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 *
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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).
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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 CollectedHeap;
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 #ifdef _LP64
185 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
186 #endif
187
188 private:
189
190 #ifdef _LP64
191 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
192
193 // Returns true if can use CDS with metaspace allocated as specified address.
194 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
195
196 static void initialize_class_space(ReservedSpace rs);
197 #endif
198 size_t class_chunk_size(size_t word_size);
199
200 public:
201
202 Metaspace(Mutex* lock, MetaspaceType type);
203 ~Metaspace();
204
205 static void ergo_initialize();
206 static void global_initialize();
207 static void post_initialize();
208
209 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
210 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
211
212 static size_t reserve_alignment() { return _reserve_alignment; }
213 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
214 static size_t commit_alignment() { return _commit_alignment; }
215 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
216
217 size_t used_words_slow(MetadataType mdtype) const;
218 size_t free_words_slow(MetadataType mdtype) const;
219 size_t capacity_words_slow(MetadataType mdtype) const;
220
221 size_t used_bytes_slow(MetadataType mdtype) const;
222 size_t capacity_bytes_slow(MetadataType mdtype) const;
223
224 size_t allocated_blocks_bytes() const;
225 size_t allocated_chunks_bytes() const;
226
227 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
228 MetaspaceObj::Type type, TRAPS);
229 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
230
231 static bool contains(const void* ptr);
232 static bool contains_non_shared(const void* ptr);
233
234 void dump(outputStream* const out) const;
235
236 // Free empty virtualspaces
237 static void purge(MetadataType mdtype);
238 static void purge();
239
240 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
241 MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
242
243 static const char* metadata_type_name(Metaspace::MetadataType mdtype);
244
245 void print_on(outputStream* st) const;
246 // Debugging support
247 void verify();
248
249 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
250
251 // Return TRUE only if UseCompressedClassPointers is True.
252 static bool using_class_space() {
253 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
254 }
255
256 static bool is_class_space_allocation(MetadataType mdType) {
257 return mdType == ClassType && using_class_space();
258 }
259
260 };
261
262 class MetaspaceAux : AllStatic {
263 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
264
265 // These methods iterate over the classloader data graph
266 // for the given Metaspace type. These are slow.
267 static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
268 static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
269 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
270 static size_t capacity_bytes_slow();
271
272 // Running sum of space in all Metachunks that has been
273 // allocated to a Metaspace. This is used instead of
274 // iterating over all the classloaders. One for each
275 // type of Metadata
276 static size_t _capacity_words[Metaspace:: MetadataTypeCount];
277 // Running sum of space in all Metachunks that
278 // are being used for metadata. One for each
279 // type of Metadata.
280 static volatile size_t _used_words[Metaspace:: MetadataTypeCount];
281
282 public:
283 // Decrement and increment _allocated_capacity_words
284 static void dec_capacity(Metaspace::MetadataType type, size_t words);
285 static void inc_capacity(Metaspace::MetadataType type, size_t words);
286
287 // Decrement and increment _allocated_used_words
288 static void dec_used(Metaspace::MetadataType type, size_t words);
289 static void inc_used(Metaspace::MetadataType type, size_t words);
290
291 // Total of space allocated to metadata in all Metaspaces.
292 // This sums the space used in each Metachunk by
293 // iterating over the classloader data graph
294 static size_t used_bytes_slow() {
295 return used_bytes_slow(Metaspace::ClassType) +
296 used_bytes_slow(Metaspace::NonClassType);
297 }
298
299 // Used by MetaspaceCounters
300 static size_t free_chunks_total_words();
301 static size_t free_chunks_total_bytes();
302 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
303
304 static size_t capacity_words(Metaspace::MetadataType mdtype) {
305 return _capacity_words[mdtype];
306 }
307 static size_t capacity_words() {
308 return capacity_words(Metaspace::NonClassType) +
309 capacity_words(Metaspace::ClassType);
310 }
311 static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
312 return capacity_words(mdtype) * BytesPerWord;
313 }
314 static size_t capacity_bytes() {
315 return capacity_words() * BytesPerWord;
316 }
317
318 static size_t used_words(Metaspace::MetadataType mdtype) {
319 return _used_words[mdtype];
320 }
321 static size_t used_words() {
322 return used_words(Metaspace::NonClassType) +
323 used_words(Metaspace::ClassType);
324 }
325 static size_t used_bytes(Metaspace::MetadataType mdtype) {
326 return used_words(mdtype) * BytesPerWord;
327 }
328 static size_t used_bytes() {
329 return used_words() * BytesPerWord;
330 }
331
332 static size_t free_bytes();
333 static size_t free_bytes(Metaspace::MetadataType mdtype);
334
335 static size_t reserved_bytes(Metaspace::MetadataType mdtype);
336 static size_t reserved_bytes() {
337 return reserved_bytes(Metaspace::ClassType) +
338 reserved_bytes(Metaspace::NonClassType);
339 }
340
341 static size_t committed_bytes(Metaspace::MetadataType mdtype);
342 static size_t committed_bytes() {
343 return committed_bytes(Metaspace::ClassType) +
344 committed_bytes(Metaspace::NonClassType);
345 }
346
347 static size_t min_chunk_size_words();
348 static size_t min_chunk_size_bytes() {
349 return min_chunk_size_words() * BytesPerWord;
350 }
351
352 static void print_metadata_for_nmt(outputStream* out, size_t scale = K);
353
354 static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
355 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
356
357 // Print change in used metadata.
358 static void print_metaspace_change(size_t prev_metadata_used);
359 static void print_on(outputStream * out);
360 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
361
362 static void print_class_waste(outputStream* out);
363 static void print_waste(outputStream* out);
364
365 // Prints an ASCII representation of the given space.
366 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype);
367
368 static void dump(outputStream* out);
369 static void verify_free_chunks();
370 // Checks that the values returned by allocated_capacity_bytes() and
371 // capacity_bytes_slow() are the same.
372 static void verify_capacity();
373 static void verify_used();
374 static void verify_metrics();
375 };
376
377 // Metaspace are deallocated when their class loader are GC'ed.
378 // This class implements a policy for inducing GC's to recover
379 // Metaspaces.
380
381 class MetaspaceGC : AllStatic {
382
383 // The current high-water-mark for inducing a GC.
384 // When committed memory of all metaspaces reaches this value,
385 // a GC is induced and the value is increased. Size is in bytes.
386 static volatile intptr_t _capacity_until_GC;
387
388 // For a CMS collection, signal that a concurrent collection should
389 // be started.
390 static bool _should_concurrent_collect;
391
392 static uint _shrink_factor;
393
394 static size_t shrink_factor() { return _shrink_factor; }
395 void set_shrink_factor(uint v) { _shrink_factor = v; }
396
397 public:
398
399 static void initialize();
400 static void post_initialize();
401
402 static size_t capacity_until_GC();
403 static bool inc_capacity_until_GC(size_t v,
404 size_t* new_cap_until_GC = NULL,
405 size_t* old_cap_until_GC = NULL);
406 static size_t dec_capacity_until_GC(size_t v);
407
408 static bool should_concurrent_collect() { return _should_concurrent_collect; }
409 static void set_should_concurrent_collect(bool v) {
410 _should_concurrent_collect = v;
411 }
412
413 // The amount to increase the high-water-mark (_capacity_until_GC)
414 static size_t delta_capacity_until_GC(size_t bytes);
415
416 // Tells if we have can expand metaspace without hitting set limits.
417 static bool can_expand(size_t words, bool is_class);
418
419 // Returns amount that we can expand without hitting a GC,
420 // measured in words.
421 static size_t allowed_expansion();
422
423 // Calculate the new high-water mark at which to induce
424 // a GC.
425 static void compute_new_size();
426 };
427
428 #endif // SHARE_VM_MEMORY_METASPACE_HPP