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 ClassLoaderData; 59 class MetaspaceTracer; 60 class MetaWord; 61 class Mutex; 62 class outputStream; 63 64 class CollectedHeap; 65 66 namespace metaspace { 67 class ChunkManager; 68 class ClassLoaderMetaspaceStatistics; 69 class Metablock; 70 class Metachunk; 71 class PrintCLDMetaspaceInfoClosure; 72 class SpaceManager; 73 class VirtualSpaceList; 74 class VirtualSpaceNode; 75 } 76 77 // Metaspaces each have a SpaceManager and allocations 78 // are done by the SpaceManager. Allocations are done 79 // out of the current Metachunk. When the current Metachunk 80 // is exhausted, the SpaceManager gets a new one from 81 // the current VirtualSpace. When the VirtualSpace is exhausted 82 // the SpaceManager gets a new one. The SpaceManager 83 // also manages freelists of available Chunks. 84 // 85 // Currently the space manager maintains the list of 86 // virtual spaces and the list of chunks in use. Its 87 // allocate() method returns a block for use as a 88 // quantum of metadata. 89 90 // Namespace for important central static functions 91 // (auxiliary stuff goes into MetaspaceUtils) 92 class Metaspace : public AllStatic { 93 94 friend class MetaspaceShared; 95 96 public: 97 enum MetadataType { 98 ClassType, 99 NonClassType, 100 MetadataTypeCount 101 }; 102 enum MetaspaceType { 103 ZeroMetaspaceType = 0, 104 StandardMetaspaceType = ZeroMetaspaceType, 105 BootMetaspaceType = StandardMetaspaceType + 1, 106 UnsafeAnonymousMetaspaceType = BootMetaspaceType + 1, 107 ReflectionMetaspaceType = UnsafeAnonymousMetaspaceType + 1, 108 MetaspaceTypeCount 109 }; 110 111 private: 112 113 // Align up the word size to the allocation word size 114 static size_t align_word_size_up(size_t); 115 116 // Aligned size of the metaspace. 117 static size_t _compressed_class_space_size; 118 119 static size_t compressed_class_space_size() { 120 return _compressed_class_space_size; 121 } 122 123 static void set_compressed_class_space_size(size_t size) { 124 _compressed_class_space_size = size; 125 } 126 127 static size_t _first_chunk_word_size; 128 static size_t _first_class_chunk_word_size; 129 130 static size_t _commit_alignment; 131 static size_t _reserve_alignment; 132 DEBUG_ONLY(static bool _frozen;) 133 134 // Virtual Space lists for both classes and other metadata 135 static metaspace::VirtualSpaceList* _space_list; 136 static metaspace::VirtualSpaceList* _class_space_list; 137 138 static metaspace::ChunkManager* _chunk_manager_metadata; 139 static metaspace::ChunkManager* _chunk_manager_class; 140 141 static const MetaspaceTracer* _tracer; 142 143 public: 144 static metaspace::VirtualSpaceList* space_list() { return _space_list; } 145 static metaspace::VirtualSpaceList* class_space_list() { return _class_space_list; } 146 static metaspace::VirtualSpaceList* get_space_list(MetadataType mdtype) { 147 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 148 return mdtype == ClassType ? class_space_list() : space_list(); 149 } 150 151 static metaspace::ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 152 static metaspace::ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 153 static metaspace::ChunkManager* get_chunk_manager(MetadataType mdtype) { 154 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 155 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 156 } 157 158 // convenience function 159 static metaspace::ChunkManager* get_chunk_manager(bool is_class) { 160 return is_class ? chunk_manager_class() : chunk_manager_metadata(); 161 } 162 163 static const MetaspaceTracer* tracer() { return _tracer; } 164 static void freeze() { 165 assert(DumpSharedSpaces, "sanity"); 166 DEBUG_ONLY(_frozen = true;) 167 } 168 static void assert_not_frozen() { 169 assert(!_frozen, "sanity"); 170 } 171 #ifdef _LP64 172 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 173 #endif 174 175 private: 176 177 #ifdef _LP64 178 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 179 180 // Returns true if can use CDS with metaspace allocated as specified address. 181 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 182 183 static void initialize_class_space(ReservedSpace rs); 184 #endif 185 186 public: 187 188 static void ergo_initialize(); 189 static void global_initialize(); 190 static void post_initialize(); 191 192 static void verify_global_initialization(); 193 194 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 195 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 196 197 static size_t reserve_alignment() { return _reserve_alignment; } 198 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 199 static size_t commit_alignment() { return _commit_alignment; } 200 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 201 202 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 203 MetaspaceObj::Type type, TRAPS); 204 205 static bool contains(const void* ptr); 206 static bool contains_non_shared(const void* ptr); 207 208 // Free empty virtualspaces 209 static void purge(MetadataType mdtype); 210 static void purge(); 211 212 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 213 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 214 215 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 216 217 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({}); 218 219 // Return TRUE only if UseCompressedClassPointers is True. 220 static bool using_class_space() { 221 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers); 222 } 223 224 static bool is_class_space_allocation(MetadataType mdType) { 225 return mdType == ClassType && using_class_space(); 226 } 227 228 }; 229 230 // Manages the metaspace portion belonging to a class loader 231 class ClassLoaderMetaspace : public CHeapObj<mtClass> { 232 friend class CollectedHeap; // For expand_and_allocate() 233 friend class ZCollectedHeap; // For expand_and_allocate() 234 friend class Metaspace; 235 friend class MetaspaceUtils; 236 friend class metaspace::PrintCLDMetaspaceInfoClosure; 237 friend class VM_CollectForMetadataAllocation; // For expand_and_allocate() 238 239 private: 240 241 void initialize(Mutex* lock, Metaspace::MetaspaceType type); 242 243 // Initialize the first chunk for a Metaspace. Used for 244 // special cases such as the boot class loader, reflection 245 // class loader and anonymous class loader. 246 void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 247 metaspace::Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 248 249 const Metaspace::MetaspaceType _space_type; 250 Mutex* const _lock; 251 metaspace::SpaceManager* _vsm; 252 metaspace::SpaceManager* _class_vsm; 253 254 metaspace::SpaceManager* vsm() const { return _vsm; } 255 metaspace::SpaceManager* class_vsm() const { return _class_vsm; } 256 metaspace::SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) { 257 assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 258 return mdtype == Metaspace::ClassType ? class_vsm() : vsm(); 259 } 260 261 Mutex* lock() const { return _lock; } 262 263 MetaWord* expand_and_allocate(size_t size, Metaspace::MetadataType mdtype); 264 265 size_t class_chunk_size(size_t word_size); 266 267 // Adds to the given statistic object. Must be locked with CLD metaspace lock. 268 void add_to_statistics_locked(metaspace::ClassLoaderMetaspaceStatistics* out) const; 269 270 Metaspace::MetaspaceType space_type() const { return _space_type; } 271 272 public: 273 274 ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type); 275 ~ClassLoaderMetaspace(); 276 277 // Allocate space for metadata of type mdtype. This is space 278 // within a Metachunk and is used by 279 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 280 MetaWord* allocate(size_t word_size, Metaspace::MetadataType mdtype); 281 282 size_t allocated_blocks_bytes() const; 283 size_t allocated_chunks_bytes() const; 284 285 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 286 287 void print_on(outputStream* st) const; 288 // Debugging support 289 void verify(); 290 291 // Adds to the given statistic object. Will lock with CLD metaspace lock. 292 void add_to_statistics(metaspace::ClassLoaderMetaspaceStatistics* out) const; 293 294 }; // ClassLoaderMetaspace 295 296 class MetaspaceUtils : AllStatic { 297 298 // Spacemanager updates running counters. 299 friend class metaspace::SpaceManager; 300 301 // Special access for error reporting (checks without locks). 302 friend class oopDesc; 303 friend class Klass; 304 305 // Running counters for statistics concerning in-use chunks. 306 // Note: capacity = used + free + waste + overhead. Note that we do not 307 // count free and waste. Their sum can be deduces from the three other values. 308 // For more details, one should call print_report() from within a safe point. 309 static size_t _capacity_words [Metaspace:: MetadataTypeCount]; 310 static size_t _overhead_words [Metaspace:: MetadataTypeCount]; 311 static volatile size_t _used_words [Metaspace:: MetadataTypeCount]; 312 313 // Atomically decrement or increment in-use statistic counters 314 static void dec_capacity(Metaspace::MetadataType mdtype, size_t words); 315 static void inc_capacity(Metaspace::MetadataType mdtype, size_t words); 316 static void dec_used(Metaspace::MetadataType mdtype, size_t words); 317 static void inc_used(Metaspace::MetadataType mdtype, size_t words); 318 static void dec_overhead(Metaspace::MetadataType mdtype, size_t words); 319 static void inc_overhead(Metaspace::MetadataType mdtype, size_t words); 320 321 322 // Getters for the in-use counters. 323 static size_t capacity_words(Metaspace::MetadataType mdtype) { return _capacity_words[mdtype]; } 324 static size_t used_words(Metaspace::MetadataType mdtype) { return _used_words[mdtype]; } 325 static size_t overhead_words(Metaspace::MetadataType mdtype) { return _overhead_words[mdtype]; } 326 327 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 328 329 // Helper for print_xx_report. 330 static void print_vs(outputStream* out, size_t scale); 331 332 // Utils to check if a pointer or range is part of a committed metaspace region 333 // without acquiring any locks. 334 static metaspace::VirtualSpaceNode* find_enclosing_virtual_space(const void* p); 335 static bool is_in_committed(const void* p); 336 static bool is_range_in_committed(const void* from, const void* to); 337 338 public: 339 340 // Collect used metaspace statistics. This involves walking the CLDG. The resulting 341 // output will be the accumulated values for all live metaspaces. 342 // Note: method does not do any locking. 343 static void collect_statistics(metaspace::ClassLoaderMetaspaceStatistics* out); 344 345 // Used by MetaspaceCounters 346 static size_t free_chunks_total_words(); 347 static size_t free_chunks_total_bytes(); 348 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 349 350 static size_t capacity_words() { 351 return capacity_words(Metaspace::NonClassType) + 352 capacity_words(Metaspace::ClassType); 353 } 354 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 355 return capacity_words(mdtype) * BytesPerWord; 356 } 357 static size_t capacity_bytes() { 358 return capacity_words() * BytesPerWord; 359 } 360 361 static size_t used_words() { 362 return used_words(Metaspace::NonClassType) + 363 used_words(Metaspace::ClassType); 364 } 365 static size_t used_bytes(Metaspace::MetadataType mdtype) { 366 return used_words(mdtype) * BytesPerWord; 367 } 368 static size_t used_bytes() { 369 return used_words() * BytesPerWord; 370 } 371 372 // Space committed but yet unclaimed by any class loader. 373 static size_t free_in_vs_bytes(); 374 static size_t free_in_vs_bytes(Metaspace::MetadataType mdtype); 375 376 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 377 static size_t reserved_bytes() { 378 return reserved_bytes(Metaspace::ClassType) + 379 reserved_bytes(Metaspace::NonClassType); 380 } 381 382 static size_t committed_bytes(Metaspace::MetadataType mdtype); 383 static size_t committed_bytes() { 384 return committed_bytes(Metaspace::ClassType) + 385 committed_bytes(Metaspace::NonClassType); 386 } 387 388 static size_t min_chunk_size_words(); 389 static size_t min_chunk_size_bytes() { 390 return min_chunk_size_words() * BytesPerWord; 391 } 392 393 // Flags for print_report(). 394 enum ReportFlag { 395 // Show usage by class loader. 396 rf_show_loaders = (1 << 0), 397 // Breaks report down by chunk type (small, medium, ...). 398 rf_break_down_by_chunktype = (1 << 1), 399 // Breaks report down by space type (anonymous, reflection, ...). 400 rf_break_down_by_spacetype = (1 << 2), 401 // Print details about the underlying virtual spaces. 402 rf_show_vslist = (1 << 3), 403 // Print metaspace map. 404 rf_show_vsmap = (1 << 4), 405 // If show_loaders: show loaded classes for each loader. 406 rf_show_classes = (1 << 5) 407 }; 408 409 // This will print out a basic metaspace usage report but 410 // unlike print_report() is guaranteed not to lock or to walk the CLDG. 411 static void print_basic_report(outputStream* st, size_t scale); 412 413 // Prints a report about the current metaspace state. 414 // Optional parts can be enabled via flags. 415 // Function will walk the CLDG and will lock the expand lock; if that is not 416 // convenient, use print_basic_report() instead. 417 static void print_report(outputStream* out, size_t scale = 0, int flags = 0); 418 419 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 420 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 421 422 // Print change in used metadata. 423 static void print_metaspace_change(size_t prev_metadata_used); 424 static void print_on(outputStream * out); 425 426 // Prints an ASCII representation of the given space. 427 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); 428 429 static void dump(outputStream* out); 430 static void verify_free_chunks(); 431 // Check internal counters (capacity, used). 432 static void verify_metrics(); 433 }; 434 435 // Metaspace are deallocated when their class loader are GC'ed. 436 // This class implements a policy for inducing GC's to recover 437 // Metaspaces. 438 439 class MetaspaceGC : AllStatic { 440 441 // The current high-water-mark for inducing a GC. 442 // When committed memory of all metaspaces reaches this value, 443 // a GC is induced and the value is increased. Size is in bytes. 444 static volatile size_t _capacity_until_GC; 445 446 // For a CMS collection, signal that a concurrent collection should 447 // be started. 448 static bool _should_concurrent_collect; 449 450 static uint _shrink_factor; 451 452 static size_t shrink_factor() { return _shrink_factor; } 453 void set_shrink_factor(uint v) { _shrink_factor = v; } 454 455 public: 456 457 static void initialize(); 458 static void post_initialize(); 459 460 static size_t capacity_until_GC(); 461 static bool inc_capacity_until_GC(size_t v, 462 size_t* new_cap_until_GC = NULL, 463 size_t* old_cap_until_GC = NULL); 464 static size_t dec_capacity_until_GC(size_t v); 465 466 static bool should_concurrent_collect() { return _should_concurrent_collect; } 467 static void set_should_concurrent_collect(bool v) { 468 _should_concurrent_collect = v; 469 } 470 471 // The amount to increase the high-water-mark (_capacity_until_GC) 472 static size_t delta_capacity_until_GC(size_t bytes); 473 474 // Tells if we have can expand metaspace without hitting set limits. 475 static bool can_expand(size_t words, bool is_class); 476 477 // Returns amount that we can expand without hitting a GC, 478 // measured in words. 479 static size_t allowed_expansion(); 480 481 // Calculate the new high-water mark at which to induce 482 // a GC. 483 static void compute_new_size(); 484 }; 485 486 #endif // SHARE_VM_MEMORY_METASPACE_HPP