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
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7 * published by the Free Software Foundation.
8 *
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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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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,
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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 // Eventually for bootstrap loader we'll have a read-only section and read-write
39 // to write for DumpSharedSpaces and read for UseSharedSpaces
40 //
41 // block X ---+ +-------------------+
42 // | | Virtualspace |
43 // | | |
44 // | | |
45 // | |-------------------|
46 // | || Chunk |
47 // | || |
48 // | ||---------- |
49 // +------>||| block 0 | |
50 // ||---------- |
51 // ||| block 1 | |
52 // ||---------- |
53 // || |
54 // |-------------------|
55 // | |
56 // | |
57 // +-------------------+
58 //
59
60 class ChunkManager;
61 class ClassLoaderData;
62 class Metablock;
63 class Metachunk;
64 class MetaspaceTracer;
65 class MetaWord;
66 class Mutex;
67 class outputStream;
68 class SpaceManager;
69 class VirtualSpaceList;
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 class Metaspace : public CHeapObj<mtClass> {
85 friend class VMStructs;
86 friend class SpaceManager;
87 friend class VM_CollectForMetadataAllocation;
88 friend class MetaspaceGC;
89 friend class MetaspaceAux;
90 friend class CollectorPolicy;
91
92 public:
93 enum MetadataType {
94 ClassType,
95 NonClassType,
96 MetadataTypeCount
97 };
98 enum MetaspaceType {
99 StandardMetaspaceType,
100 BootMetaspaceType,
101 ROMetaspaceType,
102 ReadWriteMetaspaceType,
103 AnonymousMetaspaceType,
104 ReflectionMetaspaceType
105 };
106
107 private:
108 static void verify_global_initialization();
109
110 void initialize(Mutex* lock, MetaspaceType type);
111
112 // Initialize the first chunk for a Metaspace. Used for
113 // special cases such as the boot class loader, reflection
114 // class loader and anonymous class loader.
115 void initialize_first_chunk(MetaspaceType type, MetadataType mdtype);
116 Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype);
117
118 // Align up the word size to the allocation word size
119 static size_t align_word_size_up(size_t);
120
121 // Aligned size of the metaspace.
122 static size_t _compressed_class_space_size;
123
124 static size_t compressed_class_space_size() {
125 return _compressed_class_space_size;
126 }
127
128 static void set_compressed_class_space_size(size_t size) {
129 _compressed_class_space_size = size;
130 }
131
132 static size_t _first_chunk_word_size;
133 static size_t _first_class_chunk_word_size;
134
135 static size_t _commit_alignment;
136 static size_t _reserve_alignment;
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
181 private:
182 // These 2 methods are used by DumpSharedSpaces only, where only _vsm is used. So we will
183 // maintain a single list for now.
184 void record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size);
185 void record_deallocation(void* ptr, size_t word_size);
186
187 #ifdef _LP64
188 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
189
190 // Returns true if can use CDS with metaspace allocated as specified address.
191 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
192
193 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
194
195 static void initialize_class_space(ReservedSpace rs);
196 #endif
197
198 class AllocRecord : public CHeapObj<mtClass> {
199 public:
200 AllocRecord(address ptr, MetaspaceObj::Type type, int byte_size)
201 : _next(NULL), _ptr(ptr), _type(type), _byte_size(byte_size) {}
202 AllocRecord *_next;
203 address _ptr;
204 MetaspaceObj::Type _type;
205 int _byte_size;
206 };
207
208 AllocRecord * _alloc_record_head;
209 AllocRecord * _alloc_record_tail;
210
211 size_t class_chunk_size(size_t word_size);
212
213 public:
214
215 Metaspace(Mutex* lock, MetaspaceType type);
216 ~Metaspace();
217
218 static void ergo_initialize();
219 static void global_initialize();
220 static void post_initialize();
221
222 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
223 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
224
225 static size_t reserve_alignment() { return _reserve_alignment; }
226 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
227 static size_t commit_alignment() { return _commit_alignment; }
228 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
229
230 char* bottom() const;
231 size_t used_words_slow(MetadataType mdtype) const;
232 size_t free_words_slow(MetadataType mdtype) const;
233 size_t capacity_words_slow(MetadataType mdtype) const;
234
235 size_t used_bytes_slow(MetadataType mdtype) const;
236 size_t capacity_bytes_slow(MetadataType mdtype) const;
237
238 size_t allocated_blocks_bytes() const;
239 size_t allocated_chunks_bytes() const;
240
241 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
242 bool read_only, MetaspaceObj::Type type, TRAPS);
243 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
244
245 static bool contains(const void* ptr);
246 static bool contains_non_shared(const void* ptr);
247
248 void dump(outputStream* const out) const;
249
250 // Free empty virtualspaces
251 static void purge(MetadataType mdtype);
252 static void purge();
253
254 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
255 MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
256
257 static const char* metadata_type_name(Metaspace::MetadataType mdtype);
258
259 void print_on(outputStream* st) const;
260 // Debugging support
261 void verify();
262
263 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
264
265 class AllocRecordClosure : public StackObj {
266 public:
267 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) = 0;
268 };
269
270 void iterate(AllocRecordClosure *closure);
271
272 // Return TRUE only if UseCompressedClassPointers is True and DumpSharedSpaces is False.
273 static bool using_class_space() {
274 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers && !DumpSharedSpaces);
275 }
276
277 static bool is_class_space_allocation(MetadataType mdType) {
278 return mdType == ClassType && using_class_space();
279 }
280
281 };
282
283 class MetaspaceAux : AllStatic {
284 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
285
286 // These methods iterate over the classloader data graph
287 // for the given Metaspace type. These are slow.
288 static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
289 static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
290 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
291 static size_t capacity_bytes_slow();
292
293 // Running sum of space in all Metachunks that has been
294 // allocated to a Metaspace. This is used instead of
295 // iterating over all the classloaders. One for each
296 // type of Metadata
297 static size_t _capacity_words[Metaspace:: MetadataTypeCount];
298 // Running sum of space in all Metachunks that
299 // are being used for metadata. One for each
300 // type of Metadata.
301 static size_t _used_words[Metaspace:: MetadataTypeCount];
302
303 public:
304 // Decrement and increment _allocated_capacity_words
305 static void dec_capacity(Metaspace::MetadataType type, size_t words);
306 static void inc_capacity(Metaspace::MetadataType type, size_t words);
307
308 // Decrement and increment _allocated_used_words
309 static void dec_used(Metaspace::MetadataType type, size_t words);
310 static void inc_used(Metaspace::MetadataType type, size_t words);
311
312 // Total of space allocated to metadata in all Metaspaces.
313 // This sums the space used in each Metachunk by
314 // iterating over the classloader data graph
315 static size_t used_bytes_slow() {
316 return used_bytes_slow(Metaspace::ClassType) +
317 used_bytes_slow(Metaspace::NonClassType);
318 }
319
320 // Used by MetaspaceCounters
321 static size_t free_chunks_total_words();
322 static size_t free_chunks_total_bytes();
323 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
324
325 static size_t capacity_words(Metaspace::MetadataType mdtype) {
326 return _capacity_words[mdtype];
327 }
328 static size_t capacity_words() {
329 return capacity_words(Metaspace::NonClassType) +
330 capacity_words(Metaspace::ClassType);
331 }
332 static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
333 return capacity_words(mdtype) * BytesPerWord;
334 }
335 static size_t capacity_bytes() {
336 return capacity_words() * BytesPerWord;
337 }
338
339 static size_t used_words(Metaspace::MetadataType mdtype) {
340 return _used_words[mdtype];
341 }
342 static size_t used_words() {
343 return used_words(Metaspace::NonClassType) +
344 used_words(Metaspace::ClassType);
345 }
346 static size_t used_bytes(Metaspace::MetadataType mdtype) {
347 return used_words(mdtype) * BytesPerWord;
348 }
349 static size_t used_bytes() {
350 return used_words() * BytesPerWord;
351 }
352
353 static size_t free_bytes();
354 static size_t free_bytes(Metaspace::MetadataType mdtype);
355
356 static size_t reserved_bytes(Metaspace::MetadataType mdtype);
357 static size_t reserved_bytes() {
358 return reserved_bytes(Metaspace::ClassType) +
359 reserved_bytes(Metaspace::NonClassType);
360 }
361
362 static size_t committed_bytes(Metaspace::MetadataType mdtype);
363 static size_t committed_bytes() {
364 return committed_bytes(Metaspace::ClassType) +
365 committed_bytes(Metaspace::NonClassType);
366 }
367
368 static size_t min_chunk_size_words();
369 static size_t min_chunk_size_bytes() {
370 return min_chunk_size_words() * BytesPerWord;
371 }
372
373 static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
374 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
375
376 // Print change in used metadata.
377 static void print_metaspace_change(size_t prev_metadata_used);
378 static void print_on(outputStream * out);
379 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
380
381 static void print_class_waste(outputStream* out);
382 static void print_waste(outputStream* out);
383 static void dump(outputStream* out);
384 static void verify_free_chunks();
385 // Checks that the values returned by allocated_capacity_bytes() and
386 // capacity_bytes_slow() are the same.
387 static void verify_capacity();
388 static void verify_used();
389 static void verify_metrics();
390 };
391
392 // Metaspace are deallocated when their class loader are GC'ed.
393 // This class implements a policy for inducing GC's to recover
394 // Metaspaces.
395
396 class MetaspaceGC : AllStatic {
397
398 // The current high-water-mark for inducing a GC.
399 // When committed memory of all metaspaces reaches this value,
400 // a GC is induced and the value is increased. Size is in bytes.
401 static volatile intptr_t _capacity_until_GC;
402
403 // For a CMS collection, signal that a concurrent collection should
404 // be started.
405 static bool _should_concurrent_collect;
406
407 static uint _shrink_factor;
408
409 static size_t shrink_factor() { return _shrink_factor; }
410 void set_shrink_factor(uint v) { _shrink_factor = v; }
411
412 public:
413
414 static void initialize();
415 static void post_initialize();
416
417 static size_t capacity_until_GC();
418 static bool inc_capacity_until_GC(size_t v,
419 size_t* new_cap_until_GC = NULL,
420 size_t* old_cap_until_GC = NULL);
421 static size_t dec_capacity_until_GC(size_t v);
422
423 static bool should_concurrent_collect() { return _should_concurrent_collect; }
424 static void set_should_concurrent_collect(bool v) {
425 _should_concurrent_collect = v;
426 }
427
428 // The amount to increase the high-water-mark (_capacity_until_GC)
429 static size_t delta_capacity_until_GC(size_t bytes);
430
431 // Tells if we have can expand metaspace without hitting set limits.
432 static bool can_expand(size_t words, bool is_class);
433
434 // Returns amount that we can expand without hitting a GC,
435 // measured in words.
436 static size_t allowed_expansion();
437
438 // Calculate the new high-water mark at which to induce
439 // a GC.
440 static void compute_new_size();
441 };
442
443 #endif // SHARE_VM_MEMORY_METASPACE_HPP