#ifndef lint
static const char RCSid[] = "$Id: bmalloc.c,v 2.3 2003/02/22 02:07:21 greg Exp $";
#endif
/*
* Bmalloc provides basic memory allocation without overhead (no free lists).
* Use only to take the load off of malloc for all those
* piddling little requests that you never expect to free.
* Bmalloc defers to malloc for big requests.
* Bfree should hand memory to bmalloc, but it usually fails here.
*
* External symbols declared in standard.h
*/
/* ====================================================================
* The Radiance Software License, Version 1.0
*
* Copyright (c) 1990 - 2002 The Regents of the University of California,
* through Lawrence Berkeley National Laboratory. 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. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes Radiance software
* (http://radsite.lbl.gov/)
* developed by the Lawrence Berkeley National Laboratory
* (http://www.lbl.gov/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
* and "The Regents of the University of California" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact radiance@radsite.lbl.gov.
*
* 5. Products derived from this software may not be called "Radiance",
* nor may "Radiance" appear in their name, without prior written
* permission of Lawrence Berkeley National Laboratory.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 Lawrence Berkeley National Laboratory OR
* ITS 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of Lawrence Berkeley National Laboratory. For more
* information on Lawrence Berkeley National Laboratory, please see
* .
*/
#include
#ifndef MBLKSIZ
#define MBLKSIZ 16376 /* size of memory allocation block */
#endif
#define WASTEFRAC 12 /* don't waste more than a fraction */
#ifndef ALIGNT
#define ALIGNT double /* type for alignment */
#endif
#define BYTES_WORD sizeof(ALIGNT)
static char *bposition = NULL;
static unsigned int nremain = 0;
char *
bmalloc(n) /* allocate a block of n bytes */
register unsigned int n;
{
if (n > nremain && (n > MBLKSIZ || nremain > MBLKSIZ/WASTEFRAC))
return(malloc(n)); /* too big */
n = (n+(BYTES_WORD-1))&~(BYTES_WORD-1); /* word align */
if (n > nremain && (bposition = (char *)malloc(nremain = MBLKSIZ)) == NULL) {
nremain = 0;
return(NULL);
}
bposition += n;
nremain -= n;
return(bposition - n);
}
void
bfree(p, n) /* free random memory */
register char *p;
register unsigned int n;
{
register unsigned int bsiz;
/* check alignment */
bsiz = BYTES_WORD - ((unsigned int)p&(BYTES_WORD-1));
if (bsiz < BYTES_WORD) {
p += bsiz;
n -= bsiz;
}
if (p + n == bposition) { /* just allocated? */
bposition = p;
nremain += n;
return;
}
if (n > nremain) { /* better than what we've got? */
bposition = p;
nremain = n;
return;
}
/* just throw it away, then */
}