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 *
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.
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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
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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 class CollectedHeap;
70
71 // Metaspaces each have a SpaceManager and allocations
72 // are done by the SpaceManager. Allocations are done
73 // out of the current Metachunk. When the current Metachunk
74 // is exhausted, the SpaceManager gets a new one from
75 // the current VirtualSpace. When the VirtualSpace is exhausted
76 // the SpaceManager gets a new one. The SpaceManager
77 // also manages freelists of available Chunks.
78 //
79 // Currently the space manager maintains the list of
80 // virtual spaces and the list of chunks in use. Its
81 // allocate() method returns a block for use as a
82 // quantum of metadata.
83
84 // Namespace for important central static functions
85 // (auxiliary stuff goes into MetaspaceUtils)
86 class Metaspace : public AllStatic {
87
88 friend class MetaspaceShared;
89
90 public:
91 enum MetadataType {
92 ClassType,
93 NonClassType,
94 MetadataTypeCount
95 };
96 enum MetaspaceType {
97 StandardMetaspaceType,
98 BootMetaspaceType,
99 AnonymousMetaspaceType,
100 ReflectionMetaspaceType
101 };
102
103 private:
104
105 // Align up the word size to the allocation word size
106 static size_t align_word_size_up(size_t);
107
108 // Aligned size of the metaspace.
109 static size_t _compressed_class_space_size;
110
111 static size_t compressed_class_space_size() {
112 return _compressed_class_space_size;
113 }
114
115 static void set_compressed_class_space_size(size_t size) {
116 _compressed_class_space_size = size;
117 }
118
119 static size_t _first_chunk_word_size;
120 static size_t _first_class_chunk_word_size;
121
122 static size_t _commit_alignment;
123 static size_t _reserve_alignment;
124 DEBUG_ONLY(static bool _frozen;)
125
126 // Virtual Space lists for both classes and other metadata
127 static VirtualSpaceList* _space_list;
128 static VirtualSpaceList* _class_space_list;
129
130 static ChunkManager* _chunk_manager_metadata;
131 static ChunkManager* _chunk_manager_class;
132
133 static const MetaspaceTracer* _tracer;
134
135 public:
136 static VirtualSpaceList* space_list() { return _space_list; }
137 static VirtualSpaceList* class_space_list() { return _class_space_list; }
138 static VirtualSpaceList* get_space_list(MetadataType mdtype) {
139 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
140 return mdtype == ClassType ? class_space_list() : space_list();
141 }
142
143 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
144 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; }
145 static ChunkManager* get_chunk_manager(MetadataType mdtype) {
146 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
147 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
148 }
149
150 // convenience function
151 static ChunkManager* get_chunk_manager(bool is_class) {
152 return is_class ? chunk_manager_class() : chunk_manager_metadata();
153 }
154
155 static const MetaspaceTracer* tracer() { return _tracer; }
156 static void freeze() {
157 assert(DumpSharedSpaces, "sanity");
158 DEBUG_ONLY(_frozen = true;)
159 }
160 static void assert_not_frozen() {
161 assert(!_frozen, "sanity");
162 }
163 #ifdef _LP64
164 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
165 #endif
166
167 private:
168
169 #ifdef _LP64
170 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
171
172 // Returns true if can use CDS with metaspace allocated as specified address.
173 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
174
175 static void initialize_class_space(ReservedSpace rs);
176 #endif
177
178 public:
179
180 static void ergo_initialize();
181 static void global_initialize();
182 static void post_initialize();
183
184 static void verify_global_initialization();
185
186 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
187 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
188
189 static size_t reserve_alignment() { return _reserve_alignment; }
190 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
191 static size_t commit_alignment() { return _commit_alignment; }
192 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
193
194 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
195 MetaspaceObj::Type type, TRAPS);
196 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
197
198 static bool contains(const void* ptr);
199 static bool contains_non_shared(const void* ptr);
200
201 // Free empty virtualspaces
202 static void purge(MetadataType mdtype);
203 static void purge();
204
205 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
206 MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
207
208 static const char* metadata_type_name(Metaspace::MetadataType mdtype);
209
210 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
211
212 // Return TRUE only if UseCompressedClassPointers is True.
213 static bool using_class_space() {
214 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
215 }
216
217 static bool is_class_space_allocation(MetadataType mdType) {
218 return mdType == ClassType && using_class_space();
219 }
220
221 };
222
223 // Manages the metaspace portion belonging to a class loader
224 class ClassLoaderMetaspace : public CHeapObj<mtClass> {
225 friend class CollectedHeap; // For expand_and_allocate()
226 friend class Metaspace;
227 friend class MetaspaceUtils;
228 friend class PrintCLDMetaspaceInfoClosure;
229 friend class VM_CollectForMetadataAllocation; // For expand_and_allocate()
230
231 private:
232
233 void initialize(Mutex* lock, Metaspace::MetaspaceType type);
234
235 // Initialize the first chunk for a Metaspace. Used for
236 // special cases such as the boot class loader, reflection
237 // class loader and anonymous class loader.
238 void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
239 Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
240
241 SpaceManager* _vsm;
242 SpaceManager* vsm() const { return _vsm; }
243
244 SpaceManager* _class_vsm;
245 SpaceManager* class_vsm() const { return _class_vsm; }
246 SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) {
247 assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
248 return mdtype == Metaspace::ClassType ? class_vsm() : vsm();
249 }
250
251 MetaWord* expand_and_allocate(size_t size, Metaspace::MetadataType mdtype);
252
253 size_t class_chunk_size(size_t word_size);
254
255 public:
256
257 ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type);
258 ~ClassLoaderMetaspace();
259
260 // Allocate space for metadata of type mdtype. This is space
261 // within a Metachunk and is used by
262 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
263 MetaWord* allocate(size_t word_size, Metaspace::MetadataType mdtype);
264
265 size_t used_words_slow(Metaspace::MetadataType mdtype) const;
266 size_t free_words_slow(Metaspace::MetadataType mdtype) const;
267 size_t capacity_words_slow(Metaspace::MetadataType mdtype) const;
268
269 size_t used_bytes_slow(Metaspace::MetadataType mdtype) const;
270 size_t capacity_bytes_slow(Metaspace::MetadataType mdtype) const;
271
272 size_t allocated_blocks_bytes() const;
273 size_t allocated_chunks_bytes() const;
274
275 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
276
277 void dump(outputStream* const out) const;
278
279 void print_on(outputStream* st) const;
280 // Debugging support
281 void verify();
282
283 }; // ClassLoaderMetaspace
284
285
286 class MetaspaceUtils : AllStatic {
287 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
288
289 // These methods iterate over the classloader data graph
290 // for the given Metaspace type. These are slow.
291 static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
292 static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
293 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
294 static size_t capacity_bytes_slow();
295
296 // Running sum of space in all Metachunks that has been
297 // allocated to a Metaspace. This is used instead of
298 // iterating over all the classloaders. One for each
299 // type of Metadata
300 static size_t _capacity_words[Metaspace:: MetadataTypeCount];
301 // Running sum of space in all Metachunks that
302 // are being used for metadata. One for each
303 // type of Metadata.
304 static volatile size_t _used_words[Metaspace:: MetadataTypeCount];
305
306 public:
307 // Decrement and increment _allocated_capacity_words
308 static void dec_capacity(Metaspace::MetadataType type, size_t words);
309 static void inc_capacity(Metaspace::MetadataType type, size_t words);
310
311 // Decrement and increment _allocated_used_words
312 static void dec_used(Metaspace::MetadataType type, size_t words);
313 static void inc_used(Metaspace::MetadataType type, size_t words);
314
315 // Total of space allocated to metadata in all Metaspaces.
316 // This sums the space used in each Metachunk by
317 // iterating over the classloader data graph
318 static size_t used_bytes_slow() {
319 return used_bytes_slow(Metaspace::ClassType) +
320 used_bytes_slow(Metaspace::NonClassType);
321 }
322
323 // Used by MetaspaceCounters
324 static size_t free_chunks_total_words();
325 static size_t free_chunks_total_bytes();
326 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
327
328 static size_t capacity_words(Metaspace::MetadataType mdtype) {
329 return _capacity_words[mdtype];
330 }
331 static size_t capacity_words() {
332 return capacity_words(Metaspace::NonClassType) +
333 capacity_words(Metaspace::ClassType);
334 }
335 static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
336 return capacity_words(mdtype) * BytesPerWord;
337 }
338 static size_t capacity_bytes() {
339 return capacity_words() * BytesPerWord;
340 }
341
342 static size_t used_words(Metaspace::MetadataType mdtype) {
343 return _used_words[mdtype];
344 }
345 static size_t used_words() {
346 return used_words(Metaspace::NonClassType) +
347 used_words(Metaspace::ClassType);
348 }
349 static size_t used_bytes(Metaspace::MetadataType mdtype) {
350 return used_words(mdtype) * BytesPerWord;
351 }
352 static size_t used_bytes() {
353 return used_words() * BytesPerWord;
354 }
355
356 static size_t free_bytes();
357 static size_t free_bytes(Metaspace::MetadataType mdtype);
358
359 static size_t reserved_bytes(Metaspace::MetadataType mdtype);
360 static size_t reserved_bytes() {
361 return reserved_bytes(Metaspace::ClassType) +
362 reserved_bytes(Metaspace::NonClassType);
363 }
364
365 static size_t committed_bytes(Metaspace::MetadataType mdtype);
366 static size_t committed_bytes() {
367 return committed_bytes(Metaspace::ClassType) +
368 committed_bytes(Metaspace::NonClassType);
369 }
370
371 static size_t min_chunk_size_words();
372 static size_t min_chunk_size_bytes() {
373 return min_chunk_size_words() * BytesPerWord;
374 }
375
376 static void print_metadata_for_nmt(outputStream* out, size_t scale = K);
377
378 static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
379 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
380
381 // Print change in used metadata.
382 static void print_metaspace_change(size_t prev_metadata_used);
383 static void print_on(outputStream * out);
384 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
385
386 static void print_class_waste(outputStream* out);
387 static void print_waste(outputStream* out);
388
389 // Prints an ASCII representation of the given space.
390 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype);
391
392 static void dump(outputStream* out);
393 static void verify_free_chunks();
394 // Checks that the values returned by allocated_capacity_bytes() and
395 // capacity_bytes_slow() are the same.
396 static void verify_capacity();
397 static void verify_used();
398 static void verify_metrics();
399 };
400
401 // Metaspace are deallocated when their class loader are GC'ed.
402 // This class implements a policy for inducing GC's to recover
403 // Metaspaces.
404
405 class MetaspaceGC : AllStatic {
406
407 // The current high-water-mark for inducing a GC.
408 // When committed memory of all metaspaces reaches this value,
409 // a GC is induced and the value is increased. Size is in bytes.
410 static volatile intptr_t _capacity_until_GC;
411
412 // For a CMS collection, signal that a concurrent collection should
413 // be started.
414 static bool _should_concurrent_collect;
415
416 static uint _shrink_factor;
417
418 static size_t shrink_factor() { return _shrink_factor; }
419 void set_shrink_factor(uint v) { _shrink_factor = v; }
420
421 public:
422
423 static void initialize();
424 static void post_initialize();
425
426 static size_t capacity_until_GC();
427 static bool inc_capacity_until_GC(size_t v,
428 size_t* new_cap_until_GC = NULL,
429 size_t* old_cap_until_GC = NULL);
430 static size_t dec_capacity_until_GC(size_t v);
431
432 static bool should_concurrent_collect() { return _should_concurrent_collect; }
433 static void set_should_concurrent_collect(bool v) {
434 _should_concurrent_collect = v;
435 }
436
437 // The amount to increase the high-water-mark (_capacity_until_GC)
438 static size_t delta_capacity_until_GC(size_t bytes);
439
440 // Tells if we have can expand metaspace without hitting set limits.
441 static bool can_expand(size_t words, bool is_class);
442
443 // Returns amount that we can expand without hitting a GC,
444 // measured in words.
445 static size_t allowed_expansion();
446
447 // Calculate the new high-water mark at which to induce
448 // a GC.
449 static void compute_new_size();
450 };
451
452 #endif // SHARE_VM_MEMORY_METASPACE_HPP