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 SpaceManager; 67 class 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 82 class 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 friend class MetaspaceShared; 89 friend class CollectorPolicy; 90 91 public: 92 enum MetadataType { 93 ClassType, 94 NonClassType, 95 MetadataTypeCount 96 }; 97 enum MetaspaceType { 98 StandardMetaspaceType, 99 BootMetaspaceType, 100 AnonymousMetaspaceType, 101 ReflectionMetaspaceType 102 }; 103 104 private: 105 static void verify_global_initialization(); 106 107 void initialize(Mutex* lock, MetaspaceType type); 108 109 // Initialize 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 void initialize_first_chunk(MetaspaceType type, MetadataType mdtype); 113 Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype); 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 DEBUG_ONLY(static bool _frozen;) 135 136 SpaceManager* _vsm; 137 SpaceManager* vsm() const { return _vsm; } 138 139 SpaceManager* _class_vsm; 140 SpaceManager* class_vsm() const { return _class_vsm; } 141 SpaceManager* get_space_manager(MetadataType mdtype) { 142 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 143 return mdtype == ClassType ? class_vsm() : vsm(); 144 } 145 146 // Allocate space for metadata of type mdtype. This is space 147 // within a Metachunk and is used by 148 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 149 MetaWord* allocate(size_t word_size, MetadataType mdtype); 150 151 MetaWord* expand_and_allocate(size_t size, MetadataType mdtype); 152 153 // Virtual Space lists for both classes and other metadata 154 static VirtualSpaceList* _space_list; 155 static VirtualSpaceList* _class_space_list; 156 157 static ChunkManager* _chunk_manager_metadata; 158 static ChunkManager* _chunk_manager_class; 159 160 static const MetaspaceTracer* _tracer; 161 162 public: 163 static VirtualSpaceList* space_list() { return _space_list; } 164 static VirtualSpaceList* class_space_list() { return _class_space_list; } 165 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 166 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 167 return mdtype == ClassType ? class_space_list() : space_list(); 168 } 169 170 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 171 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 172 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 173 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 174 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 175 } 176 177 static const MetaspaceTracer* tracer() { return _tracer; } 178 static void freeze() { 179 assert(DumpSharedSpaces, "sanity"); 180 DEBUG_ONLY(_frozen = true;) 181 } 182 #ifdef _LP64 183 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 184 #endif 185 186 private: 187 188 #ifdef _LP64 189 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 190 191 // Returns true if can use CDS with metaspace allocated as specified address. 192 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 193 194 static void initialize_class_space(ReservedSpace rs); 195 #endif 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 static void post_initialize(); 206 207 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 208 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 209 210 static size_t reserve_alignment() { return _reserve_alignment; } 211 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 212 static size_t commit_alignment() { return _commit_alignment; } 213 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 214 215 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 size_t allocated_blocks_bytes() const; 223 size_t allocated_chunks_bytes() const; 224 225 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 226 MetaspaceObj::Type type, TRAPS); 227 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 228 229 static bool contains(const void* ptr); 230 static bool contains_non_shared(const void* ptr); 231 232 void dump(outputStream* const out) const; 233 234 // Free empty virtualspaces 235 static void purge(MetadataType mdtype); 236 static void purge(); 237 238 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 239 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 240 241 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 242 243 void print_on(outputStream* st) const; 244 // Debugging support 245 void verify(); 246 247 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({}); 248 249 // Return TRUE only if UseCompressedClassPointers is True. 250 static bool using_class_space() { 251 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers); 252 } 253 254 static bool is_class_space_allocation(MetadataType mdType) { 255 return mdType == ClassType && using_class_space(); 256 } 257 258 }; 259 260 class MetaspaceAux : AllStatic { 261 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 262 263 // These methods iterate over the classloader data graph 264 // for the given Metaspace type. These are slow. 265 static size_t used_bytes_slow(Metaspace::MetadataType mdtype); 266 static size_t free_bytes_slow(Metaspace::MetadataType mdtype); 267 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype); 268 static size_t capacity_bytes_slow(); 269 270 // Running sum of space in all Metachunks that has been 271 // allocated to a Metaspace. This is used instead of 272 // iterating over all the classloaders. One for each 273 // type of Metadata 274 static size_t _capacity_words[Metaspace:: MetadataTypeCount]; 275 // Running sum of space in all Metachunks that 276 // are being used for metadata. One for each 277 // type of Metadata. 278 static volatile size_t _used_words[Metaspace:: MetadataTypeCount]; 279 280 public: 281 // Decrement and increment _allocated_capacity_words 282 static void dec_capacity(Metaspace::MetadataType type, size_t words); 283 static void inc_capacity(Metaspace::MetadataType type, size_t words); 284 285 // Decrement and increment _allocated_used_words 286 static void dec_used(Metaspace::MetadataType type, size_t words); 287 static void inc_used(Metaspace::MetadataType type, size_t words); 288 289 // Total of space allocated to metadata in all Metaspaces. 290 // This sums the space used in each Metachunk by 291 // iterating over the classloader data graph 292 static size_t used_bytes_slow() { 293 return used_bytes_slow(Metaspace::ClassType) + 294 used_bytes_slow(Metaspace::NonClassType); 295 } 296 297 // Used by MetaspaceCounters 298 static size_t free_chunks_total_words(); 299 static size_t free_chunks_total_bytes(); 300 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 301 302 static size_t capacity_words(Metaspace::MetadataType mdtype) { 303 return _capacity_words[mdtype]; 304 } 305 static size_t capacity_words() { 306 return capacity_words(Metaspace::NonClassType) + 307 capacity_words(Metaspace::ClassType); 308 } 309 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 310 return capacity_words(mdtype) * BytesPerWord; 311 } 312 static size_t capacity_bytes() { 313 return capacity_words() * BytesPerWord; 314 } 315 316 static size_t used_words(Metaspace::MetadataType mdtype) { 317 return _used_words[mdtype]; 318 } 319 static size_t used_words() { 320 return used_words(Metaspace::NonClassType) + 321 used_words(Metaspace::ClassType); 322 } 323 static size_t used_bytes(Metaspace::MetadataType mdtype) { 324 return used_words(mdtype) * BytesPerWord; 325 } 326 static size_t used_bytes() { 327 return used_words() * BytesPerWord; 328 } 329 330 static size_t free_bytes(); 331 static size_t free_bytes(Metaspace::MetadataType mdtype); 332 333 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 334 static size_t reserved_bytes() { 335 return reserved_bytes(Metaspace::ClassType) + 336 reserved_bytes(Metaspace::NonClassType); 337 } 338 339 static size_t committed_bytes(Metaspace::MetadataType mdtype); 340 static size_t committed_bytes() { 341 return committed_bytes(Metaspace::ClassType) + 342 committed_bytes(Metaspace::NonClassType); 343 } 344 345 static size_t min_chunk_size_words(); 346 static size_t min_chunk_size_bytes() { 347 return min_chunk_size_words() * BytesPerWord; 348 } 349 350 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 351 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 352 353 // Print change in used metadata. 354 static void print_metaspace_change(size_t prev_metadata_used); 355 static void print_on(outputStream * out); 356 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); 357 358 static void print_class_waste(outputStream* out); 359 static void print_waste(outputStream* out); 360 static void dump(outputStream* out); 361 static void verify_free_chunks(); 362 // Checks that the values returned by allocated_capacity_bytes() and 363 // capacity_bytes_slow() are the same. 364 static void verify_capacity(); 365 static void verify_used(); 366 static void verify_metrics(); 367 }; 368 369 // Metaspace are deallocated when their class loader are GC'ed. 370 // This class implements a policy for inducing GC's to recover 371 // Metaspaces. 372 373 class MetaspaceGC : AllStatic { 374 375 // The current high-water-mark for inducing a GC. 376 // When committed memory of all metaspaces reaches this value, 377 // a GC is induced and the value is increased. Size is in bytes. 378 static volatile intptr_t _capacity_until_GC; 379 380 // For a CMS collection, signal that a concurrent collection should 381 // be started. 382 static bool _should_concurrent_collect; 383 384 static uint _shrink_factor; 385 386 static size_t shrink_factor() { return _shrink_factor; } 387 void set_shrink_factor(uint v) { _shrink_factor = v; } 388 389 public: 390 391 static void initialize(); 392 static void post_initialize(); 393 394 static size_t capacity_until_GC(); 395 static bool inc_capacity_until_GC(size_t v, 396 size_t* new_cap_until_GC = NULL, 397 size_t* old_cap_until_GC = NULL); 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