, mark it as full
	297	* so that the next alloc will start a new extent. If len is (size_t)-1, this
	298	* bump will always occur. The function returns a boundary address that can
	299	* be used with pool_free_old(), or a NULL if no memory is allocated. */
	300	void *
	301	pool_boundary(alloc_pool_t p, size_t len)
	302	{
	303	struct alloc_pool pool = (struct alloc_pool )p;
	304	struct pool_extent *cur;
	305
	306	if (!pool \|\| !pool->extents)
	307	return NULL;
	308
	309	cur = pool->extents;
	310
	311	if (cur->free < len) {
	312	cur->bound += cur->free;
	313	cur->free = 0;
	314	}
	315
	316	return PTR_ADD(cur->start, cur->free);
	317	}
	318
7efdcf32	319	#define FDPRINT(label, value) \
8ea17b50 WD	320	snprintf(buf, sizeof buf, label, value), \
8ea17b50 WD	321	write(fd, buf, strlen(buf))
7efdcf32 S	322
7efdcf32 S	323	#define FDEXTSTAT(ext) \
8ea17b50	324	snprintf(buf, sizeof buf, " %12ld %5ld\n", \
7efdcf32 S	325	(long) ext->free, \
	326	(long) ext->bound), \
	327	write(fd, buf, strlen(buf))
	328
	329	void
	330	pool_stats(alloc_pool_t p, int fd, int summarize)
	331	{
	332	struct alloc_pool pool = (struct alloc_pool ) p;
51ce67d5	333	struct pool_extent *cur;
7efdcf32 S	334	char buf[BUFSIZ];
	335
	336	if (!pool)
	337	return;
	338
	339	FDPRINT(" Extent size: %12ld\n", (long) pool->size);
	340	FDPRINT(" Alloc quantum: %12ld\n", (long) pool->quantum);
	341	FDPRINT(" Extents created: %12ld\n", pool->e_created);
	342	FDPRINT(" Extents freed: %12ld\n", pool->e_freed);
	343	FDPRINT(" Alloc count: %12.0f\n", (double) pool->n_allocated);
	344	FDPRINT(" Free Count: %12.0f\n", (double) pool->n_freed);
e3d27df4 WD	345	FDPRINT(" Bytes allocated: %12.0f\n", (double) pool->b_allocated);
e3d27df4 WD	346	FDPRINT(" Bytes freed: %12.0f\n", (double) pool->b_freed);
7efdcf32 S	347
	348	if (summarize)
	349	return;
	350
676e6041	351	if (!pool->extents)
7efdcf32 S	352	return;
	353
	354	write(fd, "\n", 1);
	355
676e6041	356	for (cur = pool->extents; cur; cur = cur->next)
7efdcf32	357	FDEXTSTAT(cur);
7efdcf32	358	}