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 // Namespace for important central static functions 84 // (auxiliary stuff goes into MetaspaceUtils) 85 class Metaspace : public AllStatic { 86 87 friend class MetaspaceShared; 88 89 public: 90 enum MetadataType { 91 ClassType, 92 NonClassType, 93 MetadataTypeCount 94 }; 95 enum MetaspaceType { 96 StandardMetaspaceType, 97 BootMetaspaceType, 98 AnonymousMetaspaceType, 99 ReflectionMetaspaceType 100 }; 101 102 private: 103 104 // Align up the word size to the allocation word size 105 static size_t align_word_size_up(size_t); 106 107 // Aligned size of the metaspace. 108 static size_t _compressed_class_space_size; 109 110 static size_t compressed_class_space_size() { 111 return _compressed_class_space_size; 112 } 113 114 static void set_compressed_class_space_size(size_t size) { 115 _compressed_class_space_size = size; 116 } 117 118 static size_t _first_chunk_word_size; 119 static size_t _first_class_chunk_word_size; 120 121 static size_t _commit_alignment; 122 static size_t _reserve_alignment; 123 DEBUG_ONLY(static bool _frozen;) 124 125 // Virtual Space lists for both classes and other metadata 126 static VirtualSpaceList* _space_list; 127 static VirtualSpaceList* _class_space_list; 128 129 static ChunkManager* _chunk_manager_metadata; 130 static ChunkManager* _chunk_manager_class; 131 132 static const MetaspaceTracer* _tracer; 133 134 public: 135 static VirtualSpaceList* space_list() { return _space_list; } 136 static VirtualSpaceList* class_space_list() { return _class_space_list; } 137 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 138 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 139 return mdtype == ClassType ? class_space_list() : space_list(); 140 } 141 142 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 143 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 144 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 145 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 146 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 147 } 148 149 // convenience function 150 static ChunkManager* get_chunk_manager(bool is_class) { 151 return is_class ? chunk_manager_class() : chunk_manager_metadata(); 152 } 153 154 static const MetaspaceTracer* tracer() { return _tracer; } 155 static void freeze() { 156 assert(DumpSharedSpaces, "sanity"); 157 DEBUG_ONLY(_frozen = true;) 158 } 159 static void assert_not_frozen() { 160 assert(!_frozen, "sanity"); 161 } 162 #ifdef _LP64 163 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 164 #endif 165 166 private: 167 168 #ifdef _LP64 169 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 170 171 // Returns true if can use CDS with metaspace allocated as specified address. 172 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 173 174 static void initialize_class_space(ReservedSpace rs); 175 #endif 176 177 public: 178 179 static void ergo_initialize(); 180 static void global_initialize(); 181 static void post_initialize(); 182 183 static void verify_global_initialization(); 184 185 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 186 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 187 188 static size_t reserve_alignment() { return _reserve_alignment; } 189 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 190 static size_t commit_alignment() { return _commit_alignment; } 191 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 192 193 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 194 MetaspaceObj::Type type, TRAPS); 195 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 196 197 static bool contains(const void* ptr); 198 static bool contains_non_shared(const void* ptr); 199 200 // Free empty virtualspaces 201 static void purge(MetadataType mdtype); 202 static void purge(); 203 204 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 205 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 206 207 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 208 209 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({}); 210 211 // Return TRUE only if UseCompressedClassPointers is True. 212 static bool using_class_space() { 213 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers); 214 } 215 216 static bool is_class_space_allocation(MetadataType mdType) { 217 return mdType == ClassType && using_class_space(); 218 } 219 220 }; 221 222 // Manages the metaspace portion belonging to a class loader 223 class ClassLoaderMetaspace : public CHeapObj<mtClass> { 224 friend class CollectedHeap; // For expand_and_allocate() 225 friend class Metaspace; 226 friend class MetaspaceUtils; 227 friend class PrintCLDMetaspaceInfoClosure; 228 friend class VM_CollectForMetadataAllocation; // For expand_and_allocate() 229 230 private: 231 232 void initialize(Mutex* lock, Metaspace::MetaspaceType type); 233 234 // Initialize the first chunk for a Metaspace. Used for 235 // special cases such as the boot class loader, reflection 236 // class loader and anonymous class loader. 237 void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 238 Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 239 240 SpaceManager* _vsm; 241 SpaceManager* vsm() const { return _vsm; } 242 243 SpaceManager* _class_vsm; 244 SpaceManager* class_vsm() const { return _class_vsm; } 245 SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) { 246 assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 247 return mdtype == Metaspace::ClassType ? class_vsm() : vsm(); 248 } 249 250 MetaWord* expand_and_allocate(size_t size, Metaspace::MetadataType mdtype); 251 252 size_t class_chunk_size(size_t word_size); 253 254 public: 255 256 ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type); 257 ~ClassLoaderMetaspace(); 258 259 // Allocate space for metadata of type mdtype. This is space 260 // within a Metachunk and is used by 261 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 262 MetaWord* allocate(size_t word_size, Metaspace::MetadataType mdtype); 263 264 size_t used_words_slow(Metaspace::MetadataType mdtype) const; 265 size_t free_words_slow(Metaspace::MetadataType mdtype) const; 266 size_t capacity_words_slow(Metaspace::MetadataType mdtype) const; 267 268 size_t used_bytes_slow(Metaspace::MetadataType mdtype) const; 269 size_t capacity_bytes_slow(Metaspace::MetadataType mdtype) const; 270 271 size_t allocated_blocks_bytes() const; 272 size_t allocated_chunks_bytes() const; 273 274 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 275 276 void dump(outputStream* const out) const; 277 278 void print_on(outputStream* st) const; 279 // Debugging support 280 void verify(); 281 282 }; // ClassLoaderMetaspace 283 284 285 class MetaspaceUtils : AllStatic { 286 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 287 288 // These methods iterate over the classloader data graph 289 // for the given Metaspace type. These are slow. 290 static size_t used_bytes_slow(Metaspace::MetadataType mdtype); 291 static size_t free_bytes_slow(Metaspace::MetadataType mdtype); 292 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype); 293 static size_t capacity_bytes_slow(); 294 295 // Running sum of space in all Metachunks that has been 296 // allocated to a Metaspace. This is used instead of 297 // iterating over all the classloaders. One for each 298 // type of Metadata 299 static size_t _capacity_words[Metaspace:: MetadataTypeCount]; 300 // Running sum of space in all Metachunks that 301 // are being used for metadata. One for each 302 // type of Metadata. 303 static volatile size_t _used_words[Metaspace:: MetadataTypeCount]; 304 305 public: 306 // Decrement and increment _allocated_capacity_words 307 static void dec_capacity(Metaspace::MetadataType type, size_t words); 308 static void inc_capacity(Metaspace::MetadataType type, size_t words); 309 310 // Decrement and increment _allocated_used_words 311 static void dec_used(Metaspace::MetadataType type, size_t words); 312 static void inc_used(Metaspace::MetadataType type, size_t words); 313 314 // Total of space allocated to metadata in all Metaspaces. 315 // This sums the space used in each Metachunk by 316 // iterating over the classloader data graph 317 static size_t used_bytes_slow() { 318 return used_bytes_slow(Metaspace::ClassType) + 319 used_bytes_slow(Metaspace::NonClassType); 320 } 321 322 // Used by MetaspaceCounters 323 static size_t free_chunks_total_words(); 324 static size_t free_chunks_total_bytes(); 325 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 326 327 static size_t capacity_words(Metaspace::MetadataType mdtype) { 328 return _capacity_words[mdtype]; 329 } 330 static size_t capacity_words() { 331 return capacity_words(Metaspace::NonClassType) + 332 capacity_words(Metaspace::ClassType); 333 } 334 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 335 return capacity_words(mdtype) * BytesPerWord; 336 } 337 static size_t capacity_bytes() { 338 return capacity_words() * BytesPerWord; 339 } 340 341 static size_t used_words(Metaspace::MetadataType mdtype) { 342 return _used_words[mdtype]; 343 } 344 static size_t used_words() { 345 return used_words(Metaspace::NonClassType) + 346 used_words(Metaspace::ClassType); 347 } 348 static size_t used_bytes(Metaspace::MetadataType mdtype) { 349 return used_words(mdtype) * BytesPerWord; 350 } 351 static size_t used_bytes() { 352 return used_words() * BytesPerWord; 353 } 354 355 static size_t free_bytes(); 356 static size_t free_bytes(Metaspace::MetadataType mdtype); 357 358 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 359 static size_t reserved_bytes() { 360 return reserved_bytes(Metaspace::ClassType) + 361 reserved_bytes(Metaspace::NonClassType); 362 } 363 364 static size_t committed_bytes(Metaspace::MetadataType mdtype); 365 static size_t committed_bytes() { 366 return committed_bytes(Metaspace::ClassType) + 367 committed_bytes(Metaspace::NonClassType); 368 } 369 370 static size_t min_chunk_size_words(); 371 static size_t min_chunk_size_bytes() { 372 return min_chunk_size_words() * BytesPerWord; 373 } 374 375 static void print_metadata_for_nmt(outputStream* out, size_t scale = K); 376 377 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 378 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 379 380 // Print change in used metadata. 381 static void print_metaspace_change(size_t prev_metadata_used); 382 static void print_on(outputStream * out); 383 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); 384 385 static void print_class_waste(outputStream* out); 386 static void print_waste(outputStream* out); 387 388 // Prints an ASCII representation of the given space. 389 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); 390 391 static void dump(outputStream* out); 392 static void verify_free_chunks(); 393 // Checks that the values returned by allocated_capacity_bytes() and 394 // capacity_bytes_slow() are the same. 395 static void verify_capacity(); 396 static void verify_used(); 397 static void verify_metrics(); 398 }; 399 400 // Metaspace are deallocated when their class loader are GC'ed. 401 // This class implements a policy for inducing GC's to recover 402 // Metaspaces. 403 404 class MetaspaceGC : AllStatic { 405 406 // The current high-water-mark for inducing a GC. 407 // When committed memory of all metaspaces reaches this value, 408 // a GC is induced and the value is increased. Size is in bytes. 409 static volatile intptr_t _capacity_until_GC; 410 411 // For a CMS collection, signal that a concurrent collection should 412 // be started. 413 static bool _should_concurrent_collect; 414 415 static uint _shrink_factor; 416 417 static size_t shrink_factor() { return _shrink_factor; } 418 void set_shrink_factor(uint v) { _shrink_factor = v; } 419 420 public: 421 422 static void initialize(); 423 static void post_initialize(); 424 425 static size_t capacity_until_GC(); 426 static bool inc_capacity_until_GC(size_t v, 427 size_t* new_cap_until_GC = NULL, 428 size_t* old_cap_until_GC = NULL); 429 static size_t dec_capacity_until_GC(size_t v); 430 431 static bool should_concurrent_collect() { return _should_concurrent_collect; } 432 static void set_should_concurrent_collect(bool v) { 433 _should_concurrent_collect = v; 434 } 435 436 // The amount to increase the high-water-mark (_capacity_until_GC) 437 static size_t delta_capacity_until_GC(size_t bytes); 438 439 // Tells if we have can expand metaspace without hitting set limits. 440 static bool can_expand(size_t words, bool is_class); 441 442 // Returns amount that we can expand without hitting a GC, 443 // measured in words. 444 static size_t allowed_expansion(); 445 446 // Calculate the new high-water mark at which to induce 447 // a GC. 448 static void compute_new_size(); 449 }; 450 451 #endif // SHARE_VM_MEMORY_METASPACE_HPP