1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
/*
tre-mem.c - TRE memory allocator
Copyright (C) 2001-2004 Ville Laurikari <vl@iki.fi>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 (June
1991) as published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
This memory allocator is for allocating small memory blocks efficiently
in terms of memory overhead and execution speed. The allocated blocks
cannot be freed individually, only all at once. There can be multiple
allocators, though.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */
#include <stdlib.h>
#include <string.h>
#include "tre-internal.h"
#include "tre-mem.h"
#include "xmalloc.h"
/* Returns a new memory allocator or NULL if out of memory. */
tre_mem_t
tre_mem_new_impl(int provided, void *provided_block)
{
tre_mem_t mem;
if (provided)
{
mem = provided_block;
memset(mem, 0, sizeof(*mem));
}
else
mem = xcalloc(1, sizeof(*mem));
if (mem == NULL)
return NULL;
return mem;
}
/* Frees the memory allocator and all memory allocated with it. */
void
tre_mem_destroy(tre_mem_t mem)
{
tre_list_t *tmp, *l = mem->blocks;
while (l != NULL)
{
xfree(l->data);
tmp = l->next;
xfree(l);
l = tmp;
}
xfree(mem);
}
/* Allocates a block of `size' bytes from `mem'. Returns a pointer to the
allocated block or NULL if an underlying malloc() failed. */
void *
tre_mem_alloc_impl(tre_mem_t mem, int provided, void *provided_block,
int zero, size_t size)
{
void *ptr;
if (mem->failed)
{
DPRINT(("tre_mem_alloc: oops, called after failure?!\n"));
return NULL;
}
#ifdef MALLOC_DEBUGGING
if (!provided)
{
ptr = xmalloc(1);
if (ptr == NULL)
{
DPRINT(("tre_mem_alloc: xmalloc forced failure\n"));
mem->failed = 1;
return NULL;
}
xfree(ptr);
}
#endif /* MALLOC_DEBUGGING */
if (mem->n < size)
{
/* We need more memory than is available in the current block.
Allocate a new block. */
tre_list_t *l;
if (provided)
{
DPRINT(("tre_mem_alloc: using provided block\n"));
if (provided_block == NULL)
{
DPRINT(("tre_mem_alloc: provided block was NULL\n"));
mem->failed = 1;
return NULL;
}
mem->ptr = provided_block;
mem->n = TRE_MEM_BLOCK_SIZE;
}
else
{
int block_size;
if (size * 8 > TRE_MEM_BLOCK_SIZE)
block_size = size * 8;
else
block_size = TRE_MEM_BLOCK_SIZE;
DPRINT(("tre_mem_alloc: allocating new %d byte block\n",
block_size));
l = xmalloc(sizeof(*l));
if (l == NULL)
{
mem->failed = 1;
return NULL;
}
l->data = xmalloc(block_size);
if (l->data == NULL)
{
xfree(l);
mem->failed = 1;
return NULL;
}
l->next = NULL;
if (mem->current != NULL)
mem->current->next = l;
if (mem->blocks == NULL)
mem->blocks = l;
mem->current = l;
mem->ptr = l->data;
mem->n = block_size;
}
}
/* Make sure the next pointer will be aligned. */
size += ALIGN(mem->ptr + size, long);
/* Allocate from current block. */
ptr = mem->ptr;
mem->ptr += size;
mem->n -= size;
/* Set to zero if needed. */
if (zero)
memset(ptr, 0, size);
return ptr;
}
/* EOF */
|
