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root/radiance/ray/src/common/bmalloc.c
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Comparing ray/src/common/bmalloc.c (file contents):
Revision 1.2 by greg, Tue Sep 25 19:37:15 1990 UTC vs.
Revision 2.9 by schorsch, Sat Oct 23 18:55:52 2004 UTC

# Line 1 | Line 1
1 /* Copyright (c) 1990 Regents of the University of California */
2
1   #ifndef lint
2 < static char SCCSid[] = "$SunId$ LBL";
2 > static const char       RCSid[] = "$Id$";
3   #endif
6
4   /*
5 < * Basic memory allocation w/o overhead.
6 < * Calls malloc(3) for big requests.
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 < #define  NULL           0
14 > #include "copyright.h"
15  
16 + #include <stdlib.h>
17 +
18 + #include "rtmisc.h"
19 +
20   #ifndef  MBLKSIZ
21   #define  MBLKSIZ        16376           /* size of memory allocation block */
22   #endif
23 < #define  WASTEFRAC      4               /* don't waste more than this */
24 < #ifndef  ALIGN
25 < #define  ALIGN          int             /* type for alignment */
23 > #define  WASTEFRAC      12              /* don't waste more than a fraction */
24 > #ifndef  ALIGNT
25 > #define  ALIGNT         double          /* type for alignment */
26   #endif
27 < #define  BYTES_WORD     sizeof(ALIGN)
27 > #define  BYTES_WORD     sizeof(ALIGNT)
28  
29 + static char  *bposition = NULL;
30 + static size_t  nremain = 0;
31  
25 char *
26 bmalloc(n)              /* allocate a block of n bytes, no refunds */
27 register unsigned  n;
28 {
29        extern char  *malloc();
30        static char  *bpos = NULL;
31        static unsigned  nrem = 0;
32  
33 <        if (n > nrem && (n > MBLKSIZ || nrem > MBLKSIZ/WASTEFRAC))
33 > void *
34 > bmalloc(                /* allocate a block of n bytes */
35 > register size_t  n
36 > )
37 > {
38 >        if (n > nremain && (n > MBLKSIZ || nremain > MBLKSIZ/WASTEFRAC))
39                  return(malloc(n));                      /* too big */
40  
41          n = (n+(BYTES_WORD-1))&~(BYTES_WORD-1);         /* word align */
42  
43 <        if (n > nrem) {
44 <                if ((bpos = malloc((unsigned)MBLKSIZ)) == NULL) {
45 <                        nrem = 0;
41 <                        return(NULL);
42 <                }
43 <                nrem = MBLKSIZ;
43 >        if (n > nremain && (bposition = malloc(nremain = MBLKSIZ)) == NULL) {
44 >                nremain = 0;
45 >                return(NULL);
46          }
47 <        bpos += n;
48 <        nrem -= n;
49 <        return(bpos - n);
47 >        bposition += n;
48 >        nremain -= n;
49 >        return(bposition - n);
50   }
51  
52  
53 < bfree(p, n)                     /* free random memory */
54 < char    *p;
55 < unsigned        n;
53 > void
54 > bfree(                  /* free random memory */
55 > register void   *pp,
56 > register size_t n
57 > )
58   {
59 <        /* not implemented */
59 >        register char *p = pp;
60 >        register size_t bsiz;
61 >                                        /* check alignment */
62 >        bsiz = BYTES_WORD - ((size_t)p&(BYTES_WORD-1));
63 >        if (bsiz < BYTES_WORD) {
64 >                p += bsiz;
65 >                n -= bsiz;
66 >        }
67 >        if (p + n == bposition) {       /* just allocated? */
68 >                bposition = p;
69 >                nremain += n;
70 >                return;
71 >        }
72 >        if (n > nremain) {              /* better than what we've got? */
73 >                bposition = p;
74 >                nremain = n;
75 >                return;
76 >        }
77 >                                /* just throw it away, then */
78   }

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