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.
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.
22 *
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 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 MetaspaceShared;
91 friend class CollectedHeap;
92 friend class PrintCLDMetaspaceInfoClosure;
93 friend class MetaspaceAllocationTest;
94
95 public:
96 enum MetadataType {
97 ClassType,
98 NonClassType,
99 MetadataTypeCount
100 };
101 enum MetaspaceType {
102 StandardMetaspaceType,
103 BootMetaspaceType,
104 AnonymousMetaspaceType,
105 ReflectionMetaspaceType
106 };
107
108 private:
109 static void verify_global_initialization();
110
111 void initialize(Mutex* lock, MetaspaceType type);
112
113 // Initialize the first chunk for a Metaspace. Used for
114 // special cases such as the boot class loader, reflection
115 // class loader and anonymous class loader.
116 void initialize_first_chunk(MetaspaceType type, MetadataType mdtype);
117 Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype);
118
119 // Align up the word size to the allocation word size
120 static size_t align_word_size_up(size_t);
121
122 // Aligned size of the metaspace.
123 static size_t _compressed_class_space_size;
124
125 static size_t compressed_class_space_size() {
126 return _compressed_class_space_size;
127 }
128
129 static void set_compressed_class_space_size(size_t size) {
130 _compressed_class_space_size = size;
131 }
132
133 static size_t _first_chunk_word_size;
134 static size_t _first_class_chunk_word_size;
135
136 static size_t _commit_alignment;
137 static size_t _reserve_alignment;
138 DEBUG_ONLY(static bool _frozen;)
139
140 SpaceManager* _vsm;
141 SpaceManager* vsm() const { return _vsm; }
142
143 SpaceManager* _class_vsm;
144 SpaceManager* class_vsm() const { return _class_vsm; }
145 SpaceManager* get_space_manager(MetadataType mdtype) {
146 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
147 return mdtype == ClassType ? class_vsm() : vsm();
148 }
149
150 // Allocate space for metadata of type mdtype. This is space
151 // within a Metachunk and is used by
152 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
153 MetaWord* allocate(size_t word_size, MetadataType mdtype);
154
155 MetaWord* expand_and_allocate(size_t size, MetadataType mdtype);
156
157 // Virtual Space lists for both classes and other metadata
158 static VirtualSpaceList* _space_list;
159 static VirtualSpaceList* _class_space_list;
160
161 static ChunkManager* _chunk_manager_metadata;
162 static ChunkManager* _chunk_manager_class;
163
164 static const MetaspaceTracer* _tracer;
165
166 public:
167 static VirtualSpaceList* space_list() { return _space_list; }
168 static VirtualSpaceList* class_space_list() { return _class_space_list; }
169 static VirtualSpaceList* get_space_list(MetadataType mdtype) {
170 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
171 return mdtype == ClassType ? class_space_list() : space_list();
172 }
173
174 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
175 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; }
176 static ChunkManager* get_chunk_manager(MetadataType mdtype) {
177 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
178 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
179 }
180
181 // convenience function
182 static ChunkManager* get_chunk_manager(bool is_class) {
183 return is_class ? chunk_manager_class() : chunk_manager_metadata();
184 }
185
186 static const MetaspaceTracer* tracer() { return _tracer; }
187 static void freeze() {
188 assert(DumpSharedSpaces, "sanity");
189 DEBUG_ONLY(_frozen = true;)
190 }
191 #ifdef _LP64
192 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
193 #endif
194
195 private:
196
197 #ifdef _LP64
198 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
199
200 // Returns true if can use CDS with metaspace allocated as specified address.
201 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
202
203 static void initialize_class_space(ReservedSpace rs);
204 #endif
205 size_t class_chunk_size(size_t word_size);
206
207 public:
208
209 Metaspace(Mutex* lock, MetaspaceType type);
210 ~Metaspace();
211
212 static void ergo_initialize();
213 static void global_initialize();
214 static void post_initialize();
215
216 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
217 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
218
219 static size_t reserve_alignment() { return _reserve_alignment; }
220 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
221 static size_t commit_alignment() { return _commit_alignment; }
222 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
223
224 size_t used_words_slow(MetadataType mdtype) const;
225 size_t free_words_slow(MetadataType mdtype) const;
226 size_t capacity_words_slow(MetadataType mdtype) const;
227
228 size_t used_bytes_slow(MetadataType mdtype) const;
229 size_t capacity_bytes_slow(MetadataType mdtype) const;
230
231 size_t allocated_blocks_bytes() const;
232 size_t allocated_chunks_bytes() const;
233
234 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
235 MetaspaceObj::Type type, TRAPS);
236 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
237
238 static bool contains(const void* ptr);
239 static bool contains_non_shared(const void* ptr);
240
241 void dump(outputStream* const out) const;
242
243 // Free empty virtualspaces
244 static void purge(MetadataType mdtype);
245 static void purge();
246
247 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
248 MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
249
250 static const char* metadata_type_name(Metaspace::MetadataType mdtype);
251
252 void print_on(outputStream* st) const;
253 // Debugging support
254 void verify();
255
256 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
257
258 // Return TRUE only if UseCompressedClassPointers is True.
259 static bool using_class_space() {
260 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
261 }
262
263 static bool is_class_space_allocation(MetadataType mdType) {
264 return mdType == ClassType && using_class_space();
265 }
266
267 };
268
269 class MetaspaceAux : AllStatic {
270 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
271
272 // These methods iterate over the classloader data graph
273 // for the given Metaspace type. These are slow.
274 static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
275 static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
276 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
277 static size_t capacity_bytes_slow();
278
279 // Running sum of space in all Metachunks that has been
280 // allocated to a Metaspace. This is used instead of
281 // iterating over all the classloaders. One for each
282 // type of Metadata
283 static size_t _capacity_words[Metaspace:: MetadataTypeCount];
284 // Running sum of space in all Metachunks that
285 // are being used for metadata. One for each
286 // type of Metadata.
287 static volatile size_t _used_words[Metaspace:: MetadataTypeCount];
288
289 public:
290 // Decrement and increment _allocated_capacity_words
291 static void dec_capacity(Metaspace::MetadataType type, size_t words);
292 static void inc_capacity(Metaspace::MetadataType type, size_t words);
293
294 // Decrement and increment _allocated_used_words
295 static void dec_used(Metaspace::MetadataType type, size_t words);
296 static void inc_used(Metaspace::MetadataType type, size_t words);
297
298 // Total of space allocated to metadata in all Metaspaces.
299 // This sums the space used in each Metachunk by
300 // iterating over the classloader data graph
301 static size_t used_bytes_slow() {
302 return used_bytes_slow(Metaspace::ClassType) +
303 used_bytes_slow(Metaspace::NonClassType);
304 }
305
306 // Used by MetaspaceCounters
307 static size_t free_chunks_total_words();
308 static size_t free_chunks_total_bytes();
309 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
310
311 static size_t capacity_words(Metaspace::MetadataType mdtype) {
312 return _capacity_words[mdtype];
313 }
314 static size_t capacity_words() {
315 return capacity_words(Metaspace::NonClassType) +
316 capacity_words(Metaspace::ClassType);
317 }
318 static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
319 return capacity_words(mdtype) * BytesPerWord;
320 }
321 static size_t capacity_bytes() {
322 return capacity_words() * BytesPerWord;
323 }
324
325 static size_t used_words(Metaspace::MetadataType mdtype) {
326 return _used_words[mdtype];
327 }
328 static size_t used_words() {
329 return used_words(Metaspace::NonClassType) +
330 used_words(Metaspace::ClassType);
331 }
332 static size_t used_bytes(Metaspace::MetadataType mdtype) {
333 return used_words(mdtype) * BytesPerWord;
334 }
335 static size_t used_bytes() {
336 return used_words() * BytesPerWord;
337 }
338
339 static size_t free_bytes();
340 static size_t free_bytes(Metaspace::MetadataType mdtype);
341
342 static size_t reserved_bytes(Metaspace::MetadataType mdtype);
343 static size_t reserved_bytes() {
344 return reserved_bytes(Metaspace::ClassType) +
345 reserved_bytes(Metaspace::NonClassType);
346 }
347
348 static size_t committed_bytes(Metaspace::MetadataType mdtype);
349 static size_t committed_bytes() {
350 return committed_bytes(Metaspace::ClassType) +
351 committed_bytes(Metaspace::NonClassType);
352 }
353
354 static size_t min_chunk_size_words();
355 static size_t min_chunk_size_bytes() {
356 return min_chunk_size_words() * BytesPerWord;
357 }
358
359 static void print_metadata_for_nmt(outputStream* out, size_t scale = K);
360
361 static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
362 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
363
364 // Print change in used metadata.
365 static void print_metaspace_change(size_t prev_metadata_used);
366 static void print_on(outputStream * out);
367 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
368
369 static void print_class_waste(outputStream* out);
370 static void print_waste(outputStream* out);
371
372 // Prints an ASCII representation of the given space.
373 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype);
374
375 static void dump(outputStream* out);
376 static void verify_free_chunks();
377 // Checks that the values returned by allocated_capacity_bytes() and
378 // capacity_bytes_slow() are the same.
379 static void verify_capacity();
380 static void verify_used();
381 static void verify_metrics();
382 };
383
384 // Metaspace are deallocated when their class loader are GC'ed.
385 // This class implements a policy for inducing GC's to recover
386 // Metaspaces.
387
388 class MetaspaceGC : AllStatic {
389
390 // The current high-water-mark for inducing a GC.
391 // When committed memory of all metaspaces reaches this value,
392 // a GC is induced and the value is increased. Size is in bytes.
393 static volatile intptr_t _capacity_until_GC;
394
395 // For a CMS collection, signal that a concurrent collection should
396 // be started.
397 static bool _should_concurrent_collect;
398
399 static uint _shrink_factor;
400
401 static size_t shrink_factor() { return _shrink_factor; }
402 void set_shrink_factor(uint v) { _shrink_factor = v; }
403
404 public:
405
406 static void initialize();
407 static void post_initialize();
408
409 static size_t capacity_until_GC();
410 static bool inc_capacity_until_GC(size_t v,
411 size_t* new_cap_until_GC = NULL,
412 size_t* old_cap_until_GC = NULL);
413 static size_t dec_capacity_until_GC(size_t v);
414
415 static bool should_concurrent_collect() { return _should_concurrent_collect; }
416 static void set_should_concurrent_collect(bool v) {
417 _should_concurrent_collect = v;
418 }
419
420 // The amount to increase the high-water-mark (_capacity_until_GC)
421 static size_t delta_capacity_until_GC(size_t bytes);
422
423 // Tells if we have can expand metaspace without hitting set limits.
424 static bool can_expand(size_t words, bool is_class);
425
426 // Returns amount that we can expand without hitting a GC,
427 // measured in words.
428 static size_t allowed_expansion();
429
430 // Calculate the new high-water mark at which to induce
431 // a GC.
432 static void compute_new_size();
433 };
434
435 #endif // SHARE_VM_MEMORY_METASPACE_HPP