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 namespace internals {
36
37 size_t Metachunk::object_alignment() {
38 // Must align pointers and sizes to 8,
39 // so that 64 bit types get correctly aligned.
40 const size_t alignment = 8;
41
42 // Make sure that the Klass alignment also agree.
43 STATIC_ASSERT(alignment == (size_t)KlassAlignmentInBytes);
44
45 return alignment;
46 }
47
48 size_t Metachunk::overhead() {
49 return align_up(sizeof(Metachunk), object_alignment()) / BytesPerWord;
50 }
51
52 // Metachunk methods
53
54 Metachunk::Metachunk(ChunkIndex chunktype, bool is_class, size_t word_size,
55 VirtualSpaceNode* container)
56 : Metabase<Metachunk>(word_size),
57 _chunk_type(chunktype),
58 _is_class(is_class),
59 _sentinel(CHUNK_SENTINEL),
60 _origin(origin_normal),
61 _use_count(0),
62 _top(NULL),
63 _container(container)
64 {
65 _top = initial_top();
66 set_is_tagged_free(false);
67 #ifdef ASSERT
68 mangle(uninitMetaWordVal);
69 verify();
70 #endif
71 }
72
73 MetaWord* Metachunk::allocate(size_t word_size) {
74 MetaWord* result = NULL;
75 // If available, bump the pointer to allocate.
76 if (free_word_size() >= word_size) {
77 result = _top;
78 _top = _top + word_size;
79 }
80 return result;
81 }
82
83 // _bottom points to the start of the chunk including the overhead.
84 size_t Metachunk::used_word_size() const {
85 return pointer_delta(_top, bottom(), sizeof(MetaWord));
86 }
87
88 size_t Metachunk::free_word_size() const {
89 return pointer_delta(end(), _top, sizeof(MetaWord));
90 }
91
92 void Metachunk::print_on(outputStream* st) const {
93 st->print_cr("Metachunk:"
94 " bottom " PTR_FORMAT " top " PTR_FORMAT
95 " end " PTR_FORMAT " size " SIZE_FORMAT " (%s)",
96 p2i(bottom()), p2i(_top), p2i(end()), word_size(),
97 chunk_size_name(get_chunk_type()));
98 if (Verbose) {
99 st->print_cr(" used " SIZE_FORMAT " free " SIZE_FORMAT,
100 used_word_size(), free_word_size());
101 }
102 }
103
104 #ifdef ASSERT
105 void Metachunk::mangle(juint word_value) {
106 // Overwrite the payload of the chunk and not the links that
107 // maintain list of chunks.
108 HeapWord* start = (HeapWord*)initial_top();
109 size_t size = word_size() - overhead();
110 Copy::fill_to_words(start, size, word_value);
111 }
112
113 void Metachunk::verify() const {
114 assert(is_valid_sentinel(), "Chunk " PTR_FORMAT ": sentinel invalid", p2i(this));
115 const ChunkIndex chunk_type = get_chunk_type();
116 assert(is_valid_chunktype(chunk_type), "Chunk " PTR_FORMAT ": Invalid chunk type.", p2i(this));
117 if (chunk_type != HumongousIndex) {
118 assert(word_size() == get_size_for_nonhumongous_chunktype(chunk_type, is_class()),
119 "Chunk " PTR_FORMAT ": wordsize " SIZE_FORMAT " does not fit chunk type %s.",
120 p2i(this), word_size(), chunk_size_name(chunk_type));
121 }
122 assert(is_valid_chunkorigin(get_origin()), "Chunk " PTR_FORMAT ": Invalid chunk origin.", p2i(this));
123 assert(bottom() <= _top && _top <= (MetaWord*)end(),
124 "Chunk " PTR_FORMAT ": Chunk top out of chunk bounds.", p2i(this));
125
126 // For non-humongous chunks, starting address shall be aligned
127 // to its chunk size. Humongous chunks start address is
128 // aligned to specialized chunk size.
129 const size_t required_alignment =
130 (chunk_type != HumongousIndex ? word_size() : get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class())) * sizeof(MetaWord);
131 assert(is_aligned((address)this, required_alignment),
132 "Chunk " PTR_FORMAT ": (size " SIZE_FORMAT ") not aligned to " SIZE_FORMAT ".",
133 p2i(this), word_size() * sizeof(MetaWord), required_alignment);
134 }
135
136 #endif // ASSERT
137
138 // Helper, returns a descriptive name for the given index.
139 const char* chunk_size_name(ChunkIndex index) {
140 switch (index) {
141 case SpecializedIndex:
142 return "specialized";
143 case SmallIndex:
144 return "small";
145 case MediumIndex:
146 return "medium";
147 case HumongousIndex:
148 return "humongous";
149 default:
150 return "Invalid index";
151 }
152 }
153
154 #ifdef ASSERT
155 void do_verify_chunk(Metachunk* chunk) {
156 guarantee(chunk != NULL, "Sanity");
157 // Verify chunk itself; then verify that it is consistent with the
158 // occupany map of its containing node.
159 chunk->verify();
160 VirtualSpaceNode* const vsn = chunk->container();
161 OccupancyMap* const ocmap = vsn->occupancy_map();
162 ocmap->verify_for_chunk(chunk);
163 }
164 #endif
165
166 void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse) {
167 chunk->set_is_tagged_free(!inuse);
168 OccupancyMap* const ocmap = chunk->container()->occupancy_map();
169 ocmap->set_region_in_use((MetaWord*)chunk, chunk->word_size(), inuse);
170 }
171
172 } // namespace metaspace
173 } // namespace internals