Mercurial > hg > truffle
comparison src/share/vm/memory/metachunk.cpp @ 7208:eade6b2e4782
8003554: NPG: move Metablock and Metachunk code out of metaspace.cpp
Reviewed-by: coleenp
author | jmasa |
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date | Thu, 29 Nov 2012 10:09:04 -0800 |
parents | |
children | e51c9860cf66 |
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7207:0f80645e9c26 | 7208:eade6b2e4782 |
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1 /* | |
2 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. | |
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 * | |
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
20 * or visit www.oracle.com if you need additional information or have any | |
21 * questions. | |
22 * | |
23 */ | |
24 | |
25 #include "precompiled.hpp" | |
26 #include "memory/allocation.hpp" | |
27 #include "memory/metachunk.hpp" | |
28 #include "utilities/copy.hpp" | |
29 #include "utilities/debug.hpp" | |
30 | |
31 // | |
32 // Future modification | |
33 // | |
34 // The Metachunk can conceivable be replaced by the Chunk in | |
35 // allocation.hpp. Note that the latter Chunk is the space for | |
36 // allocation (allocations from the chunk are out of the space in | |
37 // the Chunk after the header for the Chunk) where as Metachunks | |
38 // point to space in a VirtualSpace. To replace Metachunks with | |
39 // Chunks, change Chunks so that they can be allocated out of a VirtualSpace. | |
40 | |
41 const size_t metadata_chunk_initialize = 0xf7f7f7f7; | |
42 | |
43 size_t Metachunk::_overhead = | |
44 Chunk::aligned_overhead_size(sizeof(Metachunk)) / BytesPerWord; | |
45 | |
46 // Metachunk methods | |
47 | |
48 Metachunk* Metachunk::initialize(MetaWord* ptr, size_t word_size) { | |
49 // Set bottom, top, and end. Allow space for the Metachunk itself | |
50 Metachunk* chunk = (Metachunk*) ptr; | |
51 | |
52 MetaWord* chunk_bottom = ptr + _overhead; | |
53 chunk->set_bottom(ptr); | |
54 chunk->set_top(chunk_bottom); | |
55 MetaWord* chunk_end = ptr + word_size; | |
56 assert(chunk_end > chunk_bottom, "Chunk must be too small"); | |
57 chunk->set_end(chunk_end); | |
58 chunk->set_next(NULL); | |
59 chunk->set_word_size(word_size); | |
60 #ifdef ASSERT | |
61 size_t data_word_size = pointer_delta(chunk_end, chunk_bottom, sizeof(MetaWord)); | |
62 Copy::fill_to_words((HeapWord*) chunk_bottom, data_word_size, metadata_chunk_initialize); | |
63 #endif | |
64 return chunk; | |
65 } | |
66 | |
67 | |
68 MetaWord* Metachunk::allocate(size_t word_size) { | |
69 MetaWord* result = NULL; | |
70 // If available, bump the pointer to allocate. | |
71 if (free_word_size() >= word_size) { | |
72 result = _top; | |
73 _top = _top + word_size; | |
74 } | |
75 return result; | |
76 } | |
77 | |
78 // _bottom points to the start of the chunk including the overhead. | |
79 size_t Metachunk::used_word_size() { | |
80 return pointer_delta(_top, _bottom, sizeof(MetaWord)); | |
81 } | |
82 | |
83 size_t Metachunk::free_word_size() { | |
84 return pointer_delta(_end, _top, sizeof(MetaWord)); | |
85 } | |
86 | |
87 size_t Metachunk::capacity_word_size() { | |
88 return pointer_delta(_end, _bottom, sizeof(MetaWord)); | |
89 } | |
90 | |
91 void Metachunk::print_on(outputStream* st) const { | |
92 st->print_cr("Metachunk:" | |
93 " bottom " PTR_FORMAT " top " PTR_FORMAT | |
94 " end " PTR_FORMAT " size " SIZE_FORMAT, | |
95 bottom(), top(), end(), word_size()); | |
96 } | |
97 | |
98 #ifndef PRODUCT | |
99 void Metachunk::mangle() { | |
100 // Mangle the payload of the chunk and not the links that | |
101 // maintain list of chunks. | |
102 HeapWord* start = (HeapWord*)(bottom() + overhead()); | |
103 size_t word_size = capacity_word_size() - overhead(); | |
104 Copy::fill_to_words(start, word_size, metadata_chunk_initialize); | |
105 } | |
106 #endif // PRODUCT | |
107 | |
108 void Metachunk::verify() { | |
109 #ifdef ASSERT | |
110 // Cannot walk through the blocks unless the blocks have | |
111 // headers with sizes. | |
112 assert(_bottom <= _top && | |
113 _top <= _end, | |
114 "Chunk has been smashed"); | |
115 #endif | |
116 return; | |
117 } |