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 "runtime/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 ShenandoahCollectorPolicy; 69 class SpaceManager; 70 class VirtualSpaceList; 71 72 // Metaspaces each have a SpaceManager and allocations 73 // are done by the SpaceManager. Allocations are done 74 // out of the current Metachunk. When the current Metachunk 75 // is exhausted, the SpaceManager gets a new one from 76 // the current VirtualSpace. When the VirtualSpace is exhausted 77 // the SpaceManager gets a new one. The SpaceManager 78 // also manages freelists of available Chunks. 79 // 80 // Currently the space manager maintains the list of 81 // virtual spaces and the list of chunks in use. Its 82 // allocate() method returns a block for use as a 83 // quantum of metadata. 84 85 class Metaspace : public CHeapObj<mtClass> { 86 friend class VMStructs; 87 friend class SpaceManager; 88 friend class VM_CollectForMetadataAllocation; 89 friend class MetaspaceGC; 90 friend class MetaspaceAux; 91 friend class ShenandoahCollectorPolicy; 92 93 public: 94 enum MetadataType { 95 ClassType, 96 NonClassType, 97 MetadataTypeCount 98 }; 99 enum MetaspaceType { 100 StandardMetaspaceType, 101 BootMetaspaceType, 102 ROMetaspaceType, 103 ReadWriteMetaspaceType, 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; 138 139 SpaceManager* _vsm; 140 SpaceManager* vsm() const { return _vsm; } 141 142 SpaceManager* _class_vsm; 143 SpaceManager* class_vsm() const { return _class_vsm; } 144 SpaceManager* get_space_manager(MetadataType mdtype) { 145 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 146 return mdtype == ClassType ? class_vsm() : vsm(); 147 } 148 149 // Allocate space for metadata of type mdtype. This is space 150 // within a Metachunk and is used by 151 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 152 MetaWord* allocate(size_t word_size, MetadataType mdtype); 153 154 // Virtual Space lists for both classes and other metadata 155 static VirtualSpaceList* _space_list; 156 static VirtualSpaceList* _class_space_list; 157 158 static ChunkManager* _chunk_manager_metadata; 159 static ChunkManager* _chunk_manager_class; 160 161 static const MetaspaceTracer* _tracer; 162 163 public: 164 static VirtualSpaceList* space_list() { return _space_list; } 165 static VirtualSpaceList* class_space_list() { return _class_space_list; } 166 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 167 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 168 return mdtype == ClassType ? class_space_list() : space_list(); 169 } 170 171 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 172 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 173 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 174 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 175 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 176 } 177 178 static const MetaspaceTracer* tracer() { return _tracer; } 179 180 private: 181 // These 2 methods are used by DumpSharedSpaces only, where only _vsm is used. So we will 182 // maintain a single list for now. 183 void record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size); 184 void record_deallocation(void* ptr, size_t word_size); 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 196 197 class AllocRecord : public CHeapObj<mtClass> { 198 public: 199 AllocRecord(address ptr, MetaspaceObj::Type type, int byte_size) 200 : _next(NULL), _ptr(ptr), _type(type), _byte_size(byte_size) {} 201 AllocRecord *_next; 202 address _ptr; 203 MetaspaceObj::Type _type; 204 int _byte_size; 205 }; 206 207 AllocRecord * _alloc_record_head; 208 AllocRecord * _alloc_record_tail; 209 210 size_t class_chunk_size(size_t word_size); 211 212 public: 213 214 Metaspace(Mutex* lock, MetaspaceType type); 215 ~Metaspace(); 216 217 static void ergo_initialize(); 218 static void global_initialize(); 219 static void post_initialize(); 220 221 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 222 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 223 224 static size_t reserve_alignment() { return _reserve_alignment; } 225 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 226 static size_t commit_alignment() { return _commit_alignment; } 227 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 228 229 char* bottom() const; 230 size_t used_words_slow(MetadataType mdtype) const; 231 size_t free_words_slow(MetadataType mdtype) const; 232 size_t capacity_words_slow(MetadataType mdtype) const; 233 234 size_t used_bytes_slow(MetadataType mdtype) const; 235 size_t capacity_bytes_slow(MetadataType mdtype) const; 236 237 size_t allocated_blocks_bytes() const; 238 size_t allocated_chunks_bytes() const; 239 240 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 241 bool read_only, MetaspaceObj::Type type, TRAPS); 242 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 243 244 MetaWord* expand_and_allocate(size_t size, 245 MetadataType mdtype); 246 247 static bool contains(const void* ptr); 248 249 void dump(outputStream* const out) const; 250 251 // Free empty virtualspaces 252 static void purge(MetadataType mdtype); 253 static void purge(); 254 255 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 256 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 257 258 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 259 260 void print_on(outputStream* st) const; 261 // Debugging support 262 void verify(); 263 264 class AllocRecordClosure : public StackObj { 265 public: 266 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) = 0; 267 }; 268 269 void iterate(AllocRecordClosure *closure); 270 271 // Return TRUE only if UseCompressedClassPointers is True and DumpSharedSpaces is False. 272 static bool using_class_space() { 273 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers && !DumpSharedSpaces); 274 } 275 276 static bool is_class_space_allocation(MetadataType mdType) { 277 return mdType == ClassType && using_class_space(); 278 } 279 280 }; 281 282 class MetaspaceAux : AllStatic { 283 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 284 285 // These methods iterate over the classloader data graph 286 // for the given Metaspace type. These are slow. 287 static size_t used_bytes_slow(Metaspace::MetadataType mdtype); 288 static size_t free_bytes_slow(Metaspace::MetadataType mdtype); 289 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype); 290 static size_t capacity_bytes_slow(); 291 292 // Running sum of space in all Metachunks that has been 293 // allocated to a Metaspace. This is used instead of 294 // iterating over all the classloaders. One for each 295 // type of Metadata 296 static size_t _capacity_words[Metaspace:: MetadataTypeCount]; 297 // Running sum of space in all Metachunks that 298 // are being used for metadata. One for each 299 // type of Metadata. 300 static size_t _used_words[Metaspace:: MetadataTypeCount]; 301 302 public: 303 // Decrement and increment _allocated_capacity_words 304 static void dec_capacity(Metaspace::MetadataType type, size_t words); 305 static void inc_capacity(Metaspace::MetadataType type, size_t words); 306 307 // Decrement and increment _allocated_used_words 308 static void dec_used(Metaspace::MetadataType type, size_t words); 309 static void inc_used(Metaspace::MetadataType type, size_t words); 310 311 // Total of space allocated to metadata in all Metaspaces. 312 // This sums the space used in each Metachunk by 313 // iterating over the classloader data graph 314 static size_t used_bytes_slow() { 315 return used_bytes_slow(Metaspace::ClassType) + 316 used_bytes_slow(Metaspace::NonClassType); 317 } 318 319 // Used by MetaspaceCounters 320 static size_t free_chunks_total_words(); 321 static size_t free_chunks_total_bytes(); 322 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 323 324 static size_t capacity_words(Metaspace::MetadataType mdtype) { 325 return _capacity_words[mdtype]; 326 } 327 static size_t capacity_words() { 328 return capacity_words(Metaspace::NonClassType) + 329 capacity_words(Metaspace::ClassType); 330 } 331 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 332 return capacity_words(mdtype) * BytesPerWord; 333 } 334 static size_t capacity_bytes() { 335 return capacity_words() * BytesPerWord; 336 } 337 338 static size_t used_words(Metaspace::MetadataType mdtype) { 339 return _used_words[mdtype]; 340 } 341 static size_t used_words() { 342 return used_words(Metaspace::NonClassType) + 343 used_words(Metaspace::ClassType); 344 } 345 static size_t used_bytes(Metaspace::MetadataType mdtype) { 346 return used_words(mdtype) * BytesPerWord; 347 } 348 static size_t used_bytes() { 349 return used_words() * BytesPerWord; 350 } 351 352 static size_t free_bytes(); 353 static size_t free_bytes(Metaspace::MetadataType mdtype); 354 355 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 356 static size_t reserved_bytes() { 357 return reserved_bytes(Metaspace::ClassType) + 358 reserved_bytes(Metaspace::NonClassType); 359 } 360 361 static size_t committed_bytes(Metaspace::MetadataType mdtype); 362 static size_t committed_bytes() { 363 return committed_bytes(Metaspace::ClassType) + 364 committed_bytes(Metaspace::NonClassType); 365 } 366 367 static size_t min_chunk_size_words(); 368 static size_t min_chunk_size_bytes() { 369 return min_chunk_size_words() * BytesPerWord; 370 } 371 372 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 373 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 374 375 // Print change in used metadata. 376 static void print_metaspace_change(size_t prev_metadata_used); 377 static void print_on(outputStream * out); 378 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); 379 380 static void print_class_waste(outputStream* out); 381 static void print_waste(outputStream* out); 382 static void dump(outputStream* out); 383 static void verify_free_chunks(); 384 // Checks that the values returned by allocated_capacity_bytes() and 385 // capacity_bytes_slow() are the same. 386 static void verify_capacity(); 387 static void verify_used(); 388 static void verify_metrics(); 389 }; 390 391 // Metaspace are deallocated when their class loader are GC'ed. 392 // This class implements a policy for inducing GC's to recover 393 // Metaspaces. 394 395 class MetaspaceGC : AllStatic { 396 397 // The current high-water-mark for inducing a GC. 398 // When committed memory of all metaspaces reaches this value, 399 // a GC is induced and the value is increased. Size is in bytes. 400 static volatile intptr_t _capacity_until_GC; 401 402 // For a CMS collection, signal that a concurrent collection should 403 // be started. 404 static bool _should_concurrent_collect; 405 406 static uint _shrink_factor; 407 408 static size_t shrink_factor() { return _shrink_factor; } 409 void set_shrink_factor(uint v) { _shrink_factor = v; } 410 411 public: 412 413 static void initialize(); 414 static void post_initialize(); 415 416 static size_t capacity_until_GC(); 417 static bool inc_capacity_until_GC(size_t v, 418 size_t* new_cap_until_GC = NULL, 419 size_t* old_cap_until_GC = NULL); 420 static size_t dec_capacity_until_GC(size_t v); 421 422 static bool should_concurrent_collect() { return _should_concurrent_collect; } 423 static void set_should_concurrent_collect(bool v) { 424 _should_concurrent_collect = v; 425 } 426 427 // The amount to increase the high-water-mark (_capacity_until_GC) 428 static size_t delta_capacity_until_GC(size_t bytes); 429 430 // Tells if we have can expand metaspace without hitting set limits. 431 static bool can_expand(size_t words, bool is_class); 432 433 // Returns amount that we can expand without hitting a GC, 434 // measured in words. 435 static size_t allowed_expansion(); 436 437 // Calculate the new high-water mark at which to induce 438 // a GC. 439 static void compute_new_size(); 440 }; 441 442 #endif // SHARE_VM_MEMORY_METASPACE_HPP