OpenSolaris Launch

1 files changed, 344 insertions, 0 deletions

diff --git a/usr/src/lib/libbsdmalloc/common/malloc.bsd43.c b/usr/src/lib/libbsdmalloc/common/malloc.bsd43.c
new file mode 100644
index 0000000000..621716a7d2
--- /dev/null
+++ b/usr/src/lib/libbsdmalloc/common/malloc.bsd43.c
@@ -0,0 +1,344 @@
+/*
+ * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+/*
+ * wizard:/space/4.3reno/usr/src/lib/libc/stdlib/malloc.c
+ * Copyright (c) 1983 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that: (1) source distributions retain this entire copyright
+ * notice and comment, and (2) distributions including binaries display
+ * the following acknowledgement:  ``This product includes software
+ * developed by the University of California, Berkeley and its contributors''
+ * in the documentation or other materials provided with the distribution
+ * and in all advertising materials mentioning features or use of this
+ * software. Neither the name of the University nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/*
+ * 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 bytes long (ILP32)
+ * or 2^n-8 bytes long (LP64).
+ */
+
+/*LINTLIBRARY*/
+#include <sys/types.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+
+/*
+ * 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.
+ * The order of elements is critical: ov_magic must overlay the low order
+ * bits of ov_next, and ov_magic can not be a valid ov_next bit pattern.
+ * Overhead is 4 bytes for ILP32, 8 bytes for LP64
+ */
+union	overhead {
+	union	overhead *ov_next;	/* when free */
+	struct {
+#if defined(_LITTLE_ENDIAN)
+		uchar_t	ovu_magic;	/* magic number */
+		uchar_t	ovu_index;	/* bucket # */
+		uchar_t	ovu_pad[sizeof (union overhead *) - 2];
+#elif defined(_BIG_ENDIAN)
+		uchar_t	ovu_pad[sizeof (union overhead *) - 2];
+		uchar_t	ovu_index;	/* bucket # */
+		uchar_t	ovu_magic;	/* magic number */
+#else
+#error "Endianness is not defined"
+#endif
+	} ovu;
+};
+
+#define	ov_magic	ovu.ovu_magic
+#define	ov_index	ovu.ovu_index
+
+#define	MAGIC		0xef		/* magic # on accounting info */
+
+/*
+ * nextf[i] is the pointer to the next free block of size 2^(i+EXP).
+ * The smallest allocatable block is 8 bytes (ILP32) or 16 bytes (LP64).
+ * The overhead information precedes the data area returned to the user.
+ */
+#ifdef _LP64
+#define	EXP	4
+#define	NBUCKETS 60
+#else
+#define	EXP	3
+#define	NBUCKETS 29
+#endif
+static	union overhead *nextf[NBUCKETS];
+
+static	int	pagesz;			/* page size */
+static	long	sbrk_adjust;		/* in case sbrk() does alignment */
+static	int	pagebucket;		/* page size bucket */
+static	void	morecore(int);
+static	int	findbucket(union overhead *, int);
+
+void *
+malloc(size_t nbytes)
+{
+	union overhead *op;
+	int bucket;
+	ssize_t	n;
+	size_t amt;
+
+	/*
+	 * First time malloc is called, setup page size and
+	 * align break pointer so all data will be page aligned.
+	 */
+	if (pagesz == 0) {
+		pagesz = getpagesize();
+		op = sbrk(0);
+		n = pagesz - sizeof (*op) - ((uintptr_t)op & (pagesz - 1));
+		if (n < 0)
+			n += pagesz;
+		if (n) {
+			if (sbrk(n) == (void *)-1)
+				return (NULL);
+			/*
+			 * We were careful to arrange that
+			 * sbrk(0) + sizeof (union overhead)
+			 * should end up on a page boundary.
+			 * If the underlying sbrk() performs alignment
+			 * then this is false.  We compute the adjustment.
+			 */
+			op = sbrk(0);
+			sbrk_adjust = (uintptr_t)(op + 1) & (pagesz - 1);
+		} else {
+			sbrk_adjust = 0;
+		}
+		bucket = 0;
+		amt = (1UL << EXP);
+		while (pagesz > amt) {
+			amt <<= 1;
+			bucket++;
+		}
+		pagebucket = bucket;
+	}
+	/*
+	 * Convert amount of memory requested into closest block size
+	 * stored in hash buckets which satisfies request.
+	 * Account for space used per block for accounting.
+	 */
+	if (nbytes <= (n = pagesz - sizeof (*op))) {
+		amt = (1UL << EXP);	/* size of first bucket */
+		bucket = 0;
+		n = -(ssize_t)(sizeof (*op));
+	} else {
+		amt = pagesz;
+		bucket = pagebucket;
+	}
+	while (nbytes > amt + n) {
+		amt <<= 1;
+		if (amt == 0)
+			return (NULL);
+		bucket++;
+	}
+	/*
+	 * If nothing in hash bucket right now,
+	 * request more memory from the system.
+	 */
+	if ((op = nextf[bucket]) == NULL) {
+		morecore(bucket);
+		if ((op = nextf[bucket]) == NULL)
+			return (NULL);
+	}
+	/* remove from linked list */
+	nextf[bucket] = op->ov_next;
+	op->ov_magic = MAGIC;
+	op->ov_index = (uchar_t)bucket;
+	return (op + 1);
+}
+
+/*
+ * Allocate more memory to the indicated bucket.
+ */
+static void
+morecore(int bucket)
+{
+	union overhead *op;
+	size_t sz;			/* size of desired block */
+	ssize_t amt;			/* amount to allocate */
+	long nblks;			/* how many blocks we get */
+
+	sz = 1UL << (bucket + EXP);
+	if (sz == 0)
+		return;
+	if (sz < pagesz) {
+		amt = pagesz;
+		nblks = amt / sz;
+	} else {
+		amt = sz + pagesz;
+		nblks = 1;
+	}
+	if (amt <= 0)
+		return;
+	if (amt > LONG_MAX) {
+		intptr_t	delta;
+		/*
+		 * the value required is too big for sbrk() to deal with
+		 * in one go, so use sbrk() at most 2 times instead.
+		 */
+		op = sbrk(0);
+		delta = LONG_MAX;
+		while (delta > 0) {
+			if (sbrk(delta) == (void *)-1) {
+				if (op != sbrk(0))
+					(void) sbrk(-LONG_MAX);
+				return;
+			}
+			amt -= LONG_MAX;
+			delta = amt;
+		}
+	}
+	else
+		op = sbrk(amt);
+	/* no more room! */
+	if (op == (union overhead *)-1)
+		return;
+	/* LINTED improper alignment */
+	op = (union overhead *)((caddr_t)op - sbrk_adjust);
+	/*
+	 * Add new memory allocated to that on
+	 * free list for this hash bucket.
+	 */
+	nextf[bucket] = op;
+	while (--nblks > 0) {
+		/* LINTED improper alignment */
+		op->ov_next = (union overhead *)((caddr_t)op + sz);
+		/* LINTED improper alignment */
+		op = (union overhead *)((caddr_t)op + sz);
+	}
+}
+
+void
+free(void *cp)
+{
+	int size;
+	union overhead *op;
+
+	if (cp == NULL)
+		return;
+	/* LINTED improper alignment */
+	op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
+	if (op->ov_magic != MAGIC)
+		return;			/* previously freed? */
+	size = op->ov_index;
+	op->ov_next = nextf[size];	/* also clobbers ov_magic */
+	nextf[size] = op;
+}
+
+/*
+ * 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
+ * ``realloc_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 realloc_srchlen = 4;	/* 4 should be plenty, -1 =>'s whole list */
+
+void *
+realloc(void *cp, size_t nbytes)
+{
+	size_t onb;
+	int i;
+	union overhead *op;
+	char *res;
+	int was_alloced = 0;
+
+	if (cp == NULL)
+		return (malloc(nbytes));
+	/* LINTED improper alignment */
+	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 ``realloc_srchlen'' items free'd.
+		 * If all lookups fail, then just malloc() the
+		 * space and copy the size of the new space.
+		 */
+		if ((i = findbucket(op, 1)) < 0 &&
+		    (i = findbucket(op, realloc_srchlen)) < 0) {
+			if ((res = malloc(nbytes)) != NULL)
+				(void) memmove(res, cp, nbytes);
+			return (res);
+		}
+	}
+	onb = 1UL << (i + EXP);
+	if (onb < pagesz)
+		onb -= sizeof (*op);
+	else
+		onb += pagesz - sizeof (*op);
+	/* avoid the copy if same size block */
+	if (was_alloced) {
+		size_t sz = 0;
+		if (i) {
+			sz = 1UL << (i + EXP - 1);
+			if (sz < pagesz)
+				sz -= sizeof (*op);
+			else
+				sz += pagesz - sizeof (*op);
+		}
+		if (nbytes <= onb && nbytes > sz) {
+			return (cp);
+		} else
+			free(cp);
+	}
+	if ((res = malloc(nbytes)) == NULL)
+		return (NULL);
+	if (cp != res)		/* common optimization if "compacting" */
+		(void) memmove(res, cp, (nbytes < onb) ? nbytes : onb);
+	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 int
+findbucket(union overhead *freep, int srchlen)
+{
+	union overhead *p;
+	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);
+}