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