1 /*
  2  * Copyright (c) 2018, 2025, 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 
 25 #ifndef SHARE_CDS_HEAPSHARED_HPP
 26 #define SHARE_CDS_HEAPSHARED_HPP
 27 
 28 #include "cds/cds_globals.hpp"
 29 #include "cds/dumpTimeClassInfo.hpp"
 30 #include "cds/metaspaceShared.hpp"
 31 #include "classfile/compactHashtable.hpp"
 32 #include "classfile/javaClasses.hpp"
 33 #include "gc/shared/gc_globals.hpp"
 34 #include "memory/allocation.hpp"
 35 #include "memory/allStatic.hpp"
 36 #include "oops/compressedOops.hpp"
 37 #include "oops/oop.hpp"
 38 #include "oops/oopHandle.hpp"
 39 #include "oops/oopsHierarchy.hpp"
 40 #include "utilities/growableArray.hpp"
 41 #include "utilities/resourceHash.hpp"
 42 
 43 #if INCLUDE_CDS_JAVA_HEAP
 44 class DumpedInternedStrings;
 45 class FileMapInfo;
 46 class KlassSubGraphInfo;
 47 class MetaspaceObjToOopHandleTable;
 48 class ResourceBitMap;
 49 
 50 struct ArchivableStaticFieldInfo;
 51 class ArchiveHeapInfo;
 52 
 53 #define ARCHIVED_BOOT_LAYER_CLASS "jdk/internal/module/ArchivedBootLayer"
 54 #define ARCHIVED_BOOT_LAYER_FIELD "archivedBootLayer"
 55 
 56 // A dump time sub-graph info for Klass _k. It includes the entry points
 57 // (static fields in _k's mirror) of the archived sub-graphs reachable
 58 // from _k's mirror. It also contains a list of Klasses of the objects
 59 // within the sub-graphs.
 60 class KlassSubGraphInfo: public CHeapObj<mtClass> {
 61  private:
 62   // The class that contains the static field(s) as the entry point(s)
 63   // of archived object sub-graph(s).
 64   Klass* _k;
 65   // A list of classes need to be loaded and initialized before the archived
 66   // object sub-graphs can be accessed at runtime.
 67   GrowableArray<Klass*>* _subgraph_object_klasses;
 68   // A list of _k's static fields as the entry points of archived sub-graphs.
 69   // For each entry field, it is a tuple of field_offset, field_value
 70   GrowableArray<int>* _subgraph_entry_fields;
 71 
 72   // Does this KlassSubGraphInfo belong to the archived full module graph
 73   bool _is_full_module_graph;
 74 
 75   // Does this KlassSubGraphInfo references any classes that were loaded while
 76   // JvmtiExport::is_early_phase()!=true. If so, this KlassSubGraphInfo cannot be
 77   // used at runtime if JVMTI ClassFileLoadHook is enabled.
 78   bool _has_non_early_klasses;
 79   static bool is_non_early_klass(Klass* k);
 80   static void check_allowed_klass(InstanceKlass* ik);
 81  public:
 82   KlassSubGraphInfo(Klass* k, bool is_full_module_graph) :
 83     _k(k),  _subgraph_object_klasses(nullptr),
 84     _subgraph_entry_fields(nullptr),
 85     _is_full_module_graph(is_full_module_graph),
 86     _has_non_early_klasses(false) {}
 87 
 88   ~KlassSubGraphInfo() {
 89     if (_subgraph_object_klasses != nullptr) {
 90       delete _subgraph_object_klasses;
 91     }
 92     if (_subgraph_entry_fields != nullptr) {
 93       delete _subgraph_entry_fields;
 94     }
 95   };
 96 
 97   Klass* klass()            { return _k; }
 98   GrowableArray<Klass*>* subgraph_object_klasses() {
 99     return _subgraph_object_klasses;
100   }
101   GrowableArray<int>* subgraph_entry_fields() {
102     return _subgraph_entry_fields;
103   }
104   void add_subgraph_entry_field(int static_field_offset, oop v);
105   void add_subgraph_object_klass(Klass *orig_k);
106   int num_subgraph_object_klasses() {
107     return _subgraph_object_klasses == nullptr ? 0 :
108            _subgraph_object_klasses->length();
109   }
110   bool is_full_module_graph() const { return _is_full_module_graph; }
111   bool has_non_early_klasses() const { return _has_non_early_klasses; }
112 };
113 
114 // An archived record of object sub-graphs reachable from static
115 // fields within _k's mirror. The record is reloaded from the archive
116 // at runtime.
117 class ArchivedKlassSubGraphInfoRecord {
118  private:
119   Klass* _k;
120   bool _is_full_module_graph;
121   bool _has_non_early_klasses;
122 
123   // contains pairs of field offset and value for each subgraph entry field
124   Array<int>* _entry_field_records;
125 
126   // klasses of objects in archived sub-graphs referenced from the entry points
127   // (static fields) in the containing class
128   Array<Klass*>* _subgraph_object_klasses;
129  public:
130   ArchivedKlassSubGraphInfoRecord() :
131     _k(nullptr), _entry_field_records(nullptr), _subgraph_object_klasses(nullptr) {}
132   void init(KlassSubGraphInfo* info);
133   Klass* klass() const { return _k; }
134   Array<int>* entry_field_records() const { return _entry_field_records; }
135   Array<Klass*>* subgraph_object_klasses() const { return _subgraph_object_klasses; }
136   bool is_full_module_graph() const { return _is_full_module_graph; }
137   bool has_non_early_klasses() const { return _has_non_early_klasses; }
138 };
139 #endif // INCLUDE_CDS_JAVA_HEAP
140 
141 struct LoadedArchiveHeapRegion;
142 
143 class HeapShared: AllStatic {
144   friend class VerifySharedOopClosure;
145 
146 public:
147   static bool is_subgraph_root_class(InstanceKlass* ik);
148 
149   // Scratch objects for archiving Klass::java_mirror()
150   static oop scratch_java_mirror(BasicType t)     NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
151   static oop scratch_java_mirror(Klass* k)        NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
152   static oop scratch_java_mirror(oop java_mirror) NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
153   static bool is_archived_boot_layer_available(JavaThread* current) NOT_CDS_JAVA_HEAP_RETURN_(false);
154 
155 private:
156 #if INCLUDE_CDS_JAVA_HEAP
157   static DumpedInternedStrings *_dumped_interned_strings;
158 
159   // statistics
160   constexpr static int ALLOC_STAT_SLOTS = 16;
161   static size_t _alloc_count[ALLOC_STAT_SLOTS];
162   static size_t _alloc_size[ALLOC_STAT_SLOTS];
163   static size_t _total_obj_count;
164   static size_t _total_obj_size; // in HeapWords
165 
166   static void count_allocation(size_t size);
167   static void print_stats();
168 public:
169   static void debug_trace();
170   static unsigned oop_hash(oop const& p);
171   static unsigned oop_handle_hash(OopHandle const& oh);
172   static unsigned oop_handle_hash_raw(OopHandle const& oh);
173   static bool oop_handle_equals(const OopHandle& a, const OopHandle& b);
174   static unsigned string_oop_hash(oop const& string) {
175     return java_lang_String::hash_code(string);
176   }
177 
178   class CopyKlassSubGraphInfoToArchive;
179 
180   class CachedOopInfo {
181     // Used by CDSHeapVerifier.
182     OopHandle _orig_referrer;
183 
184     // The location of this object inside ArchiveHeapWriter::_buffer
185     size_t _buffer_offset;
186 
187     // One or more fields in this object are pointing to non-null oops.
188     bool _has_oop_pointers;
189 
190     // One or more fields in this object are pointing to MetaspaceObj
191     bool _has_native_pointers;
192   public:
193     CachedOopInfo(OopHandle orig_referrer, bool has_oop_pointers)
194       : _orig_referrer(orig_referrer),
195         _buffer_offset(0),
196         _has_oop_pointers(has_oop_pointers),
197         _has_native_pointers(false) {}
198     oop orig_referrer() const;
199     void set_buffer_offset(size_t offset) { _buffer_offset = offset; }
200     size_t buffer_offset()          const { return _buffer_offset;   }
201     bool has_oop_pointers()         const { return _has_oop_pointers; }
202     bool has_native_pointers()      const { return _has_native_pointers; }
203     void set_has_native_pointers()        { _has_native_pointers = true; }
204   };
205 
206 private:
207   static const int INITIAL_TABLE_SIZE = 15889; // prime number
208   static const int MAX_TABLE_SIZE     = 1000000;
209   typedef ResizeableResourceHashtable<OopHandle, CachedOopInfo,
210       AnyObj::C_HEAP,
211       mtClassShared,
212       HeapShared::oop_handle_hash_raw,
213       HeapShared::oop_handle_equals> ArchivedObjectCache;
214   static ArchivedObjectCache* _archived_object_cache;
215 
216   class DumpTimeKlassSubGraphInfoTable
217     : public ResourceHashtable<Klass*, KlassSubGraphInfo,
218                                137, // prime number
219                                AnyObj::C_HEAP,
220                                mtClassShared,
221                                DumpTimeSharedClassTable_hash> {
222   public:
223     int _count;
224   };
225 
226 public: // solaris compiler wants this for RunTimeKlassSubGraphInfoTable
227   inline static bool record_equals_compact_hashtable_entry(
228        const ArchivedKlassSubGraphInfoRecord* value, const Klass* key, int len_unused) {
229     return (value->klass() == key);
230   }
231 
232 private:
233   typedef OffsetCompactHashtable<
234     const Klass*,
235     const ArchivedKlassSubGraphInfoRecord*,
236     record_equals_compact_hashtable_entry
237     > RunTimeKlassSubGraphInfoTable;
238 
239   static DumpTimeKlassSubGraphInfoTable* _dump_time_subgraph_info_table;
240   static RunTimeKlassSubGraphInfoTable _run_time_subgraph_info_table;
241 
242   static CachedOopInfo make_cached_oop_info(oop obj, oop referrer);
243   static ArchivedKlassSubGraphInfoRecord* archive_subgraph_info(KlassSubGraphInfo* info);
244   static void archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
245                                        bool is_full_module_graph);
246 
247   // Archive object sub-graph starting from the given static field
248   // in Klass k's mirror.
249   static void archive_reachable_objects_from_static_field(
250     InstanceKlass* k, const char* klass_name,
251     int field_offset, const char* field_name);
252 
253   static void verify_subgraph_from_static_field(
254     InstanceKlass* k, int field_offset) PRODUCT_RETURN;
255   static void verify_reachable_objects_from(oop obj) PRODUCT_RETURN;
256   static void verify_subgraph_from(oop orig_obj) PRODUCT_RETURN;
257   static void check_special_subgraph_classes();
258 
259   static KlassSubGraphInfo* init_subgraph_info(Klass *k, bool is_full_module_graph);
260   static KlassSubGraphInfo* get_subgraph_info(Klass *k);
261 
262   static void init_subgraph_entry_fields(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
263   static void init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[], TRAPS);
264 
265   // UseCompressedOops only: Used by decode_from_archive
266   static address _narrow_oop_base;
267   static int     _narrow_oop_shift;
268 
269   // !UseCompressedOops only: used to relocate pointers to the archived objects
270   static ptrdiff_t _runtime_delta;
271 
272   typedef ResizeableResourceHashtable<oop, bool,
273       AnyObj::C_HEAP,
274       mtClassShared,
275       HeapShared::oop_hash> SeenObjectsTable;
276 
277   static SeenObjectsTable *_seen_objects_table;
278   // The "special subgraph" contains all the archived objects that are reachable
279   // from the following roots:
280   //    - interned strings
281   //    - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
282   //    - ConstantPool::resolved_references()
283   //    - Universe::<xxx>_exception_instance()
284   static KlassSubGraphInfo* _dump_time_special_subgraph;              // for collecting info during dump time
285   static ArchivedKlassSubGraphInfoRecord* _run_time_special_subgraph; // for initializing classes during run time.
286 
287   static GrowableArrayCHeap<OopHandle, mtClassShared>* _pending_roots;
288   static GrowableArrayCHeap<OopHandle, mtClassShared>* _root_segments;
289   static GrowableArrayCHeap<const char*, mtClassShared>* _context; // for debugging unarchivable objects
290   static int _root_segment_max_size_elems;
291   static OopHandle _scratch_basic_type_mirrors[T_VOID+1];
292   static MetaspaceObjToOopHandleTable* _scratch_objects_table;
293 
294   static void init_seen_objects_table() {
295     assert(_seen_objects_table == nullptr, "must be");
296     _seen_objects_table = new (mtClass)SeenObjectsTable(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
297   }
298   static void delete_seen_objects_table() {
299     assert(_seen_objects_table != nullptr, "must be");
300     delete _seen_objects_table;
301     _seen_objects_table = nullptr;
302   }
303 
304   class ContextMark;
305 
306   // Statistics (for one round of start_recording_subgraph ... done_recording_subgraph)
307   static int _num_new_walked_objs;
308   static int _num_new_archived_objs;
309   static int _num_old_recorded_klasses;
310 
311   // Statistics (for all archived subgraphs)
312   static int _num_total_subgraph_recordings;
313   static int _num_total_walked_objs;
314   static int _num_total_archived_objs;
315   static int _num_total_recorded_klasses;
316   static int _num_total_verifications;
317 
318   static void start_recording_subgraph(InstanceKlass *k, const char* klass_name,
319                                        bool is_full_module_graph);
320   static void done_recording_subgraph(InstanceKlass *k, const char* klass_name);
321 
322   static bool has_been_seen_during_subgraph_recording(oop obj);
323   static void set_has_been_seen_during_subgraph_recording(oop obj);
324   static bool archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info);
325 
326   static void resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]);
327   static void resolve_classes_for_subgraph_of(JavaThread* current, Klass* k);
328   static void clear_archived_roots_of(Klass* k);
329   static const ArchivedKlassSubGraphInfoRecord*
330                resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS);
331   static void resolve_or_init(const char* klass_name, bool do_init, TRAPS);
332   static void resolve_or_init(Klass* k, bool do_init, TRAPS);
333   static void init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record);
334 
335   static int init_loaded_regions(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_regions,
336                                  MemRegion& archive_space);
337   static void sort_loaded_regions(LoadedArchiveHeapRegion* loaded_regions, int num_loaded_regions,
338                                   uintptr_t buffer);
339   static bool load_regions(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_regions,
340                            int num_loaded_regions, uintptr_t buffer);
341   static void init_loaded_heap_relocation(LoadedArchiveHeapRegion* reloc_info,
342                                           int num_loaded_regions);
343   static void fill_failed_loaded_region();
344   static void mark_native_pointers(oop orig_obj);
345   static void prepare_resolved_references();
346   static void archive_strings();
347   static void archive_subgraphs();
348 
349   // PendingOop and PendingOopStack are used for recursively discovering all cacheable
350   // heap objects. The recursion is done using PendingOopStack so we won't overflow the
351   // C stack with deep reference chains.
352   class PendingOop {
353     oop _obj;
354     oop _referrer;
355     int _level;
356 
357   public:
358     PendingOop() : _obj(nullptr), _referrer(nullptr), _level(-1) {}
359     PendingOop(oop obj, oop referrer, int level) : _obj(obj), _referrer(referrer), _level(level) {}
360 
361     oop obj()      const { return _obj; }
362     oop referrer() const { return _referrer; }
363     int level()    const { return _level; }
364   };
365 
366   class OopFieldPusher;
367   using PendingOopStack = GrowableArrayCHeap<PendingOop, mtClassShared>;
368 
369   static PendingOop _object_being_archived;
370   static bool walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
371                               oop orig_obj, oop referrer);
372 
373  public:
374   static void exit_on_error();
375   static void reset_archived_object_states(TRAPS);
376   static void create_archived_object_cache() {
377     _archived_object_cache =
378       new (mtClass)ArchivedObjectCache(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
379   }
380   static void destroy_archived_object_cache() {
381     delete _archived_object_cache;
382     _archived_object_cache = nullptr;
383   }
384   static ArchivedObjectCache* archived_object_cache() {
385     return _archived_object_cache;
386   }
387 
388   static CachedOopInfo* get_cached_oop_info(oop orig_obj) {
389     OopHandle oh(&orig_obj);
390     return _archived_object_cache->get(oh);
391   }
392 
393   static int archive_exception_instance(oop exception);
394 
395   static bool archive_reachable_objects_from(int level,
396                                              KlassSubGraphInfo* subgraph_info,
397                                              oop orig_obj);
398 
399   static void add_to_dumped_interned_strings(oop string);
400   static bool is_dumped_interned_string(oop o);
401 
402   static void track_scratch_object(oop orig_obj, oop scratch_obj);
403 
404   // Scratch objects for archiving Klass::java_mirror()
405   static void set_scratch_java_mirror(Klass* k, oop mirror);
406   static void remove_scratch_objects(Klass* k);
407   static void get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers);
408   static void set_has_native_pointers(oop src_obj);
409 
410   // We use the HeapShared::roots() array to make sure that objects stored in the
411   // archived heap region are not prematurely collected. These roots include:
412   //
413   //    - mirrors of classes that have not yet been loaded.
414   //    - ConstantPool::resolved_references() of classes that have not yet been loaded.
415   //    - ArchivedKlassSubGraphInfoRecords that have not been initialized
416   //    - java.lang.Module objects that have not yet been added to the module graph
417   //
418   // When a mirror M becomes referenced by a newly loaded class K, M will be removed
419   // from HeapShared::roots() via clear_root(), and K will be responsible for
420   // keeping M alive.
421   //
422   // Other types of roots are also cleared similarly when they become referenced.
423 
424   // Dump-time only. Returns the index of the root, which can be used at run time to read
425   // the root using get_root(index, ...).
426   static int append_root(oop obj);
427   static GrowableArrayCHeap<OopHandle, mtClassShared>* pending_roots() { return _pending_roots; }
428 
429   // Dump-time and runtime
430   static objArrayOop root_segment(int segment_idx);
431   static oop get_root(int index, bool clear=false);
432 
433   // Run-time only
434   static void clear_root(int index);
435   static void get_segment_indexes(int index, int& segment_index, int& internal_index);
436   static void setup_test_class(const char* test_class_name) PRODUCT_RETURN;
437 #endif // INCLUDE_CDS_JAVA_HEAP
438 
439  public:
440   static bool has_been_archived(oop orig_obj);
441   static oop orig_to_scratch_object(oop orig_obj);
442   static void write_heap(ArchiveHeapInfo* heap_info) NOT_CDS_JAVA_HEAP_RETURN;
443   static objArrayOop scratch_resolved_references(ConstantPool* src);
444   static void add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) NOT_CDS_JAVA_HEAP_RETURN;
445   static void init_dumping() NOT_CDS_JAVA_HEAP_RETURN;
446   static void init_scratch_objects_for_basic_type_mirrors(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
447   static void init_box_classes(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
448   static bool is_heap_region(int idx) {
449     CDS_JAVA_HEAP_ONLY(return (idx == MetaspaceShared::hp);)
450     NOT_CDS_JAVA_HEAP_RETURN_(false);
451   }
452   static void rehash_archived_object_cache() NOT_CDS_JAVA_HEAP_RETURN;
453   static void delete_tables_with_raw_oops() NOT_CDS_JAVA_HEAP_RETURN;
454 
455   static void resolve_classes(JavaThread* current) NOT_CDS_JAVA_HEAP_RETURN;
456   static void initialize_from_archived_subgraph(JavaThread* current, Klass* k) NOT_CDS_JAVA_HEAP_RETURN;
457 
458   static void init_for_dumping(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
459   static void write_subgraph_info_table() NOT_CDS_JAVA_HEAP_RETURN;
460   static void add_root_segment(objArrayOop segment_oop) NOT_CDS_JAVA_HEAP_RETURN;
461   static void init_root_segment_sizes(int max_size_elems) NOT_CDS_JAVA_HEAP_RETURN;
462   static void serialize_tables(SerializeClosure* soc) NOT_CDS_JAVA_HEAP_RETURN;
463 
464 #ifndef PRODUCT
465   static bool is_a_test_class_in_unnamed_module(Klass* ik) NOT_CDS_JAVA_HEAP_RETURN_(false);
466   static void initialize_test_class_from_archive(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
467 #endif
468 
469   static void add_to_permanent_oop_table(oop obj, int offset);
470 
471   // AOT-compile time only: get a stable index for an archived object.
472   // Returns 0 if obj is not archived.
473   static int get_archived_object_permanent_index(oop obj) NOT_CDS_JAVA_HEAP_RETURN_(-1);
474   // Runtime only: get back the same object for an index returned by
475   // get_archived_object_permanent_index().
476   static oop get_archived_object(int permanent_index) NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
477 
478   static void initialize_java_lang_invoke(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
479   static void init_classes_for_special_subgraph(Handle loader, TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
480 
481   static bool is_lambda_form_klass(InstanceKlass* ik) NOT_CDS_JAVA_HEAP_RETURN_(false);
482   static bool is_lambda_proxy_klass(InstanceKlass* ik) NOT_CDS_JAVA_HEAP_RETURN_(false);
483   static bool is_string_concat_klass(InstanceKlass* ik) NOT_CDS_JAVA_HEAP_RETURN_(false);
484   static bool is_archivable_hidden_klass(InstanceKlass* ik) NOT_CDS_JAVA_HEAP_RETURN_(false);
485 
486   // Used by AOTArtifactFinder
487   static void start_scanning_for_oops();
488   static void end_scanning_for_oops();
489   static void scan_java_class(Klass* k);
490   static void scan_java_mirror(oop orig_mirror);
491   static void copy_and_rescan_aot_inited_mirror(InstanceKlass* ik);
492 };
493 
494 class CachedCodeDirectoryInternal {
495   int _permanent_oop_count;
496   int* _permanent_oop_offsets; // offset of each permanent object from the bottom of the archived heap
497 public:
498   void dumptime_init_internal() NOT_CDS_JAVA_HEAP_RETURN;
499   void runtime_init_internal() NOT_CDS_JAVA_HEAP_RETURN;
500 };
501 
502 #if INCLUDE_CDS_JAVA_HEAP
503 class DumpedInternedStrings :
504   public ResizeableResourceHashtable<oop, bool,
505                            AnyObj::C_HEAP,
506                            mtClassShared,
507                            HeapShared::string_oop_hash>
508 {
509 public:
510   DumpedInternedStrings(unsigned size, unsigned max_size) :
511     ResizeableResourceHashtable<oop, bool,
512                                 AnyObj::C_HEAP,
513                                 mtClassShared,
514                                 HeapShared::string_oop_hash>(size, max_size) {}
515 };
516 #endif
517 
518 #endif // SHARE_CDS_HEAPSHARED_HPP