1 /*
2 * Copyright (c) 2018, 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 #ifndef SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP
26 #define SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP
27
28 #include "memory/allocation.hpp"
29 #include "memory/binaryTreeDictionary.hpp"
30 #include "memory/freeList.inline.hpp"
31 #include "memory/metaspace/metachunk.hpp"
32 #include "memory/metaspace/metaspaceStatistics.hpp"
33 #include "memory/metaspaceChunkFreeListSummary.hpp"
34 #include "utilities/globalDefinitions.hpp"
35
36 class TestVirtualSpaceNodeTest;
37
38 namespace metaspace {
39 namespace internals {
40
41 typedef class FreeList<Metachunk> ChunkList;
42 typedef BinaryTreeDictionary<Metachunk, FreeList<Metachunk> > ChunkTreeDictionary;
43
44 // Manages the global free lists of chunks.
45 class ChunkManager : public CHeapObj<mtInternal> {
46 friend class ::TestVirtualSpaceNodeTest;
47
48 // Free list of chunks of different sizes.
49 // SpecializedChunk
50 // SmallChunk
51 // MediumChunk
52 ChunkList _free_chunks[NumberOfFreeLists];
53
54 // Whether or not this is the class chunkmanager.
55 const bool _is_class;
56
57 // Return non-humongous chunk list by its index.
58 ChunkList* free_chunks(ChunkIndex index);
59
60 // Returns non-humongous chunk list for the given chunk word size.
61 ChunkList* find_free_chunks_list(size_t word_size);
62
63 // HumongousChunk
64 ChunkTreeDictionary _humongous_dictionary;
65
66 // Returns the humongous chunk dictionary.
67 ChunkTreeDictionary* humongous_dictionary() {
68 return &_humongous_dictionary;
69 }
70
71 // Size, in metaspace words, of all chunks managed by this ChunkManager
72 size_t _free_chunks_total;
73 // Number of chunks in this ChunkManager
74 size_t _free_chunks_count;
75
76 // Update counters after a chunk was added or removed removed.
77 void account_for_added_chunk(const Metachunk* c);
78 void account_for_removed_chunk(const Metachunk* c);
79
80 size_t sum_free_chunks();
81 size_t sum_free_chunks_count();
82
83 void locked_verify_free_chunks_total();
84 void slow_locked_verify_free_chunks_total() {
85 if (VerifyMetaspace) {
86 locked_verify_free_chunks_total();
87 }
88 }
89 void locked_verify_free_chunks_count();
90 void slow_locked_verify_free_chunks_count() {
91 if (VerifyMetaspace) {
92 locked_verify_free_chunks_count();
93 }
94 }
95
96 // Given a pointer to a chunk, attempts to merge it with neighboring
97 // free chunks to form a bigger chunk. Returns true if successful.
98 bool attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type);
99
100 // Helper for chunk merging:
101 // Given an address range with 1-n chunks which are all supposed to be
102 // free and hence currently managed by this ChunkManager, remove them
103 // from this ChunkManager and mark them as invalid.
104 // - This does not correct the occupancy map.
105 // - This does not adjust the counters in ChunkManager.
106 // - Does not adjust container count counter in containing VirtualSpaceNode.
107 // Returns number of chunks removed.
108 int remove_chunks_in_area(MetaWord* p, size_t word_size);
109
110 // Helper for chunk splitting: given a target chunk size and a larger free chunk,
111 // split up the larger chunk into n smaller chunks, at least one of which should be
112 // the target chunk of target chunk size. The smaller chunks, including the target
113 // chunk, are returned to the freelist. The pointer to the target chunk is returned.
114 // Note that this chunk is supposed to be removed from the freelist right away.
115 Metachunk* split_chunk(size_t target_chunk_word_size, Metachunk* chunk);
116
117 public:
118
119 ChunkManager(bool is_class)
120 : _is_class(is_class), _free_chunks_total(0), _free_chunks_count(0) {
121 _free_chunks[SpecializedIndex].set_size(get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class));
122 _free_chunks[SmallIndex].set_size(get_size_for_nonhumongous_chunktype(SmallIndex, is_class));
123 _free_chunks[MediumIndex].set_size(get_size_for_nonhumongous_chunktype(MediumIndex, is_class));
124 }
125
126 // Add or delete (return) a chunk to the global freelist.
127 Metachunk* chunk_freelist_allocate(size_t word_size);
128
129 // Map a size to a list index assuming that there are lists
130 // for special, small, medium, and humongous chunks.
131 ChunkIndex list_index(size_t size);
132
133 // Map a given index to the chunk size.
134 size_t size_by_index(ChunkIndex index) const;
135
136 bool is_class() const { return _is_class; }
137
138 // Convenience accessors.
139 size_t medium_chunk_word_size() const { return size_by_index(MediumIndex); }
140 size_t small_chunk_word_size() const { return size_by_index(SmallIndex); }
141 size_t specialized_chunk_word_size() const { return size_by_index(SpecializedIndex); }
142
143 // Take a chunk from the ChunkManager. The chunk is expected to be in
144 // the chunk manager (the freelist if non-humongous, the dictionary if
145 // humongous).
146 void remove_chunk(Metachunk* chunk);
147
148 // Return a single chunk of type index to the ChunkManager.
149 void return_single_chunk(Metachunk* chunk);
150
151 // Add the simple linked list of chunks to the freelist of chunks
152 // of type index.
153 void return_chunk_list(Metachunk* chunk);
154
155 // Total of the space in the free chunks list
156 size_t free_chunks_total_words();
157 size_t free_chunks_total_bytes();
158
159 // Number of chunks in the free chunks list
160 size_t free_chunks_count();
161
162 // Remove from a list by size. Selects list based on size of chunk.
163 Metachunk* free_chunks_get(size_t chunk_word_size);
164
165 #define index_bounds_check(index) \
166 assert(is_valid_chunktype(index), "Bad index: %d", (int) index)
167
168 size_t num_free_chunks(ChunkIndex index) const {
169 index_bounds_check(index);
170
171 if (index == HumongousIndex) {
172 return _humongous_dictionary.total_free_blocks();
173 }
174
175 ssize_t count = _free_chunks[index].count();
176 return count == -1 ? 0 : (size_t) count;
177 }
178
179 size_t size_free_chunks_in_bytes(ChunkIndex index) const {
180 index_bounds_check(index);
181
182 size_t word_size = 0;
183 if (index == HumongousIndex) {
184 word_size = _humongous_dictionary.total_size();
185 } else {
186 const size_t size_per_chunk_in_words = _free_chunks[index].size();
187 word_size = size_per_chunk_in_words * num_free_chunks(index);
188 }
189
190 return word_size * BytesPerWord;
191 }
192
193 MetaspaceChunkFreeListSummary chunk_free_list_summary() const {
194 return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex),
195 num_free_chunks(SmallIndex),
196 num_free_chunks(MediumIndex),
197 num_free_chunks(HumongousIndex),
198 size_free_chunks_in_bytes(SpecializedIndex),
199 size_free_chunks_in_bytes(SmallIndex),
200 size_free_chunks_in_bytes(MediumIndex),
201 size_free_chunks_in_bytes(HumongousIndex));
202 }
203
204 // Debug support
205 void verify();
206 void slow_verify() {
207 if (VerifyMetaspace) {
208 verify();
209 }
210 }
211 void locked_verify();
212 void slow_locked_verify() {
213 if (VerifyMetaspace) {
214 locked_verify();
215 }
216 }
217
218 void locked_print_free_chunks(outputStream* st);
219 void locked_print_sum_free_chunks(outputStream* st);
220
221 // Fill in current statistic values to the given statistics object.
222 void collect_statistics(ChunkManagerStatistics* out) const;
223
224 };
225
226 } // namespace metaspace
227 } // namespace internals
228
229
230 #endif /* SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP_ */
231