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dd3b648e RP |
1 | /* Declarations for `malloc' and friends. |
2 | Copyright 1990 Free Software Foundation | |
3 | Written May 1989 by Mike Haertel. | |
4 | ||
99a7de40 JG |
5 | The author may be reached (Email) at the address [email protected], |
6 | or (US mail) as Mike Haertel c/o Free Software Foundation. | |
dd3b648e | 7 | |
99a7de40 JG |
8 | This program is free software; you can redistribute it and/or modify |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
dd3b648e | 12 | |
99a7de40 JG |
13 | This program is distributed in the hope that it will be useful, |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
dd3b648e | 17 | |
99a7de40 JG |
18 | You should have received a copy of the GNU General Public License |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
dd3b648e RP |
21 | |
22 | #ifndef _MALLOC_H | |
23 | ||
24 | #define _MALLOC_H 1 | |
25 | ||
26 | #ifndef __ONEFILE | |
27 | #define __need_NULL | |
28 | #define __need_size_t | |
29 | #define __need_ptrdiff_t | |
30 | #include <stddef.h> | |
31 | #endif | |
32 | ||
33 | #ifdef _MALLOC_INTERNAL | |
34 | ||
35 | #ifndef __ONEFILE | |
36 | #include <limits.h> | |
37 | #endif | |
38 | ||
39 | /* The allocator divides the heap into blocks of fixed size; large | |
40 | requests receive one or more whole blocks, and small requests | |
41 | receive a fragment of a block. Fragment sizes are powers of two, | |
42 | and all fragments of a block are the same size. When all the | |
43 | fragments in a block have been freed, the block itself is freed. */ | |
44 | #define INT_BIT (CHAR_BIT * sizeof(int)) | |
45 | #define BLOCKLOG (INT_BIT > 16 ? 12 : 9) | |
46 | #define BLOCKSIZE (1 << BLOCKLOG) | |
47 | #define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE) | |
48 | ||
49 | /* Determine the amount of memory spanned by the initial heap table | |
50 | (not an absolute limit). */ | |
51 | #define HEAP (INT_BIT > 16 ? 4194304 : 65536) | |
52 | ||
53 | /* Number of contiguous free blocks allowed to build up at the end of | |
54 | memory before they will be returned to the system. */ | |
55 | #define FINAL_FREE_BLOCKS 8 | |
56 | ||
57 | /* Where to start searching the free list when looking for new memory. | |
58 | The two possible values are 0 and _heapindex. Starting at 0 seems | |
59 | to reduce total memory usage, while starting at _heapindex seems to | |
60 | run faster. */ | |
61 | #define MALLOC_SEARCH_START _heapindex | |
62 | ||
63 | /* Data structure giving per-block information. */ | |
64 | typedef union | |
65 | { | |
66 | /* Heap information for a busy block. */ | |
67 | struct | |
68 | { | |
69 | /* Zero for a large block, or positive giving the | |
70 | logarithm to the base two of the fragment size. */ | |
71 | int type; | |
72 | union | |
73 | { | |
74 | struct | |
75 | { | |
76 | size_t nfree; /* Free fragments in a fragmented block. */ | |
77 | size_t first; /* First free fragment of the block. */ | |
78 | } frag; | |
79 | /* Size (in blocks) of a large cluster. */ | |
80 | size_t size; | |
81 | } info; | |
82 | } busy; | |
83 | /* Heap information for a free block (that may be the first of | |
84 | a free cluster). */ | |
85 | struct | |
86 | { | |
87 | size_t size; /* Size (in blocks) of a free cluster. */ | |
88 | size_t next; /* Index of next free cluster. */ | |
89 | size_t prev; /* Index of previous free cluster. */ | |
90 | } free; | |
91 | } malloc_info; | |
92 | ||
93 | /* Pointer to first block of the heap. */ | |
94 | extern char *_heapbase; | |
95 | ||
96 | /* Table indexed by block number giving per-block information. */ | |
97 | extern malloc_info *_heapinfo; | |
98 | ||
99 | /* Address to block number and vice versa. */ | |
100 | #define BLOCK(A) (((char *) (A) - _heapbase) / BLOCKSIZE + 1) | |
101 | #define ADDRESS(B) ((PTR) (((B) - 1) * BLOCKSIZE + _heapbase)) | |
102 | ||
103 | /* Current search index for the heap table. */ | |
104 | extern size_t _heapindex; | |
105 | ||
106 | /* Limit of valid info table indices. */ | |
107 | extern size_t _heaplimit; | |
108 | ||
109 | /* Doubly linked lists of free fragments. */ | |
110 | struct list | |
111 | { | |
112 | struct list *next; | |
113 | struct list *prev; | |
114 | }; | |
115 | ||
116 | /* Free list headers for each fragment size. */ | |
117 | extern struct list _fraghead[]; | |
118 | ||
119 | /* Instrumentation. */ | |
120 | extern size_t _chunks_used; | |
121 | extern size_t _bytes_used; | |
122 | extern size_t _chunks_free; | |
123 | extern size_t _bytes_free; | |
124 | ||
125 | /* Internal version of free() used in morecore(). */ | |
126 | extern void EXFUN(__free, (PTR __ptr)); | |
127 | ||
128 | #endif /* _MALLOC_INTERNAL. */ | |
129 | ||
130 | /* Underlying allocation function; successive calls should | |
131 | return contiguous pieces of memory. */ | |
132 | extern PTR EXFUN((*__morecore), (ptrdiff_t __size)); | |
133 | ||
134 | /* Default value of previous. */ | |
135 | extern PTR EXFUN(__default_morecore, (ptrdiff_t __size)); | |
136 | ||
137 | /* Flag whether malloc has been called. */ | |
138 | extern int __malloc_initialized; | |
139 | ||
140 | /* Hooks for debugging versions. */ | |
141 | extern void EXFUN((*__free_hook), (PTR __ptr)); | |
142 | extern PTR EXFUN((*__malloc_hook), (size_t __size)); | |
143 | extern PTR EXFUN((*__realloc_hook), (PTR __ptr, size_t __size)); | |
144 | ||
145 | /* Activate a standard collection of debugging hooks. */ | |
146 | extern void EXFUN(mcheck, (void EXFUN((*func), (void)))); | |
147 | ||
148 | /* Statistics available to the user. */ | |
149 | struct mstats | |
150 | { | |
151 | size_t bytes_total; /* Total size of the heap. */ | |
152 | size_t chunks_used; /* Chunks allocated by the user. */ | |
153 | size_t bytes_used; /* Byte total of user-allocated chunks. */ | |
154 | size_t chunks_free; /* Chunks in the free list. */ | |
155 | size_t bytes_free; /* Byte total of chunks in the free list. */ | |
156 | }; | |
157 | ||
158 | /* Pick up the current statistics. */ | |
159 | extern struct mstats EXFUN(mstats, (NOARGS)); | |
160 | ||
161 | #endif /* malloc.h */ |