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
|
/* -*- Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 4 -*- */
/* vi: set ts=4 sw=4 expandtab: (add to ~/.vimrc: set modeline modelines=5) */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is [Open Source Virtual Machine].
*
* The Initial Developer of the Original Code is
* Adobe System Incorporated.
* Portions created by the Initial Developer are Copyright (C) 2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Adobe AS3 Team
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef __nanojit_Allocator__
#define __nanojit_Allocator__
namespace nanojit
{
/**
* Allocator is a bump-pointer allocator with an SPI for getting more
* memory from embedder-implemented allocator, such as malloc()/free().
*
* alloc() never returns NULL. The implementation of allocChunk()
* is expected to perform a longjmp or exception when an allocation can't
* proceed. fallibleAlloc() (and fallibleAllocChunk()) may return NULL.
* They should be used for large allocations whose failure can be handled
* without too much difficulty.
*/
class Allocator {
public:
Allocator();
~Allocator();
// Usable space in the minimum chunk size; there are also a few bytes
// used for administration.
static const size_t MIN_CHUNK_SZB = 2000;
void reset();
/** alloc memory, never return null. */
void* alloc(size_t nbytes) {
void* p;
nbytes = (nbytes + 7) & ~7; // round up
if (current_top + nbytes <= current_limit) {
p = current_top;
current_top += nbytes;
} else {
p = allocSlow(nbytes, /* fallible = */false);
NanoAssert(p);
}
return p;
}
/** alloc memory, maybe return null. */
void* fallibleAlloc(size_t nbytes) {
void* p;
nbytes = (nbytes + 7) & ~7; // round up
if (current_top + nbytes <= current_limit) {
p = current_top;
current_top += nbytes;
} else {
p = allocSlow(nbytes, /* fallible = */true);
}
return p;
}
protected:
void* allocSlow(size_t nbytes, bool fallible = false);
bool fill(size_t minbytes, bool fallible);
class Chunk {
public:
Chunk* prev;
int64_t data[1]; // int64_t forces 8-byte alignment.
};
Chunk* current_chunk;
char* current_top;
char* current_limit;
// allocator SPI
/** allocate another block from a host provided allocator */
void* allocChunk(size_t nbytes, bool fallible);
/** free back to the same allocator */
void freeChunk(void*);
/** hook for post-reset action. */
void postReset();
};
}
/** global new overload enabling this pattern: new (allocator) T(...) */
inline void* operator new(size_t size, nanojit::Allocator &a) {
return a.alloc(size);
}
/** global new overload enabling this pattern: new (allocator) T(...) */
inline void* operator new(size_t size, nanojit::Allocator *a) {
return a->alloc(size);
}
/** global new[] overload enabling this pattern: new (allocator) T[] */
inline void* operator new[](size_t size, nanojit::Allocator& a) {
return a.alloc(size);
}
/** global new[] overload enabling this pattern: new (allocator) T[] */
inline void* operator new[](size_t size, nanojit::Allocator* a) {
return a->alloc(size);
}
#endif // __nanojit_Allocator__
|
