/*

 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

 * 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 "precompiled.hpp"

#include "classfile/javaClasses.inline.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/vmSymbols.hpp"

#include "logging/log.hpp"

#include "logging/logMessage.hpp"

#include "logging/logStream.hpp"

#include "memory/heapShared.inline.hpp"

#include "memory/iterator.inline.hpp"

#include "memory/metadataFactory.hpp"

#include "memory/metaspaceClosure.hpp"

#include "memory/resourceArea.hpp"

#include "oops/compressedOops.inline.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/fieldDescriptor.inline.hpp"

#include "utilities/bitMap.inline.hpp"

#if INCLUDE_CDS_JAVA_HEAP

address   HeapShared::_narrow_oop_base;

int       HeapShared::_narrow_oop_shift;

HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = NULL;

HeapShared::RunTimeKlassSubGraphInfoTable   HeapShared::_run_time_subgraph_info_table;

// Get the subgraph_info for Klass k. A new subgraph_info is created if

// there is no existing one for k. The subgraph_info records the relocated

// Klass* of the original k.

KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {

  assert(DumpSharedSpaces, "dump time only");

  Klass* relocated_k = MetaspaceShared::get_relocated_klass(k);

  KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(relocated_k);

  if (info == NULL) {

    _dump_time_subgraph_info_table->put(relocated_k, KlassSubGraphInfo(relocated_k));

    info = _dump_time_subgraph_info_table->get(relocated_k);

    ++ _dump_time_subgraph_info_table->_count;

  }

  return info;

}

// Add an entry field to the current KlassSubGraphInfo.

void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {

  assert(DumpSharedSpaces, "dump time only");

  if (_subgraph_entry_fields == NULL) {

    _subgraph_entry_fields =

      new(ResourceObj::C_HEAP, mtClass) GrowableArray<juint>(10, true);

  }

  _subgraph_entry_fields->append((juint)static_field_offset);

  _subgraph_entry_fields->append(CompressedOops::encode(v));

}

// Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.

// Only objects of boot classes can be included in sub-graph.

void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k, Klass *relocated_k) {

  assert(DumpSharedSpaces, "dump time only");

  assert(relocated_k == MetaspaceShared::get_relocated_klass(orig_k),

         "must be the relocated Klass in the shared space");

  if (_subgraph_object_klasses == NULL) {

    _subgraph_object_klasses =

      new(ResourceObj::C_HEAP, mtClass) GrowableArray<Klass*>(50, true);

  }

  assert(relocated_k->is_shared(), "must be a shared class");

  if (_k == relocated_k) {

    // Don't add the Klass containing the sub-graph to it's own klass

    // initialization list.

    return;

  }

  if (relocated_k->is_instance_klass()) {

    assert(InstanceKlass::cast(relocated_k)->is_shared_boot_class(),

          "must be boot class");

    // SystemDictionary::xxx_klass() are not updated, need to check

    // the original Klass*

    if (orig_k == SystemDictionary::String_klass() ||

        orig_k == SystemDictionary::Object_klass()) {

      // Initialized early during VM initialization. No need to be added

      // to the sub-graph object class list.

      return;

    }

  } else if (relocated_k->is_objArray_klass()) {

    Klass* abk = ObjArrayKlass::cast(relocated_k)->bottom_klass();

    if (abk->is_instance_klass()) {

      assert(InstanceKlass::cast(abk)->is_shared_boot_class(),

            "must be boot class");

    }

    if (relocated_k == Universe::objectArrayKlassObj()) {

      // Initialized early during Universe::genesis. No need to be added

      // to the list.

      return;

    }

  } else {

    assert(relocated_k->is_typeArray_klass(), "must be");

    // Primitive type arrays are created early during Universe::genesis.

    return;

  }

  if (log_is_enabled(Debug, cds, heap)) {

    if (!_subgraph_object_klasses->contains(relocated_k)) {

      ResourceMark rm;

      log_debug(cds, heap)("Adding klass %s", orig_k->external_name());

    }

  }

  _subgraph_object_klasses->append_if_missing(relocated_k);

}

// Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.

void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {

  _k = info->klass();

  _entry_field_records = NULL;

  _subgraph_object_klasses = NULL;

  // populate the entry fields

  GrowableArray<juint>* entry_fields = info->subgraph_entry_fields();

  if (entry_fields != NULL) {

    int num_entry_fields = entry_fields->length();

    assert(num_entry_fields % 2 == 0, "sanity");

    _entry_field_records =

      MetaspaceShared::new_ro_array<juint>(num_entry_fields);

    for (int i = 0 ; i < num_entry_fields; i++) {

      _entry_field_records->at_put(i, entry_fields->at(i));

    }

  }

  // the Klasses of the objects in the sub-graphs

  GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();

  if (subgraph_object_klasses != NULL) {

    int num_subgraphs_klasses = subgraph_object_klasses->length();

    _subgraph_object_klasses =

      MetaspaceShared::new_ro_array<Klass*>(num_subgraphs_klasses);

    for (int i = 0; i < num_subgraphs_klasses; i++) {

      Klass* subgraph_k = subgraph_object_klasses->at(i);

      if (log_is_enabled(Info, cds, heap)) {

        ResourceMark rm;

        log_info(cds, heap)(

          "Archived object klass %s (%2d) => %s",

          _k->external_name(), i, subgraph_k->external_name());

      }

      _subgraph_object_klasses->at_put(i, subgraph_k);

    }

  }

}

struct CopyKlassSubGraphInfoToArchive : StackObj {

  CompactHashtableWriter* _writer;

  CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}

  bool do_entry(Klass* klass, KlassSubGraphInfo& info) {

    if (info.subgraph_object_klasses() != NULL || info.subgraph_entry_fields() != NULL) {

      ArchivedKlassSubGraphInfoRecord* record =

        (ArchivedKlassSubGraphInfoRecord*)MetaspaceShared::read_only_space_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));

      record->init(&info);

      unsigned int hash = primitive_hash<Klass*>(klass);

      uintx deltax = MetaspaceShared::object_delta(record);

      guarantee(deltax <= MAX_SHARED_DELTA, "must not be");

      u4 delta = u4(deltax);

      _writer->add(hash, delta);

    }

    return true; // keep on iterating

  }

};

// Build the records of archived subgraph infos, which include:

// - Entry points to all subgraphs from the containing class mirror. The entry

//   points are static fields in the mirror. For each entry point, the field

//   offset and value are recorded in the sub-graph info. The value are stored

//   back to the corresponding field at runtime.

// - A list of klasses that need to be loaded/initialized before archived

//   java object sub-graph can be accessed at runtime.

void HeapShared::write_subgraph_info_table() {

  // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.

  DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;

  CompactHashtableStats stats;

  _run_time_subgraph_info_table.reset();

  int num_buckets = CompactHashtableWriter::default_num_buckets(d_table->_count);

  CompactHashtableWriter writer(num_buckets, &stats);

  CopyKlassSubGraphInfoToArchive copy(&writer);

  _dump_time_subgraph_info_table->iterate(&copy);

  writer.dump(&_run_time_subgraph_info_table, "subgraphs");

}

void HeapShared::serialize_subgraph_info_table_header(SerializeClosure* soc) {

  _run_time_subgraph_info_table.serialize_header(soc);

}

void HeapShared::initialize_from_archived_subgraph(Klass* k) {

    return; // nothing to do

  }

  assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");

  unsigned int hash = primitive_hash<Klass*>(k);

  ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);

  // Initialize from archived data. Currently this is done only

  // during VM initialization time. No lock is needed.

  if (record != NULL) {

    Thread* THREAD = Thread::current();

    if (log_is_enabled(Info, cds, heap)) {

      ResourceMark rm;

      log_info(cds, heap)("initialize_from_archived_subgraph " PTR_FORMAT " %s", p2i(k),

                          k->external_name());

    }

    int i;

    // Load/link/initialize the klasses of the objects in the subgraph.

    // NULL class loader is used.

    Array<Klass*>* klasses = record->subgraph_object_klasses();

    if (klasses != NULL) {

      for (i = 0; i < klasses->length(); i++) {

        Klass* obj_k = klasses->at(i);

        Klass* resolved_k = SystemDictionary::resolve_or_null(

                                              (obj_k)->name(), THREAD);

        if (resolved_k != obj_k) {

          return;

        }

        if ((obj_k)->is_instance_klass()) {

          InstanceKlass* ik = InstanceKlass::cast(obj_k);

          ik->initialize(THREAD);

        } else if ((obj_k)->is_objArray_klass()) {

          ObjArrayKlass* oak = ObjArrayKlass::cast(obj_k);

          oak->initialize(THREAD);

        }

      }

    }

    if (HAS_PENDING_EXCEPTION) {

      CLEAR_PENDING_EXCEPTION;

      // None of the field value will be set if there was an exception.

      // The java code will not see any of the archived objects in the

      // subgraphs referenced from k in this case.

      return;

    }

    // Load the subgraph entry fields from the record and store them back to

    // the corresponding fields within the mirror.

    oop m = k->java_mirror();

    Array<juint>* entry_field_records = record->entry_field_records();

    if (entry_field_records != NULL) {

      int efr_len = entry_field_records->length();

      assert(efr_len % 2 == 0, "sanity");

      for (i = 0; i < efr_len;) {

        int field_offset = entry_field_records->at(i);

        // The object refereced by the field becomes 'known' by GC from this

        // point. All objects in the subgraph reachable from the object are

        // also 'known' by GC.

        m->obj_field_put(field_offset, v);

        i += 2;

        log_debug(cds, heap)("  " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));

      }

    // Done. Java code can see the archived sub-graphs referenced from k's

    // mirror after this point.

    }

  }

}

class WalkOopAndArchiveClosure: public BasicOopIterateClosure {

  int _level;

  bool _record_klasses_only;

  KlassSubGraphInfo* _subgraph_info;

  oop _orig_referencing_obj;

  oop _archived_referencing_obj;

  Thread* _thread;

 public:

  WalkOopAndArchiveClosure(int level, bool record_klasses_only,

                           KlassSubGraphInfo* subgraph_info,

                           oop orig, oop archived, TRAPS) :

    _level(level), _record_klasses_only(record_klasses_only),

    _subgraph_info(subgraph_info),

    _orig_referencing_obj(orig), _archived_referencing_obj(archived),

    _thread(THREAD) {}

  void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }

  void do_oop(      oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }

 protected:

  template <class T> void do_oop_work(T *p) {

    oop obj = RawAccess<>::oop_load(p);

    if (!CompressedOops::is_null(obj)) {

             "original objects must not point to archived objects");

      size_t field_delta = pointer_delta(p, _orig_referencing_obj, sizeof(char));

      T* new_p = (T*)(address(_archived_referencing_obj) + field_delta);

      Thread* THREAD = _thread;

      if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {

        ResourceMark rm;

        log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size %d %s", _level,

                             _orig_referencing_obj->klass()->external_name(), field_delta,

                             p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());

        LogTarget(Trace, cds, heap) log;

        LogStream out(log);

        obj->print_on(&out);

      }