/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "classfile/compactHashtable.hpp"

#include "classfile/systemDictionary.hpp"

#include "memory/allocation.hpp"

#include "memory/metaspaceShared.hpp"

#include "memory/universe.hpp"

#include "oops/objArrayKlass.hpp"

#include "oops/oop.hpp"

#include "oops/typeArrayKlass.hpp"

#include "utilities/bitMap.hpp"

#include "utilities/growableArray.hpp"

#include "utilities/resourceHash.hpp"

#if INCLUDE_CDS_JAVA_HEAP

struct ArchivableStaticFieldInfo {

  const char* klass_name;

  const char* field_name;

  InstanceKlass* klass;

  int offset;

  BasicType type;

};

// A dump time sub-graph info for Klass _k. It includes the entry points

// (static fields in _k's mirror) of the archived sub-graphs reachable

// from _k's mirror. It also contains a list of Klasses of the objects

// within the sub-graphs.

class KlassSubGraphInfo: public CHeapObj<mtClass> {

 private:

  // The class that contains the static field(s) as the entry point(s)

  // of archived object sub-graph(s).

  Klass* _k;

  // A list of classes need to be loaded and initialized before the archived

  // object sub-graphs can be accessed at runtime.

  GrowableArray<Klass*>* _subgraph_object_klasses;

  // A list of _k's static fields as the entry points of archived sub-graphs.

  // For each entry field, it is a tuple of field_offset, field_value and

  // is_closed_archive flag.

  GrowableArray<juint>*  _subgraph_entry_fields;

 public:

  KlassSubGraphInfo(Klass* k) :

    _k(k),  _subgraph_object_klasses(NULL),

    _subgraph_entry_fields(NULL) {}

  ~KlassSubGraphInfo() {

    if (_subgraph_object_klasses != NULL) {

      delete _subgraph_object_klasses;

    }

    if (_subgraph_entry_fields != NULL) {

      delete _subgraph_entry_fields;

    }

  };

  Klass* klass()            { return _k; }

  GrowableArray<Klass*>* subgraph_object_klasses() {

    return _subgraph_object_klasses;

  }

  GrowableArray<juint>*  subgraph_entry_fields() {

    return _subgraph_entry_fields;

  }

  void add_subgraph_entry_field(int static_field_offset, oop v,

                                bool is_closed_archive);

  void add_subgraph_object_klass(Klass *orig_k, Klass *relocated_k);

  int num_subgraph_object_klasses() {

    return _subgraph_object_klasses == NULL ? 0 :

           _subgraph_object_klasses->length();

  }

};

// An archived record of object sub-graphs reachable from static

// fields within _k's mirror. The record is reloaded from the archive

// at runtime.

class ArchivedKlassSubGraphInfoRecord {

 private:

  Klass* _k;

  // contains pairs of field offset and value for each subgraph entry field

  Array<juint>* _entry_field_records;

  // klasses of objects in archived sub-graphs referenced from the entry points

  // (static fields) in the containing class

  Array<Klass*>* _subgraph_object_klasses;

 public:

  ArchivedKlassSubGraphInfoRecord() :

    _k(NULL), _entry_field_records(NULL), _subgraph_object_klasses(NULL) {}

  void init(KlassSubGraphInfo* info);

  Klass* klass() const { return _k; }

  Array<juint>*  entry_field_records() const { return _entry_field_records; }

  Array<Klass*>* subgraph_object_klasses() const { return _subgraph_object_klasses; }

};

#endif // INCLUDE_CDS_JAVA_HEAP

class HeapShared: AllStatic {

  friend class VerifySharedOopClosure;

 private:

#if INCLUDE_CDS_JAVA_HEAP

  static bool _closed_archive_heap_region_mapped;

  static bool _open_archive_heap_region_mapped;

  static bool _archive_heap_region_fixed;

  static bool oop_equals(oop const& p1, oop const& p2) {

    return oopDesc::equals(p1, p2);

  }

  static unsigned oop_hash(oop const& p);

  typedef ResourceHashtable<oop, oop,

      HeapShared::oop_hash,

      HeapShared::oop_equals,

      15889, // prime number

      ResourceObj::C_HEAP> ArchivedObjectCache;

  static ArchivedObjectCache* _archived_object_cache;

  static bool klass_equals(Klass* const& p1, Klass* const& p2) {

    return primitive_equals<Klass*>(p1, p2);

  }

  static unsigned klass_hash(Klass* const& klass) {

    return primitive_hash<address>((address)klass);

  }

  class DumpTimeKlassSubGraphInfoTable

    : public ResourceHashtable<Klass*, KlassSubGraphInfo,

                               HeapShared::klass_hash,

                               HeapShared::klass_equals,

                               137, // prime number

                               ResourceObj::C_HEAP> {

  public:

    int _count;

  };

public: // solaris compiler wants this for RunTimeKlassSubGraphInfoTable

  inline static bool record_equals_compact_hashtable_entry(

       const ArchivedKlassSubGraphInfoRecord* value, const Klass* key, int len_unused) {

    return (value->klass() == key);

  }

private:

  typedef OffsetCompactHashtable<

    const Klass*,

    const ArchivedKlassSubGraphInfoRecord*,

    record_equals_compact_hashtable_entry

    > RunTimeKlassSubGraphInfoTable;

  static DumpTimeKlassSubGraphInfoTable* _dump_time_subgraph_info_table;

  static RunTimeKlassSubGraphInfoTable _run_time_subgraph_info_table;

  static void check_closed_archive_heap_region_object(InstanceKlass* k,

                                                      Thread* THREAD);

  static void archive_object_subgraphs(ArchivableStaticFieldInfo fields[],

                                       int num,

                                       bool is_closed_archive,

                                       Thread* THREAD);

  // Archive object sub-graph starting from the given static field

  // in Klass k's mirror.

  static void archive_reachable_objects_from_static_field(

    InstanceKlass* k, const char* klass_name,

    int field_offset, const char* field_name,

    bool is_closed_archive, TRAPS);

  static void verify_subgraph_from_static_field(

    InstanceKlass* k, int field_offset) PRODUCT_RETURN;

  static void verify_reachable_objects_from(oop obj, bool is_archived) PRODUCT_RETURN;

  static void verify_subgraph_from(oop orig_obj) PRODUCT_RETURN;

  static KlassSubGraphInfo* get_subgraph_info(Klass *k);

  static int num_of_subgraph_infos();

  static void build_archived_subgraph_info_records(int num_records);

  static void init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],

                                         int num, Thread* THREAD);

  // Used by decode_from_archive

  static address _narrow_oop_base;

  static int     _narrow_oop_shift;

  typedef ResourceHashtable<oop, bool,

      HeapShared::oop_hash,

      HeapShared::oop_equals,

      15889, // prime number

      ResourceObj::C_HEAP> SeenObjectsTable;

  static SeenObjectsTable *_seen_objects_table;

  static void init_seen_objects_table() {

    assert(_seen_objects_table == NULL, "must be");

    _seen_objects_table = new (ResourceObj::C_HEAP, mtClass)SeenObjectsTable();

  }

  static void delete_seen_objects_table() {

    assert(_seen_objects_table != NULL, "must be");

    delete _seen_objects_table;

    _seen_objects_table = NULL;

  }

  // Statistics (for one round of start_recording_subgraph ... done_recording_subgraph)

  static int _num_new_walked_objs;

  static int _num_new_archived_objs;

  static int _num_old_recorded_klasses;

  // Statistics (for all archived subgraphs)

  static int _num_total_subgraph_recordings;

  static int _num_total_walked_objs;

  static int _num_total_archived_objs;

  static int _num_total_recorded_klasses;

  static int _num_total_verifications;

  static void start_recording_subgraph(InstanceKlass *k, const char* klass_name);

  static void done_recording_subgraph(InstanceKlass *k, const char* klass_name);

  static bool has_been_seen_during_subgraph_recording(oop obj);

  static void set_has_been_seen_during_subgraph_recording(oop obj);

 public:

  static void create_archived_object_cache() {

    _archived_object_cache =

      new (ResourceObj::C_HEAP, mtClass)ArchivedObjectCache();

  }

  static void destroy_archived_object_cache() {

    delete _archived_object_cache;

    _archived_object_cache = NULL;

  }

  static ArchivedObjectCache* archived_object_cache() {

    return _archived_object_cache;

  }

  static oop find_archived_heap_object(oop obj);

  static oop archive_heap_object(oop obj, Thread* THREAD);

  static oop materialize_archived_object(narrowOop v);

  static void archive_klass_objects(Thread* THREAD);

  static void set_archive_heap_region_fixed() {

    _archive_heap_region_fixed = true;

  }

  static bool archive_heap_region_fixed() {

    return _archive_heap_region_fixed;

  }

  static void archive_java_heap_objects(GrowableArray<MemRegion> *closed,

                                        GrowableArray<MemRegion> *open);

  static void copy_closed_archive_heap_objects(GrowableArray<MemRegion> * closed_archive);

  static void copy_open_archive_heap_objects(GrowableArray<MemRegion> * open_archive);

  static oop archive_reachable_objects_from(int level,

                                            KlassSubGraphInfo* subgraph_info,

                                            oop orig_obj,

                                            bool is_closed_archive,

                                            TRAPS);

  static ResourceBitMap calculate_oopmap(MemRegion region);

#endif // INCLUDE_CDS_JAVA_HEAP

 public:

  static bool is_heap_object_archiving_allowed() {

    CDS_JAVA_HEAP_ONLY(return (UseG1GC && UseCompressedOops && UseCompressedClassPointers);)

    NOT_CDS_JAVA_HEAP(return false;)

  }

  static bool is_heap_region(int idx) {

    CDS_JAVA_HEAP_ONLY(return (idx >= MetaspaceShared::first_closed_archive_heap_region &&

                               idx <= MetaspaceShared::last_open_archive_heap_region));

    NOT_CDS_JAVA_HEAP_RETURN_(false);

  }

  static bool is_closed_archive_heap_region(int idx) {

    CDS_JAVA_HEAP_ONLY(return (idx >= MetaspaceShared::first_closed_archive_heap_region &&

                               idx <= MetaspaceShared::last_closed_archive_heap_region));

    NOT_CDS_JAVA_HEAP_RETURN_(false);

  }

  static bool is_open_archive_heap_region(int idx) {

    CDS_JAVA_HEAP_ONLY(return (idx >= MetaspaceShared::first_open_archive_heap_region &&

                               idx <= MetaspaceShared::last_open_archive_heap_region));

    NOT_CDS_JAVA_HEAP_RETURN_(false);

  }

  static void set_closed_archive_heap_region_mapped() {

    CDS_JAVA_HEAP_ONLY(_closed_archive_heap_region_mapped = true);

    NOT_CDS_JAVA_HEAP_RETURN;

  }

  static bool closed_archive_heap_region_mapped() {

    CDS_JAVA_HEAP_ONLY(return _closed_archive_heap_region_mapped);

    NOT_CDS_JAVA_HEAP_RETURN_(false);

  }

  static void set_open_archive_heap_region_mapped() {

    CDS_JAVA_HEAP_ONLY(_open_archive_heap_region_mapped = true);

    NOT_CDS_JAVA_HEAP_RETURN;

  }

  static bool open_archive_heap_region_mapped() {

    CDS_JAVA_HEAP_ONLY(return _open_archive_heap_region_mapped);

    NOT_CDS_JAVA_HEAP_RETURN_(false);

  }

  static void fixup_mapped_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;

  inline static bool is_archived_object(oop p) NOT_CDS_JAVA_HEAP_RETURN_(false);

  static void archive_java_heap_objects() NOT_CDS_JAVA_HEAP_RETURN;

  static char* read_archived_subgraph_infos(char* buffer) NOT_CDS_JAVA_HEAP_RETURN_(buffer);

  static void write_archived_subgraph_infos() NOT_CDS_JAVA_HEAP_RETURN;

  static void initialize_from_archived_subgraph(Klass* k) NOT_CDS_JAVA_HEAP_RETURN;

  // NarrowOops stored in the CDS archive may use a different encoding scheme

  // than Universe::narrow_oop_{base,shift} -- see FileMapInfo::map_heap_regions_impl.

  // To decode them, do not use CompressedOops::decode_not_null. Use this

  // function instead.

  inline static oop decode_from_archive(narrowOop v) NOT_CDS_JAVA_HEAP_RETURN_(NULL);

  static void init_narrow_oop_decoding(address base, int shift) NOT_CDS_JAVA_HEAP_RETURN;

  static void patch_archived_heap_embedded_pointers(MemRegion mem, address  oopmap,

                                                    size_t oopmap_in_bits) NOT_CDS_JAVA_HEAP_RETURN;

  static void init_subgraph_entry_fields(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;

  static void write_subgraph_info_table() NOT_CDS_JAVA_HEAP_RETURN;

  static void serialize_subgraph_info_table_header(SerializeClosure* soc) NOT_CDS_JAVA_HEAP_RETURN;

};