1 /*
2 * Copyright (c) 2012, 2016, 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/metaspace/metachunk.hpp"
28 #include "memory/metaspace/occupancyMap.hpp"
29 #include "memory/metaspace/virtualSpaceNode.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/copy.hpp"
32 #include "utilities/debug.hpp"
33
34 namespace metaspace {
35
36 size_t Metachunk::object_alignment() {
37 // Must align pointers and sizes to 8,
38 // so that 64 bit types get correctly aligned.
39 const size_t alignment = 8;
40
41 // Make sure that the Klass alignment also agree.
42 STATIC_ASSERT(alignment == (size_t)KlassAlignmentInBytes);
43
44 return alignment;
45 }
46
47 size_t Metachunk::overhead() {
48 return align_up(sizeof(Metachunk), object_alignment()) / BytesPerWord;
49 }
50
51 // Metachunk methods
52
53 Metachunk::Metachunk(ChunkIndex chunktype, bool is_class, size_t word_size,
54 VirtualSpaceNode* container)
55 : Metabase<Metachunk>(word_size),
56 _container(container),
57 _top(NULL),
58 _sentinel(CHUNK_SENTINEL),
59 _chunk_type(chunktype),
60 _is_class(is_class),
61 _origin(origin_normal),
62 _use_count(0)
63 {
64 _top = initial_top();
65 set_is_tagged_free(false);
66 #ifdef ASSERT
67 mangle(uninitMetaWordVal);
68 verify();
69 #endif
70 }
71
72 MetaWord* Metachunk::allocate(size_t word_size) {
73 MetaWord* result = NULL;
74 // If available, bump the pointer to allocate.
75 if (free_word_size() >= word_size) {
76 result = _top;
77 _top = _top + word_size;
78 }
79 return result;
80 }
81
82 // _bottom points to the start of the chunk including the overhead.
83 size_t Metachunk::used_word_size() const {
84 return pointer_delta(_top, bottom(), sizeof(MetaWord));
85 }
86
87 size_t Metachunk::free_word_size() const {
88 return pointer_delta(end(), _top, 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 " (%s)",
95 p2i(bottom()), p2i(_top), p2i(end()), word_size(),
96 chunk_size_name(get_chunk_type()));
97 if (Verbose) {
98 st->print_cr(" used " SIZE_FORMAT " free " SIZE_FORMAT,
99 used_word_size(), free_word_size());
100 }
101 }
102
103 #ifdef ASSERT
104 void Metachunk::mangle(juint word_value) {
105 // Overwrite the payload of the chunk and not the links that
106 // maintain list of chunks.
107 HeapWord* start = (HeapWord*)initial_top();
108 size_t size = word_size() - overhead();
109 Copy::fill_to_words(start, size, word_value);
110 }
111
112 void Metachunk::verify() const {
113 assert(is_valid_sentinel(), "Chunk " PTR_FORMAT ": sentinel invalid", p2i(this));
114 const ChunkIndex chunk_type = get_chunk_type();
115 assert(is_valid_chunktype(chunk_type), "Chunk " PTR_FORMAT ": Invalid chunk type.", p2i(this));
116 if (chunk_type != HumongousIndex) {
117 assert(word_size() == get_size_for_nonhumongous_chunktype(chunk_type, is_class()),
118 "Chunk " PTR_FORMAT ": wordsize " SIZE_FORMAT " does not fit chunk type %s.",
119 p2i(this), word_size(), chunk_size_name(chunk_type));
120 }
121 assert(is_valid_chunkorigin(get_origin()), "Chunk " PTR_FORMAT ": Invalid chunk origin.", p2i(this));
122 assert(bottom() <= _top && _top <= (MetaWord*)end(),
123 "Chunk " PTR_FORMAT ": Chunk top out of chunk bounds.", p2i(this));
124
125 // For non-humongous chunks, starting address shall be aligned
126 // to its chunk size. Humongous chunks start address is
127 // aligned to specialized chunk size.
128 const size_t required_alignment =
129 (chunk_type != HumongousIndex ? word_size() : get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class())) * sizeof(MetaWord);
130 assert(is_aligned((address)this, required_alignment),
131 "Chunk " PTR_FORMAT ": (size " SIZE_FORMAT ") not aligned to " SIZE_FORMAT ".",
132 p2i(this), word_size() * sizeof(MetaWord), required_alignment);
133 }
134
135 #endif // ASSERT
136
137 // Helper, returns a descriptive name for the given index.
138 const char* chunk_size_name(ChunkIndex index) {
139 switch (index) {
140 case SpecializedIndex:
141 return "specialized";
142 case SmallIndex:
143 return "small";
144 case MediumIndex:
145 return "medium";
146 case HumongousIndex:
147 return "humongous";
148 default:
149 return "Invalid index";
150 }
151 }
152
153 #ifdef ASSERT
154 void do_verify_chunk(Metachunk* chunk) {
155 guarantee(chunk != NULL, "Sanity");
156 // Verify chunk itself; then verify that it is consistent with the
157 // occupany map of its containing node.
158 chunk->verify();
159 VirtualSpaceNode* const vsn = chunk->container();
160 OccupancyMap* const ocmap = vsn->occupancy_map();
161 ocmap->verify_for_chunk(chunk);
162 }
163 #endif
164
165 void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse) {
166 chunk->set_is_tagged_free(!inuse);
167 OccupancyMap* const ocmap = chunk->container()->occupancy_map();
168 ocmap->set_region_in_use((MetaWord*)chunk, chunk->word_size(), inuse);
169 }
170
171 } // namespace metaspace
172