1 /*
2 * Copyright (c) 2018, 2019, 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.
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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
42 // SpaceManager - used by Metaspace to handle allocations
43 class SpaceManager : public CHeapObj<mtClass> {
44 friend class ::ClassLoaderMetaspace;
45 friend class Metadebug;
46
47 private:
48
49 // protects allocations
50 Mutex* const _lock;
51
52 // Type of metadata allocated.
53 const Metaspace::MetadataType _mdtype;
54
55 // Type of metaspace
56 const Metaspace::MetaspaceType _space_type;
57
58 // List of chunks in use by this SpaceManager. Allocations
59 // are done from the current chunk. The list is used for deallocating
60 // chunks when the SpaceManager is freed.
61 Metachunk* _chunk_list;
62 Metachunk* _current_chunk;
63
64 enum {
65
66 // Maximum number of small chunks to allocate to a SpaceManager
67 small_chunk_limit = 4,
68
69 // Maximum number of specialize chunks to allocate for anonymous and delegating
70 // metadata space to a SpaceManager
71 anon_and_delegating_metadata_specialize_chunk_limit = 4,
72
73 allocation_from_dictionary_limit = 4 * K
74
75 };
76
77 // Some running counters, but lets keep their number small to not add to much to
78 // the per-classloader footprint.
79 // Note: capacity = used + free + waste + overhead. We do not keep running counters for
80 // free and waste. Their sum can be deduced from the three other values.
81 size_t _overhead_words;
82 size_t _capacity_words;
83 size_t _used_words;
84 uintx _num_chunks_by_type[NumberOfInUseLists];
85
86 // Free lists of blocks are per SpaceManager since they
87 // are assumed to be in chunks in use by the SpaceManager
88 // and all chunks in use by a SpaceManager are freed when
89 // the class loader using the SpaceManager is collected.
90 BlockFreelist* _block_freelists;
91
92 private:
93 // Accessors
94 Metachunk* chunk_list() const { return _chunk_list; }
95
96 BlockFreelist* block_freelists() const { return _block_freelists; }
97
98 Metaspace::MetadataType mdtype() { return _mdtype; }
99
100 VirtualSpaceList* vs_list() const { return Metaspace::get_space_list(_mdtype); }
101 ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); }
102
103 Metachunk* current_chunk() const { return _current_chunk; }
104 void set_current_chunk(Metachunk* v) {
105 _current_chunk = v;
106 }
107
108 Metachunk* find_current_chunk(size_t word_size);
109
110 // Add chunk to the list of chunks in use
111 void add_chunk(Metachunk* v, bool make_current);
112 void retire_current_chunk();
113
114 Mutex* lock() const { return _lock; }
115
116 // Adds to the given statistic object. Expects to be locked with lock().
117 void add_to_statistics_locked(SpaceManagerStatistics* out) const;
118
119 // Verify internal counters against the current state. Expects to be locked with lock().
120 DEBUG_ONLY(void verify_metrics_locked() const;)
121
122 public:
123 SpaceManager(Metaspace::MetadataType mdtype,
124 Metaspace::MetaspaceType space_type,
125 Mutex* lock);
126 ~SpaceManager();
127
128 enum ChunkMultiples {
129 MediumChunkMultiple = 4
130 };
131
132 static size_t specialized_chunk_size(bool is_class) { return is_class ? ClassSpecializedChunk : SpecializedChunk; }
133 static size_t small_chunk_size(bool is_class) { return is_class ? ClassSmallChunk : SmallChunk; }
134 static size_t medium_chunk_size(bool is_class) { return is_class ? ClassMediumChunk : MediumChunk; }
135
136 static size_t smallest_chunk_size(bool is_class) { return specialized_chunk_size(is_class); }
137
138 // Accessors
139 bool is_class() const { return _mdtype == Metaspace::ClassType; }
140
141 size_t specialized_chunk_size() const { return specialized_chunk_size(is_class()); }
142 size_t small_chunk_size() const { return small_chunk_size(is_class()); }
143 size_t medium_chunk_size() const { return medium_chunk_size(is_class()); }
144
145 size_t smallest_chunk_size() const { return smallest_chunk_size(is_class()); }
146
147 size_t medium_chunk_bunch() const { return medium_chunk_size() * MediumChunkMultiple; }
148
149 bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
150
151 size_t capacity_words() const { return _capacity_words; }
152 size_t used_words() const { return _used_words; }
153 size_t overhead_words() const { return _overhead_words; }
154
155 // Adjust local, global counters after a new chunk has been added.
156 void account_for_new_chunk(const Metachunk* new_chunk);
157
158 // Adjust local, global counters after space has been allocated from the current chunk.
159 void account_for_allocation(size_t words);
160
161 // Adjust global counters just before the SpaceManager dies, after all its chunks
162 // have been returned to the freelist.
163 void account_for_spacemanager_death();
164
165 // Adjust the initial chunk size to match one of the fixed chunk list sizes,
166 // or return the unadjusted size if the requested size is humongous.
167 static size_t adjust_initial_chunk_size(size_t requested, bool is_class_space);
168 size_t adjust_initial_chunk_size(size_t requested) const;
169
170 // Get the initial chunks size for this metaspace type.
171 size_t get_initial_chunk_size(Metaspace::MetaspaceType type) const;
172
173 // Todo: remove this once we have counters by chunk type.
174 uintx num_chunks_by_type(ChunkIndex chunk_type) const { return _num_chunks_by_type[chunk_type]; }
175
176 Metachunk* get_new_chunk(size_t chunk_word_size);
177
178 // Block allocation and deallocation.
179 // Allocates a block from the current chunk
180 MetaWord* allocate(size_t word_size);
181
182 // Helper for allocations
183 MetaWord* allocate_work(size_t word_size);
184
185 // Returns a block to the per manager freelist
186 void deallocate(MetaWord* p, size_t word_size);
187
188 // Based on the allocation size and a minimum chunk size,
189 // returned chunk size (for expanding space for chunk allocation).
190 size_t calc_chunk_size(size_t allocation_word_size);
191
192 // Called when an allocation from the current chunk fails.
193 // Gets a new chunk (may require getting a new virtual space),
194 // and allocates from that chunk.
195 MetaWord* grow_and_allocate(size_t word_size);
196
197 // Notify memory usage to MemoryService.
198 void track_metaspace_memory_usage();
199
200 // debugging support.
201
202 void print_on(outputStream* st) const;
203 void locked_print_chunks_in_use_on(outputStream* st) const;
204
205 void verify();
206 void verify_chunk_size(Metachunk* chunk);
207
208 // This adjusts the size given to be greater than the minimum allocation size in
209 // words for data in metaspace. Esentially the minimum size is currently 3 words.
210 size_t get_allocation_word_size(size_t word_size) {
211 size_t byte_size = word_size * BytesPerWord;
212
213 size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock));
214 raw_bytes_size = align_up(raw_bytes_size, Metachunk::object_alignment());
215
216 size_t raw_word_size = raw_bytes_size / BytesPerWord;
217 assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
218
219 return raw_word_size;
220 }
221
222 // Adds to the given statistic object.
223 void add_to_statistics(SpaceManagerStatistics* out) const;
224
225 // Verify internal counters against the current state.
226 DEBUG_ONLY(void verify_metrics() const;)
227
228 };
229
230
231 } // namespace metaspace
232
233 #endif // SHARE_MEMORY_METASPACE_SPACEMANAGER_HPP