1 /* 2 * Copyright (c) 2011, 2014, 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 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 91 public: 92 enum MetadataType { 93 ClassType, 94 NonClassType, 95 MetadataTypeCount 96 }; 97 enum MetaspaceType { 98 StandardMetaspaceType, 99 BootMetaspaceType, 100 ROMetaspaceType, 101 ReadWriteMetaspaceType, 102 AnonymousMetaspaceType, 103 ReflectionMetaspaceType 104 }; 105 106 private: 107 void initialize(Mutex* lock, MetaspaceType type); 108 109 // Get the first chunk for a Metaspace. Used for 110 // special cases such as the boot class loader, reflection 111 // class loader and anonymous class loader. 112 Metachunk* get_initialization_chunk(MetadataType mdtype, 113 size_t chunk_word_size, 114 size_t chunk_bunch); 115 116 // Align up the word size to the allocation word size 117 static size_t align_word_size_up(size_t); 118 119 // Aligned size of the metaspace. 120 static size_t _compressed_class_space_size; 121 122 static size_t compressed_class_space_size() { 123 return _compressed_class_space_size; 124 } 125 126 static void set_compressed_class_space_size(size_t size) { 127 _compressed_class_space_size = size; 128 } 129 130 static size_t _first_chunk_word_size; 131 static size_t _first_class_chunk_word_size; 132 133 static size_t _commit_alignment; 134 static size_t _reserve_alignment; 135 136 SpaceManager* _vsm; 137 SpaceManager* vsm() const { return _vsm; } 138 139 SpaceManager* _class_vsm; 140 SpaceManager* class_vsm() const { return _class_vsm; } 141 142 // Allocate space for metadata of type mdtype. This is space 143 // within a Metachunk and is used by 144 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 145 MetaWord* allocate(size_t word_size, MetadataType mdtype); 146 147 // Virtual Space lists for both classes and other metadata 148 static VirtualSpaceList* _space_list; 149 static VirtualSpaceList* _class_space_list; 150 151 static ChunkManager* _chunk_manager_metadata; 152 static ChunkManager* _chunk_manager_class; 153 154 static const MetaspaceTracer* _tracer; 155 156 public: 157 static VirtualSpaceList* space_list() { return _space_list; } 158 static VirtualSpaceList* class_space_list() { return _class_space_list; } 159 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 160 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 161 return mdtype == ClassType ? class_space_list() : space_list(); 162 } 163 164 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 165 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 166 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 167 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 168 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 169 } 170 171 static const MetaspaceTracer* tracer() { return _tracer; } 172 173 private: 174 // These 2 methods are used by DumpSharedSpaces only, where only _vsm is used. So we will 175 // maintain a single list for now. 176 void record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size); 177 void record_deallocation(void* ptr, size_t word_size); 178 179 #ifdef _LP64 180 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 181 182 // Returns true if can use CDS with metaspace allocated as specified address. 183 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 184 185 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 186 187 static void initialize_class_space(ReservedSpace rs); 188 #endif 189 190 class AllocRecord : public CHeapObj<mtClass> { 191 public: 192 AllocRecord(address ptr, MetaspaceObj::Type type, int byte_size) 193 : _next(NULL), _ptr(ptr), _type(type), _byte_size(byte_size) {} 194 AllocRecord *_next; 195 address _ptr; 196 MetaspaceObj::Type _type; 197 int _byte_size; 198 }; 199 200 AllocRecord * _alloc_record_head; 201 AllocRecord * _alloc_record_tail; 202 203 size_t class_chunk_size(size_t word_size); 204 205 public: 206 207 Metaspace(Mutex* lock, MetaspaceType type); 208 ~Metaspace(); 209 210 static void ergo_initialize(); 211 static void global_initialize(); 212 static void post_initialize(); 213 214 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 215 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 216 217 static size_t reserve_alignment() { return _reserve_alignment; } 218 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 219 static size_t commit_alignment() { return _commit_alignment; } 220 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 221 222 char* bottom() const; 223 size_t used_words_slow(MetadataType mdtype) const; 224 size_t free_words_slow(MetadataType mdtype) const; 225 size_t capacity_words_slow(MetadataType mdtype) const; 226 227 size_t used_bytes_slow(MetadataType mdtype) const; 228 size_t capacity_bytes_slow(MetadataType mdtype) const; 229 230 size_t allocated_blocks_bytes() const; 231 size_t allocated_chunks_bytes() const; 232 233 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 234 bool read_only, MetaspaceObj::Type type, TRAPS); 235 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 236 237 MetaWord* expand_and_allocate(size_t size, 238 MetadataType mdtype); 239 240 static bool contains(const void* ptr); 241 242 void dump(outputStream* const out) const; 243 244 // Free empty virtualspaces 245 static void purge(MetadataType mdtype); 246 static void purge(); 247 248 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 249 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 250 251 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 252 253 void print_on(outputStream* st) const; 254 // Debugging support 255 void verify(); 256 257 class AllocRecordClosure : public StackObj { 258 public: 259 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) = 0; 260 }; 261 262 void iterate(AllocRecordClosure *closure); 263 264 // Return TRUE only if UseCompressedClassPointers is True and DumpSharedSpaces is False. 265 static bool using_class_space() { 266 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers && !DumpSharedSpaces); 267 } 268 269 static bool is_class_space_allocation(MetadataType mdType) { 270 return mdType == ClassType && using_class_space(); 271 } 272 273 }; 274 275 class MetaspaceAux : AllStatic { 276 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 277 278 // These methods iterate over the classloader data graph 279 // for the given Metaspace type. These are slow. 280 static size_t used_bytes_slow(Metaspace::MetadataType mdtype); 281 static size_t free_bytes_slow(Metaspace::MetadataType mdtype); 282 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype); 283 static size_t capacity_bytes_slow(); 284 285 // Running sum of space in all Metachunks that has been 286 // allocated to a Metaspace. This is used instead of 287 // iterating over all the classloaders. One for each 288 // type of Metadata 289 static size_t _capacity_words[Metaspace:: MetadataTypeCount]; 290 // Running sum of space in all Metachunks that 291 // are being used for metadata. One for each 292 // type of Metadata. 293 static size_t _used_words[Metaspace:: MetadataTypeCount]; 294 295 public: 296 // Decrement and increment _allocated_capacity_words 297 static void dec_capacity(Metaspace::MetadataType type, size_t words); 298 static void inc_capacity(Metaspace::MetadataType type, size_t words); 299 300 // Decrement and increment _allocated_used_words 301 static void dec_used(Metaspace::MetadataType type, size_t words); 302 static void inc_used(Metaspace::MetadataType type, size_t words); 303 304 // Total of space allocated to metadata in all Metaspaces. 305 // This sums the space used in each Metachunk by 306 // iterating over the classloader data graph 307 static size_t used_bytes_slow() { 308 return used_bytes_slow(Metaspace::ClassType) + 309 used_bytes_slow(Metaspace::NonClassType); 310 } 311 312 // Used by MetaspaceCounters 313 static size_t free_chunks_total_words(); 314 static size_t free_chunks_total_bytes(); 315 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 316 317 static size_t capacity_words(Metaspace::MetadataType mdtype) { 318 return _capacity_words[mdtype]; 319 } 320 static size_t capacity_words() { 321 return capacity_words(Metaspace::NonClassType) + 322 capacity_words(Metaspace::ClassType); 323 } 324 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 325 return capacity_words(mdtype) * BytesPerWord; 326 } 327 static size_t capacity_bytes() { 328 return capacity_words() * BytesPerWord; 329 } 330 331 static size_t used_words(Metaspace::MetadataType mdtype) { 332 return _used_words[mdtype]; 333 } 334 static size_t used_words() { 335 return used_words(Metaspace::NonClassType) + 336 used_words(Metaspace::ClassType); 337 } 338 static size_t used_bytes(Metaspace::MetadataType mdtype) { 339 return used_words(mdtype) * BytesPerWord; 340 } 341 static size_t used_bytes() { 342 return used_words() * BytesPerWord; 343 } 344 345 static size_t free_bytes(); 346 static size_t free_bytes(Metaspace::MetadataType mdtype); 347 348 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 349 static size_t reserved_bytes() { 350 return reserved_bytes(Metaspace::ClassType) + 351 reserved_bytes(Metaspace::NonClassType); 352 } 353 354 static size_t committed_bytes(Metaspace::MetadataType mdtype); 355 static size_t committed_bytes() { 356 return committed_bytes(Metaspace::ClassType) + 357 committed_bytes(Metaspace::NonClassType); 358 } 359 360 static size_t min_chunk_size_words(); 361 static size_t min_chunk_size_bytes() { 362 return min_chunk_size_words() * BytesPerWord; 363 } 364 365 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 366 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 367 368 // Print change in used metadata. 369 static void print_metaspace_change(size_t prev_metadata_used); 370 static void print_on(outputStream * out); 371 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); 372 373 static void print_class_waste(outputStream* out); 374 static void print_waste(outputStream* out); 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 size_t inc_capacity_until_GC(size_t v); 411 static size_t dec_capacity_until_GC(size_t v); 412 413 static bool should_concurrent_collect() { return _should_concurrent_collect; } 414 static void set_should_concurrent_collect(bool v) { 415 _should_concurrent_collect = v; 416 } 417 418 // The amount to increase the high-water-mark (_capacity_until_GC) 419 static size_t delta_capacity_until_GC(size_t bytes); 420 421 // Tells if we have can expand metaspace without hitting set limits. 422 static bool can_expand(size_t words, bool is_class); 423 424 // Returns amount that we can expand without hitting a GC, 425 // measured in words. 426 static size_t allowed_expansion(); 427 428 // Calculate the new high-water mark at which to induce 429 // a GC. 430 static void compute_new_size(); 431 }; 432 433 #endif // SHARE_VM_MEMORY_METASPACE_HPP