[p5sagit/p5-mst-13.2.git] / malloc.c

/* $Header: malloc.c,v 3.0.1.3 90/10/16 15:27:47 lwall Locked $
 *
 * $Log:	malloc.c,v $
 * Revision 3.0.1.3  90/10/16  15:27:47  lwall
 * patch29: various portability fixes
 * 
 * Revision 3.0.1.2  89/11/11  04:36:37  lwall
 * patch2: malloc pointer corruption check made more portable
 * 
 * Revision 3.0.1.1  89/10/26  23:15:05  lwall
 * patch1: some declarations were missing from malloc.c
 * patch1: sparc machines had alignment problems in malloc.c
 * 
 * Revision 3.0  89/10/18  15:20:39  lwall
 * 3.0 baseline
 * 
 */

#ifndef lint
static char sccsid[] = "@(#)malloc.c	4.3 (Berkeley) 9/16/83";

#ifdef DEBUGGING
#define RCHECK
#endif
/*
 * malloc.c (Caltech) 2/21/82
 * Chris Kingsley, kingsley@cit-20.
 *
 * This is a very fast storage allocator.  It allocates blocks of a small 
 * number of different sizes, and keeps free lists of each size.  Blocks that
 * don't exactly fit are passed up to the next larger size.  In this 
 * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
 * This is designed for use in a program that uses vast quantities of memory,
 * but bombs when it runs out. 
 */

#include "EXTERN.h"
#include "perl.h"

static findbucket(), morecore();

/* I don't much care whether these are defined in sys/types.h--LAW */

#define u_char unsigned char
#define u_int unsigned int
#define u_short unsigned short

/*
 * The overhead on a block is at least 4 bytes.  When free, this space
 * contains a pointer to the next free block, and the bottom two bits must
 * be zero.  When in use, the first byte is set to MAGIC, and the second
 * byte is the size index.  The remaining bytes are for alignment.
 * If range checking is enabled and the size of the block fits
 * in two bytes, then the top two bytes hold the size of the requested block
 * plus the range checking words, and the header word MINUS ONE.
 */
union	overhead {
	union	overhead *ov_next;	/* when free */
#if defined(mips) || defined(sparc) || defined(luna88k)
	double  strut;			/* alignment problems */
#endif
	struct {
		u_char	ovu_magic;	/* magic number */
		u_char	ovu_index;	/* bucket # */
#ifdef RCHECK
		u_short	ovu_size;	/* actual block size */
		u_int	ovu_rmagic;	/* range magic number */
#endif
	} ovu;
#define	ov_magic	ovu.ovu_magic
#define	ov_index	ovu.ovu_index
#define	ov_size		ovu.ovu_size
#define	ov_rmagic	ovu.ovu_rmagic
};

#define	MAGIC		0xff		/* magic # on accounting info */
#define OLDMAGIC	0x7f		/* same after a free() */
#define RMAGIC		0x55555555	/* magic # on range info */
#ifdef RCHECK
#define	RSLOP		sizeof (u_int)
#else
#define	RSLOP		0
#endif

/*
 * nextf[i] is the pointer to the next free block of size 2^(i+3).  The
 * smallest allocatable block is 8 bytes.  The overhead information
 * precedes the data area returned to the user.
 */
#define	NBUCKETS 30
static	union overhead *nextf[NBUCKETS];
extern	char *sbrk();

#ifdef MSTATS
/*
 * nmalloc[i] is the difference between the number of mallocs and frees
 * for a given block size.
 */
static	u_int nmalloc[NBUCKETS];
#include <stdio.h>
#endif

#ifdef debug
#define	ASSERT(p)   if (!(p)) botch("p"); else
static
botch(s)
	char *s;
{

	printf("assertion botched: %s\n", s);
	abort();
}
#else
#define	ASSERT(p)
#endif

char *
malloc(nbytes)
	register unsigned nbytes;
{
  	register union overhead *p;
  	register int bucket = 0;
  	register unsigned shiftr;

	/*
	 * Convert amount of memory requested into
	 * closest block size stored in hash buckets
	 * which satisfies request.  Account for
	 * space used per block for accounting.
	 */
  	nbytes += sizeof (union overhead) + RSLOP;
  	nbytes = (nbytes + 3) &~ 3; 
  	shiftr = (nbytes - 1) >> 2;
	/* apart from this loop, this is O(1) */
  	while (shiftr >>= 1)
  		bucket++;
	/*
	 * If nothing in hash bucket right now,
	 * request more memory from the system.
	 */
  	if (nextf[bucket] == NULL)    
  		morecore(bucket);
  	if ((p = (union overhead *)nextf[bucket]) == NULL)
  		return (NULL);
	/* remove from linked list */
#ifdef RCHECK
	if (*((int*)p) & (sizeof(union overhead) - 1))
#ifndef I286
	    fprintf(stderr,"Corrupt malloc ptr 0x%x at 0x%x\n",*((int*)p),p);
#else
	    fprintf(stderr,"Corrupt malloc ptr 0x%lx at 0x%lx\n",*((int*)p),p);
#endif
#endif
  	nextf[bucket] = p->ov_next;
	p->ov_magic = MAGIC;
	p->ov_index= bucket;
#ifdef MSTATS
  	nmalloc[bucket]++;
#endif
#ifdef RCHECK
	/*
	 * Record allocated size of block and
	 * bound space with magic numbers.
	 */
  	if (nbytes <= 0x10000)
		p->ov_size = nbytes - 1;
	p->ov_rmagic = RMAGIC;
  	*((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
#endif
  	return ((char *)(p + 1));
}

/*
 * Allocate more memory to the indicated bucket.
 */
static
morecore(bucket)
	register int bucket;
{
  	register union overhead *op;
  	register int rnu;       /* 2^rnu bytes will be requested */
  	register int nblks;     /* become nblks blocks of the desired size */
	register int siz;

  	if (nextf[bucket])
  		return;
	/*
	 * Insure memory is allocated
	 * on a page boundary.  Should
	 * make getpageize call?
	 */
  	op = (union overhead *)sbrk(0);
#ifndef I286
  	if ((int)op & 0x3ff)
  		(void)sbrk(1024 - ((int)op & 0x3ff));
#else
	/* The sbrk(0) call on the I286 always returns the next segment */
#endif

#ifndef I286
	/* take 2k unless the block is bigger than that */
  	rnu = (bucket <= 8) ? 11 : bucket + 3;
#else
	/* take 16k unless the block is bigger than that 
	   (80286s like large segments!)		*/
  	rnu = (bucket <= 11) ? 14 : bucket + 3;
#endif
  	nblks = 1 << (rnu - (bucket + 3));  /* how many blocks to get */
  	if (rnu < bucket)
		rnu = bucket;
	op = (union overhead *)sbrk(1 << rnu);
	/* no more room! */
  	if ((int)op == -1)
  		return;
	/*
	 * Round up to minimum allocation size boundary
	 * and deduct from block count to reflect.
	 */
#ifndef I286
  	if ((int)op & 7) {
  		op = (union overhead *)(((int)op + 8) &~ 7);
  		nblks--;
  	}
#else
	/* Again, this should always be ok on an 80286 */
#endif
	/*
	 * Add new memory allocated to that on
	 * free list for this hash bucket.
	 */
  	nextf[bucket] = op;
  	siz = 1 << (bucket + 3);
  	while (--nblks > 0) {
		op->ov_next = (union overhead *)((caddr_t)op + siz);
		op = (union overhead *)((caddr_t)op + siz);
  	}
}

free(cp)
	char *cp;
{   
  	register int size;
	register union overhead *op;

  	if (cp == NULL)
  		return;
	op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
#ifdef debug
  	ASSERT(op->ov_magic == MAGIC);		/* make sure it was in use */
#else
	if (op->ov_magic != MAGIC) {
		warn("%s free() ignored",
		    op->ov_magic == OLDMAGIC ? "Duplicate" : "Bad");
		return;				/* sanity */
	}
	op->ov_magic = OLDMAGIC;
#endif
#ifdef RCHECK
  	ASSERT(op->ov_rmagic == RMAGIC);
	if (op->ov_index <= 13)
		ASSERT(*(u_int *)((caddr_t)op + op->ov_size + 1 - RSLOP) == RMAGIC);
#endif
  	ASSERT(op->ov_index < NBUCKETS);
  	size = op->ov_index;
	op->ov_next = nextf[size];
  	nextf[size] = op;
#ifdef MSTATS
  	nmalloc[size]--;
#endif
}

/*
 * When a program attempts "storage compaction" as mentioned in the
 * old malloc man page, it realloc's an already freed block.  Usually
 * this is the last block it freed; occasionally it might be farther
 * back.  We have to search all the free lists for the block in order
 * to determine its bucket: 1st we make one pass thru the lists
 * checking only the first block in each; if that fails we search
 * ``reall_srchlen'' blocks in each list for a match (the variable
 * is extern so the caller can modify it).  If that fails we just copy
 * however many bytes was given to realloc() and hope it's not huge.
 */
int reall_srchlen = 4;	/* 4 should be plenty, -1 =>'s whole list */

char *
realloc(cp, nbytes)
	char *cp; 
	unsigned nbytes;
{   
  	register u_int onb;
	union overhead *op;
  	char *res;
	register int i;
	int was_alloced = 0;

  	if (cp == NULL)
  		return (malloc(nbytes));
	op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
	if (op->ov_magic == MAGIC) {
		was_alloced++;
		i = op->ov_index;
	} else {
		/*
		 * Already free, doing "compaction".
		 *
		 * Search for the old block of memory on the
		 * free list.  First, check the most common
		 * case (last element free'd), then (this failing)
		 * the last ``reall_srchlen'' items free'd.
		 * If all lookups fail, then assume the size of
		 * the memory block being realloc'd is the
		 * smallest possible.
		 */
		if ((i = findbucket(op, 1)) < 0 &&
		    (i = findbucket(op, reall_srchlen)) < 0)
			i = 0;
	}
	onb = (1 << (i + 3)) - sizeof (*op) - RSLOP;
	/* avoid the copy if same size block */
	if (was_alloced &&
	    nbytes <= onb && nbytes > (onb >> 1) - sizeof(*op) - RSLOP) {
#ifdef RCHECK
		/*
		 * Record new allocated size of block and
		 * bound space with magic numbers.
		 */
		if (op->ov_index <= 13) {
			/*
			 * Convert amount of memory requested into
			 * closest block size stored in hash buckets
			 * which satisfies request.  Account for
			 * space used per block for accounting.
			 */
			nbytes += sizeof (union overhead) + RSLOP;
			nbytes = (nbytes + 3) &~ 3; 
			op->ov_size = nbytes - 1;
			*((u_int *)((caddr_t)op + nbytes - RSLOP)) = RMAGIC;
		}
#endif
		return(cp);
	}
  	if ((res = malloc(nbytes)) == NULL)
  		return (NULL);
  	if (cp != res)			/* common optimization */
		(void)bcopy(cp, res, (int)((nbytes < onb) ? nbytes : onb));
  	if (was_alloced)
		free(cp);
  	return (res);
}

/*
 * Search ``srchlen'' elements of each free list for a block whose
 * header starts at ``freep''.  If srchlen is -1 search the whole list.
 * Return bucket number, or -1 if not found.
 */
static
findbucket(freep, srchlen)
	union overhead *freep;
	int srchlen;
{
	register union overhead *p;
	register int i, j;

	for (i = 0; i < NBUCKETS; i++) {
		j = 0;
		for (p = nextf[i]; p && j != srchlen; p = p->ov_next) {
			if (p == freep)
				return (i);
			j++;
		}
	}
	return (-1);
}

#ifdef MSTATS
/*
 * mstats - print out statistics about malloc
 * 
 * Prints two lines of numbers, one showing the length of the free list
 * for each size category, the second showing the number of mallocs -
 * frees for each size category.
 */
mstats(s)
	char *s;
{
  	register int i, j;
  	register union overhead *p;
  	int totfree = 0,
  	totused = 0;

  	fprintf(stderr, "Memory allocation statistics %s\nfree:\t", s);
  	for (i = 0; i < NBUCKETS; i++) {
  		for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
  			;
  		fprintf(stderr, " %d", j);
  		totfree += j * (1 << (i + 3));
  	}
  	fprintf(stderr, "\nused:\t");
  	for (i = 0; i < NBUCKETS; i++) {
  		fprintf(stderr, " %d", nmalloc[i]);
  		totused += nmalloc[i] * (1 << (i + 3));
  	}
  	fprintf(stderr, "\n\tTotal in use: %d, total free: %d\n",
	    totused, totfree);
}
#endif
#endif /* lint */
Commit	Line	Data
d9d8d8de	1	/* $Header: malloc.c,v 3.0.1.3 90/10/16 15:27:47 lwall Locked $
8d063cd8	2	*
8d063cd8	3	* $Log: malloc.c,v $
d9d8d8de	4	* Revision 3.0.1.3 90/10/16 15:27:47 lwall
	5	* patch29: various portability fixes
	6	*
bf38876a	7	* Revision 3.0.1.2 89/11/11 04:36:37 lwall
	8	* patch2: malloc pointer corruption check made more portable
	9	*
03a14243	10	* Revision 3.0.1.1 89/10/26 23:15:05 lwall
	11	* patch1: some declarations were missing from malloc.c
	12	* patch1: sparc machines had alignment problems in malloc.c
	13	*
a687059c	14	* Revision 3.0 89/10/18 15:20:39 lwall
a687059c	15	* 3.0 baseline
8d063cd8	16	*
	17	*/
	18
	19	#ifndef lint
	20	static char sccsid[] = "@(#)malloc.c 4.3 (Berkeley) 9/16/83";
8d063cd8	21
a687059c	22	#ifdef DEBUGGING
8d063cd8	23	#define RCHECK
a687059c	24	#endif
8d063cd8	25	/*
	26	* malloc.c (Caltech) 2/21/82
	27	* Chris Kingsley, kingsley@cit-20.
	28	*
	29	* This is a very fast storage allocator. It allocates blocks of a small
	30	* number of different sizes, and keeps free lists of each size. Blocks that
	31	* don't exactly fit are passed up to the next larger size. In this
	32	* implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
	33	* This is designed for use in a program that uses vast quantities of memory,
	34	* but bombs when it runs out.
	35	*/
	36
135863df	37	#include "EXTERN.h"
135863df	38	#include "perl.h"
135863df	39
03a14243	40	static findbucket(), morecore();
03a14243	41
135863df	42	/* I don't much care whether these are defined in sys/types.h--LAW */
	43
	44	#define u_char unsigned char
	45	#define u_int unsigned int
	46	#define u_short unsigned short
8d063cd8	47
8d063cd8	48	/*
	49	* The overhead on a block is at least 4 bytes. When free, this space
	50	* contains a pointer to the next free block, and the bottom two bits must
	51	* be zero. When in use, the first byte is set to MAGIC, and the second
	52	* byte is the size index. The remaining bytes are for alignment.
	53	* If range checking is enabled and the size of the block fits
	54	* in two bytes, then the top two bytes hold the size of the requested block
	55	* plus the range checking words, and the header word MINUS ONE.
	56	*/
	57	union overhead {
	58	union overhead ov_next; / when free */
d9d8d8de	59	#if defined(mips) \|\| defined(sparc) \|\| defined(luna88k)
a687059c	60	double strut; /* alignment problems */
a687059c	61	#endif
8d063cd8	62	struct {
	63	u_char ovu_magic; /* magic number */
	64	u_char ovu_index; /* bucket # */
	65	#ifdef RCHECK
	66	u_short ovu_size; /* actual block size */
	67	u_int ovu_rmagic; /* range magic number */
	68	#endif
	69	} ovu;
	70	#define ov_magic ovu.ovu_magic
	71	#define ov_index ovu.ovu_index
	72	#define ov_size ovu.ovu_size
	73	#define ov_rmagic ovu.ovu_rmagic
	74	};
	75
	76	#define MAGIC 0xff /* magic # on accounting info */
378cc40b	77	#define OLDMAGIC 0x7f /* same after a free() */
8d063cd8	78	#define RMAGIC 0x55555555 /* magic # on range info */
	79	#ifdef RCHECK
	80	#define RSLOP sizeof (u_int)
	81	#else
	82	#define RSLOP 0
	83	#endif
	84
	85	/*
	86	* nextf[i] is the pointer to the next free block of size 2^(i+3). The
	87	* smallest allocatable block is 8 bytes. The overhead information
	88	* precedes the data area returned to the user.
	89	*/
	90	#define NBUCKETS 30
	91	static union overhead *nextf[NBUCKETS];
	92	extern char *sbrk();
	93
	94	#ifdef MSTATS
	95	/*
	96	* nmalloc[i] is the difference between the number of mallocs and frees
	97	* for a given block size.
	98	*/
	99	static u_int nmalloc[NBUCKETS];
	100	#include <stdio.h>
	101	#endif
	102
	103	#ifdef debug
	104	#define ASSERT(p) if (!(p)) botch("p"); else
	105	static
	106	botch(s)
	107	char *s;
	108	{
	109
	110	printf("assertion botched: %s\n", s);
	111	abort();
	112	}
	113	#else
	114	#define ASSERT(p)
	115	#endif
	116
	117	char *
	118	malloc(nbytes)
	119	register unsigned nbytes;
	120	{
	121	register union overhead *p;
	122	register int bucket = 0;
	123	register unsigned shiftr;
	124
	125	/*
	126	* Convert amount of memory requested into
	127	* closest block size stored in hash buckets
	128	* which satisfies request. Account for
	129	* space used per block for accounting.
	130	*/
	131	nbytes += sizeof (union overhead) + RSLOP;
	132	nbytes = (nbytes + 3) &~ 3;
	133	shiftr = (nbytes - 1) >> 2;
	134	/* apart from this loop, this is O(1) */
	135	while (shiftr >>= 1)
	136	bucket++;
	137	/*
	138	* If nothing in hash bucket right now,
	139	* request more memory from the system.
	140	*/
	141	if (nextf[bucket] == NULL)
142	morecore(bucket);
143	if ((p = (union overhead *)nextf[bucket]) == NULL)
144	return (NULL);
145	/* remove from linked list */
bf38876a	146	#ifdef RCHECK
bf38876a	147	if (((int)p) & (sizeof(union overhead) - 1))
a687059c	148	#ifndef I286
8d063cd8	149	fprintf(stderr,"Corrupt malloc ptr 0x%x at 0x%x\n",((int)p),p);
a687059c	150	#else
	151	fprintf(stderr,"Corrupt malloc ptr 0x%lx at 0x%lx\n",((int)p),p);
	152	#endif
bf38876a	153	#endif
bf38876a	154	nextf[bucket] = p->ov_next;
8d063cd8	155	p->ov_magic = MAGIC;
	156	p->ov_index= bucket;
	157	#ifdef MSTATS
	158	nmalloc[bucket]++;
	159	#endif
	160	#ifdef RCHECK
	161	/*
	162	* Record allocated size of block and
	163	* bound space with magic numbers.
	164	*/
	165	if (nbytes <= 0x10000)
	166	p->ov_size = nbytes - 1;
	167	p->ov_rmagic = RMAGIC;
	168	((u_int )((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
	169	#endif
	170	return ((char *)(p + 1));
	171	}
	172
	173	/*
	174	* Allocate more memory to the indicated bucket.
	175	*/
	176	static
	177	morecore(bucket)
a687059c	178	register int bucket;
8d063cd8	179	{
	180	register union overhead *op;
	181	register int rnu; /* 2^rnu bytes will be requested */
	182	register int nblks; /* become nblks blocks of the desired size */
	183	register int siz;
	184
	185	if (nextf[bucket])
	186	return;
	187	/*
	188	* Insure memory is allocated
	189	* on a page boundary. Should
	190	* make getpageize call?
	191	*/
	192	op = (union overhead *)sbrk(0);
a687059c	193	#ifndef I286
8d063cd8	194	if ((int)op & 0x3ff)
a687059c	195	(void)sbrk(1024 - ((int)op & 0x3ff));
	196	#else
	197	/* The sbrk(0) call on the I286 always returns the next segment */
	198	#endif
	199
	200	#ifndef I286
8d063cd8	201	/* take 2k unless the block is bigger than that */
8d063cd8	202	rnu = (bucket <= 8) ? 11 : bucket + 3;
a687059c	203	#else
	204	/* take 16k unless the block is bigger than that
	205	(80286s like large segments!) */
	206	rnu = (bucket <= 11) ? 14 : bucket + 3;
	207	#endif
8d063cd8	208	nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */
	209	if (rnu < bucket)
	210	rnu = bucket;
	211	op = (union overhead *)sbrk(1 << rnu);
	212	/* no more room! */
	213	if ((int)op == -1)
	214	return;
	215	/*
	216	* Round up to minimum allocation size boundary
	217	* and deduct from block count to reflect.
	218	*/
a687059c	219	#ifndef I286
8d063cd8	220	if ((int)op & 7) {
	221	op = (union overhead *)(((int)op + 8) &~ 7);
	222	nblks--;
	223	}
a687059c	224	#else
	225	/* Again, this should always be ok on an 80286 */
	226	#endif
8d063cd8	227	/*
	228	* Add new memory allocated to that on
	229	* free list for this hash bucket.
	230	*/
	231	nextf[bucket] = op;
	232	siz = 1 << (bucket + 3);
	233	while (--nblks > 0) {
	234	op->ov_next = (union overhead *)((caddr_t)op + siz);
	235	op = (union overhead *)((caddr_t)op + siz);
	236	}
	237	}
	238
	239	free(cp)
	240	char *cp;
	241	{
	242	register int size;
	243	register union overhead *op;
	244
	245	if (cp == NULL)
	246	return;
	247	op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
	248	#ifdef debug
	249	ASSERT(op->ov_magic == MAGIC); /* make sure it was in use */
	250	#else
378cc40b	251	if (op->ov_magic != MAGIC) {
a687059c	252	warn("%s free() ignored",
378cc40b	253	op->ov_magic == OLDMAGIC ? "Duplicate" : "Bad");
8d063cd8	254	return; /* sanity */
378cc40b	255	}
378cc40b	256	op->ov_magic = OLDMAGIC;
8d063cd8	257	#endif
	258	#ifdef RCHECK
	259	ASSERT(op->ov_rmagic == RMAGIC);
	260	if (op->ov_index <= 13)
	261	ASSERT((u_int )((caddr_t)op + op->ov_size + 1 - RSLOP) == RMAGIC);
	262	#endif
	263	ASSERT(op->ov_index < NBUCKETS);
	264	size = op->ov_index;
	265	op->ov_next = nextf[size];
	266	nextf[size] = op;
	267	#ifdef MSTATS
	268	nmalloc[size]--;
	269	#endif
	270	}
	271
	272	/*
	273	* When a program attempts "storage compaction" as mentioned in the
	274	* old malloc man page, it realloc's an already freed block. Usually
	275	* this is the last block it freed; occasionally it might be farther
	276	* back. We have to search all the free lists for the block in order
	277	* to determine its bucket: 1st we make one pass thru the lists
	278	* checking only the first block in each; if that fails we search
378cc40b	279	* ``reall_srchlen'' blocks in each list for a match (the variable
8d063cd8	280	* is extern so the caller can modify it). If that fails we just copy
	281	* however many bytes was given to realloc() and hope it's not huge.
	282	*/
378cc40b	283	int reall_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */
8d063cd8	284
	285	char *
	286	realloc(cp, nbytes)
	287	char *cp;
	288	unsigned nbytes;
	289	{
	290	register u_int onb;
	291	union overhead *op;
	292	char *res;
	293	register int i;
	294	int was_alloced = 0;
	295
	296	if (cp == NULL)
	297	return (malloc(nbytes));
	298	op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
	299	if (op->ov_magic == MAGIC) {
	300	was_alloced++;
	301	i = op->ov_index;
	302	} else {
	303	/*
	304	* Already free, doing "compaction".
	305	*
	306	* Search for the old block of memory on the
	307	* free list. First, check the most common
	308	* case (last element free'd), then (this failing)
378cc40b	309	* the last ``reall_srchlen'' items free'd.
8d063cd8	310	* If all lookups fail, then assume the size of
	311	* the memory block being realloc'd is the
	312	* smallest possible.
	313	*/
	314	if ((i = findbucket(op, 1)) < 0 &&
378cc40b	315	(i = findbucket(op, reall_srchlen)) < 0)
8d063cd8	316	i = 0;
	317	}
	318	onb = (1 << (i + 3)) - sizeof (*op) - RSLOP;
	319	/* avoid the copy if same size block */
	320	if (was_alloced &&
a687059c	321	nbytes <= onb && nbytes > (onb >> 1) - sizeof(*op) - RSLOP) {
	322	#ifdef RCHECK
	323	/*
	324	* Record new allocated size of block and
	325	* bound space with magic numbers.
	326	*/
	327	if (op->ov_index <= 13) {
	328	/*
	329	* Convert amount of memory requested into
	330	* closest block size stored in hash buckets
	331	* which satisfies request. Account for
	332	* space used per block for accounting.
	333	*/
	334	nbytes += sizeof (union overhead) + RSLOP;
	335	nbytes = (nbytes + 3) &~ 3;
	336	op->ov_size = nbytes - 1;
	337	((u_int )((caddr_t)op + nbytes - RSLOP)) = RMAGIC;
	338	}
	339	#endif
8d063cd8	340	return(cp);
a687059c	341	}
8d063cd8	342	if ((res = malloc(nbytes)) == NULL)
	343	return (NULL);
	344	if (cp != res) /* common optimization */
a687059c	345	(void)bcopy(cp, res, (int)((nbytes < onb) ? nbytes : onb));
8d063cd8	346	if (was_alloced)
	347	free(cp);
	348	return (res);
	349	}
	350
	351	/*
	352	* Search ``srchlen'' elements of each free list for a block whose
	353	* header starts at ``freep''. If srchlen is -1 search the whole list.
	354	* Return bucket number, or -1 if not found.
	355	*/
	356	static
	357	findbucket(freep, srchlen)
	358	union overhead *freep;
	359	int srchlen;
	360	{
	361	register union overhead *p;
	362	register int i, j;
	363
	364	for (i = 0; i < NBUCKETS; i++) {
	365	j = 0;
	366	for (p = nextf[i]; p && j != srchlen; p = p->ov_next) {
	367	if (p == freep)
	368	return (i);
	369	j++;
	370	}
	371	}
	372	return (-1);
	373	}
	374
	375	#ifdef MSTATS
	376	/*
	377	* mstats - print out statistics about malloc
	378	*
	379	* Prints two lines of numbers, one showing the length of the free list
	380	* for each size category, the second showing the number of mallocs -
	381	* frees for each size category.
	382	*/
	383	mstats(s)
	384	char *s;
	385	{
	386	register int i, j;
	387	register union overhead *p;
	388	int totfree = 0,
	389	totused = 0;
	390
	391	fprintf(stderr, "Memory allocation statistics %s\nfree:\t", s);
	392	for (i = 0; i < NBUCKETS; i++) {
	393	for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
	394	;
	395	fprintf(stderr, " %d", j);
	396	totfree += j * (1 << (i + 3));
	397	}
	398	fprintf(stderr, "\nused:\t");
	399	for (i = 0; i < NBUCKETS; i++) {
	400	fprintf(stderr, " %d", nmalloc[i]);
	401	totused += nmalloc[i] * (1 << (i + 3));
	402	}
	403	fprintf(stderr, "\n\tTotal in use: %d, total free: %d\n",
	404	totused, totfree);
	405	}
	406	#endif
a687059c	407	#endif /* lint */