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 friend class MetaspaceAllocationTest; 93 94 public: 95 enum MetadataType { 96 ClassType, 97 NonClassType, 98 MetadataTypeCount 99 }; 100 enum MetaspaceType { 101 StandardMetaspaceType, 102 BootMetaspaceType, 103 AnonymousMetaspaceType, 104 ReflectionMetaspaceType 105 }; 106 107 private: 108 static void verify_global_initialization(); 109 110 void initialize(Mutex* lock, MetaspaceType type); 111 112 // Initialize the first chunk for a Metaspace. Used for 113 // special cases such as the boot class loader, reflection 114 // class loader and anonymous class loader. 115 void initialize_first_chunk(MetaspaceType type, MetadataType mdtype); 116 Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype); 117 118 // Align up the word size to the allocation word size 119 static size_t align_word_size_up(size_t); 120 121 // Aligned size of the metaspace. 122 static size_t _compressed_class_space_size; 123 124 static size_t compressed_class_space_size() { 125 return _compressed_class_space_size; 126 } 127 128 static void set_compressed_class_space_size(size_t size) { 129 _compressed_class_space_size = size; 130 } 131 132 static size_t _first_chunk_word_size; 133 static size_t _first_class_chunk_word_size; 134 135 static size_t _commit_alignment; 136 static size_t _reserve_alignment; 137 DEBUG_ONLY(static bool _frozen;) 138 139 SpaceManager* _vsm; 140 SpaceManager* vsm() const { return _vsm; } 141 142 SpaceManager* _class_vsm; 143 SpaceManager* class_vsm() const { return _class_vsm; } 144 SpaceManager* get_space_manager(MetadataType mdtype) { 145 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 146 return mdtype == ClassType ? class_vsm() : vsm(); 147 } 148 149 // Allocate space for metadata of type mdtype. This is space 150 // within a Metachunk and is used by 151 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 152 MetaWord* allocate(size_t word_size, MetadataType mdtype); 153 154 MetaWord* expand_and_allocate(size_t size, MetadataType mdtype); 155 156 // Virtual Space lists for both classes and other metadata 157 static VirtualSpaceList* _space_list; 158 static VirtualSpaceList* _class_space_list; 159 160 static ChunkManager* _chunk_manager_metadata; 161 static ChunkManager* _chunk_manager_class; 162 163 static const MetaspaceTracer* _tracer; 164 165 public: 166 static VirtualSpaceList* space_list() { return _space_list; } 167 static VirtualSpaceList* class_space_list() { return _class_space_list; } 168 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 169 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 170 return mdtype == ClassType ? class_space_list() : space_list(); 171 } 172 173 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 174 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 175 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 176 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 177 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 178 } 179 180 // convenience function 181 static ChunkManager* get_chunk_manager(bool is_class) { 182 return is_class ? chunk_manager_class() : chunk_manager_metadata(); 183 } 184 185 static const MetaspaceTracer* tracer() { return _tracer; } 186 static void freeze() { 187 assert(DumpSharedSpaces, "sanity"); 188 DEBUG_ONLY(_frozen = true;) 189 } 190 #ifdef _LP64 191 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 192 #endif 193 194 private: 195 196 #ifdef _LP64 197 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 198 199 // Returns true if can use CDS with metaspace allocated as specified address. 200 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 201 202 static void initialize_class_space(ReservedSpace rs); 203 #endif 204 size_t class_chunk_size(size_t word_size); 205 206 public: 207 208 Metaspace(Mutex* lock, MetaspaceType type); 209 ~Metaspace(); 210 211 static void ergo_initialize(); 212 static void global_initialize(); 213 static void post_initialize(); 214 215 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 216 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 217 218 static size_t reserve_alignment() { return _reserve_alignment; } 219 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 220 static size_t commit_alignment() { return _commit_alignment; } 221 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 222 223 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 MetaspaceObj::Type type, TRAPS); 235 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 236 237 static bool contains(const void* ptr); 238 static bool contains_non_shared(const void* ptr); 239 240 void dump(outputStream* const out) const; 241 242 // Free empty virtualspaces 243 static void purge(MetadataType mdtype); 244 static void purge(); 245 246 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 247 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 248 249 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 250 251 void print_on(outputStream* st) const; 252 // Debugging support 253 void verify(); 254 255 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({}); 256 257 // Return TRUE only if UseCompressedClassPointers is True. 258 static bool using_class_space() { 259 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers); 260 } 261 262 static bool is_class_space_allocation(MetadataType mdType) { 263 return mdType == ClassType && using_class_space(); 264 } 265 266 }; 267 268 class MetaspaceAux : AllStatic { 269 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 270 271 // These methods iterate over the classloader data graph 272 // for the given Metaspace type. These are slow. 273 static size_t used_bytes_slow(Metaspace::MetadataType mdtype); 274 static size_t free_bytes_slow(Metaspace::MetadataType mdtype); 275 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype); 276 static size_t capacity_bytes_slow(); 277 278 // Running sum of space in all Metachunks that has been 279 // allocated to a Metaspace. This is used instead of 280 // iterating over all the classloaders. One for each 281 // type of Metadata 282 static size_t _capacity_words[Metaspace:: MetadataTypeCount]; 283 // Running sum of space in all Metachunks that 284 // are being used for metadata. One for each 285 // type of Metadata. 286 static volatile size_t _used_words[Metaspace:: MetadataTypeCount]; 287 288 public: 289 // Decrement and increment _allocated_capacity_words 290 static void dec_capacity(Metaspace::MetadataType type, size_t words); 291 static void inc_capacity(Metaspace::MetadataType type, size_t words); 292 293 // Decrement and increment _allocated_used_words 294 static void dec_used(Metaspace::MetadataType type, size_t words); 295 static void inc_used(Metaspace::MetadataType type, size_t words); 296 297 // Total of space allocated to metadata in all Metaspaces. 298 // This sums the space used in each Metachunk by 299 // iterating over the classloader data graph 300 static size_t used_bytes_slow() { 301 return used_bytes_slow(Metaspace::ClassType) + 302 used_bytes_slow(Metaspace::NonClassType); 303 } 304 305 // Used by MetaspaceCounters 306 static size_t free_chunks_total_words(); 307 static size_t free_chunks_total_bytes(); 308 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 309 310 static size_t capacity_words(Metaspace::MetadataType mdtype) { 311 return _capacity_words[mdtype]; 312 } 313 static size_t capacity_words() { 314 return capacity_words(Metaspace::NonClassType) + 315 capacity_words(Metaspace::ClassType); 316 } 317 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 318 return capacity_words(mdtype) * BytesPerWord; 319 } 320 static size_t capacity_bytes() { 321 return capacity_words() * BytesPerWord; 322 } 323 324 static size_t used_words(Metaspace::MetadataType mdtype) { 325 return _used_words[mdtype]; 326 } 327 static size_t used_words() { 328 return used_words(Metaspace::NonClassType) + 329 used_words(Metaspace::ClassType); 330 } 331 static size_t used_bytes(Metaspace::MetadataType mdtype) { 332 return used_words(mdtype) * BytesPerWord; 333 } 334 static size_t used_bytes() { 335 return used_words() * BytesPerWord; 336 } 337 338 static size_t free_bytes(); 339 static size_t free_bytes(Metaspace::MetadataType mdtype); 340 341 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 342 static size_t reserved_bytes() { 343 return reserved_bytes(Metaspace::ClassType) + 344 reserved_bytes(Metaspace::NonClassType); 345 } 346 347 static size_t committed_bytes(Metaspace::MetadataType mdtype); 348 static size_t committed_bytes() { 349 return committed_bytes(Metaspace::ClassType) + 350 committed_bytes(Metaspace::NonClassType); 351 } 352 353 static size_t min_chunk_size_words(); 354 static size_t min_chunk_size_bytes() { 355 return min_chunk_size_words() * BytesPerWord; 356 } 357 358 static void print_metadata_for_nmt(outputStream* out, size_t scale = K); 359 360 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 361 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 362 363 // Print change in used metadata. 364 static void print_metaspace_change(size_t prev_metadata_used); 365 static void print_on(outputStream * out); 366 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); 367 368 static void print_class_waste(outputStream* out); 369 static void print_waste(outputStream* out); 370 371 // Prints an ASCII representation of the given space. 372 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); 373 374 static void dump(outputStream* out); 375 static void verify_free_chunks(); 376 // Checks that the values returned by allocated_capacity_bytes() and 377 // capacity_bytes_slow() are the same. 378 static void verify_capacity(); 379 static void verify_used(); 380 static void verify_metrics(); 381 }; 382 383 // Metaspace are deallocated when their class loader are GC'ed. 384 // This class implements a policy for inducing GC's to recover 385 // Metaspaces. 386 387 class MetaspaceGC : AllStatic { 388 389 // The current high-water-mark for inducing a GC. 390 // When committed memory of all metaspaces reaches this value, 391 // a GC is induced and the value is increased. Size is in bytes. 392 static volatile intptr_t _capacity_until_GC; 393 394 // For a CMS collection, signal that a concurrent collection should 395 // be started. 396 static bool _should_concurrent_collect; 397 398 static uint _shrink_factor; 399 400 static size_t shrink_factor() { return _shrink_factor; } 401 void set_shrink_factor(uint v) { _shrink_factor = v; } 402 403 public: 404 405 static void initialize(); 406 static void post_initialize(); 407 408 static size_t capacity_until_GC(); 409 static bool inc_capacity_until_GC(size_t v, 410 size_t* new_cap_until_GC = NULL, 411 size_t* old_cap_until_GC = NULL); 412 static size_t dec_capacity_until_GC(size_t v); 413 414 static bool should_concurrent_collect() { return _should_concurrent_collect; } 415 static void set_should_concurrent_collect(bool v) { 416 _should_concurrent_collect = v; 417 } 418 419 // The amount to increase the high-water-mark (_capacity_until_GC) 420 static size_t delta_capacity_until_GC(size_t bytes); 421 422 // Tells if we have can expand metaspace without hitting set limits. 423 static bool can_expand(size_t words, bool is_class); 424 425 // Returns amount that we can expand without hitting a GC, 426 // measured in words. 427 static size_t allowed_expansion(); 428 429 // Calculate the new high-water mark at which to induce 430 // a GC. 431 static void compute_new_size(); 432 }; 433 434 #endif // SHARE_VM_MEMORY_METASPACE_HPP