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+/*-
+ * Copyright (c) 1983, 1991 The 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.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)alloc.c 5.8 (Berkeley) 6/8/91";
+#endif /* not lint */
+
+/*
+ * tc.alloc.c from 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 <sys/types.h>
+#include <unistd.h>
+#include <string.h>
+#if __STDC__
+# include <stdarg.h>
+#else
+# include <varargs.h>
+#endif
+
+#include "csh.h"
+#include "extern.h"
+
+char *memtop = NULL; /* PWP: top of current memory */
+char *membot = NULL; /* PWP: bottom of allocatable memory */
+
+#ifndef SYSMALLOC
+
+#undef RCHECK
+#undef DEBUG
+
+
+#ifndef NULL
+#define NULL 0
+#endif
+
+
+/*
+ * 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.
+ */
+
+#define ROUNDUP 7
+
+#define ALIGN(a) (((a) + ROUNDUP) & ~ROUNDUP)
+
+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_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 0xfd /* magic # on accounting info */
+#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];
+
+static int findbucket __P((union overhead *, int));
+static void morecore __P((int));
+
+/*
+ * nmalloc[i] is the difference between the number of mallocs and frees
+ * for a given block size.
+ */
+static u_int nmalloc[NBUCKETS];
+
+
+#ifdef DEBUG
+#define CHECK(a, str, p) \
+ if (a) { \
+ xprintf(str, p); \
+ xprintf("memtop = %lx membot = %lx.\n", memtop, membot); \
+ abort(); \
+ } \
+ else
+#else
+#define CHECK(a, str, p) \
+ if (a) { \
+ xprintf(str, p); \
+ xprintf("memtop = %lx membot = %lx.\n", memtop, membot); \
+ return; \
+ } \
+ else
+#endif
+
+ptr_t
+malloc(nbytes)
+ register size_t nbytes;
+{
+#ifndef lint
+ 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 = ALIGN(ALIGN(sizeof(union overhead)) + nbytes + RSLOP);
+ 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) {
+ child++;
+#ifndef DEBUG
+ stderror(ERR_NOMEM);
+#else
+ showall();
+ xprintf("nbytes=%d: Out of memory\n", nbytes);
+ abort();
+#endif
+ /* fool lint */
+ return ((ptr_t) 0);
+ }
+ /* remove from linked list */
+ nextf[bucket] = nextf[bucket]->ov_next;
+ p->ov_magic = MAGIC;
+ p->ov_index = bucket;
+ nmalloc[bucket]++;
+#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 ((ptr_t) (((caddr_t) p) + ALIGN(sizeof(union overhead))));
+#else
+ if (nbytes)
+ return ((ptr_t) 0);
+ else
+ return ((ptr_t) 0);
+#endif /* !lint */
+}
+
+#ifndef lint
+/*
+ * Allocate more memory to the indicated bucket.
+ */
+static void
+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);
+ memtop = (char *) op;
+ if (membot == NULL)
+ membot = memtop;
+ if ((int) op & 0x3ff) {
+ memtop = (char *) sbrk(1024 - ((int) op & 0x3ff));
+ memtop += 1024 - ((int) op & 0x3ff);
+ }
+
+ /* take 2k unless the block is bigger than that */
+ rnu = (bucket <= 8) ? 11 : bucket + 3;
+ nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */
+ if (rnu < bucket)
+ rnu = bucket;
+ memtop = (char *) sbrk(1 << rnu); /* PWP */
+ op = (union overhead *) memtop;
+ memtop += 1 << rnu;
+ /* no more room! */
+ if ((int) op == -1)
+ return;
+ /*
+ * Round up to minimum allocation size boundary and deduct from block count
+ * to reflect.
+ */
+ if (((u_int) op) & ROUNDUP) {
+ op = (union overhead *) (((u_int) op + (ROUNDUP + 1)) & ~ROUNDUP);
+ nblks--;
+ }
+ /*
+ * 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);
+ }
+}
+
+#endif
+
+#ifdef sun
+int
+#else
+void
+#endif
+free(cp)
+ ptr_t cp;
+{
+#ifndef lint
+ register int size;
+ register union overhead *op;
+
+ if (cp == NULL)
+ return;
+ CHECK(!memtop || !membot, "free(%lx) called before any allocations.", cp);
+ CHECK(cp > (ptr_t) memtop, "free(%lx) above top of memory.", cp);
+ CHECK(cp < (ptr_t) membot, "free(%lx) above top of memory.", cp);
+ op = (union overhead *) (((caddr_t) cp) - ALIGN(sizeof(union overhead)));
+ CHECK(op->ov_magic != MAGIC, "free(%lx) bad block.", cp);
+
+#ifdef RCHECK
+ if (op->ov_index <= 13)
+ CHECK(*(u_int *) ((caddr_t) op + op->ov_size + 1 - RSLOP) != RMAGIC,
+ "free(%lx) bad range check.", cp);
+#endif
+ CHECK(op->ov_index >= NBUCKETS, "free(%lx) bad block index.", cp);
+ size = op->ov_index;
+ op->ov_next = nextf[size];
+ nextf[size] = op;
+
+ nmalloc[size]--;
+
+#else
+ if (cp == NULL)
+ return;
+#endif
+}
+
+ptr_t
+calloc(i, j)
+ size_t i, j;
+{
+#ifndef lint
+ register char *cp, *scp;
+
+ i *= j;
+ scp = cp = (char *) xmalloc((size_t) i);
+ if (i != 0)
+ do
+ *cp++ = 0;
+ while (--i);
+
+ return (scp);
+#else
+ if (i && j)
+ return ((ptr_t) 0);
+ else
+ return ((ptr_t) 0);
+#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.
+ */
+#ifndef lint
+int realloc_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */
+
+#endif /* lint */
+
+ptr_t
+realloc(cp, nbytes)
+ ptr_t cp;
+ size_t nbytes;
+{
+#ifndef lint
+ 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) - ALIGN(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 smallest
+ * possible.
+ */
+ if ((i = findbucket(op, 1)) < 0 &&
+ (i = findbucket(op, realloc_srchlen)) < 0)
+ i = 0;
+
+ onb = ALIGN(nbytes + ALIGN(sizeof(union overhead)) + RSLOP);
+
+ /* avoid the copy if same size block */
+ if (was_alloced && (onb < (1 << (i + 3))) && (onb >= (1 << (i + 2))))
+ return ((ptr_t) cp);
+ if ((res = malloc(nbytes)) == NULL)
+ return ((ptr_t) 0);
+ if (cp != res) /* common optimization */
+ bcopy(cp, res, nbytes);
+ if (was_alloced)
+ free(cp);
+ return (res);
+#else
+ if (cp && nbytes)
+ return ((ptr_t) 0);
+ else
+ return ((ptr_t) 0);
+#endif /* !lint */
+}
+
+
+
+#ifndef lint
+/*
+ * 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);
+}
+
+#endif
+
+
+#else /* SYSMALLOC */
+
+/**
+ ** ``Protected versions'' of malloc, realloc, calloc, and free
+ **
+ ** On many systems:
+ **
+ ** 1. malloc(0) is bad
+ ** 2. free(0) is bad
+ ** 3. realloc(0, n) is bad
+ ** 4. realloc(n, 0) is bad
+ **
+ ** Also we call our error routine if we run out of memory.
+ **/
+char *
+Malloc(n)
+ size_t n;
+{
+ ptr_t ptr;
+
+ n = n ? n : 1;
+
+ if ((ptr = malloc(n)) == (ptr_t) 0) {
+ child++;
+ stderror(ERR_NOMEM);
+ }
+ return ((char *) ptr);
+}
+
+char *
+Realloc(p, n)
+ ptr_t p;
+ size_t n;
+{
+ ptr_t ptr;
+
+ n = n ? n : 1;
+ if ((ptr = (p ? realloc(p, n) : malloc(n))) == (ptr_t) 0) {
+ child++;
+ stderror(ERR_NOMEM);
+ }
+ return ((char *) ptr);
+}
+
+char *
+Calloc(s, n)
+ size_t s, n;
+{
+ char *sptr;
+ ptr_t ptr;
+
+ n *= s;
+ n = n ? n : 1;
+ if ((ptr = malloc(n)) == (ptr_t) 0) {
+ child++;
+ stderror(ERR_NOMEM);
+ }
+
+ sptr = (char *) ptr;
+ if (n != 0)
+ do
+ *sptr++ = 0;
+ while (--n);
+
+ return ((char *) ptr);
+}
+
+void
+Free(p)
+ ptr_t p;
+{
+ if (p)
+ free(p);
+}
+
+#endif /* SYSMALLOC */
+
+/*
+ * 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
+showall()
+{
+#ifndef SYSMALLOC
+ register int i, j;
+ register union overhead *p;
+ int totfree = 0, totused = 0;
+
+ xprintf("csh current memory allocation:\nfree:\t");
+ for (i = 0; i < NBUCKETS; i++) {
+ for (j = 0, p = nextf[i]; p; p = p->ov_next, j++);
+ xprintf(" %4d", j);
+ totfree += j * (1 << (i + 3));
+ }
+ xprintf("\nused:\t");
+ for (i = 0; i < NBUCKETS; i++) {
+ xprintf(" %4d", nmalloc[i]);
+ totused += nmalloc[i] * (1 << (i + 3));
+ }
+ xprintf("\n\tTotal in use: %d, total free: %d\n",
+ totused, totfree);
+ xprintf("\tAllocated memory from 0x%lx to 0x%lx. Real top at 0x%lx\n",
+ membot, memtop, (char *) sbrk(0));
+#else
+ xprintf("Allocated memory from 0x%lx to 0x%lx (%ld).\n",
+ membot, memtop = (char *) sbrk(0), memtop - membot);
+#endif /* SYSMALLOC */
+}
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