metaspace.hpp revision 6010:abec000618bf
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 59class ChunkManager; 60class ClassLoaderData; 61class Metablock; 62class Metachunk; 63class MetaWord; 64class Mutex; 65class outputStream; 66class SpaceManager; 67class VirtualSpaceList; 68 69// Metaspaces each have a SpaceManager and allocations 70// are done by the SpaceManager. Allocations are done 71// out of the current Metachunk. When the current Metachunk 72// is exhausted, the SpaceManager gets a new one from 73// the current VirtualSpace. When the VirtualSpace is exhausted 74// the SpaceManager gets a new one. The SpaceManager 75// also manages freelists of available Chunks. 76// 77// Currently the space manager maintains the list of 78// virtual spaces and the list of chunks in use. Its 79// allocate() method returns a block for use as a 80// quantum of metadata. 81 82class Metaspace : public CHeapObj<mtClass> { 83 friend class VMStructs; 84 friend class SpaceManager; 85 friend class VM_CollectForMetadataAllocation; 86 friend class MetaspaceGC; 87 friend class MetaspaceAux; 88 89 public: 90 enum MetadataType { 91 ClassType, 92 NonClassType, 93 MetadataTypeCount 94 }; 95 enum MetaspaceType { 96 StandardMetaspaceType, 97 BootMetaspaceType, 98 ROMetaspaceType, 99 ReadWriteMetaspaceType, 100 AnonymousMetaspaceType, 101 ReflectionMetaspaceType 102 }; 103 104 private: 105 void initialize(Mutex* lock, MetaspaceType type); 106 107 // Get the first chunk for a Metaspace. Used for 108 // special cases such as the boot class loader, reflection 109 // class loader and anonymous class loader. 110 Metachunk* get_initialization_chunk(MetadataType mdtype, 111 size_t chunk_word_size, 112 size_t chunk_bunch); 113 114 // Align up the word size to the allocation word size 115 static size_t align_word_size_up(size_t); 116 117 // Aligned size of the metaspace. 118 static size_t _compressed_class_space_size; 119 120 static size_t compressed_class_space_size() { 121 return _compressed_class_space_size; 122 } 123 124 static void set_compressed_class_space_size(size_t size) { 125 _compressed_class_space_size = size; 126 } 127 128 static size_t _first_chunk_word_size; 129 static size_t _first_class_chunk_word_size; 130 131 static size_t _commit_alignment; 132 static size_t _reserve_alignment; 133 134 SpaceManager* _vsm; 135 SpaceManager* vsm() const { return _vsm; } 136 137 SpaceManager* _class_vsm; 138 SpaceManager* class_vsm() const { return _class_vsm; } 139 140 // Allocate space for metadata of type mdtype. This is space 141 // within a Metachunk and is used by 142 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 143 MetaWord* allocate(size_t word_size, MetadataType mdtype); 144 145 // Virtual Space lists for both classes and other metadata 146 static VirtualSpaceList* _space_list; 147 static VirtualSpaceList* _class_space_list; 148 149 static ChunkManager* _chunk_manager_metadata; 150 static ChunkManager* _chunk_manager_class; 151 152 public: 153 static VirtualSpaceList* space_list() { return _space_list; } 154 static VirtualSpaceList* class_space_list() { return _class_space_list; } 155 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 156 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 157 return mdtype == ClassType ? class_space_list() : space_list(); 158 } 159 160 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 161 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 162 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 163 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 164 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 165 } 166 167 private: 168 // This is used by DumpSharedSpaces only, where only _vsm is used. So we will 169 // maintain a single list for now. 170 void record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size); 171 172#ifdef _LP64 173 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 174 175 // Returns true if can use CDS with metaspace allocated as specified address. 176 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 177 178 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 179 180 static void initialize_class_space(ReservedSpace rs); 181#endif 182 183 class AllocRecord : public CHeapObj<mtClass> { 184 public: 185 AllocRecord(address ptr, MetaspaceObj::Type type, int byte_size) 186 : _next(NULL), _ptr(ptr), _type(type), _byte_size(byte_size) {} 187 AllocRecord *_next; 188 address _ptr; 189 MetaspaceObj::Type _type; 190 int _byte_size; 191 }; 192 193 AllocRecord * _alloc_record_head; 194 AllocRecord * _alloc_record_tail; 195 196 size_t class_chunk_size(size_t word_size); 197 198 public: 199 200 Metaspace(Mutex* lock, MetaspaceType type); 201 ~Metaspace(); 202 203 static void ergo_initialize(); 204 static void global_initialize(); 205 206 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 207 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 208 209 static size_t reserve_alignment() { return _reserve_alignment; } 210 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 211 static size_t commit_alignment() { return _commit_alignment; } 212 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 213 214 char* bottom() const; 215 size_t used_words_slow(MetadataType mdtype) const; 216 size_t free_words_slow(MetadataType mdtype) const; 217 size_t capacity_words_slow(MetadataType mdtype) const; 218 219 size_t used_bytes_slow(MetadataType mdtype) const; 220 size_t capacity_bytes_slow(MetadataType mdtype) const; 221 222 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 223 bool read_only, MetaspaceObj::Type type, TRAPS); 224 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 225 226 MetaWord* expand_and_allocate(size_t size, 227 MetadataType mdtype); 228 229 bool contains(const void* ptr); 230 void dump(outputStream* const out) const; 231 232 // Free empty virtualspaces 233 static void purge(MetadataType mdtype); 234 static void purge(); 235 236 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 237 MetadataType mdtype, TRAPS); 238 239 void print_on(outputStream* st) const; 240 // Debugging support 241 void verify(); 242 243 class AllocRecordClosure : public StackObj { 244 public: 245 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) = 0; 246 }; 247 248 void iterate(AllocRecordClosure *closure); 249 250 // Return TRUE only if UseCompressedClassPointers is True and DumpSharedSpaces is False. 251 static bool using_class_space() { 252 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers && !DumpSharedSpaces); 253 } 254 255 static bool is_class_space_allocation(MetadataType mdType) { 256 return mdType == ClassType && using_class_space(); 257 } 258 259}; 260 261class MetaspaceAux : AllStatic { 262 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 263 264 // These methods iterate over the classloader data graph 265 // for the given Metaspace type. These are slow. 266 static size_t used_bytes_slow(Metaspace::MetadataType mdtype); 267 static size_t free_bytes_slow(Metaspace::MetadataType mdtype); 268 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype); 269 static size_t capacity_bytes_slow(); 270 271 // Running sum of space in all Metachunks that has been 272 // allocated to a Metaspace. This is used instead of 273 // iterating over all the classloaders. One for each 274 // type of Metadata 275 static size_t _allocated_capacity_words[Metaspace:: MetadataTypeCount]; 276 // Running sum of space in all Metachunks that have 277 // are being used for metadata. One for each 278 // type of Metadata. 279 static size_t _allocated_used_words[Metaspace:: MetadataTypeCount]; 280 281 public: 282 // Decrement and increment _allocated_capacity_words 283 static void dec_capacity(Metaspace::MetadataType type, size_t words); 284 static void inc_capacity(Metaspace::MetadataType type, size_t words); 285 286 // Decrement and increment _allocated_used_words 287 static void dec_used(Metaspace::MetadataType type, size_t words); 288 static void inc_used(Metaspace::MetadataType type, size_t words); 289 290 // Total of space allocated to metadata in all Metaspaces. 291 // This sums the space used in each Metachunk by 292 // iterating over the classloader data graph 293 static size_t used_bytes_slow() { 294 return used_bytes_slow(Metaspace::ClassType) + 295 used_bytes_slow(Metaspace::NonClassType); 296 } 297 298 // Used by MetaspaceCounters 299 static size_t free_chunks_total_words(); 300 static size_t free_chunks_total_bytes(); 301 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 302 303 static size_t allocated_capacity_words(Metaspace::MetadataType mdtype) { 304 return _allocated_capacity_words[mdtype]; 305 } 306 static size_t allocated_capacity_words() { 307 return allocated_capacity_words(Metaspace::NonClassType) + 308 allocated_capacity_words(Metaspace::ClassType); 309 } 310 static size_t allocated_capacity_bytes(Metaspace::MetadataType mdtype) { 311 return allocated_capacity_words(mdtype) * BytesPerWord; 312 } 313 static size_t allocated_capacity_bytes() { 314 return allocated_capacity_words() * BytesPerWord; 315 } 316 317 static size_t allocated_used_words(Metaspace::MetadataType mdtype) { 318 return _allocated_used_words[mdtype]; 319 } 320 static size_t allocated_used_words() { 321 return allocated_used_words(Metaspace::NonClassType) + 322 allocated_used_words(Metaspace::ClassType); 323 } 324 static size_t allocated_used_bytes(Metaspace::MetadataType mdtype) { 325 return allocated_used_words(mdtype) * BytesPerWord; 326 } 327 static size_t allocated_used_bytes() { 328 return allocated_used_words() * BytesPerWord; 329 } 330 331 static size_t free_bytes(); 332 static size_t free_bytes(Metaspace::MetadataType mdtype); 333 334 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 335 static size_t reserved_bytes() { 336 return reserved_bytes(Metaspace::ClassType) + 337 reserved_bytes(Metaspace::NonClassType); 338 } 339 340 static size_t committed_bytes(Metaspace::MetadataType mdtype); 341 static size_t committed_bytes() { 342 return committed_bytes(Metaspace::ClassType) + 343 committed_bytes(Metaspace::NonClassType); 344 } 345 346 static size_t min_chunk_size_words(); 347 static size_t min_chunk_size_bytes() { 348 return min_chunk_size_words() * BytesPerWord; 349 } 350 351 // Print change in used metadata. 352 static void print_metaspace_change(size_t prev_metadata_used); 353 static void print_on(outputStream * out); 354 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); 355 356 static void print_class_waste(outputStream* out); 357 static void print_waste(outputStream* out); 358 static void dump(outputStream* out); 359 static void verify_free_chunks(); 360 // Checks that the values returned by allocated_capacity_bytes() and 361 // capacity_bytes_slow() are the same. 362 static void verify_capacity(); 363 static void verify_used(); 364 static void verify_metrics(); 365}; 366 367// Metaspace are deallocated when their class loader are GC'ed. 368// This class implements a policy for inducing GC's to recover 369// Metaspaces. 370 371class MetaspaceGC : AllStatic { 372 373 // The current high-water-mark for inducing a GC. 374 // When committed memory of all metaspaces reaches this value, 375 // a GC is induced and the value is increased. Size is in bytes. 376 static volatile intptr_t _capacity_until_GC; 377 378 // For a CMS collection, signal that a concurrent collection should 379 // be started. 380 static bool _should_concurrent_collect; 381 382 static uint _shrink_factor; 383 384 static size_t shrink_factor() { return _shrink_factor; } 385 void set_shrink_factor(uint v) { _shrink_factor = v; } 386 387 public: 388 389 static void initialize() { _capacity_until_GC = MetaspaceSize; } 390 391 static size_t capacity_until_GC(); 392 static size_t inc_capacity_until_GC(size_t v); 393 static size_t dec_capacity_until_GC(size_t v); 394 395 static bool should_concurrent_collect() { return _should_concurrent_collect; } 396 static void set_should_concurrent_collect(bool v) { 397 _should_concurrent_collect = v; 398 } 399 400 // The amount to increase the high-water-mark (_capacity_until_GC) 401 static size_t delta_capacity_until_GC(size_t bytes); 402 403 // Tells if we have can expand metaspace without hitting set limits. 404 static bool can_expand(size_t words, bool is_class); 405 406 // Returns amount that we can expand without hitting a GC, 407 // measured in words. 408 static size_t allowed_expansion(); 409 410 // Calculate the new high-water mark at which to induce 411 // a GC. 412 static void compute_new_size(); 413}; 414 415#endif // SHARE_VM_MEMORY_METASPACE_HPP 416