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 class CollectedHeap; 70 71 namespace metaspace { 72 namespace internals { 73 class ClassLoaderMetaspaceStatistics; 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 //... 104 StandardMetaspaceType = ZeroMetaspaceType, 105 BootMetaspaceType = StandardMetaspaceType + 1, 106 AnonymousMetaspaceType = BootMetaspaceType + 1, 107 ReflectionMetaspaceType = AnonymousMetaspaceType + 1, 108 //.. 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 VirtualSpaceList* _space_list; 137 static VirtualSpaceList* _class_space_list; 138 139 static ChunkManager* _chunk_manager_metadata; 140 static ChunkManager* _chunk_manager_class; 141 142 static const MetaspaceTracer* _tracer; 143 144 public: 145 static VirtualSpaceList* space_list() { return _space_list; } 146 static VirtualSpaceList* class_space_list() { return _class_space_list; } 147 static VirtualSpaceList* get_space_list(MetadataType mdtype) { 148 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 149 return mdtype == ClassType ? class_space_list() : space_list(); 150 } 151 152 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 153 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 154 static ChunkManager* get_chunk_manager(MetadataType mdtype) { 155 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 156 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 157 } 158 159 // convenience function 160 static ChunkManager* get_chunk_manager(bool is_class) { 161 return is_class ? chunk_manager_class() : chunk_manager_metadata(); 162 } 163 164 static const MetaspaceTracer* tracer() { return _tracer; } 165 static void freeze() { 166 assert(DumpSharedSpaces, "sanity"); 167 DEBUG_ONLY(_frozen = true;) 168 } 169 static void assert_not_frozen() { 170 assert(!_frozen, "sanity"); 171 } 172 #ifdef _LP64 173 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 174 #endif 175 176 private: 177 178 #ifdef _LP64 179 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 180 181 // Returns true if can use CDS with metaspace allocated as specified address. 182 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 183 184 static void initialize_class_space(ReservedSpace rs); 185 #endif 186 187 public: 188 189 static void ergo_initialize(); 190 static void global_initialize(); 191 static void post_initialize(); 192 193 static void verify_global_initialization(); 194 195 static size_t first_chunk_word_size() { return _first_chunk_word_size; } 196 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; } 197 198 static size_t reserve_alignment() { return _reserve_alignment; } 199 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; } 200 static size_t commit_alignment() { return _commit_alignment; } 201 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; } 202 203 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, 204 MetaspaceObj::Type type, TRAPS); 205 206 static bool contains(const void* ptr); 207 static bool contains_non_shared(const void* ptr); 208 209 // Free empty virtualspaces 210 static void purge(MetadataType mdtype); 211 static void purge(); 212 213 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, 214 MetaspaceObj::Type type, MetadataType mdtype, TRAPS); 215 216 static const char* metadata_type_name(Metaspace::MetadataType mdtype); 217 218 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({}); 219 220 // Return TRUE only if UseCompressedClassPointers is True. 221 static bool using_class_space() { 222 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers); 223 } 224 225 static bool is_class_space_allocation(MetadataType mdType) { 226 return mdType == ClassType && using_class_space(); 227 } 228 229 }; 230 231 // Manages the metaspace portion belonging to a class loader 232 class ClassLoaderMetaspace : public CHeapObj<mtClass> { 233 friend class CollectedHeap; // For expand_and_allocate() 234 friend class Metaspace; 235 friend class MetaspaceUtils; 236 friend class 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 Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); 248 249 const Metaspace::MetaspaceType _space_type; 250 Mutex* const _lock; 251 SpaceManager* _vsm; 252 SpaceManager* _class_vsm; 253 254 SpaceManager* vsm() const { return _vsm; } 255 SpaceManager* class_vsm() const { return _class_vsm; } 256 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::internals::ClassLoaderMetaspaceStatistics* out) const; 269 270 public: 271 272 ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type); 273 ~ClassLoaderMetaspace(); 274 275 Metaspace::MetaspaceType space_type() const { return _space_type; } 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::internals::ClassLoaderMetaspaceStatistics* out) const; 293 294 }; // ClassLoaderMetaspace 295 296 class MetaspaceUtils : AllStatic { 297 298 // Spacemanager updates running counters. 299 friend class SpaceManager; 300 301 // Running counters for statistics concerning in-use chunks. 302 // Note: capacity = used + free + waste + overhead. Note that we do not 303 // count free and waste. Their sum can be deduces from the three other values. 304 // For more details, one should call print_report() from within a safe point. 305 static size_t _capacity_words [Metaspace:: MetadataTypeCount]; 306 static size_t _overhead_words [Metaspace:: MetadataTypeCount]; 307 static volatile size_t _used_words [Metaspace:: MetadataTypeCount]; 308 309 // Atomically decrement or increment in-use statistic counters 310 static void dec_capacity(Metaspace::MetadataType mdtype, size_t words); 311 static void inc_capacity(Metaspace::MetadataType mdtype, size_t words); 312 static void dec_used(Metaspace::MetadataType mdtype, size_t words); 313 static void inc_used(Metaspace::MetadataType mdtype, size_t words); 314 static void dec_overhead(Metaspace::MetadataType mdtype, size_t words); 315 static void inc_overhead(Metaspace::MetadataType mdtype, size_t words); 316 317 318 // Getters for the in-use counters. 319 static size_t capacity_words(Metaspace::MetadataType mdtype) { return _capacity_words[mdtype]; } 320 static size_t used_words(Metaspace::MetadataType mdtype) { return _used_words[mdtype]; } 321 static size_t overhead_words(Metaspace::MetadataType mdtype) { return _overhead_words[mdtype]; } 322 323 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 324 325 // Helper for print_xx_report. 326 static void print_vs(outputStream* out, size_t scale); 327 328 public: 329 330 // Collect used metaspace statistics. This involves walking the CLDG. The resulting 331 // output will be the accumulated values for all live metaspaces. 332 // Note: method does not do any locking. 333 static void collect_statistics(metaspace::internals::ClassLoaderMetaspaceStatistics* out); 334 335 // Used by MetaspaceCounters 336 static size_t free_chunks_total_words(); 337 static size_t free_chunks_total_bytes(); 338 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 339 340 static size_t capacity_words() { 341 return capacity_words(Metaspace::NonClassType) + 342 capacity_words(Metaspace::ClassType); 343 } 344 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 345 return capacity_words(mdtype) * BytesPerWord; 346 } 347 static size_t capacity_bytes() { 348 return capacity_words() * BytesPerWord; 349 } 350 351 static size_t used_words() { 352 return used_words(Metaspace::NonClassType) + 353 used_words(Metaspace::ClassType); 354 } 355 static size_t used_bytes(Metaspace::MetadataType mdtype) { 356 return used_words(mdtype) * BytesPerWord; 357 } 358 static size_t used_bytes() { 359 return used_words() * BytesPerWord; 360 } 361 362 // Space committed but yet unclaimed by any class loader. 363 static size_t free_in_vs_bytes(); 364 static size_t free_in_vs_bytes(Metaspace::MetadataType mdtype); 365 366 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 367 static size_t reserved_bytes() { 368 return reserved_bytes(Metaspace::ClassType) + 369 reserved_bytes(Metaspace::NonClassType); 370 } 371 372 static size_t committed_bytes(Metaspace::MetadataType mdtype); 373 static size_t committed_bytes() { 374 return committed_bytes(Metaspace::ClassType) + 375 committed_bytes(Metaspace::NonClassType); 376 } 377 378 static size_t min_chunk_size_words(); 379 static size_t min_chunk_size_bytes() { 380 return min_chunk_size_words() * BytesPerWord; 381 } 382 383 // Flags for print_report(). 384 enum ReportFlag { 385 // Show usage by class loader. 386 rf_show_loaders = (1 << 0), 387 // Breaks report down by chunk type (small, medium, ...). 388 rf_break_down_by_chunktype = (1 << 1), 389 // Breaks report down by space type (anonymous, reflection, ...). 390 rf_break_down_by_spacetype = (1 << 2), 391 // Print details about the underlying virtual spaces. 392 rf_show_vslist = (1 << 3), 393 // Print metaspace map. 394 rf_show_vsmap = (1 << 4) 395 }; 396 397 // This will print out a basic metaspace usage report but 398 // unlike print_report() is guaranteed not to lock or to walk the CLDG. 399 static void print_basic_report(outputStream* st, size_t scale); 400 401 // Prints a report about the current metaspace state. 402 // Optional parts can be enabled via flags. 403 // Function will walk the CLDG and will lock the expand lock; if that is not 404 // convenient, use print_basic_report() instead. 405 static void print_report(outputStream* out, size_t scale = 0, int flags = 0); 406 407 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 408 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 409 410 // Print change in used metadata. 411 static void print_metaspace_change(size_t prev_metadata_used); 412 static void print_on(outputStream * out); 413 414 // Prints an ASCII representation of the given space. 415 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); 416 417 static void dump(outputStream* out); 418 static void verify_free_chunks(); 419 // Check internal counters (capacity, used). 420 static void verify_metrics(); 421 }; 422 423 // Metaspace are deallocated when their class loader are GC'ed. 424 // This class implements a policy for inducing GC's to recover 425 // Metaspaces. 426 427 class MetaspaceGC : AllStatic { 428 429 // The current high-water-mark for inducing a GC. 430 // When committed memory of all metaspaces reaches this value, 431 // a GC is induced and the value is increased. Size is in bytes. 432 static volatile intptr_t _capacity_until_GC; 433 434 // For a CMS collection, signal that a concurrent collection should 435 // be started. 436 static bool _should_concurrent_collect; 437 438 static uint _shrink_factor; 439 440 static size_t shrink_factor() { return _shrink_factor; } 441 void set_shrink_factor(uint v) { _shrink_factor = v; } 442 443 public: 444 445 static void initialize(); 446 static void post_initialize(); 447 448 static size_t capacity_until_GC(); 449 static bool inc_capacity_until_GC(size_t v, 450 size_t* new_cap_until_GC = NULL, 451 size_t* old_cap_until_GC = NULL); 452 static size_t dec_capacity_until_GC(size_t v); 453 454 static bool should_concurrent_collect() { return _should_concurrent_collect; } 455 static void set_should_concurrent_collect(bool v) { 456 _should_concurrent_collect = v; 457 } 458 459 // The amount to increase the high-water-mark (_capacity_until_GC) 460 static size_t delta_capacity_until_GC(size_t bytes); 461 462 // Tells if we have can expand metaspace without hitting set limits. 463 static bool can_expand(size_t words, bool is_class); 464 465 // Returns amount that we can expand without hitting a GC, 466 // measured in words. 467 static size_t allowed_expansion(); 468 469 // Calculate the new high-water mark at which to induce 470 // a GC. 471 static void compute_new_size(); 472 }; 473 474 #endif // SHARE_VM_MEMORY_METASPACE_HPP