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 ClassLoaderMetaspaceStatistics; 61 class Metablock; 62 class Metachunk; 63 class MetaspaceTracer; 64 class MetaWord; 65 class Mutex; 66 class outputStream; 67 class PrintCLDMetaspaceInfoClosure; 68 class SpaceManager; 69 class VirtualSpaceList; 70 class CollectedHeap; 71 72 // Metaspaces each have a SpaceManager and allocations 73 // are done by the SpaceManager. Allocations are done 74 // out of the current Metachunk. When the current Metachunk 75 // is exhausted, the SpaceManager gets a new one from 76 // the current VirtualSpace. When the VirtualSpace is exhausted 77 // the SpaceManager gets a new one. The SpaceManager 78 // also manages freelists of available Chunks. 79 // 80 // Currently the space manager maintains the list of 81 // virtual spaces and the list of chunks in use. Its 82 // allocate() method returns a block for use as a 83 // quantum of metadata. 84 85 // Namespace for important central static functions 86 // (auxiliary stuff goes into MetaspaceUtils) 87 class Metaspace : public AllStatic { 88 89 friend class MetaspaceShared; 90 91 public: 92 enum MetadataType { 93 ClassType, 94 NonClassType, 95 MetadataTypeCount 96 }; 97 enum MetaspaceType { 98 ZeroMetaspaceType = 0, 99 //... 100 StandardMetaspaceType = ZeroMetaspaceType, 101 BootMetaspaceType = StandardMetaspaceType + 1, 102 AnonymousMetaspaceType = BootMetaspaceType + 1, 103 ReflectionMetaspaceType = AnonymousMetaspaceType + 1, 104 //.. 105 MetaspaceTypeCount 106 }; 107 108 private: 109 110 // Align up the word size to the allocation word size 111 static size_t align_word_size_up(size_t); 112 113 // Aligned size of the metaspace. 114 static size_t _compressed_class_space_size; 115 116 static size_t compressed_class_space_size() { 117 return _compressed_class_space_size; 118 } 119 120 static void set_compressed_class_space_size(size_t size) { 121 _compressed_class_space_size = size; 122 } 123 124 static size_t _first_chunk_word_size; 125 static size_t _first_class_chunk_word_size; 126 127 static size_t _commit_alignment; 128 static size_t _reserve_alignment; 129 DEBUG_ONLY(static bool _frozen;) 130 131 // Virtual Space lists for both classes and other metadata 132 static VirtualSpaceList* _space_list; 133 static VirtualSpaceList* _class_space_list; 134 135 static ChunkManager* _chunk_manager_metadata; 136 static ChunkManager* _chunk_manager_class; 137 138 static const MetaspaceTracer* _tracer; 139 140 public: 141 static VirtualSpaceList* space_list() { return _space_list; } 142 static VirtualSpaceList* class_space_list() { return _class_space_list; } 143 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 144 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 145 return mdtype == ClassType ? class_space_list() : space_list(); 146 } 147 148 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 149 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 150 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 151 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 152 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 153 } 154 155 // convenience function 156 static ChunkManager* get_chunk_manager(bool is_class) { 157 return is_class ? chunk_manager_class() : chunk_manager_metadata(); 158 } 159 160 static const MetaspaceTracer* tracer() { return _tracer; } 161 static void freeze() { 162 assert(DumpSharedSpaces, "sanity"); 163 DEBUG_ONLY(_frozen = true;) 164 } 165 static void assert_not_frozen() { 166 assert(!_frozen, "sanity"); 167 } 168 #ifdef _LP64 169 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 170 #endif 171 172 private: 173 174 #ifdef _LP64 175 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 176 177 // Returns true if can use CDS with metaspace allocated as specified address. 178 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 179 180 static void initialize_class_space(ReservedSpace rs); 181 #endif 182 183 public: 184 185 static void ergo_initialize(); 186 static void global_initialize(); 187 static void post_initialize(); 188 189 static void verify_global_initialization(); 190 191 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 192 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 193 194 static size_t reserve_alignment() { return _reserve_alignment; } 195 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 196 static size_t commit_alignment() { return _commit_alignment; } 197 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 198 199 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 200 MetaspaceObj::Type type, TRAPS); 201 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 202 203 static bool contains(const void* ptr); 204 static bool contains_non_shared(const void* ptr); 205 206 // Free empty virtualspaces 207 static void purge(MetadataType mdtype); 208 static void purge(); 209 210 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 211 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 212 213 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 214 215 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({}); 216 217 // Return TRUE only if UseCompressedClassPointers is True. 218 static bool using_class_space() { 219 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers); 220 } 221 222 static bool is_class_space_allocation(MetadataType mdType) { 223 return mdType == ClassType && using_class_space(); 224 } 225 226 }; 227 228 // Manages the metaspace portion belonging to a class loader 229 class ClassLoaderMetaspace : public CHeapObj<mtClass> { 230 friend class CollectedHeap; // For expand_and_allocate() 231 friend class Metaspace; 232 friend class MetaspaceUtils; 233 friend class PrintCLDMetaspaceInfoClosure; 234 friend class VM_CollectForMetadataAllocation; // For expand_and_allocate() 235 236 private: 237 238 void initialize(Mutex* lock, Metaspace::MetaspaceType type); 239 240 // Initialize the first chunk for a Metaspace. Used for 241 // special cases such as the boot class loader, reflection 242 // class loader and anonymous class loader. 243 void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 244 Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 245 246 const Metaspace::MetaspaceType _space_type; 247 Mutex* const _lock; 248 SpaceManager* _vsm; 249 SpaceManager* _class_vsm; 250 251 SpaceManager* vsm() const { return _vsm; } 252 SpaceManager* class_vsm() const { return _class_vsm; } 253 SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) { 254 assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 255 return mdtype == Metaspace::ClassType ? class_vsm() : vsm(); 256 } 257 258 Mutex* lock() const { return _lock; } 259 260 MetaWord* expand_and_allocate(size_t size, Metaspace::MetadataType mdtype); 261 262 size_t class_chunk_size(size_t word_size); 263 264 // Adds to the given statistic object. Must be locked with CLD metaspace lock. 265 void add_to_statistics_locked(ClassLoaderMetaspaceStatistics* out) const; 266 267 public: 268 269 ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type); 270 ~ClassLoaderMetaspace(); 271 272 Metaspace::MetaspaceType space_type() const { return _space_type; } 273 274 // Allocate space for metadata of type mdtype. This is space 275 // within a Metachunk and is used by 276 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 277 MetaWord* allocate(size_t word_size, Metaspace::MetadataType mdtype); 278 279 size_t allocated_blocks_bytes() const; 280 size_t allocated_chunks_bytes() const; 281 282 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 283 284 void print_on(outputStream* st) const; 285 // Debugging support 286 void verify(); 287 288 // Adds to the given statistic object. Will lock with CLD metaspace lock. 289 void add_to_statistics(ClassLoaderMetaspaceStatistics* out) const; 290 291 }; // ClassLoaderMetaspace 292 293 class MetaspaceUtils : AllStatic { 294 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 295 296 // Running counters for statistics concerning in-use chunks. 297 enum StatType { 298 stat_overhead = 0, 299 stat_capacity, 300 stat_used, 301 stat_free, 302 stat_waste, 303 stat_num_values 304 }; 305 volatile size_t _in_use_stats[stat_num_values][Metaspace::MetadataTypeCount]; 306 307 template <StatType e> static void inc_stat_value(Metaspace::MetadataType mdtype, size_t words); 308 template <StatType e> static void dec_stat_value(Metaspace::MetadataType mdtype, size_t words); 309 template <StatType e> static size_t get_stat_value(Metaspace::MetadataType mdtype) const; 310 311 public: 312 313 // Collect used metaspace statistics. This involves walking the CLDG. The resulting 314 // output will be the accumulated values for all live metaspaces. 315 // Note: method does not do any locking. 316 static void collect_statistics(ClassLoaderMetaspaceStatistics* out); 317 318 // Atomically decrement or increment in-use statistic counters. 319 static void dec_capacity(Metaspace::MetadataType mdtype, size_t words) { dec_stat_value<stat_capacity>(mdtype, words); } 320 static void inc_capacity(Metaspace::MetadataType mdtype, size_t words) { inc_stat_value<stat_capacity>(mdtype, words); } 321 static size_t capacity_words(Metaspace::MetadataType mdtype) const { return get_stat_value<stat_capacity>(mdtype); } 322 323 static void dec_used(Metaspace::MetadataType mdtype, size_t words) { dec_stat_value<stat_used>(mdtype, words); } 324 static void inc_used(Metaspace::MetadataType mdtype, size_t words) { inc_stat_value<stat_used>(mdtype, words); } 325 static size_t used_words(Metaspace::MetadataType mdtype) const { return get_stat_value<stat_used>(mdtype); } 326 327 static void dec_overhead(Metaspace::MetadataType mdtype, size_t words) { dec_stat_value<stat_overhead>(mdtype, words); } 328 static void inc_overhead(Metaspace::MetadataType mdtype, size_t words) { inc_stat_value<stat_overhead>(mdtype, words); } 329 static size_t overhead_words(Metaspace::MetadataType mdtype) const { return get_stat_value<stat_overhead>(mdtype); } 330 331 static void dec_free(Metaspace::MetadataType mdtype, size_t words) { dec_stat_value<stat_free>(mdtype, words); } 332 static void inc_free(Metaspace::MetadataType mdtype, size_t words) { inc_stat_value<stat_free>(mdtype, words); } 333 static size_t free_words(Metaspace::MetadataType mdtype) const { return get_stat_value<stat_free>(mdtype); } 334 335 static void dec_waste(Metaspace::MetadataType mdtype, size_t words) { dec_stat_value<stat_waste>(mdtype, words); } 336 static void inc_waste(Metaspace::MetadataType mdtype, size_t words) { inc_stat_value<stat_waste>(mdtype, words); } 337 static size_t waste_words(Metaspace::MetadataType mdtype) const { return get_stat_value<stat_waste>(mdtype); } 338 339 // Used by MetaspaceCounters 340 static size_t free_chunks_total_words(); 341 static size_t free_chunks_total_bytes(); 342 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 343 344 static size_t capacity_words() { 345 return capacity_words(Metaspace::NonClassType) + 346 capacity_words(Metaspace::ClassType); 347 } 348 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 349 return capacity_words(mdtype) * BytesPerWord; 350 } 351 static size_t capacity_bytes() { 352 return capacity_words() * BytesPerWord; 353 } 354 355 static size_t used_words() { 356 return used_words(Metaspace::NonClassType) + 357 used_words(Metaspace::ClassType); 358 } 359 static size_t used_bytes(Metaspace::MetadataType mdtype) { 360 return used_words(mdtype) * BytesPerWord; 361 } 362 static size_t used_bytes() { 363 return used_words() * BytesPerWord; 364 } 365 366 static size_t free_bytes(); 367 static size_t free_bytes(Metaspace::MetadataType mdtype); 368 369 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 370 static size_t reserved_bytes() { 371 return reserved_bytes(Metaspace::ClassType) + 372 reserved_bytes(Metaspace::NonClassType); 373 } 374 375 static size_t committed_bytes(Metaspace::MetadataType mdtype); 376 static size_t committed_bytes() { 377 return committed_bytes(Metaspace::ClassType) + 378 committed_bytes(Metaspace::NonClassType); 379 } 380 381 static size_t min_chunk_size_words(); 382 static size_t min_chunk_size_bytes() { 383 return min_chunk_size_words() * BytesPerWord; 384 } 385 386 // Flags for print_report(). 387 enum ReportFlag { 388 // Breaks report down by class loader. 389 rf_show_loaders = (1 << 0), 390 // Breaks report down by chunk type (small, medium, ...). 391 rf_break_down_by_chunktype = (1 << 1), 392 // Breaks report down by space type (anonymous, reflection, ...). 393 rf_break_down_by_spacetype = (1 << 2), 394 // Print details about the underlying virtual spaces. 395 rf_show_vslist = (1 << 3), 396 // Print metaspace map. 397 rf_show_vsmap = (1 << 4), 398 // Print details about the free chunk list. 399 rf_show_chunk_freelist = (1 << 5), 400 }; 401 402 // Prints a report about the current metaspace state. Form of report is defined 403 // by flags (see ReportFlags). In its most basic form (flags == 0), a short 404 // overview is printed. 405 // Scale is one of 1, K, M, G - in which case numbers are printed as bytes, 406 // KB, MB, GB, respectively - or 0, in which case the most suitable scale 407 // is chosen dynamically. 408 static void print_report(outputStream* out, size_t scale = 0, int flags = 0); 409 410 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 411 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 412 413 // Print change in used metadata. 414 static void print_metaspace_change(size_t prev_metadata_used); 415 static void print_on(outputStream * out); 416 417 // Prints an ASCII representation of the given space. 418 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); 419 420 static void dump(outputStream* out); 421 static void verify_free_chunks(); 422 // Check internal counters (capacity, used). 423 static void verify_metrics(); 424 }; 425 426 // Metaspace are deallocated when their class loader are GC'ed. 427 // This class implements a policy for inducing GC's to recover 428 // Metaspaces. 429 430 class MetaspaceGC : AllStatic { 431 432 // The current high-water-mark for inducing a GC. 433 // When committed memory of all metaspaces reaches this value, 434 // a GC is induced and the value is increased. Size is in bytes. 435 static volatile intptr_t _capacity_until_GC; 436 437 // For a CMS collection, signal that a concurrent collection should 438 // be started. 439 static bool _should_concurrent_collect; 440 441 static uint _shrink_factor; 442 443 static size_t shrink_factor() { return _shrink_factor; } 444 void set_shrink_factor(uint v) { _shrink_factor = v; } 445 446 public: 447 448 static void initialize(); 449 static void post_initialize(); 450 451 static size_t capacity_until_GC(); 452 static bool inc_capacity_until_GC(size_t v, 453 size_t* new_cap_until_GC = NULL, 454 size_t* old_cap_until_GC = NULL); 455 static size_t dec_capacity_until_GC(size_t v); 456 457 static bool should_concurrent_collect() { return _should_concurrent_collect; } 458 static void set_should_concurrent_collect(bool v) { 459 _should_concurrent_collect = v; 460 } 461 462 // The amount to increase the high-water-mark (_capacity_until_GC) 463 static size_t delta_capacity_until_GC(size_t bytes); 464 465 // Tells if we have can expand metaspace without hitting set limits. 466 static bool can_expand(size_t words, bool is_class); 467 468 // Returns amount that we can expand without hitting a GC, 469 // measured in words. 470 static size_t allowed_expansion(); 471 472 // Calculate the new high-water mark at which to induce 473 // a GC. 474 static void compute_new_size(); 475 }; 476 477 #endif // SHARE_VM_MEMORY_METASPACE_HPP