1 /* 2 * Copyright (c) 2011, 2019, 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_MEMORY_METASPACE_HPP 25 #define SHARE_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 "memory/metaspace/metaspaceSizesSnapshot.hpp" 32 #include "runtime/globals.hpp" 33 #include "utilities/exceptions.hpp" 34 35 // Metaspace 36 // 37 // Metaspaces are Arenas for the VM's metadata. 38 // They are allocated one per class loader object, and one for the null 39 // bootstrap class loader 40 // 41 // block X ---+ +-------------------+ 42 // | | Virtualspace | 43 // | | | 44 // | | | 45 // | |-------------------| 46 // | || Chunk | 47 // | || | 48 // | ||---------- | 49 // +------>||| block 0 | | 50 // ||---------- | 51 // ||| block 1 | | 52 // ||---------- | 53 // || | 54 // |-------------------| 55 // | | 56 // | | 57 // +-------------------+ 58 // 59 60 class ClassLoaderData; 61 class MetaspaceTracer; 62 class Mutex; 63 class outputStream; 64 65 class CollectedHeap; 66 67 namespace metaspace { 68 class ChunkManager; 69 class ClassLoaderMetaspaceStatistics; 70 class Metablock; 71 class Metachunk; 72 class PrintCLDMetaspaceInfoClosure; 73 class SpaceManager; 74 class VirtualSpaceList; 75 class VirtualSpaceNode; 76 } 77 78 // Metaspaces each have a SpaceManager and allocations 79 // are done by the SpaceManager. Allocations are done 80 // out of the current Metachunk. When the current Metachunk 81 // is exhausted, the SpaceManager gets a new one from 82 // the current VirtualSpace. When the VirtualSpace is exhausted 83 // the SpaceManager gets a new one. The SpaceManager 84 // also manages freelists of available Chunks. 85 // 86 // Currently the space manager maintains the list of 87 // virtual spaces and the list of chunks in use. Its 88 // allocate() method returns a block for use as a 89 // quantum of metadata. 90 91 // Namespace for important central static functions 92 // (auxiliary stuff goes into MetaspaceUtils) 93 class Metaspace : public AllStatic { 94 95 friend class MetaspaceShared; 96 97 public: 98 enum MetadataType { 99 ClassType, 100 NonClassType, 101 MetadataTypeCount 102 }; 103 enum MetaspaceType { 104 ZeroMetaspaceType = 0, 105 StandardMetaspaceType = ZeroMetaspaceType, 106 BootMetaspaceType = StandardMetaspaceType + 1, 107 UnsafeAnonymousMetaspaceType = BootMetaspaceType + 1, 108 ReflectionMetaspaceType = UnsafeAnonymousMetaspaceType + 1, 109 MetaspaceTypeCount 110 }; 111 112 private: 113 114 // Align up the word size to the allocation word size 115 static size_t align_word_size_up(size_t); 116 117 // Aligned size of the metaspace. 118 static size_t _compressed_class_space_size; 119 120 static size_t compressed_class_space_size() { 121 return _compressed_class_space_size; 122 } 123 124 static void set_compressed_class_space_size(size_t size) { 125 _compressed_class_space_size = size; 126 } 127 128 static size_t _first_chunk_word_size; 129 static size_t _first_class_chunk_word_size; 130 131 static size_t _commit_alignment; 132 static size_t _reserve_alignment; 133 DEBUG_ONLY(static bool _frozen;) 134 135 // Virtual Space lists for both classes and other metadata 136 static metaspace::VirtualSpaceList* _space_list; 137 static metaspace::VirtualSpaceList* _class_space_list; 138 139 static metaspace::ChunkManager* _chunk_manager_metadata; 140 static metaspace::ChunkManager* _chunk_manager_class; 141 142 static const MetaspaceTracer* _tracer; 143 144 static bool _initialized; 145 146 public: 147 static metaspace::VirtualSpaceList* space_list() { return _space_list; } 148 static metaspace::VirtualSpaceList* class_space_list() { return _class_space_list; } 149 static metaspace::VirtualSpaceList* get_space_list(MetadataType mdtype) { 150 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 151 return mdtype == ClassType ? class_space_list() : space_list(); 152 } 153 154 static metaspace::ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 155 static metaspace::ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 156 static metaspace::ChunkManager* get_chunk_manager(MetadataType mdtype) { 157 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 158 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 159 } 160 161 // convenience function 162 static metaspace::ChunkManager* get_chunk_manager(bool is_class) { 163 return is_class ? chunk_manager_class() : chunk_manager_metadata(); 164 } 165 166 static const MetaspaceTracer* tracer() { return _tracer; } 167 static void freeze() { 168 assert(DumpSharedSpaces, "sanity"); 169 DEBUG_ONLY(_frozen = true;) 170 } 171 static void assert_not_frozen() { 172 assert(!_frozen, "sanity"); 173 } 174 #ifdef _LP64 175 static void allocate_metaspace_compressed_klass_ptrs(ReservedSpace metaspace_rs, char* requested_addr, address cds_base); 176 #endif 177 178 private: 179 180 #ifdef _LP64 181 static void set_narrow_klass_base_and_shift(ReservedSpace metaspace_rs, 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 static bool initialized() { return _initialized; } 229 230 }; 231 232 // Manages the metaspace portion belonging to a class loader 233 class ClassLoaderMetaspace : public CHeapObj<mtClass> { 234 friend class CollectedHeap; // For expand_and_allocate() 235 friend class ZCollectedHeap; // For expand_and_allocate() 236 friend class ShenandoahHeap; // For expand_and_allocate() 237 friend class Metaspace; 238 friend class MetaspaceUtils; 239 friend class metaspace::PrintCLDMetaspaceInfoClosure; 240 friend class VM_CollectForMetadataAllocation; // For expand_and_allocate() 241 242 private: 243 244 void initialize(Mutex* lock, Metaspace::MetaspaceType type); 245 246 // Initialize the first chunk for a Metaspace. Used for 247 // special cases such as the boot class loader, reflection 248 // class loader and anonymous class loader. 249 void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 250 metaspace::Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 251 252 const Metaspace::MetaspaceType _space_type; 253 Mutex* const _lock; 254 metaspace::SpaceManager* _vsm; 255 metaspace::SpaceManager* _class_vsm; 256 257 metaspace::SpaceManager* vsm() const { return _vsm; } 258 metaspace::SpaceManager* class_vsm() const { return _class_vsm; } 259 metaspace::SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) { 260 assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 261 return mdtype == Metaspace::ClassType ? class_vsm() : vsm(); 262 } 263 264 Mutex* lock() const { return _lock; } 265 266 MetaWord* expand_and_allocate(size_t size, Metaspace::MetadataType mdtype); 267 268 size_t class_chunk_size(size_t word_size); 269 270 // Adds to the given statistic object. Must be locked with CLD metaspace lock. 271 void add_to_statistics_locked(metaspace::ClassLoaderMetaspaceStatistics* out) const; 272 273 Metaspace::MetaspaceType space_type() const { return _space_type; } 274 275 public: 276 277 ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type); 278 ~ClassLoaderMetaspace(); 279 280 // Allocate space for metadata of type mdtype. This is space 281 // within a Metachunk and is used by 282 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS) 283 MetaWord* allocate(size_t word_size, Metaspace::MetadataType mdtype); 284 285 size_t allocated_blocks_bytes() const; 286 size_t allocated_chunks_bytes() const; 287 288 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); 289 290 void print_on(outputStream* st) const; 291 // Debugging support 292 void verify(); 293 294 // Adds to the given statistic object. Will lock with CLD metaspace lock. 295 void add_to_statistics(metaspace::ClassLoaderMetaspaceStatistics* out) const; 296 297 }; // ClassLoaderMetaspace 298 299 class MetaspaceUtils : AllStatic { 300 301 // Spacemanager updates running counters. 302 friend class metaspace::SpaceManager; 303 304 // Special access for error reporting (checks without locks). 305 friend class oopDesc; 306 friend class Klass; 307 308 // Running counters for statistics concerning in-use chunks. 309 // Note: capacity = used + free + waste + overhead. Note that we do not 310 // count free and waste. Their sum can be deduces from the three other values. 311 // For more details, one should call print_report() from within a safe point. 312 static size_t _capacity_words [Metaspace:: MetadataTypeCount]; 313 static size_t _overhead_words [Metaspace:: MetadataTypeCount]; 314 static volatile size_t _used_words [Metaspace:: MetadataTypeCount]; 315 316 // Atomically decrement or increment in-use statistic counters 317 static void dec_capacity(Metaspace::MetadataType mdtype, size_t words); 318 static void inc_capacity(Metaspace::MetadataType mdtype, size_t words); 319 static void dec_used(Metaspace::MetadataType mdtype, size_t words); 320 static void inc_used(Metaspace::MetadataType mdtype, size_t words); 321 static void dec_overhead(Metaspace::MetadataType mdtype, size_t words); 322 static void inc_overhead(Metaspace::MetadataType mdtype, size_t words); 323 324 325 // Getters for the in-use counters. 326 static size_t capacity_words(Metaspace::MetadataType mdtype) { return _capacity_words[mdtype]; } 327 static size_t used_words(Metaspace::MetadataType mdtype) { return _used_words[mdtype]; } 328 static size_t overhead_words(Metaspace::MetadataType mdtype) { return _overhead_words[mdtype]; } 329 330 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 331 332 // Helper for print_xx_report. 333 static void print_vs(outputStream* out, size_t scale); 334 335 public: 336 337 // Collect used metaspace statistics. This involves walking the CLDG. The resulting 338 // output will be the accumulated values for all live metaspaces. 339 // Note: method does not do any locking. 340 static void collect_statistics(metaspace::ClassLoaderMetaspaceStatistics* out); 341 342 // Used by MetaspaceCounters 343 static size_t free_chunks_total_words(); 344 static size_t free_chunks_total_bytes(); 345 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 346 347 static size_t capacity_words() { 348 return capacity_words(Metaspace::NonClassType) + 349 capacity_words(Metaspace::ClassType); 350 } 351 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 352 return capacity_words(mdtype) * BytesPerWord; 353 } 354 static size_t capacity_bytes() { 355 return capacity_words() * BytesPerWord; 356 } 357 358 static size_t used_words() { 359 return used_words(Metaspace::NonClassType) + 360 used_words(Metaspace::ClassType); 361 } 362 static size_t used_bytes(Metaspace::MetadataType mdtype) { 363 return used_words(mdtype) * BytesPerWord; 364 } 365 static size_t used_bytes() { 366 return used_words() * BytesPerWord; 367 } 368 369 // Space committed but yet unclaimed by any class loader. 370 static size_t free_in_vs_bytes(); 371 static size_t free_in_vs_bytes(Metaspace::MetadataType mdtype); 372 373 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 374 static size_t reserved_bytes() { 375 return reserved_bytes(Metaspace::ClassType) + 376 reserved_bytes(Metaspace::NonClassType); 377 } 378 379 static size_t committed_bytes(Metaspace::MetadataType mdtype); 380 static size_t committed_bytes() { 381 return committed_bytes(Metaspace::ClassType) + 382 committed_bytes(Metaspace::NonClassType); 383 } 384 385 static size_t min_chunk_size_words(); 386 387 // Flags for print_report(). 388 enum ReportFlag { 389 // Show usage by class loader. 390 rf_show_loaders = (1 << 0), 391 // Breaks report down by chunk type (small, medium, ...). 392 rf_break_down_by_chunktype = (1 << 1), 393 // Breaks report down by space type (anonymous, reflection, ...). 394 rf_break_down_by_spacetype = (1 << 2), 395 // Print details about the underlying virtual spaces. 396 rf_show_vslist = (1 << 3), 397 // Print metaspace map. 398 rf_show_vsmap = (1 << 4), 399 // If show_loaders: show loaded classes for each loader. 400 rf_show_classes = (1 << 5) 401 }; 402 403 // This will print out a basic metaspace usage report but 404 // unlike print_report() is guaranteed not to lock or to walk the CLDG. 405 static void print_basic_report(outputStream* st, size_t scale); 406 407 // Prints a report about the current metaspace state. 408 // Optional parts can be enabled via flags. 409 // Function will walk the CLDG and will lock the expand lock; if that is not 410 // convenient, use print_basic_report() instead. 411 static void print_report(outputStream* out, size_t scale = 0, int flags = 0); 412 413 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 414 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 415 416 // Log change in used metadata. 417 static void print_metaspace_change(const metaspace::MetaspaceSizesSnapshot& pre_meta_values); 418 static void print_on(outputStream * out); 419 420 // Prints an ASCII representation of the given space. 421 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); 422 423 static void dump(outputStream* out); 424 static void verify_free_chunks(); 425 // Check internal counters (capacity, used). 426 static void verify_metrics(); 427 }; 428 429 // Metaspace are deallocated when their class loader are GC'ed. 430 // This class implements a policy for inducing GC's to recover 431 // Metaspaces. 432 433 class MetaspaceGC : AllStatic { 434 435 // The current high-water-mark for inducing a GC. 436 // When committed memory of all metaspaces reaches this value, 437 // a GC is induced and the value is increased. Size is in bytes. 438 static volatile size_t _capacity_until_GC; 439 440 // For a CMS collection, signal that a concurrent collection should 441 // be started. 442 static bool _should_concurrent_collect; 443 444 static uint _shrink_factor; 445 446 static size_t shrink_factor() { return _shrink_factor; } 447 void set_shrink_factor(uint v) { _shrink_factor = v; } 448 449 public: 450 451 static void initialize(); 452 static void post_initialize(); 453 454 static size_t capacity_until_GC(); 455 static bool inc_capacity_until_GC(size_t v, 456 size_t* new_cap_until_GC = NULL, 457 size_t* old_cap_until_GC = NULL, 458 bool* can_retry = NULL); 459 static size_t dec_capacity_until_GC(size_t v); 460 461 static bool should_concurrent_collect() { return _should_concurrent_collect; } 462 static void set_should_concurrent_collect(bool v) { 463 _should_concurrent_collect = v; 464 } 465 466 // The amount to increase the high-water-mark (_capacity_until_GC) 467 static size_t delta_capacity_until_GC(size_t bytes); 468 469 // Tells if we have can expand metaspace without hitting set limits. 470 static bool can_expand(size_t words, bool is_class); 471 472 // Returns amount that we can expand without hitting a GC, 473 // measured in words. 474 static size_t allowed_expansion(); 475 476 // Calculate the new high-water mark at which to induce 477 // a GC. 478 static void compute_new_size(); 479 }; 480 481 #endif // SHARE_MEMORY_METASPACE_HPP