Mercurial > hg > truffle
annotate src/share/vm/memory/heap.hpp @ 1764:14197af1010e
Merge
author | never |
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date | Fri, 27 Aug 2010 17:35:08 -0700 |
parents | c18cbe5936b8 |
children | 1e9a9d2e6509 |
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0 | 1 /* |
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2 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
25 // Blocks | |
26 | |
27 class HeapBlock VALUE_OBJ_CLASS_SPEC { | |
28 friend class VMStructs; | |
29 | |
30 public: | |
31 struct Header { | |
32 size_t _length; // the length in segments | |
33 bool _used; // Used bit | |
34 }; | |
35 | |
36 protected: | |
37 union { | |
38 Header _header; | |
39 int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ]; | |
40 // pad to 0 mod 8 | |
41 }; | |
42 | |
43 public: | |
44 // Initialization | |
45 void initialize(size_t length) { _header._length = length; set_used(); } | |
46 | |
47 // Accessors | |
48 void* allocated_space() const { return (void*)(this + 1); } | |
49 size_t length() const { return _header._length; } | |
50 | |
51 // Used/free | |
52 void set_used() { _header._used = true; } | |
53 void set_free() { _header._used = false; } | |
54 bool free() { return !_header._used; } | |
55 }; | |
56 | |
57 class FreeBlock: public HeapBlock { | |
58 friend class VMStructs; | |
59 protected: | |
60 FreeBlock* _link; | |
61 | |
62 public: | |
63 // Initialization | |
64 void initialize(size_t length) { HeapBlock::initialize(length); _link= NULL; } | |
65 | |
66 // Merging | |
67 void set_length(size_t l) { _header._length = l; } | |
68 | |
69 // Accessors | |
70 FreeBlock* link() const { return _link; } | |
71 void set_link(FreeBlock* link) { _link = link; } | |
72 }; | |
73 | |
74 class CodeHeap : public CHeapObj { | |
75 friend class VMStructs; | |
76 private: | |
77 VirtualSpace _memory; // the memory holding the blocks | |
78 VirtualSpace _segmap; // the memory holding the segment map | |
79 | |
80 size_t _number_of_committed_segments; | |
81 size_t _number_of_reserved_segments; | |
82 size_t _segment_size; | |
83 int _log2_segment_size; | |
84 | |
85 size_t _next_segment; | |
86 | |
87 FreeBlock* _freelist; | |
88 size_t _free_segments; // No. of segments in freelist | |
89 | |
90 // Helper functions | |
91 size_t number_of_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; } | |
92 size_t size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; } | |
93 | |
94 size_t segment_for(void* p) const { return ((char*)p - _memory.low()) >> _log2_segment_size; } | |
95 HeapBlock* block_at(size_t i) const { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); } | |
96 | |
97 void mark_segmap_as_free(size_t beg, size_t end); | |
98 void mark_segmap_as_used(size_t beg, size_t end); | |
99 | |
100 // Freelist management helpers | |
101 FreeBlock* following_block(FreeBlock *b); | |
102 void insert_after(FreeBlock* a, FreeBlock* b); | |
103 void merge_right (FreeBlock* a); | |
104 | |
105 // Toplevel freelist management | |
106 void add_to_freelist(HeapBlock *b); | |
107 FreeBlock* search_freelist(size_t length); | |
108 | |
109 // Iteration helpers | |
110 void* next_free(HeapBlock* b) const; | |
111 HeapBlock* first_block() const; | |
112 HeapBlock* next_block(HeapBlock* b) const; | |
113 HeapBlock* block_start(void* p) const; | |
114 | |
115 // to perform additional actions on creation of executable code | |
116 void on_code_mapping(char* base, size_t size); | |
117 | |
118 public: | |
119 CodeHeap(); | |
120 | |
121 // Heap extents | |
122 bool reserve(size_t reserved_size, size_t committed_size, size_t segment_size); | |
123 void release(); // releases all allocated memory | |
124 bool expand_by(size_t size); // expands commited memory by size | |
125 void shrink_by(size_t size); // shrinks commited memory by size | |
126 void clear(); // clears all heap contents | |
127 | |
128 // Memory allocation | |
129 void* allocate (size_t size); // allocates a block of size or returns NULL | |
130 void deallocate(void* p); // deallocates a block | |
131 | |
132 // Attributes | |
133 void* begin() const { return _memory.low (); } | |
134 void* end() const { return _memory.high(); } | |
135 bool contains(void* p) const { return begin() <= p && p < end(); } | |
136 void* find_start(void* p) const; // returns the block containing p or NULL | |
137 size_t alignment_unit() const; // alignment of any block | |
138 size_t alignment_offset() const; // offset of first byte of any block, within the enclosing alignment unit | |
139 static size_t header_size(); // returns the header size for each heap block | |
140 | |
141 // Returns reserved area high and low addresses | |
142 char *low_boundary() const { return _memory.low_boundary (); } | |
143 char *high_boundary() const { return _memory.high_boundary(); } | |
144 | |
145 // Iteration | |
146 | |
147 // returns the first block or NULL | |
148 void* first() const { return next_free(first_block()); } | |
149 // returns the next block given a block p or NULL | |
150 void* next(void* p) const { return next_free(next_block(block_start(p))); } | |
151 | |
152 // Statistics | |
153 size_t capacity() const; | |
154 size_t max_capacity() const; | |
155 size_t allocated_capacity() const; | |
156 size_t unallocated_capacity() const { return max_capacity() - allocated_capacity(); } | |
157 | |
158 // Debugging | |
159 void verify(); | |
160 void print() PRODUCT_RETURN; | |
161 }; |