Import sources from NetBSD, tweaked for building in FreeBSD.

1 files changed, 436 insertions, 0 deletions

diff --git a/lib/libc/alpha/stdlib/netbsd_malloc.c b/lib/libc/alpha/stdlib/netbsd_malloc.c
new file mode 100644
index 0000000..98d35bf
--- /dev/null
+++ b/lib/libc/alpha/stdlib/netbsd_malloc.c
@@ -0,0 +1,436 @@
+/* $Id$
+/*	From: NetBSD: malloc.c,v 1.10 1997/07/21 14:08:55 jtc Exp */
+
+/*
+ * Copyright (c) 1983 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+
+/*
+ * 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-10) bytes long.
+ * This is designed for use in a virtual memory environment.
+ */
+
+/* include "namespace.h" */
+#if defined(DEBUG) || defined(RCHECK) || defined(MSTATS)
+#include <stdio.h>
+#endif
+#include <sys/types.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define	NULL 0
+
+
+/*
+ * 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 then a second word holds the size of the
+ * requested block, less 1, rounded up to a multiple of sizeof(RMAGIC).
+ * 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.
+ */
+union	overhead {
+	union	overhead *ov_next;	/* when free */
+	struct {
+		u_char	ovu_magic;	/* magic number */
+		u_char	ovu_index;	/* bucket # */
+#ifdef RCHECK
+		u_short	ovu_rmagic;	/* range magic number */
+		u_long	ovu_size;	/* actual block size */
+#endif
+	} ovu;
+#define	ov_magic	ovu.ovu_magic
+#define	ov_index	ovu.ovu_index
+#define	ov_rmagic	ovu.ovu_rmagic
+#define	ov_size		ovu.ovu_size
+};
+
+#define	MAGIC		0xef		/* magic # on accounting info */
+#define RMAGIC		0x5555		/* magic # on range info */
+
+#ifdef RCHECK
+#define	RSLOP		sizeof (u_short)
+#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];
+
+static	int pagesz;			/* page size */
+static	int pagebucket;			/* page size bucket */
+
+#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
+
+static void morecore __P((int));
+static int findbucket __P((union overhead *, int));
+#ifdef MSTATS
+void mstats __P((char *));
+#endif
+
+#if defined(DEBUG) || defined(RCHECK)
+#define	ASSERT(p)   if (!(p)) botch(__STRING(p))
+
+static botch __P((char *));
+
+static
+botch(s)
+	char *s;
+{
+	fprintf(stderr, "\r\nassertion botched: %s\r\n", s);
+ 	(void) fflush(stderr);		/* just in case user buffered it */
+	abort();
+}
+#else
+#define	ASSERT(p)
+#endif
+
+void *
+malloc(nbytes)
+	size_t nbytes;
+{
+  	register union overhead *op;
+	register int bucket;
+  	register long n;
+	register unsigned amt;
+
+	/*
+	 * First time malloc is called, setup page size and
+	 * align break pointer so all data will be page aligned.
+	 */
+	if (pagesz == 0) {
+		pagesz = n = getpagesize();
+		op = (union overhead *)sbrk(0);
+  		n = n - sizeof (*op) - ((long)op & (n - 1));
+		if (n < 0)
+			n += pagesz;
+  		if (n) {
+  			if (sbrk(n) == (char *)-1)
+				return (NULL);
+		}
+		bucket = 0;
+		amt = 8;
+		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) - RSLOP)) {
+#ifndef RCHECK
+		amt = 8;	/* size of first bucket */
+		bucket = 0;
+#else
+		amt = 16;	/* size of first bucket */
+		bucket = 1;
+#endif
+		n = -((long)sizeof (*op) + RSLOP);
+	} 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 = bucket;
+#ifdef MSTATS
+  	nmalloc[bucket]++;
+#endif
+#ifdef RCHECK
+	/*
+	 * Record allocated size of block and
+	 * bound space with magic numbers.
+	 */
+	op->ov_size = (nbytes + RSLOP - 1) & ~(RSLOP - 1);
+	op->ov_rmagic = RMAGIC;
+  	*(u_short *)((caddr_t)(op + 1) + op->ov_size) = RMAGIC;
+#endif
+  	return ((char *)(op + 1));
+}
+
+/*
+ * Allocate more memory to the indicated bucket.
+ */
+static void
+morecore(bucket)
+	int bucket;
+{
+  	register union overhead *op;
+	register long sz;		/* size of desired block */
+  	long amt;			/* amount to allocate */
+  	int nblks;			/* how many blocks we get */
+
+	/*
+	 * sbrk_size <= 0 only for big, FLUFFY, requests (about
+	 * 2^30 bytes on a VAX, I think) or for a negative arg.
+	 */
+	sz = 1 << (bucket + 3);
+#ifdef DEBUG
+	ASSERT(sz > 0);
+#else
+	if (sz <= 0)
+		return;
+#endif
+	if (sz < pagesz) {
+		amt = pagesz;
+  		nblks = amt / sz;
+	} else {
+		amt = sz + pagesz;
+		nblks = 1;
+	}
+	op = (union overhead *)sbrk(amt);
+	/* no more room! */
+  	if ((long)op == -1)
+  		return;
+	/*
+	 * Add new memory allocated to that on
+	 * free list for this hash bucket.
+	 */
+  	nextf[bucket] = op;
+  	while (--nblks > 0) {
+		op->ov_next = (union overhead *)((caddr_t)op + sz);
+		op = (union overhead *)((caddr_t)op + sz);
+  	}
+}
+
+void
+free(cp)
+	void *cp;
+{   
+  	register long 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)
+		return;				/* sanity */
+#endif
+#ifdef RCHECK
+  	ASSERT(op->ov_rmagic == RMAGIC);
+	ASSERT(*(u_short *)((caddr_t)(op + 1) + op->ov_size) == RMAGIC);
+#endif
+  	size = op->ov_index;
+  	ASSERT(size < NBUCKETS);
+	op->ov_next = nextf[size];	/* also clobbers ov_magic */
+  	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
+ * ``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(cp, nbytes)
+	void *cp; 
+	size_t nbytes;
+{   
+  	register u_long onb;
+	register long i;
+	union overhead *op;
+  	char *res;
+	int was_alloced = 0;
+
+  	if (cp == NULL)
+  		return (malloc(nbytes));
+	if (nbytes == 0) {
+		free (cp);
+		return NULL;
+	}
+	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 assume the size of
+		 * the memory block being realloc'd is the
+		 * largest possible (so that all "nbytes" of new
+		 * memory are copied into).  Note that this could cause
+		 * a memory fault if the old area was tiny, and the moon
+		 * is gibbous.  However, that is very unlikely.
+		 */
+		if ((i = findbucket(op, 1)) < 0 &&
+		    (i = findbucket(op, realloc_srchlen)) < 0)
+			i = NBUCKETS;
+	}
+	onb = 1 << (i + 3);
+	if (onb < pagesz)
+		onb -= sizeof (*op) + RSLOP;
+	else
+		onb += pagesz - sizeof (*op) - RSLOP;
+	/* avoid the copy if same size block */
+	if (was_alloced) {
+		if (i) {
+			i = 1 << (i + 2);
+			if (i < pagesz)
+				i -= sizeof (*op) + RSLOP;
+			else
+				i += pagesz - sizeof (*op) - RSLOP;
+		}
+		if (nbytes <= onb && nbytes > i) {
+#ifdef RCHECK
+			op->ov_size = (nbytes + RSLOP - 1) & ~(RSLOP - 1);
+			*(u_short *)((caddr_t)(op + 1) + op->ov_size) = RMAGIC;
+#endif
+			return(cp);
+		} else
+			free(cp);
+	}
+  	if ((res = malloc(nbytes)) == NULL)
+  		return (NULL);
+  	if (cp != res)		/* common optimization if "compacting" */
+		bcopy(cp, res, (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(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.
+ */
+void
+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