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