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 PrintCLDMetaspaceInfoClosure; 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 friend class MetaspaceShared; 90 friend class CollectedHeap; 91 friend class PrintCLDMetaspaceInfoClosure; 92 93 public: 94 enum MetadataType { 95 ClassType, 96 NonClassType, 97 MetadataTypeCount 98 }; 99 enum MetaspaceType { 100 StandardMetaspaceType, 101 BootMetaspaceType, 102 AnonymousMetaspaceType, 103 ReflectionMetaspaceType 104 }; 105 106 private: 107 static void verify_global_initialization(); 108 109 void initialize(Mutex* lock, MetaspaceType type); 110 111 // Initialize the first chunk for a Metaspace. Used for 112 // special cases such as the boot class loader, reflection 113 // class loader and anonymous class loader. 114 void initialize_first_chunk(MetaspaceType type, MetadataType mdtype); 115 Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype); 116 117 // Align up the word size to the allocation word size 118 static size_t align_word_size_up(size_t); 119 120 // Aligned size of the metaspace. 121 static size_t _compressed_class_space_size; 122 123 static size_t compressed_class_space_size() { 124 return _compressed_class_space_size; 125 } 126 127 static void set_compressed_class_space_size(size_t size) { 128 _compressed_class_space_size = size; 129 } 130 131 static size_t _first_chunk_word_size; 132 static size_t _first_class_chunk_word_size; 133 134 static size_t _commit_alignment; 135 static size_t _reserve_alignment; 136 DEBUG_ONLY(static bool _frozen;) 137 138 SpaceManager* _vsm; 139 SpaceManager* vsm() const { return _vsm; } 140 141 SpaceManager* _class_vsm; 142 SpaceManager* class_vsm() const { return _class_vsm; } 143 SpaceManager* get_space_manager(MetadataType mdtype) { 144 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 145 return mdtype == ClassType ? class_vsm() : vsm(); 146 } 147 148 // Allocate space for metadata of type mdtype. This is space 149 // within a Metachunk and is used by 150 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 151 MetaWord* allocate(size_t word_size, MetadataType mdtype); 152 153 MetaWord* expand_and_allocate(size_t size, MetadataType mdtype); 154 155 // Virtual Space lists for both classes and other metadata 156 static VirtualSpaceList* _space_list; 157 static VirtualSpaceList* _class_space_list; 158 159 static ChunkManager* _chunk_manager_metadata; 160 static ChunkManager* _chunk_manager_class; 161 162 static const MetaspaceTracer* _tracer; 163 164 public: 165 static VirtualSpaceList* space_list() { return _space_list; } 166 static VirtualSpaceList* class_space_list() { return _class_space_list; } 167 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 168 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 169 return mdtype == ClassType ? class_space_list() : space_list(); 170 } 171 172 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 173 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 174 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 175 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 176 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 177 } 178 179 static const MetaspaceTracer* tracer() { return _tracer; } 180 static void freeze() { 181 assert(DumpSharedSpaces, "sanity"); 182 DEBUG_ONLY(_frozen = true;) 183 } 184 #ifdef _LP64 185 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 186 #endif 187 188 private: 189 190 #ifdef _LP64 191 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 192 193 // Returns true if can use CDS with metaspace allocated as specified address. 194 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 195 196 static void initialize_class_space(ReservedSpace rs); 197 #endif 198 size_t class_chunk_size(size_t word_size); 199 200 public: 201 202 Metaspace(Mutex* lock, MetaspaceType type); 203 ~Metaspace(); 204 205 static void ergo_initialize(); 206 static void global_initialize(); 207 static void post_initialize(); 208 209 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 210 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 211 212 static size_t reserve_alignment() { return _reserve_alignment; } 213 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 214 static size_t commit_alignment() { return _commit_alignment; } 215 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 216 217 size_t used_words_slow(MetadataType mdtype) const; 218 size_t free_words_slow(MetadataType mdtype) const; 219 size_t capacity_words_slow(MetadataType mdtype) const; 220 221 size_t used_bytes_slow(MetadataType mdtype) const; 222 size_t capacity_bytes_slow(MetadataType mdtype) const; 223 224 size_t allocated_blocks_bytes() const; 225 size_t allocated_chunks_bytes() const; 226 227 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 228 MetaspaceObj::Type type, TRAPS); 229 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 230 231 static bool contains(const void* ptr); 232 static bool contains_non_shared(const void* ptr); 233 234 void dump(outputStream* const out) const; 235 236 // Free empty virtualspaces 237 static void purge(MetadataType mdtype); 238 static void purge(); 239 240 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 241 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 242 243 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 244 245 void print_on(outputStream* st) const; 246 // Debugging support 247 void verify(); 248 249 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({}); 250 251 // Return TRUE only if UseCompressedClassPointers is True. 252 static bool using_class_space() { 253 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers); 254 } 255 256 static bool is_class_space_allocation(MetadataType mdType) { 257 return mdType == ClassType && using_class_space(); 258 } 259 260 }; 261 262 class MetaspaceAux : AllStatic { 263 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 264 265 // These methods iterate over the classloader data graph 266 // for the given Metaspace type. These are slow. 267 static size_t used_bytes_slow(Metaspace::MetadataType mdtype); 268 static size_t free_bytes_slow(Metaspace::MetadataType mdtype); 269 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype); 270 static size_t capacity_bytes_slow(); 271 272 // Running sum of space in all Metachunks that has been 273 // allocated to a Metaspace. This is used instead of 274 // iterating over all the classloaders. One for each 275 // type of Metadata 276 static size_t _capacity_words[Metaspace:: MetadataTypeCount]; 277 // Running sum of space in all Metachunks that 278 // are being used for metadata. One for each 279 // type of Metadata. 280 static volatile size_t _used_words[Metaspace:: MetadataTypeCount]; 281 282 public: 283 // Decrement and increment _allocated_capacity_words 284 static void dec_capacity(Metaspace::MetadataType type, size_t words); 285 static void inc_capacity(Metaspace::MetadataType type, size_t words); 286 287 // Decrement and increment _allocated_used_words 288 static void dec_used(Metaspace::MetadataType type, size_t words); 289 static void inc_used(Metaspace::MetadataType type, size_t words); 290 291 // Total of space allocated to metadata in all Metaspaces. 292 // This sums the space used in each Metachunk by 293 // iterating over the classloader data graph 294 static size_t used_bytes_slow() { 295 return used_bytes_slow(Metaspace::ClassType) + 296 used_bytes_slow(Metaspace::NonClassType); 297 } 298 299 // Used by MetaspaceCounters 300 static size_t free_chunks_total_words(); 301 static size_t free_chunks_total_bytes(); 302 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 303 304 static size_t capacity_words(Metaspace::MetadataType mdtype) { 305 return _capacity_words[mdtype]; 306 } 307 static size_t capacity_words() { 308 return capacity_words(Metaspace::NonClassType) + 309 capacity_words(Metaspace::ClassType); 310 } 311 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 312 return capacity_words(mdtype) * BytesPerWord; 313 } 314 static size_t capacity_bytes() { 315 return capacity_words() * BytesPerWord; 316 } 317 318 static size_t used_words(Metaspace::MetadataType mdtype) { 319 return _used_words[mdtype]; 320 } 321 static size_t used_words() { 322 return used_words(Metaspace::NonClassType) + 323 used_words(Metaspace::ClassType); 324 } 325 static size_t used_bytes(Metaspace::MetadataType mdtype) { 326 return used_words(mdtype) * BytesPerWord; 327 } 328 static size_t used_bytes() { 329 return used_words() * BytesPerWord; 330 } 331 332 static size_t free_bytes(); 333 static size_t free_bytes(Metaspace::MetadataType mdtype); 334 335 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 336 static size_t reserved_bytes() { 337 return reserved_bytes(Metaspace::ClassType) + 338 reserved_bytes(Metaspace::NonClassType); 339 } 340 341 static size_t committed_bytes(Metaspace::MetadataType mdtype); 342 static size_t committed_bytes() { 343 return committed_bytes(Metaspace::ClassType) + 344 committed_bytes(Metaspace::NonClassType); 345 } 346 347 static size_t min_chunk_size_words(); 348 static size_t min_chunk_size_bytes() { 349 return min_chunk_size_words() * BytesPerWord; 350 } 351 352 static void print_metadata_for_nmt(outputStream* out, size_t scale = K); 353 354 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 355 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 356 357 // Print change in used metadata. 358 static void print_metaspace_change(size_t prev_metadata_used); 359 static void print_on(outputStream * out); 360 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); 361 362 static void print_class_waste(outputStream* out); 363 static void print_waste(outputStream* out); 364 365 // Prints an ASCII representation of the given space. 366 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); 367 368 static void dump(outputStream* out); 369 static void verify_free_chunks(); 370 // Checks that the values returned by allocated_capacity_bytes() and 371 // capacity_bytes_slow() are the same. 372 static void verify_capacity(); 373 static void verify_used(); 374 static void verify_metrics(); 375 }; 376 377 // Metaspace are deallocated when their class loader are GC'ed. 378 // This class implements a policy for inducing GC's to recover 379 // Metaspaces. 380 381 class MetaspaceGC : AllStatic { 382 383 // The current high-water-mark for inducing a GC. 384 // When committed memory of all metaspaces reaches this value, 385 // a GC is induced and the value is increased. Size is in bytes. 386 static volatile intptr_t _capacity_until_GC; 387 388 // For a CMS collection, signal that a concurrent collection should 389 // be started. 390 static bool _should_concurrent_collect; 391 392 static uint _shrink_factor; 393 394 static size_t shrink_factor() { return _shrink_factor; } 395 void set_shrink_factor(uint v) { _shrink_factor = v; } 396 397 public: 398 399 static void initialize(); 400 static void post_initialize(); 401 402 static size_t capacity_until_GC(); 403 static bool inc_capacity_until_GC(size_t v, 404 size_t* new_cap_until_GC = NULL, 405 size_t* old_cap_until_GC = NULL); 406 static size_t dec_capacity_until_GC(size_t v); 407 408 static bool should_concurrent_collect() { return _should_concurrent_collect; } 409 static void set_should_concurrent_collect(bool v) { 410 _should_concurrent_collect = v; 411 } 412 413 // The amount to increase the high-water-mark (_capacity_until_GC) 414 static size_t delta_capacity_until_GC(size_t bytes); 415 416 // Tells if we have can expand metaspace without hitting set limits. 417 static bool can_expand(size_t words, bool is_class); 418 419 // Returns amount that we can expand without hitting a GC, 420 // measured in words. 421 static size_t allowed_expansion(); 422 423 // Calculate the new high-water mark at which to induce 424 // a GC. 425 static void compute_new_size(); 426 }; 427 428 #endif // SHARE_VM_MEMORY_METASPACE_HPP