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_SPACEMANAGER_HPP_
26 #define SHARE_MEMORY_METASPACE_SPACEMANAGER_HPP_
27
28 #include "memory/allocation.hpp"
29 #include "memory/metaspace.hpp"
30 #include "memory/metaspace/blockFreelist.hpp"
31 #include "memory/metaspace/metaspaceCommon.hpp"
32 #include "memory/metaspace/metachunk.hpp"
33 #include "memory/metaspace/metaspaceStatistics.hpp"
34 #include "utilities/debug.hpp"
35 #include "utilities/globalDefinitions.hpp"
36
37 class outputStream;
38 class Mutex;
39
40 namespace metaspace {
41 namespace internals {
42
43 // SpaceManager - used by Metaspace to handle allocations
44 class SpaceManager : public CHeapObj<mtClass> {
45 friend class ::ClassLoaderMetaspace;
46 friend class Metadebug;
47
48 private:
49
50 // protects allocations
51 Mutex* const _lock;
52
53 // Type of metadata allocated.
54 const Metaspace::MetadataType _mdtype;
55
56 // Type of metaspace
57 const Metaspace::MetaspaceType _space_type;
58
59 // List of chunks in use by this SpaceManager. Allocations
60 // are done from the current chunk. The list is used for deallocating
61 // chunks when the SpaceManager is freed.
62 Metachunk* _chunk_list;
63 Metachunk* _current_chunk;
64
65 enum {
66
67 // Maximum number of small chunks to allocate to a SpaceManager
68 small_chunk_limit = 4,
69
70 // Maximum number of specialize chunks to allocate for anonymous and delegating
71 // metadata space to a SpaceManager
72 anon_and_delegating_metadata_specialize_chunk_limit = 4,
73
74 allocation_from_dictionary_limit = 4 * K
75
76 };
77
78 // Some running counters, but lets keep their number small to not add to much to
79 // the per-classloader footprint.
80 // Note: capacity = used + free + waste + overhead. We do not keep running counters for
81 // free and waste. Their sum can be deduced from the three other values.
82 size_t _overhead_words;
83 size_t _capacity_words;
84 size_t _used_words;
85 uintx _num_chunks_by_type[NumberOfInUseLists];
86
87 // Free lists of blocks are per SpaceManager since they
88 // are assumed to be in chunks in use by the SpaceManager
89 // and all chunks in use by a SpaceManager are freed when
90 // the class loader using the SpaceManager is collected.
91 BlockFreelist* _block_freelists;
92
93 private:
94 // Accessors
95 Metachunk* chunk_list() const { return _chunk_list; }
96
97 BlockFreelist* block_freelists() const { return _block_freelists; }
98
99 Metaspace::MetadataType mdtype() { return _mdtype; }
100
101 VirtualSpaceList* vs_list() const { return Metaspace::get_space_list(_mdtype); }
102 ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); }
103
104 Metachunk* current_chunk() const { return _current_chunk; }
105 void set_current_chunk(Metachunk* v) {
106 _current_chunk = v;
107 }
108
109 Metachunk* find_current_chunk(size_t word_size);
110
111 // Add chunk to the list of chunks in use
112 void add_chunk(Metachunk* v, bool make_current);
113 void retire_current_chunk();
114
115 Mutex* lock() const { return _lock; }
116
117 // Adds to the given statistic object. Expects to be locked with lock().
118 void add_to_statistics_locked(SpaceManagerStatistics* out) const;
119
120 // Verify internal counters against the current state. Expects to be locked with lock().
121 DEBUG_ONLY(void verify_metrics_locked() const;)
122
123 public:
124 SpaceManager(Metaspace::MetadataType mdtype,
125 Metaspace::MetaspaceType space_type,
126 Mutex* lock);
127 ~SpaceManager();
128
129 enum ChunkMultiples {
130 MediumChunkMultiple = 4
131 };
132
133 static size_t specialized_chunk_size(bool is_class) { return is_class ? ClassSpecializedChunk : SpecializedChunk; }
134 static size_t small_chunk_size(bool is_class) { return is_class ? ClassSmallChunk : SmallChunk; }
135 static size_t medium_chunk_size(bool is_class) { return is_class ? ClassMediumChunk : MediumChunk; }
136
137 static size_t smallest_chunk_size(bool is_class) { return specialized_chunk_size(is_class); }
138
139 // Accessors
140 bool is_class() const { return _mdtype == Metaspace::ClassType; }
141
142 size_t specialized_chunk_size() const { return specialized_chunk_size(is_class()); }
143 size_t small_chunk_size() const { return small_chunk_size(is_class()); }
144 size_t medium_chunk_size() const { return medium_chunk_size(is_class()); }
145
146 size_t smallest_chunk_size() const { return smallest_chunk_size(is_class()); }
147
148 size_t medium_chunk_bunch() const { return medium_chunk_size() * MediumChunkMultiple; }
149
150 bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
151
152 size_t capacity_words() const { return _capacity_words; }
153 size_t used_words() const { return _used_words; }
154 size_t overhead_words() const { return _overhead_words; }
155
156 // Adjust local, global counters after a new chunk has been added.
157 void account_for_new_chunk(const Metachunk* new_chunk);
158
159 // Adjust local, global counters after space has been allocated from the current chunk.
160 void account_for_allocation(size_t words);
161
162 // Adjust global counters just before the SpaceManager dies, after all its chunks
163 // have been returned to the freelist.
164 void account_for_spacemanager_death();
165
166 // Adjust the initial chunk size to match one of the fixed chunk list sizes,
167 // or return the unadjusted size if the requested size is humongous.
168 static size_t adjust_initial_chunk_size(size_t requested, bool is_class_space);
169 size_t adjust_initial_chunk_size(size_t requested) const;
170
171 // Get the initial chunks size for this metaspace type.
172 size_t get_initial_chunk_size(Metaspace::MetaspaceType type) const;
173
174 // Todo: remove this once we have counters by chunk type.
175 uintx num_chunks_by_type(ChunkIndex chunk_type) const { return _num_chunks_by_type[chunk_type]; }
176
177 Metachunk* get_new_chunk(size_t chunk_word_size);
178
179 // Block allocation and deallocation.
180 // Allocates a block from the current chunk
181 MetaWord* allocate(size_t word_size);
182
183 // Helper for allocations
184 MetaWord* allocate_work(size_t word_size);
185
186 // Returns a block to the per manager freelist
187 void deallocate(MetaWord* p, size_t word_size);
188
189 // Based on the allocation size and a minimum chunk size,
190 // returned chunk size (for expanding space for chunk allocation).
191 size_t calc_chunk_size(size_t allocation_word_size);
192
193 // Called when an allocation from the current chunk fails.
194 // Gets a new chunk (may require getting a new virtual space),
195 // and allocates from that chunk.
196 MetaWord* grow_and_allocate(size_t word_size);
197
198 // Notify memory usage to MemoryService.
199 void track_metaspace_memory_usage();
200
201 // debugging support.
202
203 void print_on(outputStream* st) const;
204 void locked_print_chunks_in_use_on(outputStream* st) const;
205
206 void verify();
207 void verify_chunk_size(Metachunk* chunk);
208
209 // This adjusts the size given to be greater than the minimum allocation size in
210 // words for data in metaspace. Esentially the minimum size is currently 3 words.
211 size_t get_allocation_word_size(size_t word_size) {
212 size_t byte_size = word_size * BytesPerWord;
213
214 size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock));
215 raw_bytes_size = align_up(raw_bytes_size, Metachunk::object_alignment());
216
217 size_t raw_word_size = raw_bytes_size / BytesPerWord;
218 assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
219
220 return raw_word_size;
221 }
222
223 // Adds to the given statistic object.
224 void add_to_statistics(SpaceManagerStatistics* out) const;
225
226 // Verify internal counters against the current state.
227 DEBUG_ONLY(void verify_metrics() const;)
228
229 };
230
231
232 } // namespace metaspace
233 } // namespace internals
234
235 #endif /* SHARE_MEMORY_METASPACE_SPACEMANAGER_HPP_ */