1 /*
  2  * Copyright (c) 2018, 2020, 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_MEMORY_HEAPSHARED_HPP
 26 #define SHARE_MEMORY_HEAPSHARED_HPP
 27 
 28 #include "classfile/compactHashtable.hpp"
 29 #include "classfile/javaClasses.hpp"
 30 #include "classfile/systemDictionary.hpp"
 31 #include "memory/allocation.hpp"
 32 #include "memory/metaspaceShared.hpp"
 33 #include "oops/compressedOops.hpp"
 34 #include "oops/objArrayKlass.hpp"
 35 #include "oops/oop.hpp"
 36 #include "oops/typeArrayKlass.hpp"
 37 #include "utilities/bitMap.hpp"
 38 #include "utilities/growableArray.hpp"
 39 #include "utilities/resourceHash.hpp"
 40 
 41 #if INCLUDE_CDS_JAVA_HEAP
 42 class DumpedInternedStrings;
 43 
 44 struct ArchivableStaticFieldInfo {
 45   const char* klass_name;
 46   const char* field_name;
 47   InstanceKlass* klass;
 48   int offset;
 49   BasicType type;
 50 };
 51 
 52 // A dump time sub-graph info for Klass _k. It includes the entry points
 53 // (static fields in _k's mirror) of the archived sub-graphs reachable
 54 // from _k's mirror. It also contains a list of Klasses of the objects
 55 // within the sub-graphs.
 56 class KlassSubGraphInfo: public CHeapObj<mtClass> {
 57  private:
 58   // The class that contains the static field(s) as the entry point(s)
 59   // of archived object sub-graph(s).
 60   Klass* _k;
 61   // A list of classes need to be loaded and initialized before the archived
 62   // object sub-graphs can be accessed at runtime.
 63   GrowableArray<Klass*>* _subgraph_object_klasses;
 64   // A list of _k's static fields as the entry points of archived sub-graphs.
 65   // For each entry field, it is a tuple of field_offset, field_value and
 66   // is_closed_archive flag.
 67   GrowableArray<int>* _subgraph_entry_fields;
 68 
 69   // Does this KlassSubGraphInfo belong to the arcived full module graph
 70   bool _is_full_module_graph;
 71 
 72   // Does this KlassSubGraphInfo references any classes that were loaded while
 73   // JvmtiExport::is_early_phase()!=true. If so, this KlassSubGraphInfo cannot be
 74   // used at runtime if JVMTI ClassFileLoadHook is enabled.
 75   bool _has_non_early_klasses;
 76   static bool is_non_early_klass(Klass* k);
 77 
 78  public:
 79   KlassSubGraphInfo(Klass* k, bool is_full_module_graph) :
 80     _k(k),  _subgraph_object_klasses(NULL),
 81     _subgraph_entry_fields(NULL),
 82     _is_full_module_graph(is_full_module_graph),
 83     _has_non_early_klasses(false) {}
 84   ~KlassSubGraphInfo() {
 85     if (_subgraph_object_klasses != NULL) {
 86       delete _subgraph_object_klasses;
 87     }
 88     if (_subgraph_entry_fields != NULL) {
 89       delete _subgraph_entry_fields;
 90     }
 91   };
 92 
 93   Klass* klass()            { return _k; }
 94   GrowableArray<Klass*>* subgraph_object_klasses() {
 95     return _subgraph_object_klasses;
 96   }
 97   GrowableArray<int>* subgraph_entry_fields() {
 98     return _subgraph_entry_fields;
 99   }
100   void add_subgraph_entry_field(int static_field_offset, oop v,
101                                 bool is_closed_archive);
102   void add_subgraph_object_klass(Klass *orig_k, Klass *relocated_k);
103   int num_subgraph_object_klasses() {
104     return _subgraph_object_klasses == NULL ? 0 :
105            _subgraph_object_klasses->length();
106   }
107   bool is_full_module_graph() const { return _is_full_module_graph; }
108   bool has_non_early_klasses() const { return _has_non_early_klasses; }
109 };
110 
111 // An archived record of object sub-graphs reachable from static
112 // fields within _k's mirror. The record is reloaded from the archive
113 // at runtime.
114 class ArchivedKlassSubGraphInfoRecord {
115  private:
116   Klass* _k;
117   bool _is_full_module_graph;
118   bool _has_non_early_klasses;
119 
120   // contains pairs of field offset and value for each subgraph entry field
121   Array<int>* _entry_field_records;
122 
123   // klasses of objects in archived sub-graphs referenced from the entry points
124   // (static fields) in the containing class
125   Array<Klass*>* _subgraph_object_klasses;
126  public:
127   ArchivedKlassSubGraphInfoRecord() :
128     _k(NULL), _entry_field_records(NULL), _subgraph_object_klasses(NULL) {}
129   void init(KlassSubGraphInfo* info);
130   Klass* klass() const { return _k; }
131   Array<int>* entry_field_records() const { return _entry_field_records; }
132   Array<Klass*>* subgraph_object_klasses() const { return _subgraph_object_klasses; }
133   bool is_full_module_graph() const { return _is_full_module_graph; }
134   bool has_non_early_klasses() const { return _has_non_early_klasses; }
135 };
136 #endif // INCLUDE_CDS_JAVA_HEAP
137 
138 class HeapShared: AllStatic {
139   friend class VerifySharedOopClosure;
140  private:
141 
142 #if INCLUDE_CDS_JAVA_HEAP
143   static bool _closed_archive_heap_region_mapped;
144   static bool _open_archive_heap_region_mapped;
145   static bool _archive_heap_region_fixed;
146   static DumpedInternedStrings *_dumped_interned_strings;
147 
148 public:
149   static bool oop_equals(oop const& p1, oop const& p2) {
150     return p1 == p2;
151   }
152   static unsigned oop_hash(oop const& p);
153   static unsigned string_oop_hash(oop const& string) {
154     return java_lang_String::hash_code(string);
155   }
156 
157 private:
158   typedef ResourceHashtable<oop, oop,
159       HeapShared::oop_hash,
160       HeapShared::oop_equals,
161       15889, // prime number
162       ResourceObj::C_HEAP> ArchivedObjectCache;
163   static ArchivedObjectCache* _archived_object_cache;
164 
165   static bool klass_equals(Klass* const& p1, Klass* const& p2) {
166     return primitive_equals<Klass*>(p1, p2);
167   }
168 
169   static unsigned klass_hash(Klass* const& klass) {
170     // Generate deterministic hashcode even if SharedBaseAddress is changed due to ASLR.
171     return primitive_hash<address>(address(klass) - SharedBaseAddress);
172   }
173 
174   class DumpTimeKlassSubGraphInfoTable
175     : public ResourceHashtable<Klass*, KlassSubGraphInfo,
176                                HeapShared::klass_hash,
177                                HeapShared::klass_equals,
178                                137, // prime number
179                                ResourceObj::C_HEAP> {
180   public:
181     int _count;
182   };
183 
184 public: // solaris compiler wants this for RunTimeKlassSubGraphInfoTable
185   inline static bool record_equals_compact_hashtable_entry(
186        const ArchivedKlassSubGraphInfoRecord* value, const Klass* key, int len_unused) {
187     return (value->klass() == key);
188   }
189 
190 private:
191   typedef OffsetCompactHashtable<
192     const Klass*,
193     const ArchivedKlassSubGraphInfoRecord*,
194     record_equals_compact_hashtable_entry
195     > RunTimeKlassSubGraphInfoTable;
196 
197   static DumpTimeKlassSubGraphInfoTable* _dump_time_subgraph_info_table;
198   static RunTimeKlassSubGraphInfoTable _run_time_subgraph_info_table;
199 
200   static void check_closed_archive_heap_region_object(InstanceKlass* k,
201                                                       Thread* THREAD);
202 
203   static void archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
204                                        int num,
205                                        bool is_closed_archive,
206                                        bool is_full_module_graph,
207                                        Thread* THREAD);
208 
209   // Archive object sub-graph starting from the given static field
210   // in Klass k's mirror.
211   static void archive_reachable_objects_from_static_field(
212     InstanceKlass* k, const char* klass_name,
213     int field_offset, const char* field_name,
214     bool is_closed_archive, TRAPS);
215 
216   static void verify_subgraph_from_static_field(
217     InstanceKlass* k, int field_offset) PRODUCT_RETURN;
218   static void verify_reachable_objects_from(oop obj, bool is_archived) PRODUCT_RETURN;
219   static void verify_subgraph_from(oop orig_obj) PRODUCT_RETURN;
220 
221   static KlassSubGraphInfo* init_subgraph_info(Klass *k, bool is_full_module_graph);
222   static KlassSubGraphInfo* get_subgraph_info(Klass *k);
223 
224   static void init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
225                                          int num, Thread* THREAD);
226 
227   // Used by decode_from_archive
228   static address _narrow_oop_base;
229   static int     _narrow_oop_shift;
230 
231   typedef ResourceHashtable<oop, bool,
232       HeapShared::oop_hash,
233       HeapShared::oop_equals,
234       15889, // prime number
235       ResourceObj::C_HEAP> SeenObjectsTable;
236 
237   static SeenObjectsTable *_seen_objects_table;
238 
239   static void init_seen_objects_table() {
240     assert(_seen_objects_table == NULL, "must be");
241     _seen_objects_table = new (ResourceObj::C_HEAP, mtClass)SeenObjectsTable();
242   }
243   static void delete_seen_objects_table() {
244     assert(_seen_objects_table != NULL, "must be");
245     delete _seen_objects_table;
246     _seen_objects_table = NULL;
247   }
248 
249   // Statistics (for one round of start_recording_subgraph ... done_recording_subgraph)
250   static int _num_new_walked_objs;
251   static int _num_new_archived_objs;
252   static int _num_old_recorded_klasses;
253 
254   // Statistics (for all archived subgraphs)
255   static int _num_total_subgraph_recordings;
256   static int _num_total_walked_objs;
257   static int _num_total_archived_objs;
258   static int _num_total_recorded_klasses;
259   static int _num_total_verifications;
260 
261   static void start_recording_subgraph(InstanceKlass *k, const char* klass_name,
262                                        bool is_full_module_graph);
263   static void done_recording_subgraph(InstanceKlass *k, const char* klass_name);
264 
265   static bool has_been_seen_during_subgraph_recording(oop obj);
266   static void set_has_been_seen_during_subgraph_recording(oop obj);
267 
268   static void check_module_oop(oop orig_module_obj);
269   static void copy_roots();
270 
271   static void resolve_classes_for_subgraphs(ArchivableStaticFieldInfo fields[],
272                                             int num, TRAPS);
273   static void resolve_classes_for_subgraph_of(Klass* k, TRAPS);
274   static void clear_archived_roots_of(Klass* k);
275   static const ArchivedKlassSubGraphInfoRecord*
276                resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS);
277   static void resolve_or_init(Klass* k, bool do_init, TRAPS);
278   static void init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record, TRAPS);
279  public:
280   static void reset_archived_object_states(TRAPS);
281   static void create_archived_object_cache() {
282     _archived_object_cache =
283       new (ResourceObj::C_HEAP, mtClass)ArchivedObjectCache();
284   }
285   static void destroy_archived_object_cache() {
286     delete _archived_object_cache;
287     _archived_object_cache = NULL;
288   }
289   static ArchivedObjectCache* archived_object_cache() {
290     return _archived_object_cache;
291   }
292 
293   static oop find_archived_heap_object(oop obj);
294   static oop archive_heap_object(oop obj, Thread* THREAD);
295   static oop materialize_archived_object(narrowOop v);
296 
297   static void archive_klass_objects(Thread* THREAD);
298 
299   static void set_archive_heap_region_fixed() {
300     _archive_heap_region_fixed = true;
301   }
302   static bool archive_heap_region_fixed() {
303     return _archive_heap_region_fixed;
304   }
305 
306   static void archive_java_heap_objects(GrowableArray<MemRegion> *closed,
307                                         GrowableArray<MemRegion> *open);
308   static void copy_closed_archive_heap_objects(GrowableArray<MemRegion> * closed_archive);
309   static void copy_open_archive_heap_objects(GrowableArray<MemRegion> * open_archive);
310 
311   static oop archive_reachable_objects_from(int level,
312                                             KlassSubGraphInfo* subgraph_info,
313                                             oop orig_obj,
314                                             bool is_closed_archive,
315                                             TRAPS);
316 
317   static ResourceBitMap calculate_oopmap(MemRegion region);
318   static void add_to_dumped_interned_strings(oop string);
319 
320   // We use the HeapShared::roots() array to make sure that objects stored in the
321   // archived heap regions are not prematurely collected. These roots include:
322   //
323   //    - mirrors of classes that have not yet been loaded.
324   //    - ConstantPool::resolved_references() of classes that have not yet been loaded.
325   //    - ArchivedKlassSubGraphInfoRecords that have not been initialized
326   //    - java.lang.Module objects that have not yet been added to the module graph
327   //
328   // When a mirror M becomes referenced by a newly loaded class K, M will be removed
329   // from HeapShared::roots() via clear_root(), and K will be responsible for
330   // keeping M alive.
331   //
332   // Other types of roots are also cleared similarly when they become referenced.
333 
334   // Dump-time only. Returns the index of the root, which can be used at run time to read
335   // the root using get_root(index, ...).
336   static int append_root(oop obj);
337 
338   // Dump-time and runtime
339   static objArrayOop roots();
340   static oop get_root(int index, bool clear=false);
341 
342   // Run-time only
343   static void set_roots(narrowOop roots);
344   static void clear_root(int index);
345 #endif // INCLUDE_CDS_JAVA_HEAP
346 
347  public:
348   static void run_full_gc_in_vm_thread() NOT_CDS_JAVA_HEAP_RETURN;
349 
350   static bool is_heap_object_archiving_allowed() {
351     CDS_JAVA_HEAP_ONLY(return (UseG1GC && UseCompressedOops && UseCompressedClassPointers);)
352     NOT_CDS_JAVA_HEAP(return false;)
353   }
354 
355   static bool is_heap_region(int idx) {
356     CDS_JAVA_HEAP_ONLY(return (idx >= MetaspaceShared::first_closed_archive_heap_region &&
357                                idx <= MetaspaceShared::last_open_archive_heap_region));
358     NOT_CDS_JAVA_HEAP_RETURN_(false);
359   }
360 
361   static void set_closed_archive_heap_region_mapped() {
362     CDS_JAVA_HEAP_ONLY(_closed_archive_heap_region_mapped = true);
363     NOT_CDS_JAVA_HEAP_RETURN;
364   }
365   static bool closed_archive_heap_region_mapped() {
366     CDS_JAVA_HEAP_ONLY(return _closed_archive_heap_region_mapped);
367     NOT_CDS_JAVA_HEAP_RETURN_(false);
368   }
369   static void set_open_archive_heap_region_mapped() {
370     CDS_JAVA_HEAP_ONLY(_open_archive_heap_region_mapped = true);
371     NOT_CDS_JAVA_HEAP_RETURN;
372   }
373   static bool open_archive_heap_region_mapped() {
374     CDS_JAVA_HEAP_ONLY(return _open_archive_heap_region_mapped);
375     NOT_CDS_JAVA_HEAP_RETURN_(false);
376   }
377   static bool is_mapped() {
378     return closed_archive_heap_region_mapped() && open_archive_heap_region_mapped();
379   }
380 
381   static void fixup_mapped_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;
382 
383   inline static bool is_archived_object(oop p) NOT_CDS_JAVA_HEAP_RETURN_(false);
384 
385   static void resolve_classes(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
386   static void initialize_from_archived_subgraph(Klass* k, TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
387 
388   // NarrowOops stored in the CDS archive may use a different encoding scheme
389   // than CompressedOops::{base,shift} -- see FileMapInfo::map_heap_regions_impl.
390   // To decode them, do not use CompressedOops::decode_not_null. Use this
391   // function instead.
392   inline static oop decode_from_archive(narrowOop v) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
393 
394   static void init_narrow_oop_decoding(address base, int shift) NOT_CDS_JAVA_HEAP_RETURN;
395 
396   static void patch_archived_heap_embedded_pointers(MemRegion mem, address  oopmap,
397                                                     size_t oopmap_in_bits) NOT_CDS_JAVA_HEAP_RETURN;
398 
399   static void init_for_dumping(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
400   static void init_subgraph_entry_fields(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
401   static void write_subgraph_info_table() NOT_CDS_JAVA_HEAP_RETURN;
402   static void serialize_subgraph_info_table_header(SerializeClosure* soc) NOT_CDS_JAVA_HEAP_RETURN;
403 };
404 
405 #if INCLUDE_CDS_JAVA_HEAP
406 class DumpedInternedStrings :
407   public ResourceHashtable<oop, bool,
408                            HeapShared::string_oop_hash,
409                            HeapShared::oop_equals,
410                            15889, // prime number
411                            ResourceObj::C_HEAP>
412 {};
413 #endif
414 
415 #endif // SHARE_MEMORY_HEAPSHARED_HPP