1 /* 2 * Copyright (c) 2011, 2013, 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 "runtime/virtualspace.hpp" 30 #include "utilities/exceptions.hpp" 31 32 // Metaspace 33 // 34 // Metaspaces are Arenas for the VM's metadata. 35 // They are allocated one per class loader object, and one for the null 36 // bootstrap class loader 37 // Eventually for bootstrap loader we'll have a read-only section and read-write 38 // to write for DumpSharedSpaces and read for UseSharedSpaces 39 // 40 // block X ---+ +-------------------+ 41 // | | Virtualspace | 42 // | | | 43 // | | | 44 // | |-------------------| 45 // | || Chunk | 46 // | || | 47 // | ||---------- | 48 // +------>||| block 0 | | 49 // ||---------- | 50 // ||| block 1 | | 51 // ||---------- | 52 // || | 53 // |-------------------| 54 // | | 55 // | | 56 // +-------------------+ 57 // 58 59 class ChunkManager; 60 class ClassLoaderData; 61 class Metablock; 62 class Metachunk; 63 class MetaspaceTracer; 64 class MetaWord; 65 class Mutex; 66 class outputStream; 67 class SpaceManager; 68 class VirtualSpaceList; 69 70 // Metaspaces each have a SpaceManager and allocations 71 // are done by the SpaceManager. Allocations are done 72 // out of the current Metachunk. When the current Metachunk 73 // is exhausted, the SpaceManager gets a new one from 74 // the current VirtualSpace. When the VirtualSpace is exhausted 75 // the SpaceManager gets a new one. The SpaceManager 76 // also manages freelists of available Chunks. 77 // 78 // Currently the space manager maintains the list of 79 // virtual spaces and the list of chunks in use. Its 80 // allocate() method returns a block for use as a 81 // quantum of metadata. 82 83 class Metaspace : public CHeapObj<mtClass> { 84 friend class VMStructs; 85 friend class SpaceManager; 86 friend class VM_CollectForMetadataAllocation; 87 friend class MetaspaceGC; 88 friend class MetaspaceAux; 89 90 public: 91 enum MetadataType { 92 ClassType, 93 NonClassType, 94 MetadataTypeCount 95 }; 96 enum MetaspaceType { 97 StandardMetaspaceType, 98 BootMetaspaceType, 99 ROMetaspaceType, 100 ReadWriteMetaspaceType, 101 AnonymousMetaspaceType, 102 ReflectionMetaspaceType 103 }; 104 105 private: 106 void initialize(Mutex* lock, MetaspaceType type); 107 108 // Get the first chunk for a Metaspace. Used for 109 // special cases such as the boot class loader, reflection 110 // class loader and anonymous class loader. 111 Metachunk* get_initialization_chunk(MetadataType mdtype, 112 size_t chunk_word_size, 113 size_t chunk_bunch); 114 115 // Align up the word size to the allocation word size 116 static size_t align_word_size_up(size_t); 117 118 // Aligned size of the metaspace. 119 static size_t _compressed_class_space_size; 120 121 static size_t compressed_class_space_size() { 122 return _compressed_class_space_size; 123 } 124 125 static void set_compressed_class_space_size(size_t size) { 126 _compressed_class_space_size = size; 127 } 128 129 static size_t _first_chunk_word_size; 130 static size_t _first_class_chunk_word_size; 131 132 static size_t _commit_alignment; 133 static size_t _reserve_alignment; 134 135 SpaceManager* _vsm; 136 SpaceManager* vsm() const { return _vsm; } 137 138 SpaceManager* _class_vsm; 139 SpaceManager* class_vsm() const { return _class_vsm; } 140 141 // Allocate space for metadata of type mdtype. This is space 142 // within a Metachunk and is used by 143 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 144 MetaWord* allocate(size_t word_size, MetadataType mdtype); 145 146 // Virtual Space lists for both classes and other metadata 147 static VirtualSpaceList* _space_list; 148 static VirtualSpaceList* _class_space_list; 149 150 static ChunkManager* _chunk_manager_metadata; 151 static ChunkManager* _chunk_manager_class; 152 153 static const MetaspaceTracer* _tracer; 154 155 public: 156 static VirtualSpaceList* space_list() { return _space_list; } 157 static VirtualSpaceList* class_space_list() { return _class_space_list; } 158 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 159 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 160 return mdtype == ClassType ? class_space_list() : space_list(); 161 } 162 163 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 164 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 165 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 166 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 167 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 168 } 169 170 static const MetaspaceTracer* tracer() { return _tracer; } 171 172 private: 173 // This is used by DumpSharedSpaces only, where only _vsm is used. So we will 174 // maintain a single list for now. 175 void record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size); 176 177 #ifdef _LP64 178 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 179 180 // Returns true if can use CDS with metaspace allocated as specified address. 181 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 182 183 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 184 185 static void initialize_class_space(ReservedSpace rs); 186 #endif 187 188 class AllocRecord : public CHeapObj<mtClass> { 189 public: 190 AllocRecord(address ptr, MetaspaceObj::Type type, int byte_size) 191 : _next(NULL), _ptr(ptr), _type(type), _byte_size(byte_size) {} 192 AllocRecord *_next; 193 address _ptr; 194 MetaspaceObj::Type _type; 195 int _byte_size; 196 }; 197 198 AllocRecord * _alloc_record_head; 199 AllocRecord * _alloc_record_tail; 200 201 size_t class_chunk_size(size_t word_size); 202 203 public: 204 205 Metaspace(Mutex* lock, MetaspaceType type); 206 ~Metaspace(); 207 208 static void ergo_initialize(); 209 static void global_initialize(); 210 211 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 212 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 213 214 static size_t reserve_alignment() { return _reserve_alignment; } 215 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 216 static size_t commit_alignment() { return _commit_alignment; } 217 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 218 219 char* bottom() const; 220 size_t used_words_slow(MetadataType mdtype) const; 221 size_t free_words_slow(MetadataType mdtype) const; 222 size_t capacity_words_slow(MetadataType mdtype) const; 223 224 size_t used_bytes_slow(MetadataType mdtype) const; 225 size_t capacity_bytes_slow(MetadataType mdtype) const; 226 227 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 228 bool read_only, MetaspaceObj::Type type, TRAPS); 229 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 230 231 MetaWord* expand_and_allocate(size_t size, 232 MetadataType mdtype); 233 234 bool contains(const void* ptr); 235 void dump(outputStream* const out) const; 236 237 // Free empty virtualspaces 238 static void purge(MetadataType mdtype); 239 static void purge(); 240 241 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 242 MetadataType mdtype, TRAPS); 243 244 void print_on(outputStream* st) const; 245 // Debugging support 246 void verify(); 247 248 class AllocRecordClosure : public StackObj { 249 public: 250 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) = 0; 251 }; 252 253 void iterate(AllocRecordClosure *closure); 254 255 // Return TRUE only if UseCompressedClassPointers is True and DumpSharedSpaces is False. 256 static bool using_class_space() { 257 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers && !DumpSharedSpaces); 258 } 259 260 static bool is_class_space_allocation(MetadataType mdType) { 261 return mdType == ClassType && using_class_space(); 262 } 263 264 }; 265 266 class MetaspaceAux : AllStatic { 267 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 268 269 // These methods iterate over the classloader data graph 270 // for the given Metaspace type. These are slow. 271 static size_t used_bytes_slow(Metaspace::MetadataType mdtype); 272 static size_t free_bytes_slow(Metaspace::MetadataType mdtype); 273 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype); 274 static size_t capacity_bytes_slow(); 275 276 // Running sum of space in all Metachunks that has been 277 // allocated to a Metaspace. This is used instead of 278 // iterating over all the classloaders. One for each 279 // type of Metadata 280 static size_t _allocated_capacity_words[Metaspace:: MetadataTypeCount]; 281 // Running sum of space in all Metachunks that have 282 // are being used for metadata. One for each 283 // type of Metadata. 284 static size_t _allocated_used_words[Metaspace:: MetadataTypeCount]; 285 286 public: 287 // Decrement and increment _allocated_capacity_words 288 static void dec_capacity(Metaspace::MetadataType type, size_t words); 289 static void inc_capacity(Metaspace::MetadataType type, size_t words); 290 291 // Decrement and increment _allocated_used_words 292 static void dec_used(Metaspace::MetadataType type, size_t words); 293 static void inc_used(Metaspace::MetadataType type, size_t words); 294 295 // Total of space allocated to metadata in all Metaspaces. 296 // This sums the space used in each Metachunk by 297 // iterating over the classloader data graph 298 static size_t used_bytes_slow() { 299 return used_bytes_slow(Metaspace::ClassType) + 300 used_bytes_slow(Metaspace::NonClassType); 301 } 302 303 // Used by MetaspaceCounters 304 static size_t free_chunks_total_words(); 305 static size_t free_chunks_total_bytes(); 306 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 307 308 static size_t allocated_capacity_words(Metaspace::MetadataType mdtype) { 309 return _allocated_capacity_words[mdtype]; 310 } 311 static size_t allocated_capacity_words() { 312 return allocated_capacity_words(Metaspace::NonClassType) + 313 allocated_capacity_words(Metaspace::ClassType); 314 } 315 static size_t allocated_capacity_bytes(Metaspace::MetadataType mdtype) { 316 return allocated_capacity_words(mdtype) * BytesPerWord; 317 } 318 static size_t allocated_capacity_bytes() { 319 return allocated_capacity_words() * BytesPerWord; 320 } 321 322 static size_t allocated_used_words(Metaspace::MetadataType mdtype) { 323 return _allocated_used_words[mdtype]; 324 } 325 static size_t allocated_used_words() { 326 return allocated_used_words(Metaspace::NonClassType) + 327 allocated_used_words(Metaspace::ClassType); 328 } 329 static size_t allocated_used_bytes(Metaspace::MetadataType mdtype) { 330 return allocated_used_words(mdtype) * BytesPerWord; 331 } 332 static size_t allocated_used_bytes() { 333 return allocated_used_words() * BytesPerWord; 334 } 335 336 static size_t free_bytes(); 337 static size_t free_bytes(Metaspace::MetadataType mdtype); 338 339 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 340 static size_t reserved_bytes() { 341 return reserved_bytes(Metaspace::ClassType) + 342 reserved_bytes(Metaspace::NonClassType); 343 } 344 345 static size_t committed_bytes(Metaspace::MetadataType mdtype); 346 static size_t committed_bytes() { 347 return committed_bytes(Metaspace::ClassType) + 348 committed_bytes(Metaspace::NonClassType); 349 } 350 351 static size_t min_chunk_size_words(); 352 static size_t min_chunk_size_bytes() { 353 return min_chunk_size_words() * BytesPerWord; 354 } 355 356 // Print change in used metadata. 357 static void print_metaspace_change(size_t prev_metadata_used); 358 static void print_on(outputStream * out); 359 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); 360 361 static void print_class_waste(outputStream* out); 362 static void print_waste(outputStream* out); 363 static void dump(outputStream* out); 364 static void verify_free_chunks(); 365 // Checks that the values returned by allocated_capacity_bytes() and 366 // capacity_bytes_slow() are the same. 367 static void verify_capacity(); 368 static void verify_used(); 369 static void verify_metrics(); 370 }; 371 372 // Metaspace are deallocated when their class loader are GC'ed. 373 // This class implements a policy for inducing GC's to recover 374 // Metaspaces. 375 376 class MetaspaceGC : AllStatic { 377 378 // The current high-water-mark for inducing a GC. 379 // When committed memory of all metaspaces reaches this value, 380 // a GC is induced and the value is increased. Size is in bytes. 381 static volatile intptr_t _capacity_until_GC; 382 383 // For a CMS collection, signal that a concurrent collection should 384 // be started. 385 static bool _should_concurrent_collect; 386 387 static uint _shrink_factor; 388 389 static size_t shrink_factor() { return _shrink_factor; } 390 void set_shrink_factor(uint v) { _shrink_factor = v; } 391 392 public: 393 394 static void initialize() { _capacity_until_GC = MetaspaceSize; } 395 396 static size_t capacity_until_GC(); 397 static size_t inc_capacity_until_GC(size_t v); 398 static size_t dec_capacity_until_GC(size_t v); 399 400 static bool should_concurrent_collect() { return _should_concurrent_collect; } 401 static void set_should_concurrent_collect(bool v) { 402 _should_concurrent_collect = v; 403 } 404 405 // The amount to increase the high-water-mark (_capacity_until_GC) 406 static size_t delta_capacity_until_GC(size_t bytes); 407 408 // Tells if we have can expand metaspace without hitting set limits. 409 static bool can_expand(size_t words, bool is_class); 410 411 // Returns amount that we can expand without hitting a GC, 412 // measured in words. 413 static size_t allowed_expansion(); 414 415 // Calculate the new high-water mark at which to induce 416 // a GC. 417 static void compute_new_size(); 418 }; 419 420 #endif // SHARE_VM_MEMORY_METASPACE_HPP