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

/* $Header: malloc.c,v 4.0 91/03/20 01:28:52 lwall Locked $
 *
 * $Log:	malloc.c,v $
 * Revision 4.0  91/03/20  01:28:52  lwall
 * 4.0 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 ALIGNBYTES > 4
	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);
  	}
}

void
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
fe14fcc3	1	/* $Header: malloc.c,v 4.0 91/03/20 01:28:52 lwall Locked $
8d063cd8	2	*
8d063cd8	3	* $Log: malloc.c,v $
fe14fcc3	4	* Revision 4.0 91/03/20 01:28:52 lwall
fe14fcc3	5	* 4.0 baseline.
8d063cd8	6	*
	7	*/
	8
	9	#ifndef lint
	10	static char sccsid[] = "@(#)malloc.c 4.3 (Berkeley) 9/16/83";
8d063cd8	11
a687059c	12	#ifdef DEBUGGING
8d063cd8	13	#define RCHECK
a687059c	14	#endif
8d063cd8	15	/*
	16	* malloc.c (Caltech) 2/21/82
	17	* Chris Kingsley, kingsley@cit-20.
	18	*
	19	* This is a very fast storage allocator. It allocates blocks of a small
	20	* number of different sizes, and keeps free lists of each size. Blocks that
	21	* don't exactly fit are passed up to the next larger size. In this
	22	* implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
	23	* This is designed for use in a program that uses vast quantities of memory,
	24	* but bombs when it runs out.
	25	*/
	26
135863df	27	#include "EXTERN.h"
135863df	28	#include "perl.h"
135863df	29
03a14243	30	static findbucket(), morecore();
03a14243	31
135863df	32	/* I don't much care whether these are defined in sys/types.h--LAW */
	33
	34	#define u_char unsigned char
	35	#define u_int unsigned int
	36	#define u_short unsigned short
8d063cd8	37
8d063cd8	38	/*
	39	* The overhead on a block is at least 4 bytes. When free, this space
	40	* contains a pointer to the next free block, and the bottom two bits must
	41	* be zero. When in use, the first byte is set to MAGIC, and the second
	42	* byte is the size index. The remaining bytes are for alignment.
	43	* If range checking is enabled and the size of the block fits
	44	* in two bytes, then the top two bytes hold the size of the requested block
	45	* plus the range checking words, and the header word MINUS ONE.
	46	*/
	47	union overhead {
	48	union overhead ov_next; / when free */
c623bd54	49	#if ALIGNBYTES > 4
c623bd54	50	double strut; /* alignment problems */
a687059c	51	#endif
8d063cd8	52	struct {
	53	u_char ovu_magic; /* magic number */
	54	u_char ovu_index; /* bucket # */
	55	#ifdef RCHECK
	56	u_short ovu_size; /* actual block size */
	57	u_int ovu_rmagic; /* range magic number */
	58	#endif
	59	} ovu;
	60	#define ov_magic ovu.ovu_magic
	61	#define ov_index ovu.ovu_index
	62	#define ov_size ovu.ovu_size
	63	#define ov_rmagic ovu.ovu_rmagic
	64	};
	65
	66	#define MAGIC 0xff /* magic # on accounting info */
378cc40b	67	#define OLDMAGIC 0x7f /* same after a free() */
8d063cd8	68	#define RMAGIC 0x55555555 /* magic # on range info */
	69	#ifdef RCHECK
	70	#define RSLOP sizeof (u_int)
	71	#else
	72	#define RSLOP 0
	73	#endif
	74
	75	/*
	76	* nextf[i] is the pointer to the next free block of size 2^(i+3). The
	77	* smallest allocatable block is 8 bytes. The overhead information
	78	* precedes the data area returned to the user.
	79	*/
	80	#define NBUCKETS 30
	81	static union overhead *nextf[NBUCKETS];
	82	extern char *sbrk();
	83
	84	#ifdef MSTATS
	85	/*
	86	* nmalloc[i] is the difference between the number of mallocs and frees
	87	* for a given block size.
	88	*/
	89	static u_int nmalloc[NBUCKETS];
	90	#include <stdio.h>
	91	#endif
	92
	93	#ifdef debug
	94	#define ASSERT(p) if (!(p)) botch("p"); else
	95	static
	96	botch(s)
	97	char *s;
	98	{
	99
	100	printf("assertion botched: %s\n", s);
	101	abort();
	102	}
	103	#else
	104	#define ASSERT(p)
	105	#endif
	106
	107	char *
	108	malloc(nbytes)
	109	register unsigned nbytes;
	110	{
	111	register union overhead *p;
	112	register int bucket = 0;
	113	register unsigned shiftr;
	114
	115	/*
	116	* Convert amount of memory requested into
	117	* closest block size stored in hash buckets
	118	* which satisfies request. Account for
	119	* space used per block for accounting.
	120	*/
	121	nbytes += sizeof (union overhead) + RSLOP;
	122	nbytes = (nbytes + 3) &~ 3;
	123	shiftr = (nbytes - 1) >> 2;
	124	/* apart from this loop, this is O(1) */
	125	while (shiftr >>= 1)
	126	bucket++;
	127	/*
	128	* If nothing in hash bucket right now,
	129	* request more memory from the system.
	130	*/
	131	if (nextf[bucket] == NULL)
132	morecore(bucket);
133	if ((p = (union overhead *)nextf[bucket]) == NULL)
134	return (NULL);
135	/* remove from linked list */
bf38876a	136	#ifdef RCHECK
bf38876a	137	if (((int)p) & (sizeof(union overhead) - 1))
a687059c	138	#ifndef I286
8d063cd8	139	fprintf(stderr,"Corrupt malloc ptr 0x%x at 0x%x\n",((int)p),p);
a687059c	140	#else
	141	fprintf(stderr,"Corrupt malloc ptr 0x%lx at 0x%lx\n",((int)p),p);
	142	#endif
bf38876a	143	#endif
bf38876a	144	nextf[bucket] = p->ov_next;
8d063cd8	145	p->ov_magic = MAGIC;
	146	p->ov_index= bucket;
	147	#ifdef MSTATS
	148	nmalloc[bucket]++;
	149	#endif
	150	#ifdef RCHECK
	151	/*
	152	* Record allocated size of block and
	153	* bound space with magic numbers.
	154	*/
	155	if (nbytes <= 0x10000)
	156	p->ov_size = nbytes - 1;
	157	p->ov_rmagic = RMAGIC;
	158	((u_int )((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
	159	#endif
	160	return ((char *)(p + 1));
	161	}
	162
	163	/*
	164	* Allocate more memory to the indicated bucket.
	165	*/
	166	static
	167	morecore(bucket)
a687059c	168	register int bucket;
8d063cd8	169	{
	170	register union overhead *op;
	171	register int rnu; /* 2^rnu bytes will be requested */
	172	register int nblks; /* become nblks blocks of the desired size */
	173	register int siz;
	174
	175	if (nextf[bucket])
	176	return;
	177	/*
	178	* Insure memory is allocated
	179	* on a page boundary. Should
	180	* make getpageize call?
	181	*/
	182	op = (union overhead *)sbrk(0);
a687059c	183	#ifndef I286
8d063cd8	184	if ((int)op & 0x3ff)
a687059c	185	(void)sbrk(1024 - ((int)op & 0x3ff));
	186	#else
	187	/* The sbrk(0) call on the I286 always returns the next segment */
	188	#endif
	189
	190	#ifndef I286
8d063cd8	191	/* take 2k unless the block is bigger than that */
8d063cd8	192	rnu = (bucket <= 8) ? 11 : bucket + 3;
a687059c	193	#else
	194	/* take 16k unless the block is bigger than that
	195	(80286s like large segments!) */
	196	rnu = (bucket <= 11) ? 14 : bucket + 3;
	197	#endif
8d063cd8	198	nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */
	199	if (rnu < bucket)
	200	rnu = bucket;
	201	op = (union overhead *)sbrk(1 << rnu);
	202	/* no more room! */
	203	if ((int)op == -1)
	204	return;
	205	/*
	206	* Round up to minimum allocation size boundary
	207	* and deduct from block count to reflect.
	208	*/
a687059c	209	#ifndef I286
8d063cd8	210	if ((int)op & 7) {
	211	op = (union overhead *)(((int)op + 8) &~ 7);
	212	nblks--;
	213	}
a687059c	214	#else
	215	/* Again, this should always be ok on an 80286 */
	216	#endif
8d063cd8	217	/*
	218	* Add new memory allocated to that on
	219	* free list for this hash bucket.
	220	*/
	221	nextf[bucket] = op;
	222	siz = 1 << (bucket + 3);
	223	while (--nblks > 0) {
	224	op->ov_next = (union overhead *)((caddr_t)op + siz);
	225	op = (union overhead *)((caddr_t)op + siz);
	226	}
	227	}
	228
fe14fcc3	229	void
8d063cd8	230	free(cp)
	231	char *cp;
	232	{
	233	register int size;
	234	register union overhead *op;
	235
	236	if (cp == NULL)
	237	return;
	238	op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
	239	#ifdef debug
	240	ASSERT(op->ov_magic == MAGIC); /* make sure it was in use */
	241	#else
378cc40b	242	if (op->ov_magic != MAGIC) {
a687059c	243	warn("%s free() ignored",
378cc40b	244	op->ov_magic == OLDMAGIC ? "Duplicate" : "Bad");
8d063cd8	245	return; /* sanity */
378cc40b	246	}
378cc40b	247	op->ov_magic = OLDMAGIC;
8d063cd8	248	#endif
	249	#ifdef RCHECK
	250	ASSERT(op->ov_rmagic == RMAGIC);
	251	if (op->ov_index <= 13)
	252	ASSERT((u_int )((caddr_t)op + op->ov_size + 1 - RSLOP) == RMAGIC);
	253	#endif
	254	ASSERT(op->ov_index < NBUCKETS);
	255	size = op->ov_index;
	256	op->ov_next = nextf[size];
	257	nextf[size] = op;
	258	#ifdef MSTATS
	259	nmalloc[size]--;
	260	#endif
	261	}
	262
	263	/*
	264	* When a program attempts "storage compaction" as mentioned in the
	265	* old malloc man page, it realloc's an already freed block. Usually
	266	* this is the last block it freed; occasionally it might be farther
	267	* back. We have to search all the free lists for the block in order
	268	* to determine its bucket: 1st we make one pass thru the lists
	269	* checking only the first block in each; if that fails we search
378cc40b	270	* ``reall_srchlen'' blocks in each list for a match (the variable
8d063cd8	271	* is extern so the caller can modify it). If that fails we just copy
	272	* however many bytes was given to realloc() and hope it's not huge.
	273	*/
378cc40b	274	int reall_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */
8d063cd8	275
	276	char *
	277	realloc(cp, nbytes)
	278	char *cp;
	279	unsigned nbytes;
	280	{
	281	register u_int onb;
	282	union overhead *op;
	283	char *res;
	284	register int i;
	285	int was_alloced = 0;
	286
	287	if (cp == NULL)
	288	return (malloc(nbytes));
	289	op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
	290	if (op->ov_magic == MAGIC) {
	291	was_alloced++;
	292	i = op->ov_index;
	293	} else {
	294	/*
	295	* Already free, doing "compaction".
	296	*
	297	* Search for the old block of memory on the
	298	* free list. First, check the most common
	299	* case (last element free'd), then (this failing)
378cc40b	300	* the last ``reall_srchlen'' items free'd.
8d063cd8	301	* If all lookups fail, then assume the size of
	302	* the memory block being realloc'd is the
	303	* smallest possible.
	304	*/
	305	if ((i = findbucket(op, 1)) < 0 &&
378cc40b	306	(i = findbucket(op, reall_srchlen)) < 0)
8d063cd8	307	i = 0;
	308	}
	309	onb = (1 << (i + 3)) - sizeof (*op) - RSLOP;
	310	/* avoid the copy if same size block */
	311	if (was_alloced &&
a687059c	312	nbytes <= onb && nbytes > (onb >> 1) - sizeof(*op) - RSLOP) {
	313	#ifdef RCHECK
	314	/*
	315	* Record new allocated size of block and
	316	* bound space with magic numbers.
	317	*/
	318	if (op->ov_index <= 13) {
	319	/*
	320	* Convert amount of memory requested into
	321	* closest block size stored in hash buckets
	322	* which satisfies request. Account for
	323	* space used per block for accounting.
	324	*/
	325	nbytes += sizeof (union overhead) + RSLOP;
	326	nbytes = (nbytes + 3) &~ 3;
	327	op->ov_size = nbytes - 1;
	328	((u_int )((caddr_t)op + nbytes - RSLOP)) = RMAGIC;
	329	}
	330	#endif
8d063cd8	331	return(cp);
a687059c	332	}
8d063cd8	333	if ((res = malloc(nbytes)) == NULL)
	334	return (NULL);
	335	if (cp != res) /* common optimization */
a687059c	336	(void)bcopy(cp, res, (int)((nbytes < onb) ? nbytes : onb));
8d063cd8	337	if (was_alloced)
	338	free(cp);
	339	return (res);
	340	}
	341
	342	/*
	343	* Search ``srchlen'' elements of each free list for a block whose
	344	* header starts at ``freep''. If srchlen is -1 search the whole list.
	345	* Return bucket number, or -1 if not found.
	346	*/
	347	static
	348	findbucket(freep, srchlen)
	349	union overhead *freep;
	350	int srchlen;
	351	{
	352	register union overhead *p;
	353	register int i, j;
	354
	355	for (i = 0; i < NBUCKETS; i++) {
	356	j = 0;
	357	for (p = nextf[i]; p && j != srchlen; p = p->ov_next) {
	358	if (p == freep)
	359	return (i);
	360	j++;
	361	}
	362	}
	363	return (-1);
	364	}
	365
	366	#ifdef MSTATS
	367	/*
	368	* mstats - print out statistics about malloc
	369	*
	370	* Prints two lines of numbers, one showing the length of the free list
	371	* for each size category, the second showing the number of mallocs -
	372	* frees for each size category.
	373	*/
	374	mstats(s)
	375	char *s;
	376	{
	377	register int i, j;
	378	register union overhead *p;
	379	int totfree = 0,
	380	totused = 0;
	381
	382	fprintf(stderr, "Memory allocation statistics %s\nfree:\t", s);
	383	for (i = 0; i < NBUCKETS; i++) {
	384	for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
	385	;
	386	fprintf(stderr, " %d", j);
	387	totfree += j * (1 << (i + 3));
	388	}
	389	fprintf(stderr, "\nused:\t");
	390	for (i = 0; i < NBUCKETS; i++) {
	391	fprintf(stderr, " %d", nmalloc[i]);
	392	totused += nmalloc[i] * (1 << (i + 3));
	393	}
	394	fprintf(stderr, "\n\tTotal in use: %d, total free: %d\n",
	395	totused, totfree);
	396	}
	397	#endif
a687059c	398	#endif /* lint */