1 /*
2 * Copyright (c) 2011, 2017, 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 *
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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23 */
24 #ifndef SHARE_VM_MEMORY_METASPACE_HPP
25 #define SHARE_VM_MEMORY_METASPACE_HPP
26
27 #include "memory/allocation.hpp"
28 #include "memory/memRegion.hpp"
29 #include "memory/metaspaceChunkFreeListSummary.hpp"
30 #include "memory/virtualspace.hpp"
31 #include "utilities/exceptions.hpp"
32
33 // Metaspace
34 //
35 // Metaspaces are Arenas for the VM's metadata.
36 // They are allocated one per class loader object, and one for the null
37 // bootstrap class loader
38 //
39 // block X ---+ +-------------------+
40 // | | Virtualspace |
41 // | | |
42 // | | |
43 // | |-------------------|
44 // | || Chunk |
45 // | || |
46 // | ||---------- |
47 // +------>||| block 0 | |
48 // ||---------- |
49 // ||| block 1 | |
50 // ||---------- |
51 // || |
52 // |-------------------|
53 // | |
54 // | |
55 // +-------------------+
56 //
57
58 class ChunkManager;
59 class ClassLoaderData;
60 class Metablock;
61 class Metachunk;
62 class MetaspaceTracer;
63 class MetaWord;
64 class Mutex;
65 class outputStream;
66 class PrintCLDMetaspaceInfoClosure;
67 class SpaceManager;
68 class VirtualSpaceList;
69
70 // Metaspaces each have a SpaceManager and allocations
71 // are done by the SpaceManager. Allocations are done
72 // out of the current Metachunk. When the current Metachunk
73 // is exhausted, the SpaceManager gets a new one from
74 // the current VirtualSpace. When the VirtualSpace is exhausted
75 // the SpaceManager gets a new one. The SpaceManager
76 // also manages freelists of available Chunks.
77 //
78 // Currently the space manager maintains the list of
79 // virtual spaces and the list of chunks in use. Its
80 // allocate() method returns a block for use as a
81 // quantum of metadata.
82
83 class Metaspace : public CHeapObj<mtClass> {
84 friend class VMStructs;
85 friend class SpaceManager;
86 friend class VM_CollectForMetadataAllocation;
87 friend class MetaspaceGC;
88 friend class MetaspaceAux;
89 friend class MetaspaceShared;
90 friend class CollectorPolicy;
91 friend class PrintCLDMetaspaceInfoClosure;
92
93 public:
94 enum MetadataType {
95 ClassType,
96 NonClassType,
97 MetadataTypeCount
98 };
99 enum MetaspaceType {
100 StandardMetaspaceType,
101 BootMetaspaceType,
102 AnonymousMetaspaceType,
103 ReflectionMetaspaceType
104 };
105
106 private:
107 static void verify_global_initialization();
108
109 void initialize(Mutex* lock, MetaspaceType type);
110
111 // Initialize the first chunk for a Metaspace. Used for
112 // special cases such as the boot class loader, reflection
113 // class loader and anonymous class loader.
114 void initialize_first_chunk(MetaspaceType type, MetadataType mdtype);
115 Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype);
116
117 // Align up the word size to the allocation word size
118 static size_t align_word_size_up(size_t);
119
120 // Aligned size of the metaspace.
121 static size_t _compressed_class_space_size;
122
123 static size_t compressed_class_space_size() {
124 return _compressed_class_space_size;
125 }
126
127 static void set_compressed_class_space_size(size_t size) {
128 _compressed_class_space_size = size;
129 }
130
131 static size_t _first_chunk_word_size;
132 static size_t _first_class_chunk_word_size;
133
134 static size_t _commit_alignment;
135 static size_t _reserve_alignment;
136 DEBUG_ONLY(static bool _frozen;)
137
138 SpaceManager* _vsm;
139 SpaceManager* vsm() const { return _vsm; }
140
141 SpaceManager* _class_vsm;
142 SpaceManager* class_vsm() const { return _class_vsm; }
143 SpaceManager* get_space_manager(MetadataType mdtype) {
144 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
145 return mdtype == ClassType ? class_vsm() : vsm();
146 }
147
148 // Allocate space for metadata of type mdtype. This is space
149 // within a Metachunk and is used by
150 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
151 MetaWord* allocate(size_t word_size, MetadataType mdtype);
152
153 MetaWord* expand_and_allocate(size_t size, MetadataType mdtype);
154
155 // Virtual Space lists for both classes and other metadata
156 static VirtualSpaceList* _space_list;
157 static VirtualSpaceList* _class_space_list;
158
159 static ChunkManager* _chunk_manager_metadata;
160 static ChunkManager* _chunk_manager_class;
161
162 static const MetaspaceTracer* _tracer;
163
164 public:
165 static VirtualSpaceList* space_list() { return _space_list; }
166 static VirtualSpaceList* class_space_list() { return _class_space_list; }
167 static VirtualSpaceList* get_space_list(MetadataType mdtype) {
168 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
169 return mdtype == ClassType ? class_space_list() : space_list();
170 }
171
172 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
173 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; }
174 static ChunkManager* get_chunk_manager(MetadataType mdtype) {
175 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
176 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
177 }
178
179 static const MetaspaceTracer* tracer() { return _tracer; }
180 static void freeze() {
181 assert(DumpSharedSpaces, "sanity");
182 DEBUG_ONLY(_frozen = true;)
183 }
184 private:
185
186 #ifdef _LP64
187 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
188
189 // Returns true if can use CDS with metaspace allocated as specified address.
190 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
191
192 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
193
194 static void initialize_class_space(ReservedSpace rs);
195 #endif
196 size_t class_chunk_size(size_t word_size);
197
198 public:
199
200 Metaspace(Mutex* lock, MetaspaceType type);
201 ~Metaspace();
202
203 static void ergo_initialize();
204 static void global_initialize();
205 static void post_initialize();
206
207 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
208 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
209
210 static size_t reserve_alignment() { return _reserve_alignment; }
211 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
212 static size_t commit_alignment() { return _commit_alignment; }
213 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
214
215 size_t used_words_slow(MetadataType mdtype) const;
216 size_t free_words_slow(MetadataType mdtype) const;
217 size_t capacity_words_slow(MetadataType mdtype) const;
218
219 size_t used_bytes_slow(MetadataType mdtype) const;
220 size_t capacity_bytes_slow(MetadataType mdtype) const;
221
222 size_t allocated_blocks_bytes() const;
223 size_t allocated_chunks_bytes() const;
224
225 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
226 MetaspaceObj::Type type, TRAPS);
227 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
228
229 static bool contains(const void* ptr);
230 static bool contains_non_shared(const void* ptr);
231
232 void dump(outputStream* const out) const;
233
234 // Free empty virtualspaces
235 static void purge(MetadataType mdtype);
236 static void purge();
237
238 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
239 MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
240
241 static const char* metadata_type_name(Metaspace::MetadataType mdtype);
242
243 void print_on(outputStream* st) const;
244 // Debugging support
245 void verify();
246
247 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
248
249 // Return TRUE only if UseCompressedClassPointers is True.
250 static bool using_class_space() {
251 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
252 }
253
254 static bool is_class_space_allocation(MetadataType mdType) {
255 return mdType == ClassType && using_class_space();
256 }
257
258 };
259
260 class MetaspaceAux : AllStatic {
261 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
262
263 // These methods iterate over the classloader data graph
264 // for the given Metaspace type. These are slow.
265 static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
266 static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
267 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
268 static size_t capacity_bytes_slow();
269
270 // Running sum of space in all Metachunks that has been
271 // allocated to a Metaspace. This is used instead of
272 // iterating over all the classloaders. One for each
273 // type of Metadata
274 static size_t _capacity_words[Metaspace:: MetadataTypeCount];
275 // Running sum of space in all Metachunks that
276 // are being used for metadata. One for each
277 // type of Metadata.
278 static size_t _used_words[Metaspace:: MetadataTypeCount];
279
280 public:
281 // Decrement and increment _allocated_capacity_words
282 static void dec_capacity(Metaspace::MetadataType type, size_t words);
283 static void inc_capacity(Metaspace::MetadataType type, size_t words);
284
285 // Decrement and increment _allocated_used_words
286 static void dec_used(Metaspace::MetadataType type, size_t words);
287 static void inc_used(Metaspace::MetadataType type, size_t words);
288
289 // Total of space allocated to metadata in all Metaspaces.
290 // This sums the space used in each Metachunk by
291 // iterating over the classloader data graph
292 static size_t used_bytes_slow() {
293 return used_bytes_slow(Metaspace::ClassType) +
294 used_bytes_slow(Metaspace::NonClassType);
295 }
296
297 // Used by MetaspaceCounters
298 static size_t free_chunks_total_words();
299 static size_t free_chunks_total_bytes();
300 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
301
302 static size_t capacity_words(Metaspace::MetadataType mdtype) {
303 return _capacity_words[mdtype];
304 }
305 static size_t capacity_words() {
306 return capacity_words(Metaspace::NonClassType) +
307 capacity_words(Metaspace::ClassType);
308 }
309 static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
310 return capacity_words(mdtype) * BytesPerWord;
311 }
312 static size_t capacity_bytes() {
313 return capacity_words() * BytesPerWord;
314 }
315
316 static size_t used_words(Metaspace::MetadataType mdtype) {
317 return _used_words[mdtype];
318 }
319 static size_t used_words() {
320 return used_words(Metaspace::NonClassType) +
321 used_words(Metaspace::ClassType);
322 }
323 static size_t used_bytes(Metaspace::MetadataType mdtype) {
324 return used_words(mdtype) * BytesPerWord;
325 }
326 static size_t used_bytes() {
327 return used_words() * BytesPerWord;
328 }
329
330 static size_t free_bytes();
331 static size_t free_bytes(Metaspace::MetadataType mdtype);
332
333 static size_t reserved_bytes(Metaspace::MetadataType mdtype);
334 static size_t reserved_bytes() {
335 return reserved_bytes(Metaspace::ClassType) +
336 reserved_bytes(Metaspace::NonClassType);
337 }
338
339 static size_t committed_bytes(Metaspace::MetadataType mdtype);
340 static size_t committed_bytes() {
341 return committed_bytes(Metaspace::ClassType) +
342 committed_bytes(Metaspace::NonClassType);
343 }
344
345 static size_t min_chunk_size_words();
346 static size_t min_chunk_size_bytes() {
347 return min_chunk_size_words() * BytesPerWord;
348 }
349
350 static void print_cld_metadata(outputStream* out);
351
352 static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
353 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
354
355 // Print change in used metadata.
356 static void print_metaspace_change(size_t prev_metadata_used);
357 static void print_on(outputStream * out);
358 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
359
360 static void print_class_waste(outputStream* out);
361 static void print_waste(outputStream* out);
362 static void dump(outputStream* out);
363 static void verify_free_chunks();
364 // Checks that the values returned by allocated_capacity_bytes() and
365 // capacity_bytes_slow() are the same.
366 static void verify_capacity();
367 static void verify_used();
368 static void verify_metrics();
369 };
370
371 // Metaspace are deallocated when their class loader are GC'ed.
372 // This class implements a policy for inducing GC's to recover
373 // Metaspaces.
374
375 class MetaspaceGC : AllStatic {
376
377 // The current high-water-mark for inducing a GC.
378 // When committed memory of all metaspaces reaches this value,
379 // a GC is induced and the value is increased. Size is in bytes.
380 static volatile intptr_t _capacity_until_GC;
381
382 // For a CMS collection, signal that a concurrent collection should
383 // be started.
384 static bool _should_concurrent_collect;
385
386 static uint _shrink_factor;
387
388 static size_t shrink_factor() { return _shrink_factor; }
389 void set_shrink_factor(uint v) { _shrink_factor = v; }
390
391 public:
392
393 static void initialize();
394 static void post_initialize();
395
396 static size_t capacity_until_GC();
397 static bool inc_capacity_until_GC(size_t v,
398 size_t* new_cap_until_GC = NULL,
399 size_t* old_cap_until_GC = NULL);
400 static size_t dec_capacity_until_GC(size_t v);
401
402 static bool should_concurrent_collect() { return _should_concurrent_collect; }
403 static void set_should_concurrent_collect(bool v) {
404 _should_concurrent_collect = v;
405 }
406
407 // The amount to increase the high-water-mark (_capacity_until_GC)
408 static size_t delta_capacity_until_GC(size_t bytes);
409
410 // Tells if we have can expand metaspace without hitting set limits.
411 static bool can_expand(size_t words, bool is_class);
412
413 // Returns amount that we can expand without hitting a GC,
414 // measured in words.
415 static size_t allowed_expansion();
416
417 // Calculate the new high-water mark at which to induce
418 // a GC.
419 static void compute_new_size();
420 };
421
422 #endif // SHARE_VM_MEMORY_METASPACE_HPP