Use somewhat customized version of malloc, in stead of relying on a
crummy sbrk() backend; proper aligment must be guaranteed on all archs. Drafting dlopen, dlsym, et.al.
This commit is contained in:
pk
parent
90cfba21cb
commit
d27581fb4b
@ -1,7 +1,7 @@
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# $Id: Makefile,v 1.7 1993/12/10 05:10:30 mycroft Exp $
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# $Id: Makefile,v 1.8 1994/01/28 21:01:20 pk Exp $
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PROG= ld.so
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SRCS= mdprologue.S rtld.c sbrk.c shlib.c etc.c md.c
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SRCS= mdprologue.S rtld.c malloc.c shlib.c etc.c md.c
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NOMAN= noman
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LDDIR?= $(.CURDIR)/..
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#PICFLAG=-pic
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481
gnu/usr.bin/ld/rtld/malloc.c
Normal file
481
gnu/usr.bin/ld/rtld/malloc.c
Normal file
@ -0,0 +1,481 @@
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/*
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* Copyright (c) 1983 Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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||||
* notice, this list of conditions and the following disclaimer.
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||||
* 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.
|
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* 3. All advertising materials mentioning features or use of this software
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||||
* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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/*static char *sccsid = "from: @(#)malloc.c 5.11 (Berkeley) 2/23/91";*/
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static char *rcsid = "$Id: malloc.c,v 1.1 1994/01/28 21:01:22 pk Exp $";
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#endif /* LIBC_SCCS and not lint */
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/*
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* malloc.c (Caltech) 2/21/82
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* Chris Kingsley, kingsley@cit-20.
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*
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* This is a very fast storage allocator. It allocates blocks of a small
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* number of different sizes, and keeps free lists of each size. Blocks that
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* don't exactly fit are passed up to the next larger size. In this
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* implementation, the available sizes are 2^n-4 (or 2^n-10) bytes long.
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* This is designed for use in a virtual memory environment.
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*/
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#include <sys/types.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/param.h>
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#include <sys/mman.h>
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#ifndef BSD
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#define MAP_COPY MAP_PRIVATE
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#define MAP_FILE 0
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#define MAP_ANON 0
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#endif
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#ifndef BSD /* Need do better than this */
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#define NEED_DEV_ZERO 1
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#endif
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#define NULL 0
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static void morecore();
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static int findbucket();
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/*
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* Pre-allocate mmap'ed pages
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*/
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#define getpagesize() NBPG
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#define NPOOLPAGES (32*1024/NBPG)
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static caddr_t pagepool_start, pagepool_end;
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static int morepages();
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/*
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* The overhead on a block is at least 4 bytes. When free, this space
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* contains a pointer to the next free block, and the bottom two bits must
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* be zero. When in use, the first byte is set to MAGIC, and the second
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* byte is the size index. The remaining bytes are for alignment.
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* If range checking is enabled then a second word holds the size of the
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* requested block, less 1, rounded up to a multiple of sizeof(RMAGIC).
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* The order of elements is critical: ov_magic must overlay the low order
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* bits of ov_next, and ov_magic can not be a valid ov_next bit pattern.
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*/
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union overhead {
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union overhead *ov_next; /* when free */
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struct {
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u_char ovu_magic; /* magic number */
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u_char ovu_index; /* bucket # */
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#ifdef RCHECK
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u_short ovu_rmagic; /* range magic number */
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u_int ovu_size; /* actual block size */
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#endif
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} ovu;
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#define ov_magic ovu.ovu_magic
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#define ov_index ovu.ovu_index
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#define ov_rmagic ovu.ovu_rmagic
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#define ov_size ovu.ovu_size
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};
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#define MAGIC 0xef /* magic # on accounting info */
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#define RMAGIC 0x5555 /* magic # on range info */
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#ifdef RCHECK
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#define RSLOP sizeof (u_short)
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#else
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#define RSLOP 0
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#endif
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/*
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* nextf[i] is the pointer to the next free block of size 2^(i+3). The
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* smallest allocatable block is 8 bytes. The overhead information
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* precedes the data area returned to the user.
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*/
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#define NBUCKETS 30
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static union overhead *nextf[NBUCKETS];
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extern char *sbrk();
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static int pagesz; /* page size */
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static int pagebucket; /* page size bucket */
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#ifdef MSTATS
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/*
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* nmalloc[i] is the difference between the number of mallocs and frees
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* for a given block size.
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*/
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static u_int nmalloc[NBUCKETS];
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#include <stdio.h>
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#endif
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#if defined(DEBUG) || defined(RCHECK)
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#define ASSERT(p) if (!(p)) botch("p")
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#include <stdio.h>
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static
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botch(s)
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char *s;
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{
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fprintf(stderr, "\r\nassertion botched: %s\r\n", s);
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(void) fflush(stderr); /* just in case user buffered it */
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abort();
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}
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#else
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#define ASSERT(p)
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#endif
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void *
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malloc(nbytes)
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size_t nbytes;
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{
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register union overhead *op;
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register int bucket, n;
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register unsigned amt;
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/*
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* First time malloc is called, setup page size and
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* align break pointer so all data will be page aligned.
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*/
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if (pagesz == 0) {
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pagesz = n = getpagesize();
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if (morepages(NPOOLPAGES) == 0)
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return NULL;
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op = (union overhead *)(pagepool_start);
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n = n - sizeof (*op) - ((int)op & (n - 1));
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if (n < 0)
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n += pagesz;
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if (n) {
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pagepool_start += n;
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}
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bucket = 0;
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amt = 8;
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while (pagesz > amt) {
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amt <<= 1;
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bucket++;
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}
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pagebucket = bucket;
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}
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/*
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* Convert amount of memory requested into closest block size
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* stored in hash buckets which satisfies request.
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* Account for space used per block for accounting.
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*/
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if (nbytes <= (n = pagesz - sizeof (*op) - RSLOP)) {
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#ifndef RCHECK
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amt = 8; /* size of first bucket */
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bucket = 0;
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#else
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amt = 16; /* size of first bucket */
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bucket = 1;
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#endif
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n = -(sizeof (*op) + RSLOP);
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} else {
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amt = pagesz;
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bucket = pagebucket;
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}
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while (nbytes > amt + n) {
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amt <<= 1;
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if (amt == 0)
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return (NULL);
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bucket++;
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}
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/*
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* If nothing in hash bucket right now,
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* request more memory from the system.
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*/
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if ((op = nextf[bucket]) == NULL) {
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morecore(bucket);
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if ((op = nextf[bucket]) == NULL)
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return (NULL);
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}
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/* remove from linked list */
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nextf[bucket] = op->ov_next;
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op->ov_magic = MAGIC;
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op->ov_index = bucket;
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#ifdef MSTATS
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nmalloc[bucket]++;
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#endif
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#ifdef RCHECK
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/*
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* Record allocated size of block and
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* bound space with magic numbers.
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*/
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op->ov_size = (nbytes + RSLOP - 1) & ~(RSLOP - 1);
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op->ov_rmagic = RMAGIC;
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*(u_short *)((caddr_t)(op + 1) + op->ov_size) = RMAGIC;
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#endif
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return ((char *)(op + 1));
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}
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/*
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* Allocate more memory to the indicated bucket.
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*/
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static void
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morecore(bucket)
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int bucket;
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{
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register union overhead *op;
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register int sz; /* size of desired block */
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int amt; /* amount to allocate */
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int nblks; /* how many blocks we get */
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/*
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* sbrk_size <= 0 only for big, FLUFFY, requests (about
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* 2^30 bytes on a VAX, I think) or for a negative arg.
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*/
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sz = 1 << (bucket + 3);
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#ifdef DEBUG
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ASSERT(sz > 0);
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#else
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if (sz <= 0)
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return;
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#endif
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if (sz < pagesz) {
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amt = pagesz;
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nblks = amt / sz;
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} else {
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amt = sz + pagesz;
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nblks = 1;
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}
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if (amt > pagepool_end - pagepool_start)
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if (morepages(amt/pagesz + NPOOLPAGES) == 0)
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return;
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op = (union overhead *)pagepool_start;
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pagepool_start += amt;
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/*
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* Add new memory allocated to that on
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* free list for this hash bucket.
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*/
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nextf[bucket] = op;
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while (--nblks > 0) {
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op->ov_next = (union overhead *)((caddr_t)op + sz);
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op = (union overhead *)((caddr_t)op + sz);
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}
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}
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void
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free(cp)
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void *cp;
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{
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register int size;
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register union overhead *op;
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if (cp == NULL)
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return;
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op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
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#ifdef DEBUG
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ASSERT(op->ov_magic == MAGIC); /* make sure it was in use */
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#else
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if (op->ov_magic != MAGIC)
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return; /* sanity */
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#endif
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#ifdef RCHECK
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ASSERT(op->ov_rmagic == RMAGIC);
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ASSERT(*(u_short *)((caddr_t)(op + 1) + op->ov_size) == RMAGIC);
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#endif
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size = op->ov_index;
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ASSERT(size < NBUCKETS);
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op->ov_next = nextf[size]; /* also clobbers ov_magic */
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nextf[size] = op;
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#ifdef MSTATS
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nmalloc[size]--;
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#endif
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}
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/*
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* When a program attempts "storage compaction" as mentioned in the
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* old malloc man page, it realloc's an already freed block. Usually
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* this is the last block it freed; occasionally it might be farther
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||||
* back. We have to search all the free lists for the block in order
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* to determine its bucket: 1st we make one pass thru the lists
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||||
* checking only the first block in each; if that fails we search
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||||
* ``realloc_srchlen'' blocks in each list for a match (the variable
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||||
* is extern so the caller can modify it). If that fails we just copy
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||||
* however many bytes was given to realloc() and hope it's not huge.
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*/
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||||
int realloc_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */
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||||
void *
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realloc(cp, nbytes)
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void *cp;
|
||||
size_t nbytes;
|
||||
{
|
||||
register u_int onb;
|
||||
register int i;
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||||
union overhead *op;
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char *res;
|
||||
int was_alloced = 0;
|
||||
|
||||
if (cp == NULL)
|
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return (malloc(nbytes));
|
||||
op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
|
||||
if (op->ov_magic == MAGIC) {
|
||||
was_alloced++;
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||||
i = op->ov_index;
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||||
} else {
|
||||
/*
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||||
* Already free, doing "compaction".
|
||||
*
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||||
* Search for the old block of memory on the
|
||||
* free list. First, check the most common
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||||
* 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
|
||||
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
|
||||
|
||||
|
||||
static int
|
||||
morepages(n)
|
||||
int n;
|
||||
{
|
||||
int fd = -1;
|
||||
int offset;
|
||||
|
||||
#ifdef NEED_DEV_ZERO
|
||||
fd = open("/dev/zero", O_RDWR, 0);
|
||||
if (fd == -1)
|
||||
perror("/dev/zero");
|
||||
#endif
|
||||
|
||||
if (pagepool_end - pagepool_start > pagesz) {
|
||||
caddr_t addr = (caddr_t)
|
||||
(((int)pagepool_start + pagesz - 1) & ~(pagesz - 1));
|
||||
if (munmap(addr, pagepool_end - addr) != 0)
|
||||
perror("munmap");
|
||||
}
|
||||
|
||||
offset = (int)pagepool_start - ((int)pagepool_start & ~(pagesz - 1));
|
||||
|
||||
if ((pagepool_start = mmap(0, n * pagesz,
|
||||
PROT_READ|PROT_WRITE,
|
||||
MAP_ANON|MAP_COPY, fd, 0)) == (caddr_t)-1) {
|
||||
xprintf("Cannot map anonymous memory");
|
||||
return 0;
|
||||
}
|
||||
pagepool_end = pagepool_start + n * pagesz;
|
||||
pagepool_start += offset;
|
||||
|
||||
#ifdef NEED_DEV_ZERO
|
||||
close(fd);
|
||||
#endif
|
||||
return n;
|
||||
}
|
||||
File diff suppressed because it is too large
Load Diff
@ -1,7 +1,7 @@
|
||||
# $Id: Makefile,v 1.7 1993/12/10 05:10:30 mycroft Exp $
|
||||
# $Id: Makefile,v 1.8 1994/01/28 21:01:20 pk Exp $
|
||||
|
||||
PROG= ld.so
|
||||
SRCS= mdprologue.S rtld.c sbrk.c shlib.c etc.c md.c
|
||||
SRCS= mdprologue.S rtld.c malloc.c shlib.c etc.c md.c
|
||||
NOMAN= noman
|
||||
LDDIR?= $(.CURDIR)/..
|
||||
#PICFLAG=-pic
|
||||
|
||||
481
libexec/ld.aout_so/malloc.c
Normal file
481
libexec/ld.aout_so/malloc.c
Normal file
@ -0,0 +1,481 @@
|
||||
/*
|
||||
* 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.
|
||||
*/
|
||||
|
||||
#if defined(LIBC_SCCS) && !defined(lint)
|
||||
/*static char *sccsid = "from: @(#)malloc.c 5.11 (Berkeley) 2/23/91";*/
|
||||
static char *rcsid = "$Id: malloc.c,v 1.1 1994/01/28 21:01:22 pk Exp $";
|
||||
#endif /* LIBC_SCCS and not lint */
|
||||
|
||||
/*
|
||||
* 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 <sys/types.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
#include <sys/param.h>
|
||||
#include <sys/mman.h>
|
||||
#ifndef BSD
|
||||
#define MAP_COPY MAP_PRIVATE
|
||||
#define MAP_FILE 0
|
||||
#define MAP_ANON 0
|
||||
#endif
|
||||
|
||||
#ifndef BSD /* Need do better than this */
|
||||
#define NEED_DEV_ZERO 1
|
||||
#endif
|
||||
|
||||
#define NULL 0
|
||||
|
||||
static void morecore();
|
||||
static int findbucket();
|
||||
|
||||
/*
|
||||
* Pre-allocate mmap'ed pages
|
||||
*/
|
||||
#define getpagesize() NBPG
|
||||
#define NPOOLPAGES (32*1024/NBPG)
|
||||
static caddr_t pagepool_start, pagepool_end;
|
||||
static int morepages();
|
||||
|
||||
/*
|
||||
* 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_int 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];
|
||||
extern char *sbrk();
|
||||
|
||||
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
|
||||
|
||||
#if defined(DEBUG) || defined(RCHECK)
|
||||
#define ASSERT(p) if (!(p)) botch("p")
|
||||
#include <stdio.h>
|
||||
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, 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();
|
||||
if (morepages(NPOOLPAGES) == 0)
|
||||
return NULL;
|
||||
op = (union overhead *)(pagepool_start);
|
||||
n = n - sizeof (*op) - ((int)op & (n - 1));
|
||||
if (n < 0)
|
||||
n += pagesz;
|
||||
if (n) {
|
||||
pagepool_start += n;
|
||||
}
|
||||
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 = -(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 int sz; /* size of desired block */
|
||||
int 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;
|
||||
}
|
||||
if (amt > pagepool_end - pagepool_start)
|
||||
if (morepages(amt/pagesz + NPOOLPAGES) == 0)
|
||||
return;
|
||||
op = (union overhead *)pagepool_start;
|
||||
pagepool_start += amt;
|
||||
|
||||
/*
|
||||
* 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 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)
|
||||
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_int onb;
|
||||
register int i;
|
||||
union overhead *op;
|
||||
char *res;
|
||||
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 ``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
|
||||
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
|
||||
|
||||
|
||||
static int
|
||||
morepages(n)
|
||||
int n;
|
||||
{
|
||||
int fd = -1;
|
||||
int offset;
|
||||
|
||||
#ifdef NEED_DEV_ZERO
|
||||
fd = open("/dev/zero", O_RDWR, 0);
|
||||
if (fd == -1)
|
||||
perror("/dev/zero");
|
||||
#endif
|
||||
|
||||
if (pagepool_end - pagepool_start > pagesz) {
|
||||
caddr_t addr = (caddr_t)
|
||||
(((int)pagepool_start + pagesz - 1) & ~(pagesz - 1));
|
||||
if (munmap(addr, pagepool_end - addr) != 0)
|
||||
perror("munmap");
|
||||
}
|
||||
|
||||
offset = (int)pagepool_start - ((int)pagepool_start & ~(pagesz - 1));
|
||||
|
||||
if ((pagepool_start = mmap(0, n * pagesz,
|
||||
PROT_READ|PROT_WRITE,
|
||||
MAP_ANON|MAP_COPY, fd, 0)) == (caddr_t)-1) {
|
||||
xprintf("Cannot map anonymous memory");
|
||||
return 0;
|
||||
}
|
||||
pagepool_end = pagepool_start + n * pagesz;
|
||||
pagepool_start += offset;
|
||||
|
||||
#ifdef NEED_DEV_ZERO
|
||||
close(fd);
|
||||
#endif
|
||||
return n;
|
||||
}
|
||||
File diff suppressed because it is too large
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Reference in New Issue
Block a user