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 "utilities/exceptions.hpp" 33 34 // Metaspace 35 // 36 // Metaspaces are Arenas for the VM's metadata. 37 // They are allocated one per class loader object, and one for the null 38 // bootstrap class loader 39 // 40 // block X ---+ +-------------------+ 41 // | | Virtualspace | 42 // | | | 43 // | | | 44 // | |-------------------| 45 // | || Chunk | 46 // | || | 47 // | ||---------- | 48 // +------>||| block 0 | | 49 // ||---------- | 50 // ||| block 1 | | 51 // ||---------- | 52 // || | 53 // |-------------------| 54 // | | 55 // | | 56 // +-------------------+ 57 // 58 59 class ClassLoaderData; 60 class MetaspaceTracer; 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 static bool _initialized; 144 145 public: 146 static metaspace::VirtualSpaceList* space_list() { return _space_list; } 147 static metaspace::VirtualSpaceList* class_space_list() { return _class_space_list; } 148 static metaspace::VirtualSpaceList* get_space_list(MetadataType mdtype) { 149 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 150 return mdtype == ClassType ? class_space_list() : space_list(); 151 } 152 153 static metaspace::ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } 154 static metaspace::ChunkManager* chunk_manager_class() { return _chunk_manager_class; } 155 static metaspace::ChunkManager* get_chunk_manager(MetadataType mdtype) { 156 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); 157 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata(); 158 } 159 160 // convenience function 161 static metaspace::ChunkManager* get_chunk_manager(bool is_class) { 162 return is_class ? chunk_manager_class() : chunk_manager_metadata(); 163 } 164 165 static const MetaspaceTracer* tracer() { return _tracer; } 166 static void freeze() { 167 assert(DumpSharedSpaces, "sanity"); 168 DEBUG_ONLY(_frozen = true;) 169 } 170 static void assert_not_frozen() { 171 assert(!_frozen, "sanity"); 172 } 173 #ifdef _LP64 174 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base); 175 #endif 176 177 private: 178 179 #ifdef _LP64 180 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base); 181 182 // Returns true if can use CDS with metaspace allocated as specified address. 183 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base); 184 185 static void initialize_class_space(ReservedSpace rs); 186 #endif 187 188 public: 189 190 static void ergo_initialize(); 191 static void global_initialize(); 192 static void post_initialize(); 193 194 static void verify_global_initialization(); 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 static bool initialized() { return _initialized; } 228 229 }; 230 231 class MetaspaceUtils : AllStatic { 232 233 // Spacemanager updates running counters. 234 friend class metaspace::SpaceManager; 235 236 // Special access for error reporting (checks without locks). 237 friend class oopDesc; 238 friend class Klass; 239 240 // Running counters for statistics concerning in-use chunks. 241 // Note: capacity = used + free + waste + overhead. Note that we do not 242 // count free and waste. Their sum can be deduces from the three other values. 243 // For more details, one should call print_report() from within a safe point. 244 static size_t _capacity_words [Metaspace:: MetadataTypeCount]; 245 static size_t _overhead_words [Metaspace:: MetadataTypeCount]; 246 static volatile size_t _used_words [Metaspace:: MetadataTypeCount]; 247 248 // Atomically decrement or increment in-use statistic counters 249 static void dec_capacity(Metaspace::MetadataType mdtype, size_t words); 250 static void inc_capacity(Metaspace::MetadataType mdtype, size_t words); 251 static void dec_used(Metaspace::MetadataType mdtype, size_t words); 252 static void inc_used(Metaspace::MetadataType mdtype, size_t words); 253 static void dec_overhead(Metaspace::MetadataType mdtype, size_t words); 254 static void inc_overhead(Metaspace::MetadataType mdtype, size_t words); 255 256 257 // Getters for the in-use counters. 258 static size_t capacity_words(Metaspace::MetadataType mdtype) { return _capacity_words[mdtype]; } 259 static size_t used_words(Metaspace::MetadataType mdtype) { return _used_words[mdtype]; } 260 static size_t overhead_words(Metaspace::MetadataType mdtype) { return _overhead_words[mdtype]; } 261 262 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); 263 264 // Helper for print_xx_report. 265 static void print_vs(outputStream* out, size_t scale); 266 267 public: 268 269 // Collect used metaspace statistics. This involves walking the CLDG. The resulting 270 // output will be the accumulated values for all live metaspaces. 271 // Note: method does not do any locking. 272 static void collect_statistics(metaspace::ClassLoaderMetaspaceStatistics* out); 273 274 // Used by MetaspaceCounters 275 static size_t free_chunks_total_words(); 276 static size_t free_chunks_total_bytes(); 277 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype); 278 279 static size_t capacity_words() { 280 return capacity_words(Metaspace::NonClassType) + 281 capacity_words(Metaspace::ClassType); 282 } 283 static size_t capacity_bytes(Metaspace::MetadataType mdtype) { 284 return capacity_words(mdtype) * BytesPerWord; 285 } 286 static size_t capacity_bytes() { 287 return capacity_words() * BytesPerWord; 288 } 289 290 static size_t used_words() { 291 return used_words(Metaspace::NonClassType) + 292 used_words(Metaspace::ClassType); 293 } 294 static size_t used_bytes(Metaspace::MetadataType mdtype) { 295 return used_words(mdtype) * BytesPerWord; 296 } 297 static size_t used_bytes() { 298 return used_words() * BytesPerWord; 299 } 300 301 // Space committed but yet unclaimed by any class loader. 302 static size_t free_in_vs_bytes(); 303 static size_t free_in_vs_bytes(Metaspace::MetadataType mdtype); 304 305 static size_t reserved_bytes(Metaspace::MetadataType mdtype); 306 static size_t reserved_bytes() { 307 return reserved_bytes(Metaspace::ClassType) + 308 reserved_bytes(Metaspace::NonClassType); 309 } 310 311 static size_t committed_bytes(Metaspace::MetadataType mdtype); 312 static size_t committed_bytes() { 313 return committed_bytes(Metaspace::ClassType) + 314 committed_bytes(Metaspace::NonClassType); 315 } 316 317 static size_t min_chunk_size_words(); 318 319 // Flags for print_report(). 320 enum ReportFlag { 321 // Show usage by class loader. 322 rf_show_loaders = (1 << 0), 323 // Breaks report down by chunk type (small, medium, ...). 324 rf_break_down_by_chunktype = (1 << 1), 325 // Breaks report down by space type (anonymous, reflection, ...). 326 rf_break_down_by_spacetype = (1 << 2), 327 // Print details about the underlying virtual spaces. 328 rf_show_vslist = (1 << 3), 329 // Print metaspace map. 330 rf_show_vsmap = (1 << 4), 331 // If show_loaders: show loaded classes for each loader. 332 rf_show_classes = (1 << 5) 333 }; 334 335 // This will print out a basic metaspace usage report but 336 // unlike print_report() is guaranteed not to lock or to walk the CLDG. 337 static void print_basic_report(outputStream* st, size_t scale); 338 339 // Prints a report about the current metaspace state. 340 // Optional parts can be enabled via flags. 341 // Function will walk the CLDG and will lock the expand lock; if that is not 342 // convenient, use print_basic_report() instead. 343 static void print_report(outputStream* out, size_t scale = 0, int flags = 0); 344 345 static bool has_chunk_free_list(Metaspace::MetadataType mdtype); 346 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); 347 348 // Log change in used metadata. 349 static void print_metaspace_change(const metaspace::MetaspaceSizesSnapshot& pre_meta_values); 350 static void print_on(outputStream * out); 351 352 // Prints an ASCII representation of the given space. 353 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); 354 355 static void dump(outputStream* out); 356 static void verify_free_chunks(); 357 // Check internal counters (capacity, used). 358 static void verify_metrics(); 359 }; 360 361 // Metaspace are deallocated when their class loader are GC'ed. 362 // This class implements a policy for inducing GC's to recover 363 // Metaspaces. 364 365 class MetaspaceGC : AllStatic { 366 367 // The current high-water-mark for inducing a GC. 368 // When committed memory of all metaspaces reaches this value, 369 // a GC is induced and the value is increased. Size is in bytes. 370 static volatile size_t _capacity_until_GC; 371 372 // For a CMS collection, signal that a concurrent collection should 373 // be started. 374 static bool _should_concurrent_collect; 375 376 static uint _shrink_factor; 377 378 static size_t shrink_factor() { return _shrink_factor; } 379 void set_shrink_factor(uint v) { _shrink_factor = v; } 380 381 public: 382 383 static void initialize(); 384 static void post_initialize(); 385 386 static size_t capacity_until_GC(); 387 static bool inc_capacity_until_GC(size_t v, 388 size_t* new_cap_until_GC = NULL, 389 size_t* old_cap_until_GC = NULL, 390 bool* can_retry = NULL); 391 static size_t dec_capacity_until_GC(size_t v); 392 393 static bool should_concurrent_collect() { return _should_concurrent_collect; } 394 static void set_should_concurrent_collect(bool v) { 395 _should_concurrent_collect = v; 396 } 397 398 // The amount to increase the high-water-mark (_capacity_until_GC) 399 static size_t delta_capacity_until_GC(size_t bytes); 400 401 // Tells if we have can expand metaspace without hitting set limits. 402 static bool can_expand(size_t words, bool is_class); 403 404 // Returns amount that we can expand without hitting a GC, 405 // measured in words. 406 static size_t allowed_expansion(); 407 408 // Calculate the new high-water mark at which to induce 409 // a GC. 410 static void compute_new_size(); 411 }; 412 413 #endif // SHARE_MEMORY_METASPACE_HPP