src/common/bmalloc.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#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 [email protected].
 *
 * 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
 * <http://www.lbl.gov/>.
 */

#include <stdlib.h>

#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 */
}
Revision:	2.3
Committed:	Sat Feb 22 02:07:21 2003 UTC (22 years, 8 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.2:	+71 -16 lines
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.3	static const char RCSid[] = "$Id$";
3	greg	1.1	#endif
4			/*
5	greg	1.3	* Bmalloc provides basic memory allocation without overhead (no free lists).
6			* Use only to take the load off of malloc for all those
7			* piddling little requests that you never expect to free.
8			* Bmalloc defers to malloc for big requests.
9			* Bfree should hand memory to bmalloc, but it usually fails here.
10	greg	2.3	*
11			* External symbols declared in standard.h
12	greg	1.1	*/
13
14	greg	2.3	/* ====================================================================
15			* The Radiance Software License, Version 1.0
16			*
17			* Copyright (c) 1990 - 2002 The Regents of the University of California,
18			* through Lawrence Berkeley National Laboratory. All rights reserved.
19			*
20			* Redistribution and use in source and binary forms, with or without
21			* modification, are permitted provided that the following conditions
22			* are met:
23			*
24			* 1. Redistributions of source code must retain the above copyright
25			* notice, this list of conditions and the following disclaimer.
26			*
27			* 2. Redistributions in binary form must reproduce the above copyright
28			* notice, this list of conditions and the following disclaimer in
29			* the documentation and/or other materials provided with the
30			* distribution.
31			*
32			* 3. The end-user documentation included with the redistribution,
33			* if any, must include the following acknowledgment:
34			* "This product includes Radiance software
35			* (http://radsite.lbl.gov/)
36			* developed by the Lawrence Berkeley National Laboratory
37			* (http://www.lbl.gov/)."
38			* Alternately, this acknowledgment may appear in the software itself,
39			* if and wherever such third-party acknowledgments normally appear.
40			*
41			* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
42			* and "The Regents of the University of California" must
43			* not be used to endorse or promote products derived from this
44			* software without prior written permission. For written
45			* permission, please contact [email protected].
46			*
47			* 5. Products derived from this software may not be called "Radiance",
48			* nor may "Radiance" appear in their name, without prior written
49			* permission of Lawrence Berkeley National Laboratory.
50			*
51			* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
52			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
53			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
54			* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
55			* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
56			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
57			* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
58			* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
59			* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
60			* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
61			* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62			* SUCH DAMAGE.
63			* ====================================================================
64			*
65			* This software consists of voluntary contributions made by many
66			* individuals on behalf of Lawrence Berkeley National Laboratory. For more
67			* information on Lawrence Berkeley National Laboratory, please see
68			* <http://www.lbl.gov/>.
69			*/
70
71			#include <stdlib.h>
72	greg	1.2
73	greg	1.1	#ifndef MBLKSIZ
74			#define MBLKSIZ 16376 /* size of memory allocation block */
75			#endif
76	greg	1.3	#define WASTEFRAC 12 /* don't waste more than a fraction */
77	greg	2.3	#ifndef ALIGNT
78			#define ALIGNT double /* type for alignment */
79	greg	1.1	#endif
80	greg	2.3	#define BYTES_WORD sizeof(ALIGNT)
81	greg	1.1
82	greg	1.3	static char *bposition = NULL;
83	greg	2.3	static unsigned int nremain = 0;
84	greg	1.3
85
86	greg	1.1	char *
87	greg	2.2	bmalloc(n) /* allocate a block of n bytes */
88	greg	2.3	register unsigned int n;
89	greg	1.1	{
90	greg	1.3	if (n > nremain && (n > MBLKSIZ \|\| nremain > MBLKSIZ/WASTEFRAC))
91	greg	1.2	return(malloc(n)); /* too big */
92	greg	1.1
93			n = (n+(BYTES_WORD-1))&~(BYTES_WORD-1); /* word align */
94
95	greg	2.3	if (n > nremain && (bposition = (char *)malloc(nremain = MBLKSIZ)) == NULL) {
96	greg	2.2	nremain = 0;
97			return(NULL);
98	greg	1.1	}
99	greg	1.3	bposition += n;
100			nremain -= n;
101			return(bposition - n);
102	greg	1.1	}
103
104
105	greg	2.3	void
106	greg	1.1	bfree(p, n) /* free random memory */
107	greg	1.3	register char *p;
108	greg	2.3	register unsigned int n;
109	greg	1.1	{
110	greg	2.3	register unsigned int bsiz;
111	greg	1.3	/* check alignment */
112	greg	2.3	bsiz = BYTES_WORD - ((unsigned int)p&(BYTES_WORD-1));
113	greg	1.3	if (bsiz < BYTES_WORD) {
114			p += bsiz;
115			n -= bsiz;
116			}
117			if (p + n == bposition) { /* just allocated? */
118			bposition = p;
119			nremain += n;
120			return;
121			}
122			if (n > nremain) { /* better than what we've got? */
123			bposition = p;
124			nremain = n;
125			return;
126			}
127			/* just throw it away, then */
128	greg	1.1	}