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
#	Content
1	#ifndef lint
2	static const char RCSid[] = "$Id$";
3	#endif
4	/*
5	* 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	*
11	* External symbols declared in standard.h
12	*/
13
14	/* ====================================================================
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
73	#ifndef MBLKSIZ
74	#define MBLKSIZ 16376 /* size of memory allocation block */
75	#endif
76	#define WASTEFRAC 12 /* don't waste more than a fraction */
77	#ifndef ALIGNT
78	#define ALIGNT double /* type for alignment */
79	#endif
80	#define BYTES_WORD sizeof(ALIGNT)
81
82	static char *bposition = NULL;
83	static unsigned int nremain = 0;
84
85
86	char *
87	bmalloc(n) /* allocate a block of n bytes */
88	register unsigned int n;
89	{
90	if (n > nremain && (n > MBLKSIZ \|\| nremain > MBLKSIZ/WASTEFRAC))
91	return(malloc(n)); /* too big */
92
93	n = (n+(BYTES_WORD-1))&~(BYTES_WORD-1); /* word align */
94
95	if (n > nremain && (bposition = (char *)malloc(nremain = MBLKSIZ)) == NULL) {
96	nremain = 0;
97	return(NULL);
98	}
99	bposition += n;
100	nremain -= n;
101	return(bposition - n);
102	}
103
104
105	void
106	bfree(p, n) /* free random memory */
107	register char *p;
108	register unsigned int n;
109	{
110	register unsigned int bsiz;
111	/* check alignment */
112	bsiz = BYTES_WORD - ((unsigned int)p&(BYTES_WORD-1));
113	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	}